Testis-specific murine centrin, Cetn1: Genomic characterization and evidence for retroposition of a gene encoding a centrosome protein

Centrin is a centrosome component in species from yeast to humans. Here, th e mouse centrin 1 gene (Cetn1) is analyzed with respect to its genomic stru cture, chromosome localization, tissue-specific expression, and phylogeneti c relationship to the other mouse centrin genes and their human orthologs. Cetn1 is an intronless gene located on chromosome 18A2 that encodes a 172-a mino-acid protein with a predicted molecular mass of 19,696 Da (pl 4.61) an d all of the structural features common to centrin. Cetn1 possesses the seq uence features of an expressed retroposon: the gene lacks introns, the open reading frame is not interrupted by stop codons, and the coding region is flanked by a pair of direct repeats. Reverse transcriptase-polymerase chain reaction and Northern blot analysis demonstrate that Cetn1 expression is l imited exclusively to the testis in adult male mice, Cetn1 expression is fi rst seen in the neonatal testis at 14 days postpartum, reaching adult level s by day 17. These observations provide new insight into the regulation, fu nction, and evolutionary history of centrin in higher eukaryotes. (C) 1999 Academic Press.