| Popis: |
Most actin-related proteins (Arps) are highly conserved in eukaryotes, where they carry out well-defined cellular functions.Drosophilaand mammals also encode divergent non-canonical Arps in their male-germline whose roles remain unknown. Here, we show that Arp53D, a rapidly-evolvingDrosophilaArp, localizes to fusomes and actin cones, two male germline-specific actin structures critical for sperm maturation, via its non-canonical N-terminal tail. Although we expected thatArp53Dloss would reduce male fertility, we instead find thatArp53D-KO males are more fertile, both in isolation and in competition with wildtype males. Upon investigating why evolution would retain a gene that negatively impacts male fertility, we unexpectedly found thatArp53D-KOfemales are less fertile. Moreover, KO embryos exhibit reduced viability, which worsens under heat stress. We conclude that ‘testis-specific’Arp53Dis detrimental to male fertility, but is required for female fertility and early development, leading to its long-term retention and recurrent adaptation inDrosophila. |
