It might sound like a scientific baffle, but if Xerces blue weren't in fact a genetically distinct line, it wouldn't technically really be extinct.
MainteHowever, the researchers sequenced an almost complete mitochondrial genome from a 93-year-old museum specimen, suggesting that Xerces blue was a separate species, which they believed could be correctly named Glaucopsyche xerces, according to one. article published Wednesday in Letters of biology .
"That shows how essential it is not only to collect specimens, but to protect them, ”said Corrie Moreau, director and curator of insect at Cornell University. collection and an author on paper. "We cannot imagine how they will be used in 100 years.
Durrell Kapan, senior researcher at the California Academy of Sciences who has was not involved in the research, stated thatHe found the new findings "suggestive and very exciting", but added that there might be limits to this type of research because "what makes two organisms of different species is not always straightforward. addressable with genetic information ”.
Dr. Kapan is working on a target separate genomics project on Xerces blue butterflies and their relatives with Revive & Restore, a non-profit initiative to restore extinct and threatened species through genetic engineering and biotechnology . Image F Elix Grewe, left, and Corrie Moreau working in the Pritzker DNA lab at the Field Museum. Credit ... The Field Museum
Researchers began work on the project several years ago A few years ago, when Dr. Moreau was at the Field Museum in Chicago, she and Felix Grewe, now director of the museum's Grainger Bioinformatics Center phylogenomics initiative, sifted through the archives of the Xerces Blue Butterfly Museum to find the least damaged specimen, which would theoretically produce the best-preserved DNA.
"You are crushing a piece of an extinct butterfly ", said Dr Moreau. "You only have one chance.
Dr. Moreau removed a third of the butterfly 's abdomen, part of the body loaded with muscle, fat and other tissues, and sequenced it. Such ancient DNA breaks down into short fragments. HisTorically, the researchers sequenced long, unbroken stretches of DNA by cutting and reconstructing them. But new sequencing technology allows researchers to work with DNA that has already been cut and fragmented. "We are just leaving that step aside " said Dr Grewe.
After retrieving their sequences, the researchers examined the publicly available data other related butterfly specimens.
Their mitochondrial DNA sequences did not appear to be similar. They suggested that the Blue Xerces was a separate species, and that two other butterflies traditionally considered to be subspecies of the Silver Blue butterfly - the Australis and Pseudoxerces clades - could also be separate species and the closest living relatives of the Blue Xerces.
These results are surprising, because these two butterfliescan be found in Southern California, a long w ay from the original home of Xerces blue on the San Francisco Peninsula. Image A drawer of collections of Xerces blue extinct butterflies at the Field Museum. Credit ... The Field Museum
The sequencing of the new article focused on the mitochondrial bar-coding gene CO1. Mitochondrial DNA is a great option for older museum specimens because a single cell contains many more copies of the mitochondrial genome than the nuclear genome, the researchers said. Mitochondrial DNA is inherited from the mother, while nuclear DNA is inherited from both parents.
But the CO1 gene represents a " very small sample of the genome, "Dr Kapan said, adding that he didn't think the new document had finally settled the species debate.
At the California Academy of Sciences, genomics researcher Athena Lam, Dr. Kapan and others want to shed light on where Xerces fits on the evolutionary scale , Dr Lam said.
These types of genomic studies, Dr Kapan said, could reveal where to find populations of species survivors of the genus Glaucopsyche who may well be suitable for a potential reintroduction into the sand dunes of San Francisco. According to the new article, good candidates to investigate would be australis or pseudoxerces, the latter having wings reminiscent of Xerces' brilliant blue hue.
Dr. Moreau said she hoped the new study would shed light on theThe currently endangered blue butterflies, such as the El Segundo blue, which lives in the coastal sand dunes of southern California, and the Karner blue, which is most commonly found in Wisconsin where the lupine wild grows.
And although the Xerces blue is long gone, the deer grass it needed has recently been replanted in the sand dunes of the Presidio, waiting for a somewhat familiar butterfly future.