Toxic masculinity in male flies: The Y-chromosome is responsible for a shorter life span
The repetitive sections of chromosome Y may cause males to live shorter lives than females as they age. The new findings are part of a study published by Doris Bachtrog of University of California, Berkeley on April 22, in PLOS genetics.
Females live longer in humans and other species that have XY chromosomes. This disparity could be explained by repetitive sequences in the genome. Scientists have speculated that while both males and women carry these repetitive sequences, the high number of repeats in the Y-chromosome could create a toxic y effect that reduces the lifespan of males. Bachtrog tested this theory by studying male Drosophila Miranda fruit flies, which had twice as much repeating DNA as the females, and a shorter life span. The researchers found that the repeat sections of DNA are switched off when it is tightly packed inside the cells. As the flies get older, the DNA takes on a more loose form, which can activate the repeated sections and cause toxic side effects.
The new study shows that Y chromosomes with high repeat counts are a genomic liability in males. These findings support the link between repeat DNA, aging and ageing in general, which is currently poorly understood. In fruit flies, previous studies have shown that repeat sections can impair memory and shorten lifespan, as well as cause DNA damage. The damage caused by repeat DNA is likely to contribute to the physiological effects of aging. However, more research is needed to discover how this toxic effect occurs.
Source:
https://phys.org/news/2021-04-toxic-masculinity-chromosome-contributes-shorter.html
