Centrosomin: A Complex Mix of Long and Short Isoforms is Required for Centrosome Function During Early Development in Drosophila melanogaster

Centrosomin (Cnn) is a required core component in mitotic centrosomes during syncytial development and the presence of Cnn at centrosomes has become synonymous with fully functional centrosomes in Drosophila melanogaster. Previous studies of Cnn have attributed this embryonic function to a single isoform or splice variant. In this study, we present new evidence that significantly increases the complexity cnn. Rather than a single isoform, Cnn function can be attributed to two unique classes of proteins that comprise a total of at least ten encoded protein isoforms. We present the initial characterization of a new class of Cnn short isoforms required for centrosome function during gametogenesis and embryogenesis. We also introduce new evidence for a complex mix of Cnn isoforms present during early embryogenesis. Finally, we re-examine cnn mutations, in light of the short isoforms, and find previously overlooked differences attributable to allele specific mutant phenotypes. This study addresses several questions surrounding Cnn function at the centrosome during embryogenesis, and shows that cnn function cannot be ascribed to a single protein.

Key Words: Cnn, Drosophila, centrosome, embryogenesis, isoforms

Online ISSN: 1943-2361  Print ISSN: 0016-6731
Copyright 2009 by the Genetics Society of America
phone: 412-268-1812   fax: 412-268-1813   email: genetics-gsa{at}andrew.cmu.edu