The Himalayan Marmot and a Genome for High-Altitude Life

The Himalayan marmot is a fascinating mammal because it often lives at high altitudes. It makes its home in the Himalayas and on the Tibetan Plateau. It apparently has no problem dealing with the very cold temperatures, low oxygen levels, and high intensity of ultraviolet light in much of its environment. In fact, it’s thought to have a large population. A new study has analyzed the animal’s genome and found genes that help it survive under the seemingly harsh conditions at high elevation, especially when it's hibernating in winter.

A Himalayan marmot in Bhutan

Christopher J. Fynn, via Wikimedia Commons, CC BY-SA 3.0 License

The Himalayan Marmot or Marmota himalayana

The Himalayan marmot has a wide range and can be found in Pakistan, India, Nepal, Bhutan, and China. Like other marmots, the animal has a stout body with short legs and a stubby tail. The back legs are longer than the front ones. Its coat is thick and is buff in colour with dark or black patches. One of the black patches is often on the nose and another is often on the forehead. A black line may travel down the face to connect the two areas.

Diet and Life

Himalayan marmots feed mainly on herbs and grasses but occasionally eat fruits and roots. They live in colonies, which vary in size, and spend their nights in burrows. They hibernate in groups. Winter burrows may be as deep as thirty metres. The depth enables the animals to survive the most severe environmental conditions. Nevertheless, they experience low temperatures and low oxygen concentrations during hibernation. The animal hibernates for the impressively-long time of more than six months—from late September to some time in April.

Gestation reportedly lasts for one month. Between two and eleven youngsters are said to be born in either late spring or early summer. This data needs to be confirmed, however. Reproduction is one aspect of the marmot’s biology that needs to be further studied.

Studying the Animal’s Genome

Some Chinese scientists have recently finished sequencing the genome of the Himalayan marmot. They’ve made some interesting discoveries with respect to genes that seem to be adapted to help the animal survive hypoxia (low oxygen) and cold temperatures.

The scientists compared genome activity in Himalayan marmots living at high altitude with the activity in animals living at a comparatively low altitude. The animals are found at elevations of around 1,900 to 5,000 metres. As part of their research, the scientists observing transcriptional changes in the animals.

Genes do their job by making proteins. Transcription is the process in which the instructions encoded in a gene in a DNA molecule are copied onto a messenger RNA (mRNA) molecule. The mRNA leaves the nucleus, where the DNA is located, and travels to a ribosome in the cell. Here the protein coded for by the DNA is made. The fact that transcriptional changes appeared in the scientists' study of the marmots meant that the activity of genes had changed.

The analysis of the marmot's genome is preliminary, but the researchers have already made some interesting discoveries. One is that the Himalayan marmot separated from the Mongolian marmot about 1.98 million years ago. Some other highlights of the research are described below.

Genome Discoveries

The scientists found that during hibernation there was an increased activity of genes involved in fatty acid breakdown and decreased activity of genes involved in fatty acid manufacture. The researchers also observed a decreased synthesis of amino acids, decreased breakdown of carbohydrates, and a decrease in activity of genes involved in the circadian rhythm. The circadian rhythm is a cycle of biological activity over an approximately twenty-four hour period.

The activity of a gene known as Slc25a14 and a pseudogene known as ψAamp was different in the high and low elevation marmots and may be involved in helping the animal survive under harsh conditions. A pseudogene is similar to a real gene in structure but doesn’t code for a protein. Researchers have discovered that some pseudogenes aren’t completely inactive and have a regulatory function. This appears to be the case for the ψAamp pseudogene.

In hibernating animals living at high elevation, Slc25a14 activity stimulates processes that help to protect the marmot from hypoxia. The pseudogene appears to decrease the activity of the Aamp gene, resulting in a decrease in angiogenesis, or new blood vessel formation. This may be beneficial during very hypoxic conditions during hibernation.

Previous research has shown that the brains of hibernating animals living at high altitude are exposed to temperatures near freezing and have decreased blood flow. This puts the animals at an increased risk for blood clots in the brain—or it would do, if their body didn’t respond appropriately. The new research has shown that the genes involved in blood clotting become less active. In addition, genes involved in regulating stem cells become more active. Stem cells are unspecialized but divide to form specialized ones. The activation of stem cells may enable brain cells damaged during hibernation to be replaced.

Clues for Further Research

As the researchers say, their discoveries should act as clues for other scientists. The researchers acknowledge that more research is needed, but the discoveries so far are very interesting. The Himalayan marmot is a common animal, but it seems that there is still a lot to learn about it.

References

Information about the Himalayan marmot from Wildscreen Arkive

Marmota himalayana entry from the IUCN Red List

Himalayan marmot genome offers clues to life at extremely high altitudes from the EurekAlert news service

Hypoxic and Cold Adaptation Insights from the Himalayan Marmot Genome from iScience, Cell Press

The Asian Longhorned Tick: Facts and Potential Problems

Ticks are small animals that survive by drinking blood. They are classified as ectoparasites because they live on animal or human skin. The Asian longhorned tick, or Haemaphysalis longicornis, is native to East Asia but has arrived in the U.S. It has been found in nine states in the eastern part of the country (at the time when this post was written). Ticks are of concern not only for the fact that they bite us and remove some of our blood. They can also transmit disease.

