HYLS1 and Infertility: Male fertility can be fully rescued by a ubiquitously expressed WT hyls1 transgene (Ubq-hyls1-GFP), but not by restricted rescue of HYLS1 in neurons (elav-GAL4; pUAS-hyls1-GFP), indicating that infertility is not likely due to the impaired sensory or courtship capacity but owing to defects in spermatogenesis and/or embryogenesis after fertilization (Figure 8C).