Biology Newsletter - Issue 21

Biology Department Newsletter Issue 20: Spring term, 2022

‘The humble bee’ – Mr Gauntlett I love this time of year. Spring is creeping up on us, the weather is improving, the days are getting longer, and mother nature is slowly waking from her slumber.

For me, one of the first signs that spring is on the way is when I see my first bumblebee. It’s a wonderful moment when I hear that mellow buzz and then see one purposefully going about its business. You might be lucky enough to glimpse one as early as February, but certainly by late March and early April many are active.

When I see that first bumblebee, it gets me thinking about what it’s up to, and what lies ahead.

The bumblebee was not always so. In fact, until the early twentieth century, it was widely referred to as the ‘humble’ bee, not due to its modest tendencies, but owing to the pleasant humming sound it produces in flight. Charles Darwin was fascinated by them and like others of his generation referred to them by their original name. An etymological transformation gradually crept in though, probably between the 1920s and 1940s, and after becoming a contentious issue amongst naturalists, the term ‘bumble’ bee eventually came to dominate.

Personally, I much prefer this name as it doesn’t incorrectly type cast them as clumsy animals which they most certainly are not.

As such I will continue to refer to them in their original nomenclature.

The first thing you will notice about these early humblebees is that they are usually rather large. I rescued an absolute whopper from the staff common room just the other morning which had become stuck in a window. These are the queens, freshly emerged from underground burrows where they spend the winter in a state of hibernation. After several months without food, they are unsurprisingly rather hungry and set out in search of flowers. There are slim pickings at this early stage of spring but one of the humblebees’ go-to favourites is the pussy willow which can produce its catkins (flowers) as early as January. The queens first seek out the female catkins which are a rich source of carbohydrates in the form of nectar, and then male catkins which provide plentiful protein-packed pollen.

Queen in search of pussy willow catkins

‘The humble bee’ – Mr Gauntlett Once fully nourished, a queen will set to work finding a suitable site to build a nest.

This is often a disused burrow of a small mammals, a tree hole, under a garden shed or in an abandoned nest box. Once a nest is located, she will get to work gathering more nectar and pollen to establish her colony.

Inside the nest she will produce a wax cell into which she will lay fertilised eggs (the sperm needed to fertilise them has been stored inside her since late summer!). A ball of pollen is placed inside which the developing larvae will use as food.

Finally, she fashions a little pot which she fills up with nectar. This is to sustain her as she will need to sit on her eggs and incubate them for several days.

She will, however, continue to lay eggs.

The nests vary in size, but by the end of summer can contain anything from fifty to several hundred individuals.

Interestingly, worker bees vary in size, often with the first to hatch being much smaller. This is due to the limited food available with the queen initially doing all the work. So, if you see some rather small looking humblebees, you now know that these are probably from a newly established nest.

Workers can lay their own eggs, but the queen is cunning, and releases hormones that supress their ability to do so. Some workers, have ideas of their own however, and try regardless. Any such attempts are met with brutal punishment and rebellious workers are repeatedly stung and physically dominated. If any workers successfully lays eggs, the queen will simply eat them. Don’t get on the wrong side of mum! Genetic studies have shown that some workers do manage to produce their own offspring despite these challenges.

Queen with her pot of nectar

Eventually, the eggs hatch into larvae which need feeding, and the queen will set off again in search of more pollen and nectar. The larvae will metamorphose into ‘workers’ which are all female. Humblebee society is female dominated. These workers carry out jobs such as cleaning and guarding the nest, but most will take on the role of collecting pollen and nectar for their growing siblings. The queen will go out and forage for her initial clutch of offspring but then will never leave the nest again, instead relying on her workers.

Workers foraging for the nest

‘The humble bee’ – Mr Gauntlett By late summer, the queen turns her thoughts to producing the next generation.

She lays fertilised eggs that develop into new queens and unfertilised eggs that develop into males, also known as drones.

Males have one job, and that is to leave the nest and find queens from other colonies to reproduce with. They are not even equipped with a stinger. After depositing their sperm in a queen, they really serve no purpose, and will see out their remaining days foraging for the diminishing supplies of pollen and nectar before freezing to death when temperatures drop in the autumn. Any workers that have survived the summer will meet the same fate. The queen too perishes in the nest, but importantly her genes have been passed on.

In the last days of summer, you can look out again for larger humblebees as the new queens set about fuelling up before finding a place to hibernate. This is usually some loose soil into which they burrow down until spring arrives again.

So, when you next see a bumblebee, depending on the time of year, maybe you too can ponder what it's up to.

Things to try: Hunt for a bumblebee nest. You might even have one in your garden! Next time you see one, try and following it and see where it goes. If it goes down to the ground there’s a good chance its going into its nest. Don’t disturb a nest, but trying counting how many bees come in and out.

