07-P009 Doublesex variants in the honey bee, Apis mellifera: Lack of sex-specific expression and characterization of novel transcripts

Abstract

embryo and differentiated adult tissues, with particular focus on a cancer associated variant that excludes the 4th exon (DE4), but retains replication function. Using RT-PCR, qPCR and immunohistochemistry, we find that, although Ciz1 is present in most cells throughout development, high levels are restricted to adult testes, with temporal regulation within the developing germ cell lineage. Over 40% of adult testicular transcripts are alternatively spliced, with some variants unique to this tissue. The regulated induction and alternative splicing of Ciz1 coincides with activation of the spermatogenic cycle. The protein is dynamically regulated in germ cells at discreet stages of the differentiation process, characterised most notably by loss of Ciz1 from post-replicative cells and subsequent re-activation at greatly enhanced levels later in the differentiation process. Our data suggests that following initial replicative phases in spermatogonia and pre-leptotene spermatocytes ‘old’ Ciz1 is released or degraded. ‘New’ Ciz1 is then produced in copious amounts, indicating that Ciz1 has a novel post-replicative role in the mammalian germ cell differentiation process.