Lingering threat

PCB. Lingering threat.

Slinking up food chains, silent.

Killing the killers.

 

PCBs – polychlorinated biphenyls – were widely used in a variety of manufacturing techniques until they were linked to health problems such as increasing the risk of cancer, disrupting the immune system and impairing reproduction. Despite a ban on their use, the compounds remain an environmental contamination and can accumulate in the tissues of animals, passing up the food chain to accumulate in dangerous levels in apex predators.

Whilst killer whales are one of the most populous mammal species on the planet, research by Desforges et al (2018) suggests that PCB pollution could result in a collapse in over 50% of the world’s killer whale populations. The researchers amalgamated data on PCB concentrations in killer whale tissues from across the world and modelled the predicted impacts of PCB pollution over the next 100 years. The results highlight how important it is to be aware of potential environmental issues, even with species that appear to be thriving.

Original research: http://science.sciencemag.org/content/361/6409/1373

These membrane proteins by Chris Gillen

These membrane proteins

might reclaim salt from urine

or suck it from ponds.

 

Mosquitoes face extraordinary challenges to their salt and water balance during their complex life-cycles. Larva of most species live in freshwater environments in which they lose salt by diffusion and gain water by osmosis. In contrast, adults live in terrestrial environments where water loss is a problem. Finally, female mosquitoes ingest large amounts of salt and water when they take a blood meal.

In vertebrates, the sodium-potassium-chloride cotransporters (NKCCs) participate in both salt secretion and absorption. Whereas secretory roles for this group of transporters are well-described in insects, their roles in salt absorption are less well studied. Piermarini et al (2017) recently identified yellow fever mosquito transport proteins that have sequence similarity to the vertebrate NKCCs. Two of these transporters apparently resulted from gene duplications early in the insect and mosquito lineages, suggesting that they have diverged into roles related to mosquito osmoregulation. The transporters may contribute to salt absorption, because the researchers found them in adult hindgut and larval anal papillae, both tissues that transport salt into the body.

Original research: Piermarini, P. M., Akuma, D. C., Crow, J. C., Jamil, T. L., Kerkhoff, W. G., Viel, K. C. M. F., and Gillen, C. M. (2017) Differential expression of putative sodium-dependent cation-chloride cotransporters in Aedes aegypti. Comp. Biochem. Physiol. A 214, 40-49. https://doi.org/10.1016/j.cbpa.2017.09.007

Chris Gillen teaches animal physiology and science writing at Kenyon College in Gambier, Ohio.  He is author of The Hidden Mechanics of Exercise (Harvard, 2014) and Reading Primary Literature (Pearson, 2007).

No catch-22

Does the protected

lion eat conserved zebra?

Phew! No catch-22!

 

Recovering predator populations as a result of conservation work can result in impacts on their prey species populations, causing issues if those prey species are themselves endangered. One case in particular is whether lions exert top-down pressure on Grevy’s zebra in Kenya – does the recovery plan of one species negatively affect the conservation of another?

A study by O’Brien et al (2018) suggests we need not worry in this case – working in Laikipia County in Kenya the researchers found that lions were less likely to prey on Grevy’s zebra than expected. In fact, population trends suggest that the Grevy’s zebra population in Kenya may be stabilising. The researchers conclude that the most likely threat to Grevy’s zebra are competition for grass with Plain’s zebra and the impact of livestock.

Original research: http://dx.doi.org/10.1371/journal.pone.0201983

Fluttering by at dusk by Roy McGhie

Fluttering by at dusk,

dawn, and in between.

Crop diversity!

Recent research by Olimpi & Philpott (2018) concludes that crop diversity as a management practice drives bat activity, and that crop diversity and less frequent pesticide use increase bats’ insect prey populations. The study notes that this could be a useful management tool where other options, such as hedgerow or tree management, are not available.

Original research: https://doi.org/10.1016/j.agee.2018.06.008

Roy McGhie works for Natural England as an Uplands Advisor. You can connect with him on LinkedIn here. If you enjoyed his sciku, check out his previous poems Ghost Ponds, A Heady Mixture and Hedgerow Snuffling.

Where are all the wildflowers?

Monoculture crops.

Where are all the wildflowers?

