Welcome to this week’s Sunday Science, with a walking whale, whole-body regeneration, how the cell can compensate for harmful mutations, protection against pre-eclampsia, ninja kangaroo rats, and more…

The regenerative property of some animals has intrigued scientists for a long time, such as the ability of a salamander to regrow a limb. Some worms are even able to grow two complete new worms when chopped in half. A big new study has uncovered lots of the DNA switches responsible for this whole-body regeneration in the Panther worm (after sequencing its entire genome). Key to the entire process seems to be activation of a “master control gene” called EGR. Original research article here (paywalled)

As if the physiological stress pregnancy puts on the human body weren’t bad enough, apparently it can also cause an increase in misfolded proteins. Accumulations of these are implicated in many human diseases, for example beta-amyloid – this is a well-known culprit in Alzheimer’s disease, but less well-known is that it can cause pre-eclampsia. This potentially life-threatening condition is characterised by protein in the urine and dangerously high blood pressure. A new study shows that pregnant women usually protect against this by up-regulation of a protein called “pregnancy zone protein” (PZP) helps protect against the accumulation of misfolded proteins. PZP is a “chaperone” protein – one that helps other proteins fold correctly. This offers the possibility of potential treatments for pre-eclampsia.

If a gene is mutated such that it doesn’t produce a functional protein, it’s called a “knockout” – often done deliberately during genetic experiments. This can, of course, be very bad news for the organism, but in some cases it appears to have no effect even for proteins that seem to be very important. Now, two intriguing new studies have uncovered a mechanism whereby the cellular machinery compensates for the knockout of a protein – by up-regulating related proteins. Mutations that lead to a premature “stop” signal in the DNA coding sequence for a protein usually triggers a process called nonsense-mediated decay, in which the truncated message RNA molecule is targeted for breakdown. It appears that some of the molecules involved in this degradation process also travel to the nucleus and act to up-regulate genes that might be able to compensate. Original research articles here and here (paywalled).

The immune systems of newborn babies undergo drastic changes after they are born and go from the protected environment of the womb into the outside world. Screening of newborn blood has revealed some of those dramatic changes: it’s hoped analysis of the changes in immune system molecules and cells will help inform effective vaccine development. Original paper here.

The Global Seed Vault at Svalbard, which currently holds nearly a million samples, is designed to preserve the genetic diversity of the world’s crops in the face of natural or manmade disaster. The location was chosen because it was both politically and climatically stable. But the rapidly changing climate means that it’s not as stable as it once was: melting of the permafrost is threatening the vault.

Restoring natural forests is the best way to remove carbon from the atmosphere to fight climate change, argues this piece. According to the IPCC, increasing the total area of the world’s wooded areas – by 24 million hectares a year until 2030 –  could store around one quarter of the carbon needed to keep warming below 1.5C. Many countries are actually aiming for huge increases in tree planting – but a lot of that will be in the form of plantations, which won’t help that much, as they are regularly harvested and re-release their stored carbon.

Women are “naturally” more risk-averse than men, right? Well, probably not. It appears it’s at least partly culturally determined. In the matrilineal Musuo culture, boys are more risk-averse than girls, whereas in the patriarchal Han society, it’s the opposite. The study showed that Musuo children mixing with predominantly Han-children at school adopted that culture, with the girls becoming more risk averse.

A whale with four legs and hooves? (featured image). It sounds fanciful, but it is known that modern whales evolved from land animals. A new fossil of a four-legged proto-whale called Peregocetus has been found that fills in a key link in this evolutionary timeline. It was semi-aquatic, able to swim, but also had four legs. The original paper is here and includes a really good video summary of whale evolution and their findings.

And finally…”ninja” kangaroo rats use super-fast leaps and kicks to get away from striking rattlesnake, as this rather fun video shows:

Featured image

Reconstruction of the Peregocetus whale. A. Gennari/CellPress


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