Ventral (lower surface) view of a female Asian longhorned tick
Photo credit: James Gathany and the CDC, public domain license

Facts About Haemaphysalis longicornis

Ticks aren’t insects. They belong to the class Arachnida, like spiders. The Asian longhorned tick is a member of the family Ixodidae within the class Arachnida. The animal is only three to four millimetres long when it hasn’t drunk blood lately. When it has fed recently, its body expands and is more noticeable. According to the University of Virginia, an adult filled with blood is about the size of a pea. The engorged animal has a very different appearance from the hungry one, as shown in the photo below. Before feeding on blood, the animal is red-brown in colour.

Like other ticks, H. longicornis often lives in areas with tall grass and a humid environment close to the ground. It can also be found in bushy or wooded areas. Some people have ticks in their backyard. The animals climb a blade of grass or a woody stem and perform a behaviour called questing to detect a passing host. A tick holds on to its support with its head facing downwards while questing. It then extends its front pair of legs outwards so that it can grab hold of an animal or a human that passes by. Various clues indicate that a potential host is present. Chemicals emitted by the animal, the body heat that's released, or vibrations caused by movement may tell a tick that a suitable host is near by.

Life Cycle

The tick has four stages in its life cycle. The larva, nymph, and adult all feed on blood. The timing of each stage's appearance and the animal's lifespan may vary depending on locality and environmental conditions.

• The egg hatches to produce a larva. Unlike the adult, the larva has only six legs. It’s also very small and will likely be unnoticed by many people. It may become inactive during winter.
• When the weather warms, the larva becomes active. It feeds on blood and then molts, forming a nymph. The nymph has eight legs, like the adult. Like the larva, however, it may become inactive in winter.
• When the environmental conditions are suitable, the larva feeds on blood and then molts to become an adult. The adult female must drink blood in order to produce her eggs, which number in the hundreds. Once she’s done this, she dies.

Interestingly, the tick is believed to be parthenogenic in the U.S. Parthenogenesis is a process in which a female produces young without being fertilized by a male. In Asia, the tick reproduces as we would expect, with both males and females in the population. In the United States, all of the ticks are thought to be females.

An engorged female
Photo credit: Commonsource, CC BY 3.0 License

Possible Problems Caused by a Tick Bite

The Asian longhorned tick was introduced into the United States in 2017 (or perhaps earlier) and is spreading. At the moment, it hasn’t been linked to health problems in the country. Some researchers think that this is only a matter of time, however. In some countries, the species has made people very sick.

Other ticks in the U.S. can cause some unpleasant and in some cases even life-threatening diseases, including Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, anaplasmosis, Powassan virus disease, and other illnesses. In humans, the Asian longhorned tick has been associated with all of the diseases in this list. It has also been associated with a potentially very nasty condition called severe fever with thrombocytopenia syndrome. The tick seems to be more commonly known as a problem for cows, however. 

Ticks ingest bacteria or viruses as they suck blood from an infected animal. When they bite a new host, some of the pathogens may enter the host’s blood, multiply, and make them sick.

How to Reduce the Chance of Disease Caused by a Tick Bite

A common recommendation is to avoid areas where ticks may live or to stay in the centre of trail in these areas so that the body doesn’t brush against grass or branches. Health agencies often recommend that we cover our body with clothing. They say we should wear long-sleeved shirts, tuck shirts in, tuck the bottom of pant legs into shoes, and put tick repellent on our clothing and skin. The use of repellent needs to be investigated carefully. The benefits, risks, and precautions associated with the various types need to be explored. These considerations are important for our pets, too, since they can be infected by ticks.

People who have been travelling in tick country also need to inspect their skin and clothing carefully when they return from a walk. Taking a shower is said to be a good idea as well. The CDC reference given at the end of this post has an illustration showing the prime areas on the body where ticks may be found. The animals tend to home in on hidden areas, such as under the arms, behind the knees, and inside the navel.

Removing Ticks From the Skin

Removing ticks is important even though they may have attached to the skin early in a trip and weren’t discovered until much later. The CDC says that it may take as long as twenty-four hours after attachment for Lyme disease bacteria to transfer from the tick to the victim (This may not be true for all of the pathogens in ticks, however, including those in Asian longhorned ticks.) The sooner the ticks are removed, the lower the chance of contracting Lyme disease and perhaps some other diseases.

If a tick is discovered, it needs to be removed carefully so that the mouth parts don’t stay in the skin. The CDC and the Mayo Clinic recommend the use of fine-tipped tweezers. The tick should be grasped with the tweezers and then pulled steadily away from the skin in a straight line without jerking or twisting. Suitable tweezers should be part of a first aid kit taken on a journey through wild areas.

Should We Be Worried?

The spread of the longhorned tick is predicted to continue in the United States. The animal may enter southern Canada as well. Investigators are reminding the public that no pathogens have been found in the ticks that have been examined in the U.S. so far, however. They also say that even in countries where H. cornalis is relatively common, not all of the ticks carry pathogens. Still, they are monitoring the situation carefully. 

Longhorned ticks can infest cows in large numbers, causing serious blood loss. Their potential for carrying pathogens that can seriously harm humans is certainly a concern. Since North America already contains species of ticks that are known to do this, however, it’s a good idea to take precautions when necessary and to do some research about tick location if we decide to visit a new area.