Where is all the life?

 

Modern intensive agricultural practices have had a devastating impact upon the native wildlife that inhabits arable land, from the density of worms in the soil to the number of apex predators patrolling the skies. In particular, monoculture crops, herbicides, pesticides and the removal of hedgerows have resulted in depleted numbers of invertebrates and subsequently the numbers and variety of birds and other vertebrates that feed upon them.

The farmer and writer John Lewis-Stempel approached this issue by taking a small arable field in south Herefordshire, UK, and spending a year growing wheat following traditional methods. Whilst sowing a mix of wheat he also sowed various species of wildflower, both in the margins of the field and amongst the crop itself. As the year processed he charted the wildlife that appeared in the field, from harvestmen and worms to hares and barn owls.

The blossoming of life was astonishing, absent in the vast, monoculture fields that dominate much of agricultural Britain. Lewis-Stempel’s work begs the question whether such endeavours if repeated across the countryside could transform the levels of biodiversity in the UK? Are the (supposed) gains that modern intensive farming bring worth the environmental devastation they create? As a consumer I am guilty of benefitting from cheap food, it’s hard not to be. But as Lewis-Stempel says “every time one buys the lie of cheap food a flower or a bird dies”. I do believe in flowers and birds, I do, I do.

I can’t recommend his book documenting the project enough: ‘The Running Hare: The Secret Life of Farmland’. From the quality of the prose to the clearly outlined arguments throughout, it is outstanding. If you care about native species, conservation or agriculture then this is essential reading. For everyone else it’s just highly recommended. (And how nice it is to see Herefordshire getting any form of recognition or acknowledgement in the media).

Oh ketchup packet!

Oh ketchup packet!

How to get the last sauce out?

Hydrocarbon films!

 

Waste from packaging where food products can’t be completely extracted builds up. Now research by Mukherjee et al (2018) suggests a solution might be at hand. The researchers found that hydrocarbon-based polymer films can be stably impregnated with vegetable oils. The resulting material is slippery and durable, ideal for the inside of packaging to reduce food sticking and waste.

Whilst this sounds high-tech the researchers were actually inspired by the pitcher plant which uses a slippery coating on its leaves to capture visiting insects.

Original research: http://dx.doi.org/10.1038/s41598-018-29823-7

Eggy difference

The Baltic flounder:

Native to namesake region.

Eggy difference.

 

A new species of flounder has been identified as separate from the European flounder by Momigliano et al (2018). The Baltic flounder (Platichthys solemdali sp.) is native only to the Baltic Sea – the first fish species to be identified as endemic to the area.

Its reproductive behaviour differs from the European flounder, spawning eggs that sink in coastal areas as opposed to buoyant eggs in open water. There are also differences between the species in egg morphology, egg and sperm physiology. Unfortunately, the small morphological differences mean that it is difficult to unambiguously distinguish the species and genetic methods or egg/sperm analyses are required.

Original research: http://dx.doi.org/10.3389/fmars.2018.00225

Extrapolation

Extrapolation

from laboratory tests.

Not always correct?

 

Experiments within the laboratory are often used to understand biological interactions in a controlled manner. Yet research by Comforth et al (2018) suggests that what we learn from the laboratory may not always represent what happens in reality.

The researchers found that Pseudomonas bacteria (a pathogen that threatens immunocompromised people) behaved differently in humans compared to under laboratory conditions. This was particularly apparent in the levels of gene expression involved in antibiotic resistance, cell to cell communication and metabolism. The implications of this work suggest laboratory studies only take us so far and further understanding bacterial behaviour in humans is just as important.

Original research: https://doi.org/10.1073/pnas.1717525115

Snakeskin secrets

Learning from nature:

Snakeskin secrets revealing

lessons in friction.

 

The natural world has inspired engineering and design in countless ways. Now researchers are looking at snakeskins in an attempt to better understand an understudied engineering area: friction.

Abdel-Aal (2018) summarises findings from 40 species of snake to understand how the textural traits of snake skin compare to the standard features of textured industrial surfaces. This exploratory framework could subsequently lead to new, nature-inspired smart surfaces.

Original paper: https://doi.org/10.1016/j.jmbbm.2017.11.008

Chestnut menace

Invading clonal

wasps. Chestnut menace spreading

yet no males required.

