Butterfly Wing Patterns Emerge

 A study funded by the National Science Foundation has uncovered a set of DNA patterns that is responsible for the pattern of butterfly wings. These DNA sequences sit between genes, sometimes referred to as "non-coding" DNA. These coils of DNA become unwound in order to interact with genes. Researchers used ATAC-seq to identify where the DNA has unraveled. Researchers then used CRISPR-Cas gene editing technology to disable 46 elements one at a time, and note the changes that were caused to the wing pattern. 

They hypothesize that this DNA has kept a plan of patterns for millions of years, and that it works like a switch, flipping up and down to create different patterns. 

Previous work has uncovered specific genes responsible for different aspects of wing pattern. Optix controls color and iridescence, and WntA controls stripes. 

Relevant Article: https://www.sciencedaily.com/releases/2022/10/221021145842.htm

Split-sexed Organisms, More Common Than You Would Think

An article at the New York Times discusses split-sexed butterflies, and other multi-sexed creatures, that influenced the research that many scientists have conducted. It also goes on to discuss how split-sexed animals are much more common than many believe them to be, and that the genetics behind these creatures, as known as Gynandromorphs, can tell scientists a lot about how to treat sex related human diseases. One scientist talked about how sex has an impact on several different diseases, and on several aspects of life so understanding how these multi-sexed organisms operate genetically could be beneficial. The article also talks about the different mechanisms that can allow for these types of organisms to occur.

I think that this article was rather fascinating because I didn’t realize that there we so many different ways for these split-sexed creatures to occur, or how common they actually were in the wild. I also think that the possible applications of the information being learned from these unique creatures is quite interesting because its a rather unconventional way at studying human disease.  

New butterfly species discovered in Russia with an unusual set of 46 chromosomes

       Researchers, Vladimir Lukhtanov and Alexander Dantchenko, have recently discovered a new species of butterfly in Russia. Named the South-Russian blue (Polyommatus australorossicus), the butterfly was found flying over the northern slopes of the Caucasus mountains in southern Russia. Previously, the population of South-Russian blues was believed to be a common blue butterfly species. However, in the mid-nineties, Lukhtanov began studying every species of Russian butterflies with the goals of learning more about their ecology and biology. Then, in 1997, Dantchenko began sampling butterflies from the northern slopes of the Caucasus mountains. Dantchenko identified the butterflies as Azerbaijani blue (Polyommatus aserbeidschanus).

            However, when the scientists got together and began looking at different butterflies under the microscope, they found that the butterflies had a very unusual chromosome count, 46, which is the same number as humans. For the next 20 years, until 2017, the researchers have been studying the chromosomes of more than a hundred blue butterfly species. In addition, the researchers have also sequenced the DNA from all closely related species of butterflies. They have finally concluded that these butterflies comprise a new species, the South-Russian blue (Polyommatus australorossicus).

            The researchers have discovered that the caterpillars of genetically related species feed on different, but very similar plants. This discovery will help scientists discover new butterfly species with the help of botanic information, in addition to helping protect and conserve all butterfly species.

I think that this discovery is amazing. These two researchers have dedicated twenty years of their lives to identifying a new species. It is crazy to think that we may have many more species on the planet than we think we do. If two butterfly experts can think that two different species are actually the same, then many other people are probably making the same mistake with different organisms.  This research could help scientists discover new species, in the future.

Article

Original Article in Comparative Cytogenetics

How a 'flipped' gene helped butterflies evolve mimicry

In a study published on Nature Communications, scientist from the University of Chicago analyzed different species of swallowtail butterflies from different geographic locations. They analyzed the butterflies and found that butterflies from different regions had different mimicking patterns. The scientists believed that the mimicry occurred about two million years ago when a double sex gene flipped at some point. They saw variation in butterflies and believe some of the original undisguised forms of butterflies might have been lost by prey because of their inability to flip the gene like the other butterflies. They also saw that some butterfly populations have maintained multiple female forms for millions of years, while other butterflies without the mimic patterns diminished.

I found this article interesting because this study explored on how and when the swallowtail butterfly developed mimic patterns. This is a interesting discovery because scientists previously believed that the butterfly mimic was controlled by "supergenes", which were groups of several tightly linked genes that were always inherited as groups, which is not the case. This could help us understand how the flipping of  a double sex gene works and the advantages and disadvantages of it.



https://www.sciencedaily.com/releases/2017/11/171107113214.htm

https://sciencelife.uchospitals.edu/2017/11/07/how-a-flipped-gene-helped-butterflies-evolve-mimicry/

Parasites Alter Butterfly Genomes Using Viruses

Genetically modified organisms (GMO's) are usually known as a creation of human, but insect studies show otherwise. Researchers have found modified genetics in butterflies and moths, but they weren't caused from humans. These modified genetics were caused by a virus that weaves through DNA. Parasitic insects known as braconid wasps lay eggs inside of caterpillars and hatch into larvae. The wasps also inject bracoviruses that incorporate themselves into the genome of caterpillars. These modifications will be passed on to other generations. Scientists believe that some butterflies and moths have kept these wasp genes because they protect against other viruses that could be harmful. Scientists also believe that insects that are genetically modified by humans have the potential to transfer to other insects, and therefore we must be fully aware of what genes are modified.

This article was very interesting to read. I am on the fence about genetically modified organisms, and when I found out that insects that are genetically modified by humans have the potential to spread those modified genetics to other insects, it pushed me even further away from GMO's. What was also very interesting is that the wasp virus can completely change the genome of a caterpillar, and that genome is passed on to other generations. This is the first time I've heard of naturally occurring GMO's.

Original Link

Solving the Puzzles of Mimicry in Nature

A New York Times article discusses the recent advances in the understanding of mimicry occurring in nature. This study comes from a similar location to that of Charles Darwin's studies: Brazil. The main individual of study is the butterfly. Mimicry is when an population begins to adapt similar colors, patterns and overall looks to another. In butterfly species, a non-poisonous population will begin to mimic the colors and patterns of poisonous populations. The benefits of this natural occurrence are numerous and help protect the non poisonous populations from becoming prey. Not only were non-poisonous populations mimicking poisonous ones, but poisonous species began mimicking each other. Mueller theorized that in this fashion, the butterflies formed a sort of "army" where all other species would know they were not the be eaten.

Until recently, however, how mimicry occurred was unknown. That was until Mueller proposed that mimicry stemmed from two sources: independent evolution or gene swapping. The genes controlling the causes of mimicry have been recently identified. Using this knowledge, it is safe to say that source of mimicry comes form both mechanisms working cooperatively. Although interbreeding is rarely seen between different populations, due to the extreme advantages of mimicry, one individual can spread the gene through the population quickly.

This mimicry is crucial to the survival of butterfly species in Brazil.

DNA to flutter by

The first long-distance insect, the Monarch Butterfly, has had their genome completed and deciphered in a genetic instruction book. By sequencing these genes, scientist have found a protein that can help the butterflies navigate the sun and fir trees in Mexico. Mexico is the location where the Monarch Butterflies spend their winter. The genome of the butterfly is made up of 273 million DNA units. Within these million of DNA units, there were complete sets of genes for juvenile hormone which butterflies use to kick start reproduction. The genes of Monarch Butterflies are similar to those of the silk moths. The scientists also unearthed from the genome a gear previously thought to be missing from the butterfly’s daily, or circadian, clock, which helps the monarchs maintain a straight path.

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