The τCstF-64 Polyadenylation Protein Controls Genome Expression in Testis

<div><p>The τCstF-64 polyadenylation protein (gene symbol <em>Cstf2t</em>) is a testis-expressed orthologue of CstF-64. Mice in which <em>Cstf2t</em> was knocked out had a phenotype that was only detected in meiotic and postmeiotic male germ cells, giving us the opportunity to examine CstF-64 function in an isolated developmental system. We performed massively parallel clonally amplified sequencing of cDNAs from testes of wild type and <em>Cstf2t^−/−</em> mice. These results revealed that loss of τCstF-64 resulted in large-scale changes in patterns of genome expression. We determined that there was a significant overrepresentation of RNAs from introns and intergenic regions in testes of <em>Cstf2t^−/−</em> mice, and a concomitant use of more distal polyadenylation sites. We observed this effect particularly in intronless small genes, many of which are expressed retroposons that likely co-evolved with τCstF-64. Finally, we observed overexpression of long interspersed nuclear element (LINE) sequences in <em>Cstf2t^−/−</em> testes. These results suggest that τCstF-64 plays a role in 3′ end determination and transcription termination for a large range of germ cell-expressed genes.</p>