 

The Chestnut gall wasp arrived in Europe in 2006, imported accidentally from China. Since then it has begun to spread and devastate European Chestnut trees.

Bonal et al (2018) have now revealed that the European population has very low genetic diversity due to 1) the founding of the population by a small number of individuals, 2) an endosymbiont bacterial infection present within the population that is known to have male-killing tendencies and 3) it’s parthenogenetic reproduction strategy. This is where females are able to reproduce and produce female offspring without the need to be fertilised by males. No males have been observed in the European population and the females and their offspring are effectively clones of one another.

Original research: https://doi.org/10.1038/s41598-018-23754-z

Forgotten value

Forgotten value

of seagrass meadows. Crucial

for world’s fisheries.

Life in the ocean is under threat from a variety of manmade issues, including climate change, mining and over-fishing. Yet our understanding of marine ecosystems still remains far from complete.

New research by Unsworth et al (2018) has revealed just how important seagrass meadows are for fish populations and as a result for humanity’s fisheries. Seagrass meadows are found in the shallow seas around all the continents (aside from Antarctica) between the intertidal zone and 60 meters deep.

The researchers found that seagrass meadows provide a nursery habitat for over a fifth of the world’s largest 25 fisheries and provide support to a large number of other small-scale fisheries around the world. The study indicates that these seagrass meadows should be maintained in order to maximise their role in global fisheries production.

Original research: https://doi.org/10.1111/conl.12566

Interested in seagrass meadows? They also play a hugely important role in sequestering carbon. Find out more with this sciku here.

Giant becomes five

Giant becomes five

endangered salamanders.

Hidden extinction?

 

The Chinese Giant salamander is the world’s largest amphibian, adults can be 2 meters long and weigh up to 50 kg. It’s critically endangered in the wild due to habitat destruction, fungal infection and because the species is used as a luxury food source in China. It is kept in far greater numbers in captivity as a result of it being farmed for food. Two studies published in Current Biology add additional concerns for the future of this species in the wild.

In what is thought to be the largest wildlife survey conducted in China, Turvey et al (2018) found that giant salamander populations were either critically depleted or had been eradicated, as well as finding plenty of evidence for illegal poaching. The researchers were unable to confirm the survival of wild Chinese giant salamanders at any of their survey sites, raising the question of whether this species is all but extinct in the wild.

In a companion piece of research, Yan et al (2018) performed a genetic analysis on Chinese giant salamanders and found that the species actually consists of at least five species-level lineages, potentially up to eight. This suggests that some of these distinct lineages (effectively separate species) may well have already gone extinct in the wild – a phenomenon known as cryptic or hidden extinction. This has crucial importance for conservation efforts, particularly with regards to re-releases from captive populations where the five lineages have been mixed and the resulting offspring are effectively hybrids.

Original research:

Turvey et al (2018): https://doi.org/10.1016/j.cub.2018.04.005

Yan et al (2018): https://doi.org/10.1016/j.cub.2018.04.004

Sleep disruption

Modern screens can cause

sleep disruption if used late.

Weekends may top up?

 

Research suggests that sleep duration is important for health, making maintaining decent sleeping patterns important for a healthy lifestyle. Chinoy et al (2018) have found evidence that the use of electronic tablet devices with light-emitting screens close to bedtime can result in later bedtimes and disrupted circadian rhythms and result in lower alertness in the morning.

Many of us like a lie in at the weekend, as if we are making up for the week gone by. Research by Åkerstedt et al (2018) studying over 40,000 subjects across 13 years suggests that longer weekend sleep may indeed compensate for shorter weekday sleep.

Original research:

Chinoy et al (2018): https://physoc.onlinelibrary.wiley.com/doi/10.14814/phy2.13692

Åkerstedt et al (2018): https://doi.org/10.1111/jsr.12712

The year’s best species

Mystery protist.

Apes, snailfish and amphipods.

The year’s best species.

