Monarch Predators Have Also Evolved to Withstand Toxic Milkweeds

Monarch butterflies are famous for their beautiful colors and their long migration patterns. They are also well known for being poisonous due to their consumption of the milkweed plant. A genetic mutation found in monarchs block the plant’s toxins while also allowing said toxic to accumulate in the insect. This mutation is found in 3 copies of a gene for the sodium-potassium pump and is critical to the monarch’s ability to tolerate the toxins of the milkweed found a group of researchers two years ago. This mutation, along with the monarch’s warning color has helped as a deterrent to hungry predators.

However, monarchs are not the only species that can tolerate the milkweed’s toxins. This article shows that four different predators of monarchs were recently discovered to have the same genetic mutation that monarchs have. These organisms are the black-headed grosbeak, the eastern deer mouse, a tiny wasp that parasitizes monarch eggs, and a nematode that parasitizes monarch larvae. All four organisms have at least one or more copies of the gene. The black-headed grosbeak and wasp has evolved single-nucleotide mutations in their sodium pump gene in two of the three locations where monarchs evolved the mutation. The eastern deer mouse and nematode have their changes in all three locations. Noah Whiteman, evolutionary biologist and member of the study, noted that this might be the first time we are seeing the same resistance mutations that have been found in the second and third trophic levels that evolved due to the second trophic level’s ability to feed on toxic plants. The team suspects that there are other organism in the food chain that begins with the milkweed that also have the same mutations found in monarchs.

Worm Genes Explain High Temperature Resistance

 

https://www.sciencenews.org/article/devil-worm-genes-hold-clues-how-some-animals-survive-extreme-heat

https://www.sciencemag.org/news/2011/06/hungry-worms-hell

"Devil" worms, scientifically referred to as Halicephalobus mephisto, is a nematode that obtained its nickname from the extreme environments from which is resides. The original sample of the nematodes studied was found 1.3km underground in an environment with low oxygen levels, high methane levels and a temperature of 37 degrees Celsius. This parental sample laid eight eggs to which researchers have used to their fullest advantage to being to decode its genome. Researchers want to know how these microscopic worms can resist extreme temperatures and they believe it resides in their genome.

Scientists discovered that these nematodes have two gene duplications that aid in heat shock resistance and cell sustainability. These genes are linked to specific proteins, Hsp70 proteins, which restructure other denaturing proteins that unravel due to heat stress, this nematode has three times more of these proteins present compared to some of its closest relatives. Scientists also believe there is another gene at work to aid in the resistance of these extreme environments. They discovered that the AIG1 gene is heavily present in this nematode, which controls individual cells life span. Combining the functions AIG1 gene and the Hsp70 protein is a good start to the explanation of the ability to survive in extreme environments, but the researchers say there is still more to be studied to complete a conclusion.

Microbe Might Provide Key to a Longer Healthier Life for Humans

The organism Caenorhabditis elegans has a simple structure but has genetic similarities to humans. This organism is able to change it's cuticle, a skin-like barrier, in response to infection. The nervous system changes the structure of the cuticle. Originally it was believed that the cuticle and human skin work in similar ways, they are just a barrier to infection, there was no response. This discovery may be able to help human health. The researchers used gene splicing and CRISPR gene editing to show that a G-protein-coupled receptor tied to a gene called NPR-8 regulates collagens. Collagens are proteins that are a key part to the structural component of the cuticle. When the NPR-8 was removed, the organism survived longer when exposed to pathogens. Without the receptor, the cuticle was also smooth instead of wrinkled like the wild type. Pathogens try to destroy the cuticle in order to infect the organism and the results showed that the nervous system was able to change its structure based on an immune response. Collagen loss can cause a lot of issues in humans, so studying this natural regulation of collagen may be beneficial to human health.

It would be very beneficial to people if some type of treatment can be made to help collagen regulation, based on the research done on this organism. Humans have an extracellular matrix on all of their organs that have collagen in them. If there is too much or too little collagen, then problems can arise. It would be very cool to see how this organisms natural process of regulating collagen may help people in the future.

Link: https://www.sciencedaily.com/releases/2019/11/191120144950.htm

Related Article: https://advances.sciencemag.org/content/5/11/eaaw4717

Worms against cancer.

According to this article, scientists in Wyoming have discovered several genes within nematode worms that they believe could assist in the battle against cancer. David S. Fay, Ph.D. and his colleagues used these worms to study a gene ("LIN-35") that is similar to one found in human cancers ("pRb"). In human cancers, this gene is tumor suppressor protein that is inactive, allowing for the cell growth and spread. While studying the LIN-53 gene in the worms, the researchers deactivated other genes in the genome and found that some were able to reverse the defects caused by the deactivated LIN-53. Because of this, they believe these genes could be used as targets for anti-cancer drugs and therapies. This article also comes with the suggestion of a companion piece as an educational resource for genetic students. 

This seems like a good article to look into, as the studies help in something that has affected everyone in one way or another. By looking at these genes, scientists have another possibility at stopping the cell growth and spreading of cancer. Personally, my grandfather died this last Christmas day due to a long battle with Leukemia and my grandmother died ten years previously, also on Christmas, so I think any possible advancements toward the end of cancer is a good thing.

Genetic Code of Bookworm Published

The entire genome for the parasite Panagrellus redivivus, commonly known as the bookworm, has been completed.  In an article in Science Daily, the specifics on cracking the genetic code of the parasitic worm are listed.  The nematode was found to have over 24,000 genes encoded in its DNA, which is nearly the same number as the human genome.  Jagan Srinivasan, an assistant professor of biology and biotechnology at Worchester Polytechnic Institute, remarked,

"Humans and nematodes share a common ancestor that lived in the oceans more than 600 million years ago."

The bookworm's genome being sequenced is significant because it is the first time the genome of a free-living nematode has been sequenced other than the widely studied C. elegans.  Scientists hope to learn from the genome of the bookworm, because they share a common ancestor with humans that dates back 600 million years, in addition to the similar numbers of genes in their DNA.  Much has already been learned from C. elegans in recent years, and researchers hope that the bookworm will provide similar breakthroughs.  The differences between the male and female nematode, and how they are able to mate is being studied as well.  The behavior of the worms will lead to new information about their species for scientists to process, and to learn more about human genetics in comparison.  More information on the nematode C. elegans is available in this description.