A group of researchers from the University of California, Berkeley discovered that in mammals, males are XY and tend to live shorter lives than XX females. This is due to the Y chromosome as its genetic elements tend to jump around causing mutations. The Y chromosome densely packs DNA, called heterochromatin, keeps these elements in check. It is the heterochromatin when it deteriorates as organism age. This eventually plays a role in how long individuals live. As compared to females the heterochromatin in the genome stayed steady as compared to males this densely packed DNA was greatly reduced. The team, later on, created flies with abnormal numbers of Y chromosomes, and as a result, the females carrying the Y chromosomes and males with an extra Y did not live as long their wild types equivalents. Similar genetics elements were seen in these flies as in selfish, the males with no Y chromosome lived a lot longer than normal XY males. Drosophila aging is an attractive topic that is drawing many researchers in developing new studies such as these.
Article link: https://www.the-scientist.com/the-literature/male-flies-y-chromosome-may-contribute-to-earlier-deaths-67683
Second Link(Heterochromatin): https://www.nature.com/scitable/topicpage/the-formation-of-heterochromatin-and-rna-interference-14169031/