 

Every year since 2008 the College of Environmental Science and Forestry has released a Top 10 New Species list. 2018’s selection include single celled organisms, plants and animals (including two species of beetle) as well as a prehistoric marsupial lion identified from fossils. All 10 species are fascinating but those highlighted in the sciku are:

Protist – Ancoracysta twista, a single celled predatory Eukaryote with harpoon-like organelles that it uses to immobilise its prey. Intriguingly its evolutionary origins are unclear and it doesn’t fit neatly within any known groups.

Ape – Orangutans now come in three flavours: Bornean, Sumatran and now a newly identified Southern Sumatran species of orangutans. It is the most endangered great ape in the world.

Snailfish – Whilst snailfish are found at all depths, 2018’s species is the deepest fish in the sea, found in the Mariana Trench at 7,966 meters below the surface. It appears to be the top predator in its benthic community and is tadpole-like and around 4 inches long.

Amphipod – Epimeria quasimodo is found in the Antarctic Ocean. The 2 inch long crustacean takes its name from the hunchback of Notre Dame and has beautiful vivid colours.

You aren’t one of us.

Help! Help! Predator!

Guys, why aren’t you helping me?

You aren’t one of us.

 

Jackdaws respond to anti-predator calls to join the caller in mobbing the predator and driving it away. Yet researchers have now found that who the caller is will affect the level of response.

In playback experiments Woods et al (2018) that the highest response was to nestbox residents who would be highly familiar with the caller. The level of response to an anti-predator call diminished as familiarity decreased from colony members to non-colony members and then to rooks (a species that often lives alongside jackdaws).

Original research: http://dx.doi.org/10.1038/s41598-018-25793-y

 

TF gets in on the bud by Jolene Ramsey

Fat tags the protein

To the surface it transits

Wrapped in the virus

Living cells are like microscopic cities. The proteins, which are the workhorses of a cell, must accurately navigate to the place where they will perform their assigned tasks. Sometimes we equate the way that proteins get to their final destination to adding an address to a letter.

When a virus infects a cell, its proteins must conform to the cell norm or rewire the system. It is of interest to understand how viruses approach this problem. In the case of a small accessory protein called TF that is found in the virions of Sindbis virus, adding lipids to the protein serves as its ‘address’ to get it to the location where new virions are released from an infected cell.

Original research: https://dx.doi.org/10.1128%2FJVI.02000-16

During graduate school, Jolene Ramsey studied the molecular mechanisms governing enveloped eukaryotic virus assembly. She has a long-term interest in understanding how viruses exploit host cells to build more virions.  You can follow her on Twitter under the handle @jrrmicro

Enjoyed Jolene’s sciku? Check out her other sciku ‘Click click go!’, ‘Privateer, the phage’, ‘The Phriendly Phage’ and Saba, the morning breeze.

My dreams escape me

My dreams escape me.

Vitamin B6 could help

my recollection.

 

It’s often hard to remember the details of dreams when we wake – some people even keep notebooks by their beds to scribble their dreams down whilst they are fresh in their memories.

A study by Aspy et al (2018) has now found evidence to suggest that taking vitamin B6 before bed for 5 days increased dream recall ability (although not dream vividness, bizarreness or colour). Interestingly taking a range of B vitamins did not affect dream recall and even resulted in participants having a lower sleep quality and feeling more tired.

Original research: http://dx.doi.org/10.1177/0031512518770326

 

 

Cuckoo bee

No longer extinct,

cuckoo bee, nest parasite,

found further afield.

 

The Macropis Cuckoo Bee was thought to be extinct until the early 2000s when a specimen was found in Nova Scotia. The bee is one of the rarest bees in North America, with only a handful found during the past decades. A new specimen found in Alberta and reported by Sheffield and Heron (2018) has now pushed the known geographical range of the Macropis Cuckoo Bee further west and gives hope to the continued survival of this species.

The Macropis Cuckoo Bee lays its eggs in the nests of Macropis bees and therefore requires the presence of its hosts in order to reproduce, yet cuckoo bees are not always found where their hosts are. In turn Macropis bees are entirely dependent on plants of the primrose genus meaning that the there is a chain of co-dependence between the plants, bees and cuckoo bees.

Original research: http://dx.doi.org/10.3897/BDJ.6.e22837

 

Have frog, will travel

Have frog, will travel,

yet what impact on welfare?

Best to avoid moss.