Identify a bumblebee. There are in fact 24 species in the UK, 7 of which are common, and you can tell them apart by the colouration and pattern of their stripes. When feeding on a flower, you can usually get pretty close, and you might even want to take a photo to help. Bumblebees are very unlikely to sting you unless you interfere with them. Go here to identify your humblebee: https://www.bumblebeeconservation.org/ident ify-a-bumblebee/ Rescue a bumblebee? Most likely they don’t need rescuing! It's often suggested to give bumblebees sugar water but there’s a good chance they don’t need it. Bumblebees like to rest, especially queens out foraging in spring, and they sometimes rest for up to 45 minutes. If one gets trapped inside, or in bad weather and isn’t moving much for more than 45 minutes then first try moving her to a bee friendly flower and failing that you can give her a couple of drops of sugar water.

Images sourced www.bumblebeeconservation.org

A bumblebee nest (©Permaphotos Wildlife/Naturepl.com)

from:

References: www.bumblebeeconservation.org, A Buzz in the meadow by Dave Goulson, The Guardian: How the humblebee became the bumblebee by Richard Jones

‘The importance of bees’ – Freddie 9J

‘Xenotransplantation: Are pigs the future of organ transplants?’ – Mrs Shiradski Xenotransplantation: defined as ‘the moving of organs from one species to another’ - is aimed at reducing the need for human organs for transplant, which are in short supply.

In September 2021, a patient named Jim Parsons, who was brain-dead, was the recipient of donated kidneys from a ‘10gene pig’ (after his own kidneys were donated to a recipient and with permission from his family). The operation performed by the surgical team at the University of Alabama was considered a success and a medical breakthrough; the kidney was not rejected, functioned, and produced urine for three days.

On 11th Jan 2022, in The University of Maryland Medical Center, David Bennett, aged 57, received a heart transplant from a genetically modified pig – the first time this has been done successfully. Bennett was suffering from terminal heart disease, and therefore was ineligible for traditional options of a human heart transplant or an artificial heart pump. Whilst Bennett died 2 months after surgery on 8th March 2022, the procedure is considered a medical breakthrough: the genetically modified pig’s heart functioned like a human heart without immediate rejection by the immune system.

The heart for Bennett came from a ’10gene pig’ - the donor pig was genetically modified to inhibit organ rejection and improve human immune response. Three genes, responsible for rapid antibodymediated rejection of pig organs by humans, were removed in the donor pig.

Additionally, six human genes responsible for immune acceptance of the pig heart were inserted into the pig genome. An additional gene in the pig was knocked out to prevent excessive growth of the donated pig heart tissue, in order to prevent it responding to human growth hormones and it growing out of control.

These 10-gene pigs are raised in sterile conditions, so they are suitable for transplant. Once transplanted into the human recipient, a new drug was used alongside conventional immunosuppressant drugs to help aid rejection of the foreign heart.

Whilst marvelling at the recent success of Bennett’s pig heart transplant and potential future applications, Xenotransplantation raises many ethical considerations, which I will leave you with:

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Surgeon Bartley P Griffith pictured with David Bennett in January, University of Maryland School of Medicine

Could it solve the global shortage of human organs for transplants?

Should xenotransplantation be encouraged, permitted, frowned upon or perhaps even forbidden?

Is it safe?

Is it necessary?

What are the animal welfare implications?

Are there any religious considerations?

Could xenotransplantation change the nature of humans?

‘Raising awareness of the issues surrounding kidney trafficking’ – Peter 10J Do YOU know about the booming trade in organ trafficking, especially the kidney trade? Yes, you heard that right, people sell other people’s kidneys for money...gross right? Well by reading this and raising awareness, we, together, can stop kidney trafficking and make a dent in the global organ trade. Well to start, lets look at why people are involved with this in the first place. There are two groups of people – the trafficking gangs and the desperate patients. The trafficking gangs are groups of people who illegally abduct others and then forcefully remove their kidney for a small price. They would then sell the kidney on the black market for around $100,000.

However, trafficking networks also target poor European countries such as Estonia, Bulgaria, Turkey, Georgia, Russia, Romania, Moldova, and Ukraine, where people are pressured into selling their kidneys for as little as $2000 as they need it for food and water. For example, Europe's poorest country, Moldova, where the average monthly salary is less than $50, is a prime target for traffickers. Kidney trafficking is thought to be most prevalent in Israel, India, China, Pakistan, Turkey, Brazil, Nepal, the Philippines, Kosovo and Iran.

The second group are the desperate patients. These are people who need an urgent kidney transplant for conditions like cancer, infections, and kidney failure.

