Required for optimal embryo development, particularly under heat stress conditions (PubMed:34282725). Also appears to have a role in negatively regulating spermatocyte cyst development (PubMed:34282725). Under heat stress conditions, required for the correct organization and migration of nuclei during early embryogenesis, and therefore possibly functions by regulating embryonic actin networks during the heat stress response (PubMed:34282725). In spermatocyte cysts, detected only during and after meiosis (PubMed:34282725). Localizes to two germline-specific actin structures: the fusome and actin cones (PubMed:34282725). First localizes to the fusome during meiosis (PubMed:34282725). Then once spermatid elongation is complete, localizes to the leading edge of the forming actin cones where it remains until the actin cones are destroyed following the completion of sperm individualization (PubMed:34282725). High expression in males whereas expression in females is very low (PubMed:34282725). In adult males, highest levels of expression are in the testis (PubMed:34282725). In adult females, expressed only in the ovaries at very low levels (PubMed:34282725). In larvae, highly expressed in the imaginal disk whereas in prepupae and pupae modest levels of expression occur in the fat body (PubMed:34282725). Increases male fertility but overall population fitness is decreased (PubMed:34282725). Males develop significantly more spermatocyte cysts with actin cones per testis, suggesting that sperm production is accelerated (PubMed:34282725). No effect on female fertility at 25 degrees Celsius (PubMed:34282725). However at 29 degrees Celsius (heat stress conditions), embryos lacking either maternal and/or zygotic Arp53D activity display gross nuclear abnormalities and nuclei appear disorganized and uncompacted (PubMed:34282725). As a result females produce fewer progeny that reach the adult stage (PubMed:34282725). No effect on number of eggs laid or the percent of fertilized eggs (PubMed:34282725). Belongs to the actin family. ARP1 subfamily.