Transporting animals for research, agricultural, conservation or leisure reasons can involve a range of potential stressors. It’s therefore important to be aware of the impact of transportation on animals so as to minimise any negative effects.

African clawed frogs are a common laboratory animal, used for a range of developmental studies. Holmes et al (2018) investigated the impact of transportation between research facilities. They found that transportation and re-housing had a negative impact across a short- and longer-term, with corticosterone (a ‘stress hormone’) remaining high for 1 week and body mass remaining low for 5 weeks after transportation. Investigating further the researchers found evidence that being transported in moss might be the least preferable transport medium, with water or sponge appearing to be more suitable.

Original research: https://doi.org/10.1016/j.ygcen.2018.03.015

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Clawed frogs indicate‘, ‘Xenopus enrichment‘, ‘Fungal culprit‘ and ‘Reservoir or predator‘.

How you handle mice

How you handle mice

affects response to rewards.

Science improves too!

 

There is an increasing body of research to suggest that handling laboratory mice by the tail is both bad for their welfare and the science that the mice are studied for. Tail handling has negative impacts on mouse behaviour and physiology, with tunnel and cupping handling techniques resulting in behavioural improvements across various common behavioural bioassays, including the elevated plus maze, the open field test and the habituation-dishabituation paradigm.

Now new research suggests that handling is also important for reward-based behavioural assays. A study by Clarkson et al (2018) examined mouse response to sucrose solution (a common reward). They found that tail handled mice showed a reduced response to the sucrose than the tunnel handling method, a finding indicative of the tail handled mice having a ‘decreased responsiveness to reward and potentially a more depressive-like state’.

Across eight years and five research papers, from three distinct research groups in two countries, the field of laboratory mouse research has been irrevocably changed. Combined, the research suggests that tail handling results in poor animal welfare and potentially erroneous scientific results. The National Centre for the Replacement, Refinement & Reduction of Animals in Research now has extensive information on mouse handling techniques, example videos, tips and testimonials for researchers and animal carers to find out more about changing their current mouse handling methods to the tunnel or cupping techniques.

Original research: http://dx.doi.org/10.1038/s41598-018-20716-3

 

Tunnels and cupping

Tunnels and cupping

beat tail handling mice for

behavioural tests.

 

Laboratory mouse handling method can affect mouse behaviour and physiology, and new research suggests that it can also impinge on mouse performance in behavioural tests. Research by Gouveia and Hurst (2017) found that tail handled mice performed poorly in a habituation-dishabituation paradigm test in comparison to cupped or tunnel handled mice. The tail handled mice ‘showed little willingness to explore and investigate test stimuli’ and even prior familiarisation with the test arena didn’t improve their performance much.

Combined with the previous research findings on mouse handling this research continues to expand on the long-reaching impacts of mouse handling technique on both mouse welfare and scientific experimental rigour and asks the question – just how valid are behavioural tests using laboratory mice that have been tail handled? Yet the story of mouse handling is not yet done, click here for the final instalment of this tale/tail!

Original research: http://dx.doi.org/10.1038/srep44999

 

Cup handled mice

Cup handled mice show

improved glucose tolerance

and less anxiousness.

 

When performing scientific research with animals, it’s important to ensure that the procedures used do not themselves impact upon the results obtained. Laboratory mouse handling method has already been shown to impact upon mouse anxiety in common behavioural tests. However it seems that handling can have physiological impacts too.

Ghosal et al (2015) compared the behavioural and physiological responses of laboratory mice to either tail handling or cupped handling techniques. Cupped handled mice showed fewer anxious behaviours in a common behavioural test, reduced blood glucose levels and a lower stress-induced plasma corticosterone concentration in response to an overnight fast compared to tail handled mice. The researchers also found that obese laboratory mice handled using the cupped method demonstrated improved glucose tolerance.

Replication and repeatability are crucial components of science and this paper is a perfect demonstration of this – the researchers are from different research laboratories and in a different country to the mouse handling work that preceded it. In this way not only does it build on what came before, it also strengthens those earlier findings. Yet the mouse handling story is not finished yet, click here for the next chapter of this tale/tail!

Original research: https://doi.org/10.1016/j.physbeh.2015.06.021

 

Reducing mouse anxiety

Further reducing

mouse anxiety using

familiar tunnels.