Between 15% and 30% of European patients die while waiting for a kidney transplantation, owing to a chronic shortage of organs, the average wait for a legal transplant being approximately three years and is expected to increase. There is a shortage of legal donors, as, although kidneys for transplantation can come from living donors or deceased donors, a very small number of people die in circumstances where their organs are suitable for transplant (fewer than 1% of the population) so there is always a shortage. A kidney from a living donor is the ‘gold standard’ for transplants. The success rate for transplants from living donors is better than that for transplants from deceased donors: 90-95% are working well one year after transplantation, compared with 8590% for those received from a deceased donor, however obviously, many do not want to give up a kidney. It is in this way that people are forced to go abroad into trafficking countries to try and source a kidney, which then is sold to them by traffickers with a supposedly good kidney.

Organ trade is the trading of human organs, tissues, or other body products, usually for transplantation. According to the World Health Organization, organ trade is a commercial transplantation where there is a profit, or transplantations that occur outside of national medical systems.

Raising awareness of the issues surrounding kidney trafficking’ – Peter, Yr 10 Once obtained, trafficked organs can be transplanted to recipients in the most reputable of hospitals in major cities throughout the world but makeshift operating rooms in houses have often been the secret locations for such transplants. As mentioned before, traffickers orchestrate the recruitment of the donor often from a place of vulnerability, and victims are not necessarily properly screened for their qualifications to be a healthy donor. Not only is this dangerous for the donor, travel for transplantation that involves organ trafficking or if the resources (organs, professionals, and transplant centres) devoted to providing transplants to patients from outside a country undermine the country’s own ability to provide transplant services for its own population. This could lead to more shortages and deaths while waiting.

So, how do we stop this process from happening? For the general people, there is not much to do apart from raising awareness and reaching out to people who have kidney issues and educating them on the risks of overseas transplantation. However, in the long term, bigger scale, developing better systems of deceased organ donation; encouraging unselfish living kidney donation and preventing needs for transplantation by treating diseases that lead to organ failure such as diabetes and hepatitis can all help to curb the demand for trafficked kidneys, forcing these gangs to stop the supply.

Things to do this Easter in London for free*

*whilst the NHM is free, you do have to pay to see the Wildlife Photographer of the Year exhibition but it is well worth it!

‘Biology in the news’ – Mr Glanville Animal blood comes rainbow of colours.

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From milky blue to lime green, organisms have evolved different types of blood—and ways to move oxygen around the body.

A very interesting National Geographic Article explains why animals have different colour blood including transparent, green and blue. Some crustaceans, squid, and octopuses have blue blood due to the oxygen-transporting protein hemocyanin, which contains copper, says Stephen Palumbi, a marine biologist at Stanford University. In marine animals, hemocyanin is colourless, but turns blue when it binds with oxygen.

Hemocyanin, which evolved nearly 2.5 billion years ago, originally served to detoxify oxygen for primordial organisms in Earth’s anaerobic, or low-oxygen, environment, says Christopher Coates, a comparative immunologist at Swansea University in Wales. Later, when the atmosphere became more oxygen-rich, the protein evolved again to deliver oxygen throughout an organism’s body.

Haemoglobin evolved much later, possibly about 400 million years ago.

Coates says it likely came about because vertebrates have more complex respiratory systems than do simple organisms. Indeed, most mammal, fish, reptile, amphibian, and bird blood is red because of haemoglobin, whose protein is made of hemes, or iron-containing molecules that fuse with oxygen.

Horseshoe crabs swarm in Deleware Bay

In some cases, animal blood has useful applications for human health. The milky-blue, hemocyanin-rich blood of Atlantic horseshoe crabs, for instance, clots when it comes in contact with bacterial toxins. This makes it a valuable tool for ensuring medical drugs or products—particularly vaccines—are safe and free from contaminants.

Harvesting blood from horseshoe crabs

Atlantic horseshoe crabs make an annual visit to the shoreline to lay eggs in sandy, wet beaches, with the biggest populations gathering along the Delaware Bay in the eastern U.S. However, the process of collecting and bleeding the crabs—up to half a million annually—can kill them, and it’s caused the species’ numbers to drop in the U.S. midAtlantic region in recent years. That’s why scientists are working to find synthetic alternatives that would reduce the need for catching wild animals.

Can plants warn other plants of danger?

Animals often use highly specific signals to warn their herd about approaching predators. Surprisingly, similar behaviours are also observed among plants. Shedding more light on this phenomenon, Tokyo University of Science researchers have discovered one such mechanism. Using the plant Arabidopsis thaliana as a model system, the researchers have shown that herbivore-damaged plants give off volatile chemical "scents" that trigger epigenetic modifications in the defence genes of neighbouring plants. These genes subsequently trigger anti-herbivore defence systems.