References

The longhorned tick from Virginia State University

A new tick in the United States from the CDC (Centers for Disease Control and Prevention)

An Asian tick that can clone itself from CNN

Jewel Wasps and Zombie Cockroaches: An Intriguing Relationship

The American cockroach and the jewel wasp are interesting insects in their own right. Their interaction is especially intriguing, however. The wasp stings the cockroach, changing it into a zombie. It then leads the roach to a nest and lays an egg beside its body. The larva that hatches feeds on the living roach. Researchers have recently discovered that the cockroach has a defence mechanism that often but not always works. The roach uses a “karate kick” to repel its attacker.

A jewel wasp (Ampulex compressa)
Photo credit: Muhammad Mahdi Karim, GFDL 1.2 license

The Jewel Wasp

The jewel wasp is also known as the emerald cockroach wasp and has the scientific name Ampulex compressa. The insect has a blue-green body with a metallic sheen. The “thighs” of its second and third pair of legs are red. It’s not hard to see why one of the animal’s common names is jewel wasp. Its colouration is very attractive. The wasp is a solitary insect that lives in tropical parts of the world, including Africa, South Asia, and the Pacific Islands. It’s particularly interesting for its method of subduing and controlling a cockroach without immediately killing the animal.

The American Cockroach

The scientific name of the American cockroach is Periplaneta americana. Despite the insect’s common and scientific names, it’s native to Africa and the Middle East, not the United States. The animal is believed to have been introduced to North America in the seventeenth century, where it has become a pest. Though it’s often a highly disliked insect, especially in buildings, some people may feel sorry for its fate when it meets a jewel wasp that is ready to lay an egg.

The American cockroach
Photo credit: Jan Drewes, CC BY-SA 2.5 license

Creation of a Zombie Cockroach

The jewel wasp first grabs hold of the cockroach with her mouth and then aims her stinger at the thorax between the first pair of legs. The secretion that she injects quickly paralyzes the cockroach, enabling the wasp to take more care with her next jabs. She carefully searches for the right places to inject her venom in the roach's brain, or ganglia. Amazingly, she can detect the location of these areas by touch as she moves her stinger around inside her victim’s head. She chooses two specific spots for the injections. 

Although the venom for the head injections is apparently the same as the one used in the thorax, different effects are produced. When the wasp has finished her work, the roach starts grooming itself. It continues to do this while the wasp flies away to find a dark and secluded spot for a nest. Researchers have discovered that the cockroach isn’t paralyzed at this stage. It could still move away, but it doesn’t. In addition, if the insect is rescued, it stops grooming itself in about thirty minutes and its behaviour slowly returns to normal. This doesn’t normally happen in nature because the wasp soon returns. 

The Journey to the Nest

When the jewel wasp returns to its victim, it break off part of the roach's antennae and feeds on the hemolymph (the insect equivalent of blood) that emerges. This apparently gives the wasp energy for her next task. She grabs hold of the remains of one of the roach’s antennae and leads the insect to the nest. The roach may be six times as large as the wasp, but it doesn't resist the wasp's control. It moves willingly without stumbling. 

Once the pair have entered the nest that the wasp has created, she lays an egg on one of the roach's legs. She then seals the opening to the nest with items such as pebbles and bits of wood and flies off, perhaps to find another victim. She has many eggs to lay. The video below shows the wasp attacking and subduing the cockroach, leading it into the nest, and then laying an egg. 

The Wasp Egg and the Larva

The remarkable venom slows the cockroach’s metabolism so that its body is still in good condition when the egg hatches into a larva. At first the roach is alive as the larva chews a hole in its abdomen and enters its body to feed, but eventually it dies. The larva eats the roach's organs in a specific order so that it stays alive as long as possible.

The larva becomes a pupa inside the cockroach. Lab studies have shown that the roach doesn't respond to the attack, even as it's being eaten alive. The new wasp that is produced is able to remove the blocked opening of the nest and escape, leaving the remains of the cockroach's body behind.

Roach Karate Kicks

Though cockroaches are generally not well liked, some people may be sympathetic for what the insects experience during a wasp's attack. A researcher at Vanderbilt University has recently discovered that the roach is not completely helpless, at least in some cases. Ken Catania used slow speed videography to record cockroach behaviour as a jewel wasp approached. He found that the roaches often applied a swift kick to the wasp with one of their spiny hind legs. The process is shown in the video above. 63% of the time, the roach successfully repelled the wasp and survived. The wasp left to look for another victim.

The good news for the cockroach: the defense worked for 63 percent of adults that tried it. The bad news: juveniles almost always failed and got stung in the brain. Quotation from Heidi Hall, Vanderbilt University news release

There's probably a lot more to learn about the relationship between the wasp and the roach. The nature of the venom that's injected would be fascinating to explore in more detail, since it has pronounced and unusual effects. The effects of the venom on the cockroach are also intriguing. Scientists are gradually identifying some of the chemicals involved and their effects, but more studies are needed to fully understand the venom. Nature never ceases to be interesting. 

