Coral reef fish breed offspring from other fish

The unusual behaviour of coral reef fish was studied by a team of researchers from the University of California at Santa Cruz. This is an example of incubation parasitism, a phenomenon that can be observed in different species of animals, often birds, and that occurs when children are not cared for by their parents. In fact, you can see bird species that lay eggs in nests of other species, not in their own.

Researcher Giacomo Bernardi, Professor of Ecology and Evolutionary Biology, has studied this phenomenon in fish of the genus Altrichthys. According to the researcher himself, this is a very rare phenomenon in fish coral reefs, as the larvae deposited by the fish living in this environment, usually dissipate and drift with the streams before settling on the reef itself. The very birth of these fish and their initial development is a lottery, as 99% of eggs are eaten by predators.

Researchers have noted a species that did not provide parental care, and, after various genetic tests, found that many of Altricht’s parents usually take care of mixed manure. These litters often consisted of children from genetically different families, but of the same size. The researcher believes that there are fish that lay eggs in the nests of other couples, and that this is therefore an example of parasitic hatching: “If it is not tribal parasitism, then a series of fish should swim and be adopted. This seems unlikely because the nests are very remote and the mortality rate for unprotected children is huge.”

If this practice were confirmed, it would be an important survival strategy for these fish. However, controlling the nests of these fish, which are very deep inside the coral, would be too destructive for the latter, and for this reason, the researcher intends to experiment with Altrichthys inside the controlled tanks.


Sources & Recommended Reading:

https://onlinelibrary.wiley.com/doi/abs/10.1111/mec.15243

Scientists create a compound that can block cell death

A compound that helps cells live and function was developed by an Australian research team. A study published in Nature Chemical Biology shows that this compound can prevent so-called apoptosis, cell death, which can be important in cases of emergency medical procedures or reduce cell damage after heart attacks, as well as save organs for transplantation.

Researchers have created a specific compound that successfully disables two proteins, called BAK and BAX, which are part of the BCL-2 family of proteins. When BAK and BAX are activated, the cells pass the “point of no return” and die. The compound, based on a new small molecule of tricyclic sulfone, stops this “cascading” process, which causes cell death where it begins and before the mitochondrial damage is done.

The result came after 11 years of research conducted by researchers at the Walter Ed Elise Hall Institute. One of the researchers involved in the study, Guillaume Lessen, talks about “blocking cell death” as a result of “solely because of its ability to keep cells alive and well in the laboratory.”

Another researcher involved in the study, David Huang, explains that these results can be very useful to prevent uncontrolled cell death, for example, after an acute injury, to speed up the recovery of patients or even to save his life.

Benjamin Kyle, currently a researcher at Monash University, was also involved in the study.


Sources & Recommended Reading:

https://www.wehi.edu.au/news/cell-death-blocker-prevents-healthy-cells-dying

https://www.nature.com/articles/s41589-019-0365-8

Stick insects: researchers make discoveries about their unique evolution

The extraordinary ability to blend in with the environment of insect sticks was the subject of a new study published in Frontiers in Ecology and Evolution. These insects have been able to count on an amazing evolutionary history compared to other insects or other animals that tend to merge with the environment.

Many species have taken on shapes that are extremely similar to those of branches, leaves, bark or other parts of plants. Sven Bradler of the University of Göttingen and the senior author of the study, together with their colleagues, analyzed 38 species of stick insects and deciduous insects.

With this new set of genetic data, the researchers made their first discovery: the genealogy of these insects reflects more the geographical distribution than the anatomical similarity of animals. As Sarah Bank, a graduate student at the University of Göttingen and co-author of the study, said, Madagascar’s sticks, for example, originate from a single ancestral species that colonized the island 45 million years ago.

This could mean that different groups of insects used the same evolutionary approach, namely that they increasingly resembled branches and leaves in different contexts and areas of the planet.
They later discovered that the phylogenetic tree of stick insects, which appeared after the extinction of the dinosaurs, occurred 66 million years ago.

Thus, this level of camouflage with the environment was designed by these insects to avoid predators, mostly represented by mammals and birds. However, the genes found in this study are so numerous that the same researchers believe that new discoveries can be made in the future to better understand the incredible evolution that characterizes these insects.


Sources & Recommended Reading:

https://www.frontiersin.org/articles/10.3389/fevo.2019.00345/full

Scientists put “memories” into birds’ brains, teaching them to sing

A group of researchers from the University of Southwest Texas claims to have been able to bring “memories” into the brain of a finch species, teaching them a song they have never heard before. In particular, they have performed this technique on mandarin diamonds, which are widespread especially in Australia.

The singing of these birds is a vocal ability that is transmitted from father to son: in fact, fathers usually sing their melodies to the chicks, and soon they start to imitate them. However, the researchers have given good thought to directly manipulating the brains of chicks of this bird species without parental intervention.

They used optogenetics, a technique of the latest generation in which light flashes are used to stimulate certain areas of the brain and certain groups of neurons. They have focused on a particular area of the brain of these chicks that handles what the animal hears.

Using a kind of Morse code, the researchers were able to teach finches how long the different parts of the melody should last, and eventually the chicks, when they grew up, really learned to sing a song they had never heard before.

However, this is a very simple song compared to the songs that these birds usually sing when they become adults, and for this reason the same researchers admit that they have not taught birds everything they need to know about singing, and because they have focused on only two specific areas of the brain when much more needs to be involved.

Therefore, the researchers want to discover these other brain ways to teach young birds to sing their own songs without the intervention of their parents.


Sources & Recommended Reading:

https://www.utsouthwestern.edu/newsroom/articles/year-2019/implanted-memories-teach-birds-song.html#page

https://science.sciencemag.org/content/366/6461/83

Flies can become genetically modified to become poisonous to predators

Using the CRISPR technique, a group of researchers from the University of California at Berkeley genetically modified some specimens of fruit flies (Drosophila melanogaster) so that they could obtain a significant advantage over its predators, one of those advantages that are usually acquired after thousands of years of evolution.

The researcher Noah Whiteman, together with his colleagues, has in fact modified three genes in the fruit fly giving it the ability to eat toxic plants and extract, within his body, the toxins to then use them as a defense against predators, ie frogs and birds.

This is the same way of defense put in place by the monarch butterflies that thus manages to keep at bay many predators who tend not to eat it just to avoid vomiting everything or even die.

It is the first time that CRISPR is used to genetically modify a multicellular organism so that it can be endowed with a mutation that usually occurs only in the course of evolution, in a much longer time.

Scientists modified midges can eat particular poisonous plants and assimilate toxins into their bodies while they are still in the larval phase and can retain them even after they have become adult flies.


Sources & Recommended Reading:

https://news.berkeley.edu/2019/10/02/crispred-flies-mimic-monarch-butterfly-and-could-make-you-puke/

https://www.nature.com/articles/s41586-019-1610-8/