 

Building on the finding that handling laboratory mice using a tunnel resulted in lower anxiety than picking them up by the tail, Gouveia and Hurst (2013) next investigated whether familiarity with the tunnel might be an important factor. Once again they found that tunnel handling resulted in lower anxiety than tail handling during an elevated plus maze (a common behavioural test for laboratory mice).

This time they found differences between mouse strains, with C57BL/6 mice being most interactive towards tunnels from their home cage and ICR mice showing no difference in interaction between familiar home cage tunnels and novel tunnels previously used for handling mice from other cages. The researchers suggest that ‘as home cage tunnels can further improve response to handling in some mice, we recommend that mice are handled with a tunnel provided in their home cage where possible as a simple, practical method to minimise handling stress’. The tunnel would also act as a form of environmental enrichment for the home cage.

In science it’s rare to tell a complete story through the findings of two research papers, click here for the next chapter of this tale/tail!

Original research: https://doi.org/10.1371/journal.pone.0066401

 

The little changes

The little changes

can make a big difference:

Handle mice with care.

 

Traditionally laboratory mice are handled by picking them up by the tail, yet increasing evidence suggests that this is bad, both for the mice themselves and the quality of the science they are being used for. The evidence for this started building from Hurst and West’s 2010 study which demonstrated that handling by the tail resulted in increased aversion and anxiety.

The researchers proposed two alternative methods for handling laboratory mice: holding the mice cupped in the hands or using tunnels that the mice can crawl into and be transported by carrying the tunnels. These novel methods of handling led to the mice approaching the handler voluntarily, being more accepting of physical restraint and showing lower levels of anxiety.

In science it’s rare to tell a complete story through the findings of a single research paper, click here for the next chapter of this tale/tail!

Original research: http://dx.doi.org/10.1038/nmeth.1500

 

Letter from Ternate by Prof Donald M Waller

Thinking to respond

Darwin despaired, paused, then shared.

Pressed to Origin.

 

Charles Darwin first conceived of his theory of evolution by natural selection in the late 1830s and began work in earnest on his “big book” in the 1840s. Yet it was not until he received a letter from Ternate, Indonesia, from the younger naturalist Alfred Russell Wallace in 1858, threatening to rob him of his originality for the idea, that he was pressed into months of intense activity to publish in 1859 an “abstract” of his longer work that appeared as “On the Origin of Species by Means of Natural Selection . . ”

Darwin was thrown into great anguish by Wallace’s letter and request from Wallace to help get it published.  He confided in scientist friends who urged him to prepare a parallel brief summary of his own ideas, extracted from his private essay of 1842. They arranged for both papers to be read before the Royal Society.  These did not attract much interest, but “On the Origin” certainly did.

Further reading:

A.C. Brackman.  1980.  A Delicate Arrangement:  The strange case of Charles Darwin and Alfred Russell Wallace

Quammen.  2006.  The Reluctant Mr. Darwin:  An intimate portrait of Charles Darwin and the Making of His Theory of Evolution.

Don Waller teaches ecology, evolution, and conservation biology at the University of Wisconsin-Madison. He trained in evolutionary ecology, seeking to understand population dynamics, life history and mating system evolution, and the causes and consequences of inbreeding. He then morphed into a conservation biologist studying rare plants and threats to diversity. He now studies meta-community dynamics and the forces driving long-term changes in temperate forest plant communities. These include habitat fragmentation, aerial N deposition, invasive species, and overabundant deer. He also seeks to use science to improve forest, wildlife, and environmental management. To better understand deer and hunters, he became a bow hunter.

 

Knuckle cracking maths

Knuckle cracking maths:

Synovial bubbles pop

in partial collapse.

 

The debate over how knuckles cause a popping sound when cracked has lasted for decades. Now, Chandran Suja and Barakat (2018) have created three equations to mathematically model how the sound is produced. The first equation describes variations in pressure inside the joint, the second describes how pressure variations results in bubble size variations, whilst the third equation links the size variation of bubbles with the production of acoustic pressure waves.