References

How cockroaches turn wasps into zombies from Scientific American

The wasp that enslaves cockroaches from Wired Science

Karate kicks keep cockroaches from becoming zombies from Vanderbilt University

A Spider That Makes a Liquid Resembling Milk for Its Young

The production of milk to nourish a baby is a characteristic of mammals, or members of the class Mammalia. The female has glands that have the impressive ability to make a liquid that supplies all of the nutritional needs of the baby. Scientists have recently discovered that a particular species of jumping spider also makes a nutritious liquid that supports the growth of its young. Although the liquid doesn't have the same composition as mammalian milk, the researchers refer to it as milk in their report to the public. It appears to be essential for the development of the spiderlings.

An adult male jumping spider (Phidippus audax)
Credit: Opoterser, CC BY-SA 3.0 license

Some Features of Jumping Spiders

Like other spiders, jumping spiders belong to the class Arachnida. They are members of the family Salticidae within the class Arachnida. People may be most familiar with the types of spiders that they encounter in homes, which belong to several different families. The family Salticidae is the largest family in terms of number of species, however.

The animals in the family have excellent eyesight compared to other spiders and are great jumpers, as their name suggests. They have eight eyes: two pairs in the front of their head and two pairs on the top of the head. The two frontmost eyes are very large compared to the others, as shown in the photo above. The rest of the eyes can be seen in the photo below. Most jumping spiders are three quarters of an inch or less in length.

The spiders are carnivorous and feed on insects. Scientists have noticed that some species drink nectar in addition to eating insects. Jumping spiders produce silk, but they don’t make webs. The silk is used to make a dragline. Scientists investigating the dragline have shown that it does more than just support the body. The spiders use it to control their orientation in space as well as to stabilize their body when they jump.

An adult female jumping spider (Colonus sylvanus)
Credit: Kaldari, public domain license

A Jumping Spider That Resembles an Ant

The research into spider milk was performed by scientists at the Xishuangbanna Tropical Botanical Garden, which is part of the Chinese Academy of Sciences. The spider that they studied was Toxeus magnus, a species of jumping spider that resembles an ant. 

Some spiders mimic ants, which helps to protect them from an attack by a predator. The ants produce formic acid, which can irritate and injure the predator. Spiders don’t produce the acid, but having a body that resembles an ant’s can discourage predators from attacking them. Since they are insects, ants have six legs, not eight like a spider. One species of jumping spider that resembles an ant sometimes holds its front pair of legs in the air, making them look like a pair of insect antennae.

A male Toxeus magnus
Credit: Sarefo, CC BY-SA 3.0 License

The Epigastric Furrow

The body of a spider consists of two segments: the cephalothorax and the abdomen. The segments are joined by a narrow stalk called the pedicel. The underside or ventral surface of the abdomen has a horizontal furrow just behind the openings to the book lungs and the epigyne in between them. The furrow is known as the epigastric furrow and releases the milk. The illustration below shows the openings to the book lungs and the epigyne, or epigynum, but not the furrow behind them.

The book lungs, or respiratory organs, contain plate-like structures that look like the pages of a book. The organs contain hemolymph, which is the liquid that replaces blood in spiders. The hemolymph absorbs oxygen and releases carbon dioxide. The epigyne is the opening that leads to the female's reproductive system.

Ventral surface of a spider
Credit: James Henry Emeron, public domain license

Spider “Milk”

With the aid of a microscope, the researchers discovered that the female Toxeus magnus released droplets of liquid from her epigastric furrow. The spiderlings fed on this liquid for forty days, although they also started hunting for food themselves when they were twenty days old. The spiderlings were considered to be adults at fifty-two days of age.

The researchers discovered that if spiderlings that had just emerged from the egg were prevented from drinking the "milk", they stopped their development and died within ten days. This indicated that the milk was essential for both their development and their survival in the early stage of their life. 

The Importance of Maternal Care

Interestingly, the researchers found that after twenty days (when the spiderlings started finding food for themselves as well as drinking milk), the youngsters apparently didn't experience any more benefits from the milk provision on its own. They did benefit from receiving the milk combined with the care of their mother during this time, however.

In addition to feeding the young, the spider mothers took good care of the nest and their offspring. They removed the waste released by the youngsters and repaired any damage to the nest. This activity increased the survival rate of the spiderlings and enabled them to reach the normal body size of an adult. 

It’s interesting that an animal that many people consider to be relatively primitive has such seemingly advanced behaviour. More research into spider milk and how and exactly where it's produced is needed, but the preliminary results are intriguing. Researchers are finding some surprising features in the animal kingdom. Nature is always fascinating

References

Jumping spider facts from the Menunkatuck Audubon Society (Part of the National Audubon Society)

Jumping spiders mimic ants to defy predators from Cornell University

Mammal-like milk in a jumping spider from the Science Daily news service

The Cook Pine: A Tree That Leans Towards the Equator

The Cook pine, or Araucaria columnaris, is native to New Caledonia. The tree is famous for the fact that it often tilts instead of growing upright. Researchers have discovered that it leans towards the equator. In the northern hemisphere, the tree leans towards the south. In the southern hemisphere, it leans towards the north. The further away the plant is from the equator, the greater the angle of the tilt.

Plants in the genus Araucaria were abundant in the Mesozoic era, which began about 252 million years ago. The plants co-existed with dinosaurs. Today they are far less common than in the distant past. The trees that do exist are admired by many people, however. The monkey puzzle tree, the Bunya pine, and the Norfolk pine belong to the genus.

