RT Journal Article SR Electronic T1 Gametic specialization of centromeric histone paralogs in Drosophila virilis JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202000992 DO 10.26508/lsa.202000992 VO 4 IS 7 A1 Kursel, Lisa E A1 McConnell, Hannah A1 de la Cruz, Aida Flor A A1 Malik, Harmit S YR 2021 UL http://www.life-science-alliance.org/content/4/7/e202000992.abstract AB In most eukaryotes, centromeric histone (CenH3) proteins mediate mitosis and meiosis and ensure epigenetic inheritance of centromere identity. We hypothesized that disparate chromatin environments in soma versus germline might impose divergent functional requirements on single CenH3 genes, which could be ameliorated by gene duplications and subsequent specialization. Here, we analyzed the cytological localization of two recently identified CenH3 paralogs, Cid1 and Cid5, in Drosophila virilis using specific antibodies and epitope-tagged transgenic strains. We find that only ancestral Cid1 is present in somatic cells, whereas both Cid1 and Cid5 are expressed in testes and ovaries. However, Cid1 is lost in male meiosis but retained throughout oogenesis, whereas Cid5 is lost during female meiosis but retained in mature sperm. Following fertilization, only Cid1 is detectable in the early embryo, suggesting that maternally deposited Cid1 is rapidly loaded onto paternal centromeres during the protamine-to-histone transition. Our studies reveal mutually exclusive gametic specialization of divergent CenH3 paralogs. Duplication and divergence might allow essential centromeric genes to resolve an intralocus conflict between maternal and paternal centromeric requirements in many animal species.