When cracking your fingers the joints are pulled apart, the pressure goes down and bubbles appear in the synovial fluid which lubricates the joint. During knuckle cracking the pressure changes within the joint causing the size of the bubbles to fluctuate quickly resulting in the popping sound. The new model reveals that the bubbles don’t need to completely collapse in order to produce the sound, explaining why bubbles are observed following knuckle cracking.

Original research: http://dx.doi.org/10.1038/s41598-018-22664-4

Patches on Venus

Patches on Venus:

Atmosphere harbouring the

conditions for life?

 

In the hunt for extra-terrestrial life, Venus is rarely considered due to the high surface temperatures (~465 °C) and the intense atmospheric pressure (92 times that on Earth). Yet a new study by Limaye et al (2018) suggests that life off the surface of the planet may be possible since the lower cloud layer harbours conditions suitable for microbial life: water, solutes, ~60 °C and an atmospheric pressure roughly equivalent to Earth.

What’s more, observations of Venus have revealed dark patches in the atmosphere that change shape, size and position over time. These are made up of particles roughly the same size as common Earth bacteria and also absorb light of at a similar spectrum. The changes in patch patterns could therefore be the equivalent of algae blooms.

Venus is thought to have once had water on its surface, potentially for as long as 2 billion years providing enough time for life to evolve. As the surface water evaporated the microorganisms could have been transported to the clouds, in similar ways to how bacteria have been found in the atmosphere of Earth (although on Earth aerial microbes do not appear to remain aloft indefinitely). Life on the second planet from the sun therefore remains a possibility and only further observations and potentially even atmospheric sampling will reveal whether the changing dark patches are indeed patterns of microbial life.

Original research: https://doi.org/10.1089/ast.2017.1783

Egg quality

Low egg quality –

the impact of age. Blocking

proteins slows decline.

 

As women age their reproductive ability decreases due to declining egg quality. However, research by Templeman et al (2018) suggests that blocking a particular group of proteins may help to slow this decline, potentially extending the reproductive period.

The proteins, known as cathepsin B proteases, are more common in age-degraded oocytes (unfertilised eggs) and appear to be part of the problem of decreasing quality. By blocking the proteins in C. elegans worms oocyte quality was maintained for much longer, regardless of whether the drug was administered at the beginning or part way through the worms’ reproductive period. Whilst it’s not ready for testing with humans, it points the way towards an interesting new approach.

Original research: http://dx.doi.org/10.1016/j.cub.2018.01.052

 

Crop blighter

Rice blast: crop blighter.

Inhibiting one protein

stops the fungal spread.

 

Up to 30% of rice crop is destroyed by rice blast every year, causing huge welfare and economic costs. Sakulkoo et al (2018) have found that inhibiting a single protein enzyme in the fungus stops the spread of the blight through a rice plant.

The fungus’s mitogen-activated protein Pmk1 plays a role in suppressing its host’s immune system and controls the ability of the fungus to move from one rice cell to another. By inhibiting Pmk1’s kinase the fungus is trapped within the infected rice cell and is unable to spread and infect the rest of the rice plant. This latest discovery could point the way towards new rice blast control methods, resulting in increased food security and economic development.

Original research: http://dx.doi.org/10.1126/science.aaq0892

 

Reservoir or predator

African clawed frog –

reservoir or predator

of the fungal blight?

Amphibian populations worldwide are being devastated by a fungal infection (known as chytrid or Bd). As an invasive species and carrier of the fungal infection African clawed frogs are often blamed for the spread of chytrid and the current conservation crisis.

Research by Wilson et al (2018) suggests the story is more complicated than it at first seems though. Field studies in California suggest a 10% level of Bd infection in the frogs, with infected individuals having very low levels of infection. Additionally, larval clawed frogs appear to eat the Bd zoospores and may therefore actually be helping to reduce the negative impact and spread of the fungus. Unfortunately the study also suggests that the frog larvae also eat Daphnia, which are another predator of the Bd zoospores.

This latest research adds to growing evidence suggesting that African clawed frogs may not be as guilty as they seemed at first.

Original research: https://doi.org/10.1371/journal.pone.0191537

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Clawed frogs indicate‘, ‘Have frog, will travel‘, ‘Fungal culprit‘ and ‘Xenopus enrichment‘.