Cook pines on the Isle of Pines, New Caledonia
Credit: NC21, CC BY 2.0 License

New Caledonia

Many species of Araucaria live in New Caledonia, which is an archipelago in the southwest Pacific Ocean. It’s located about 750 miles east of Australia but is classified as a special collectivity of France. Captain James Cook from Britain is recognized as the first European to discover the archipelago.

James Cook was an officer in the Royal Navy and an explorer who travelled in the ship HMS Resolution. He discovered New Caledonia on his second voyage in the ship, which lasted from 1772 to 1775. He named the area after an old word for Scotland because some of the landscape features reminded him of that country. The name Cook pine is derived from the name of the explorer.

Features of the Tree

The Cook pine is not a true pine tree. It belongs to the order Pinales, like other conifers, and the family Araucariaceae. Pine trees belong to the family Pinaceae. The Cook pine is also known as the New Caledonia pine and the coral reef araucaria. The tree is able to grow in calcareous soil. On the Isle of Pines (part of the New Caledonia archipelago), it grows on top of coral reefs, which gives it one of its common names.

The tree is a popular ornamental plant beyond its native habitat and has some unusual features. It has a narrow, conical shape and in New Caledonia can grow as high as two hundred feet. Its branches are roughly horizontal and are arranged in whorls around its trunk. The triangular and overlapping leaves are tightly wrapped around the branches and are spiky. The grey trunk has a papery surface and sheds its bark in strips. The seed or female cones are oval or egg-shaped. They are larger than the elongated pollen or seed cones.

Credit: Forest and Kim Starr, CC BY 3.0 License

The Leaning Trees

Though people had obviously notice the fact that many Cook pines lean before, a 2017 study discovered how widespread the growth habit was. The study was initiated by botanists at the California Polytechnic State University. Matt Ritter (one of the botanists) contacted a colleague in Australia and discovered that the trees there leaned in a different direction from those in California. This discovery stimulated further research.

With the help of other investigators, the California researchers obtained measurements from 256 trees on five continents. They not only found that the trees leaned but also discovered that their tilt was greater when they were further away from the equator.

Why and How Do the Trees Lean?

Scientists don’t know for certain why the trees lean. It may offer the advantage of the leaves meeting the sun’s rays at a more efficient angle. As in other plants, the trees produce food by photosynthesis. In this process light is absorbed by the leaves and used to make carbohydrates. If the trees do bend in order to absorb light better, the puzzle is why are they are apparently the only tree to develop this behaviour.

The mechanism of the lean is also a puzzle. The researchers speculate that it may have something to do with the way in which the wood responds to gravity and that it may involve a particular mutation or mutations.

Although the natural habitat of the tree is restricted, its population is currently not in any trouble. According to the IUCN (International Union for Conservation of Nature), it grows well in New Caledonia and is respected by the local people. I'm interested in seeing what scientists discover next about the biology of the intriguing Cook pine.

References

Araucaria columnaris data from The Gymnosperm Database

The strange Cook pine from New Scientist

Araucaria columnaris entry from the IUCN

Dance Flies: Bigger Abdominal Air Sacs Attract More Males

Dance flies (Rhamphomyia longicauda) have some interesting features. Females have expandable, air-filled sacs under their abdomen as well as hairy legs. A multinational research team has found that males are attracted to females with bigger abdominal air sacs. The flies belong to the family Empididae and are also known as balloon flies and as dagger flies. The latter name is derived from the piercing mouthparts of some species in the family.

A female Ramphomyia longicauda
Katja Shulz, CC BY 2.0 License

What Is a Dance Fly?

The term “dance flies” is sometimes used as a general term for insects in the family Empididae as well as those in the family Hybotidae. The name comes from the behaviour of the insects during their mating ritual. The flies form a swarm flying around in a dance-like motion. The swarms generally develop near sunset and can be enjoyable to watch. Rhamphomyia longicauda is found in the northeastern part of North America. It lives in wooded areas that contain wetlands or bodies of water and swarms near water.

Rhamphomyia longicauda

Rhamphomyia longicauda has a black upper surface. The head is small but has large orange or red eyes. The abdominal air sac of the female is also orange. The insect has a slender body with a long abdomen. The species name of the insect is derived from two Latin words meaning long and tail.

The females have two interesting features that differentiate them from the males. One is their abdominal air sacs. The other is the presence of stiff hairs (technically pinnate scales) forming a fringe on their legs. The fringe is most noticeable on the middle and hind legs. Though the hairs have an advantage, as described below, according to the BugGuide site they make it more likely that the female will become trapped in spider webs.

Swarming and Mating

Researchers from the University of Toronto in Canada and the University of Stirling in Scotland have made some intriguing discoveries about the mating swarm of the species. The females swallow air to fill their abdominal sac just before they take flight. Once they have taken to the air, they pull their legs in and up so that they one leg is folded on each side of the abdomen. This adds to the impression that the females have a huge abdomen relative to their body size. One researcher says that the behaviour makes a female look like a helicopter.

