The 3’UTR of the orb2 gene encoding the Drosophila CPEB translation factor plays a critical role in spermatogenesis

CPEB proteins are conserved translation regulators involved in multiple biological processes. One of these proteins in , Orb2, is a principal player in spermatogenesis. It is required for meiosis and spermatid differentiation. During the later process mRNAs and proteins are localized within the developing spermatid. To evaluate the role of mRNA 3’UTR in spermatogenesis, we used the CRISPR/Cas9 system to generate a deletion of the 3’UTR, . This deletion disrupts the process of spermatid differentiation, but has no apparent effect on meiosis. While this deletion appears to destabilize the mRNA and reduce the levels of Orb2 protein, this is not the primary cause of the differentiation defects. Instead, differentiation appears to be disrupted because mRNAs and proteins are not properly localized within the differentiating spermatids. Other transcripts and proteins involved in spermatogenesis are also mislocalized in spermatids.