Support for Y-compensation of mother's curse affecting lifespan in Drosophila melanogaster.

Mother's curse refers to male-biased deleterious mutations that may accumulate on mitochondria due to its strict maternal inheritance. If these mutations persist, males should ideally compensate through mutations on Y-chromosomes given its strict paternal inheritance. Previous work addressed this hypothesis by comparing coevolved and non-coevolved Y-mitochondria pairs placed alongside completely foreign autosomal backgrounds, expecting males with coevolved pairs to exhibit greater fitness due to Y-compensation.

Gene-poor Y-chromosomes substantially impact male trait heritabilities and may help shape sexually dimorphic evolution.

How natural selection facilitates sexually dimorphic evolution despite a shared genome is unclear. The patrilineal inheritance of Y-chromosomes makes them an appealing solution. However, they have largely been dismissed due to their gene-poor, heterochromatic nature and because the additive genetic variation necessary for adaptive evolution is theoretically difficult to maintain.