When a male and female have made the decision to mate, they leave the swarm. The researchers have observed that the males prefer females with bigger air sacs. Though we can’t tell what an insect is thinking, researchers believe that the male “thinks” that the females who are faking the appearance of a bigger abdomen contain a larger group of mature eggs that are ready to be fertilized. The female’s behaviour is actually a form of subterfuge. The researchers have also discovered that if two females have abdominal air sacs of the same size, a male choses the one with the hairier legs. The protruding scales that form the hairs likely increase the impression that the female has a large abdomen.

An Exchange of Gifts

The male flies and the larvae feed on smaller insects. The adult females don’t catch their own prey but depend on food brought to them by males. A male gives a female a bit of dead insect prey in exchange for copulation. The female mates with multiple males and gets multiple meals, enabling her to survive and produce offspring.

Some people may not think much about flies, except when the insects become a nuisance. They are interesting animals, though, especially some species, such as dance flies. I think they are worth studying.

References

Male dance flies favour females with bigger abdomens from the phys.org news service

Rhamphomyia longicauda facts from BugGuide

New Species of Snailfish in the Atacama Trench

Snailfish are unusual animals. They have an elongated and scaleless body that is often said to resemble a tadpole in shape. The animals have a widespread distribution in the colder parts of the ocean and are found in shallow to deep water. Despite these facts, they aren't very well known or understood. Scientists have recently found three new and surprising species at a depth of 7,500 metres in the Atacama Trench.

A festive snailfish or Liparis marmoratus (a species not found in the Atacama Trench)
Kitty Mecklenburg, via Wikipedia, public domain license

Snailfish

Snailfish belong to the family Liparidae. The fish have large heads relative to their size but small eyes. They are benthic animals, which means they live on the ocean bottom. In most snailfish, the pelvic fins are modified to form an adhesive disk that attaches the body to a surface. Hadal snailfish are those that live at a depth of greater than 6,000 metres and are still somewhat mysterious. These fish have been found in the Mariana Trench as well as the Atacama one.

The Atacama Trench

The Atacama Trench is also known as the Peru-Chile Trench. It’s located in the Pacific Ocean about a hundred miles off the coast of Peru and Chile. The Nazca Plate is moving under the South American Plate in the area, a process known as subduction. The trench has a maximum depth of just over 8,000 metres and an area of around 590,000 square kilometres. In the depths of the trench the environment is dark, the water cold, and the pressure enormous, yet a surprising number of species thrive there.

The Peru-Chile or Atacama Trench (the dark line)
NOAA, via Wikipedia, public domain license

The Expedition

A recent exploration of the trench by a multinational team of scientists has revealed three new species that they believe are snailfish. The large team consisted of 40 researchers who came from a total of 17 countries. The scientists sent a remote-control lander down to the area that they wanted to explore in a trip that covered four and a half miles. One of the researchers involved in the expedition said that the walls of the vessel were made of steel almost an inch thick and the window was made of “super strong” sapphire glass. This type of glass is almost as hard as diamonds.

The lander took photos and videos and trapped specimens. It returned to the surface as a result of an acoustic signal sent from the surface. It brought one of the new fish species with it, which the researchers examined and classified as a snailfish. Some of the discoveries made by the lander are shown in the video below.

Three New Species

The new fish are being referred to as the pink, the blue, and the purple snailfish for now. Though they are different in colour, they also differ in overall appearance and are believed to be three different species. They are unusual animals because they don’t look like many of the other fish that are found in deep and dark water. They have a translucent and gelatinous appearance instead of a dark, fanged, and menacing one. Their bodies look too delicate to withstand the pressure and cold temperatures at such depths, but the fish seemed healthy and appear to be very successful in their habitat. I think the blue species is particularly interesting. Unlike the pink and purple fish, the blue animal has long, sail-like pectoral fins and a relatively long snout.

One of the purple animals entered the lander’s trap and was carried to the surface. The nine-centimetre long animal was preserved and its body CT scanned. Scans like this are important in case physical specimens of organisms and items are destroyed, as happened in the horrible fire at the National Museum of Brazil recently. Though preserved animals and a detailed scan of the animal’s external and internal features are certainly useful, they aren’t as good as observations of a living animal. Hopefully much will be learned about the new fish in their natural habitat. The remoteness of the area makes it difficult to explore, however. It also makes the trench and its unusual and specially-adapted inhabitants fascinating.

References

Three new species of snailfish discovered from the ScienceDaily news service

Finding snailfish in the deep ocean from The Conversation

Plants at the PNE Fair: Black-Eyed Susans

Wherever I go for a walk—in cities or in rural areas—I'm on the lookout for plants and animals. Even when other sights are interesting, I'm glad to see signs of nature. The annual fair at the PNE in Vancouver is a popular event. Exploring nature may not be high on many people’s list when they walk through the fair, but it is on mine.

The Fair at the PNE

The Pacific National Exhibition and the neighbouring Playland Amusement Park are permanent facilities in Hastings Park in east Vancouver. In the last two weeks of August, the number of enclosures in the area temporarily increases in order to create the fair. Many people appreciate the fair for the rides, the food, the entertainment, and the wide variety of items that can be purchased. The event started out as an agricultural exhibition, however, and still stays true to its roots.

