Amazon Molly Survives 100,000 Years Without Males by Using Gene Conversion
Updated
Updated · BBC.com · Jun 2
Amazon Molly Survives 100,000 Years Without Males by Using Gene Conversion
1 articles · Updated · BBC.com · Jun 2
Whole-genome sequencing found the all-female Amazon molly repeatedly overwrites parts of its DNA through gene conversion, helping it avoid the harmful mutation buildup that theory predicts should doom asexual species.
Researchers said the repair process is especially active in the most dangerous parts of the genome, where one gene copy can serve as a template to fix another and preserve genetic health.
The fish likely gained an early advantage from its origin about 100,000 years ago as a hybrid of Atlantic and sailfin mollies, leaving it with two similar but distinct ancestral gene sets to work from.
The finding challenges the idea that sex is the only reliable way to keep genomes healthy and suggests other long-lived asexual species may also use alternative mutation-control mechanisms.
This fish uses males but discards their DNA. How did this bizarre strategy unlock a powerful defense against genetic decay?
A fish cheats genetic decay while cloned mice fail. Does its DNA repair trick hold the key to fighting human disease?
100,000 Years Without Sex: How Gene Conversion Powers the Amazon Molly’s Longevity
Overview
In May 2024, researchers discovered that gene conversion is the key to the Amazon molly’s remarkable longevity. This all-female fish has thrived for over 100,000 years, defying the usual problems of asexual reproduction, such as harmful mutations and low genetic diversity. Gene conversion allows the Amazon molly to shuffle and repair its genes, helping it avoid the genetic pitfalls that once seemed unavoidable for asexual species. This finding challenges long-held beliefs about asexual reproduction and reshapes how scientists view the evolutionary potential of species that reproduce without males.