Animals and Plants on Display

While viewing so-called “market animals” at the PNE fair is always sad, looking at the other ones is enjoyable. The horse show is always interesting. The show includes horse jumping competitions and Clydesdale draft horses demonstrating their skills. The fair contains plant displays as well. In addition, there are two gardens and one natural park on the fairground, which are interesting to explore. The Italian Garden always has a beautiful display of blooming black-eyed Susans during the fair. The flowers bloom in late summer and early fall and are at their prime at the start of the fair. The species is found in the wild and in cultivation. Multiple cultivars exist. Some bloom earlier in the summer than the ones on the PNE grounds. The plants are perennials, biennials, or annuals, depending on the variety.

The Black-Eyed Susan

The black-eyed Susan’s scientific name is Rudbeckia hirta. Its genus was named after Olaus Rudbeck the younger (1660-1740)  He was a professor at the University of Uppsala in Sweden and taught Carl Linnaeus. The latter scientist is credited with the creation of the binomial system of naming organisms (genus plus species).

The black-eyed Susan is native to eastern and central North America but has been introduced to other areas. The vibrant flowers of the species are greatly admired. The plant belongs to the sunflower family, which is not hard to believe when the beautiful yellow to orange petals of the flowers are seen. The “petals” aren’t what they seem, however. The plant has a composite flower, or an inflorescence. The raised, black or purple disk in the centre is composed of disk florets and each yellow extension is part of a ray floret. The flowers are pollinated by insects. When I visited the fair and took the photos in this article, the day was sunny and bees were visiting the flowers. Watching their activities can be an absorbing pastime.

The leaves of the plant are oval and toothed and have a pointed tip. They are also hairy. They are mostly basal, but some can be found on the flowering stems. Parts of the the black-eyed Susan plant have been used medicinally by the indigenous people of North America. The plant as a whole isn’t considered to be edible, however, so it’s important that it’s not eaten.

The Italian Garden 

The stone face that can be seen on the left in the photo of the flowers below is a depiction of Canio. He's the character who plays the role of a clown in the theatre troop depicted in the opera Pagliacci. The face on the right represents Turandot. The area of the garden with the statues and the black-eyed Susans in front is called the Opera Walk. Characters from several famous Italian operas can be seen along the walk.

When the fair is not in operation, the fence between the Italian Garden and the road that passes by it (Renfrew Street) is removed. This allows people to freely access the garden, the PNE grounds, and the other garden and park areas of the fairground (but not Playland). The Italian Garden is quite small but has several attractions, including fountains and statues other than those of the Opera Walk. It’s well worth visiting at any time of year, but especially in the summer. Hastings Park beyond the PNE and Playland offers natural attractions and is also worth visiting. Attractive landscaping and a walking trail have been established in the area and a stream that was covered for sixty years has been revealed. Hastings Park, which has long been commercialized, is being partially returned to nature.

Attending the Fair

The fair generally has promotional days when people can enter the fairground for a reduced price if certain conditions are met. On specific days they can even enter the site for free. The possibilities for reduced or free entry rates vary each year, however. The PNE’s website has information about the special admission days. The days can be useful for people who would like to save their money for rides, foods, and entertainment (although most of the performances at the fair are free). They can also be useful for visitors who are curious about what the fair offers but are particularly interested in late-August nature on the fairground, like me. The area of the park beyond the PNE and Playland is free to explore at any time of the year.

Elephant Genes and Protection From Cancer

Very interesting research has revealed why elephants—at least in captivity—have a much lower cancer rate than us. Elephants live about as long as humans yet have far more cells. Like all cells, elephant ones could potentially become cancerous. It would seem that elephants should have a higher rate of cancer than humans instead of a lower one because of their larger size and their greater number of cells. Researchers have discovered two interesting genetic reasons that might explain why this isn’t the case.

An estimated 17 percent of humans worldwide die from cancer, but less than five percent of captive elephants—who also live for about 70 years, and have about 100 times as many potentially cancerous cells as humans—die from the disease. Quote from the University of Chicago Medical Center via the phys.org news service

An African elephant

ajoheyho, CC0 public domain license

The P53 Gene

A gene known as P53 seems to be important in protecting elephants from cancer. It’s sometimes referred to as a master tumour suppressor gene. We have the gene, too. The difference is that we have only one copy of the gene (on paired chromosomes) while elephants have twenty. The activated gene causes the destruction of cells with DNA damage. This damage often precedes the conversion of the cell to a cancerous one. The extra genes in elephants likely enables their body to destroy more potentially dangerous cells.

A Resurrected Pseudogene

The second genetic benefit in elephants is linked to something called a pseudogene, which is sometimes referred to as a dead gene. When genes are copied, a mistake is sometimes made and non-functional copies are produced. While the researchers were studying P53 genes in elephant cells, they encountered an active form of the LI6 gene, which was a surprise. The gene was inactivated long ago in the elephant’s evolutionary history and was though to be still “dead”.

The full name of the LI6 gene is the leukaemia inhibitory factor 6 gene. Like other genes, it codes for proteins. In this case, the protein molecules travel to the mitochondria of cells with damaged DNA. As a result, the mitochondria of the cell are damaged and the cell dies. Mitochondria generate most of the energy required by the cell and are vital organelles. Studies in elephant cells suggest that the P53 gene activates the LI6 gene.

A young African elephant

Mariamichelle, CC0 public domain license

Manipulating the Human Genome

More studies are needed in order to understand the function and interactions of the elephant genes. The exploration might not only be fascinating biologically but also useful in understanding and treating cancer in humans. Researchers are making progress in treating cancer and have made significant discoveries recently, but the disease is still serious. Although we are smaller than elephants, we have many cells and many chances for DNA errors and damage to occur.  The actual number of cells in the human body is unknown.

The short answer is that the body of an average man contains around 30 to 40 trillion cells. The long answer is that scientists do not yet know the exact number. Plus, it depends on whether or not you include the bacteria that are present in and on our bodies. Quote from Yelia Hewings-Martin, Medical News Today

Humans have 20,000 to 25,000 genes. Gene activation and activity are complex processes. Trying to manipulate the human genome without understanding what we’re doing could have unintended consequences. Still, the research in elephant cells may help us learn about useful genes or chemicals in human cells and perhaps lead to beneficial discoveries that don't require the manipulation of genes. Understanding the human body and developing better treatments for diseases are wonderful goals.

References

Resisting cancer by waking a zombie gene from the phys.org news service
Cancer rarely strikes elephants from National Geographic
Number of cells in the human body from Medical News Today

The Unusual Sleeping Sickness Parasite or Trypanosoma

Trypanosoma is a microscopic and unicellular parasite of humans and other animals. It can produce some very serious effects, but it’s a fascinating organism with some unusual characteristics. In humans, two species of Trypanosoma cause the disorder known as sleeping sickness. One of the symptoms of this disease is daytime sleepiness and disruption of sleep patterns at night. The disorder can be treated, although the drugs that are used are often quite toxic. If it’s not treated, the disease is very often deadly.

Trypanosoma sp.
Photo credit: CDC/Dr. Myron G. Schultz

Sleeping Sickness

Sleeping sickness is technically known as trypanosomiasis. It’s sometimes called African sleeping sickness because it occurs in the continent of Africa. Two subspecies of Trypanosoma brucei cause the illness: T. b. rhodesiense (which causes East African sleeping sickness) and T. b. gambiense (which is responsible for West Africa sleeping sickness). The latter organism causes most cases of the disease.

The parasite requires both a human and a tsetse fly (genus Glossina) in order to complete its life cycle. One of the common symptoms of sleeping sickness is a sore in the area where the fly bites, which is sometimes known as a chancre. Other common symptoms include a fever, headache, aching muscles and joints, a skin rash, and swollen lymph nodes. If the parasite invades the central nervous system, confusion, personality changes, and extreme fatigue may appear.

The effects are slightly different in the two types of sleeping sickness. The East African variety develops faster and if untreated can lead to an earlier death. A doctor’s diagnosis is required to confirm the presence of either form of the disease and to prescribe treatment.

The Trypanosoma Parasite and the Kinetoplast

In its mature form, Trypanosoma has an elongated cell with a tapered shape. It moves by beating its flagellum, or the whip-like appendage extending from its cell. It exists in specific forms in its insect host and in its human host and has a complex life cycle. Tsetse flies feed on human blood and pass the parasite to people while feeding on them.

Trypanosoma is sometimes referred to as a kinetoplastid. Kinetoplastids are organisms that contain a special structure in their mitochondrion known as a kinetoplast. Trypanosoma has a single and very large mitochondrion. The mitochondria are the organelles that produce energy. They are the only cellular location of DNA outside the nucleus in either the parasite or us. Unlike the parasite, we have numerous mitochondria in our cells.

The kinetoplast looks like a large and very dense granule in electron micrographs. It contains kinetoplast DNA or kDNA. This exists as a network of interlocking large and small mitochondrial DNA rings. The interesting arrangement is often said to resemble chain mail. RNA is also present in the kinetoplast. The nature, behaviour, and function of the structure are still being investigated.

Evading the Immune System With a Protein Coat

One reason why Trypanosoma is such a potent pathogen is it has the ability to evade our immune system. Its cells are covered by identical proteins. Our immune system recognizes these proteins as inappropriate for our body and destroys the parasite. This sounds like it should be the end of the story and the problem, but the parasite has a very useful feature that protects it from the immune system.

The proteins borne by the parasite are known as variable surface glycoproteins, or VSGs. A glycoprotein is a protein with attached carbohydrates. The proteins cover the cell membrane of the parasite in a dense, tightly-packed layer that prevents the immune system from attacking the membrane.

Occasionally, the parasite changes the identity of its VSGs. As is true for other proteins, the code for making VSGs is found in the genes located in the DNA of the nucleus. Trypanosoma has many VSG genes, each coding for a different protein. During an infection, parasite cells that haven’t yet been killed by the immune system activate a different VSG gene and make different surface proteins. One researcher likens the process to putting on a different coat. The antibodies produced by the immune system don’t recognize the new coat and the parasite concentration builds up again. Understanding the details of the process could be useful in improving the treatment of the disease.

Dealing With the Disease and the Parasite

Ideally, sleeping sickness either wouldn’t exist or every incidence of the disease would be quickly and successfully treated. From a biological point of view, however, the parasite that causes the disease is a very interesting entity. The scientific study of its complex life cycle, cell structure, and behaviour might help us to understand not only the parasite's biology but also the biology of other cells, including those of humans.

References

Sleeping sickness from the CDC (Centers for Disease Control and Prevention)

Facts about kinetoplasts from Tulane University

Trypanosoma camouflage from the phys.org news service