Cell-specific transcriptional regulation of the major sperm protein in Caenorhabditis elegans

Abstract

The major protein found in nematode sperm exhibits a distinct pattern of developmental regulation. In the nematode Caenorhabditis elegans, the synthesis of the major sperm protein (15K) begins with the onset of spermatogenesis in both the male and hermaphrodite. Both spermatogenesis and 15K synthesis continue for the life of the male while in the protandrous hermaphrodite the major sperm protein is synthesized only during the fourth larval stage. Inhibitor studies using actinomycin D and α-amanitin as well as Northern blot analysis have shown that the primary regulatory mechanism of this gene is at the transcriptional level. Recombinant molecules have been selected bearing the 15K genomic sequence by a positive hybridization translation assay. Using one of these cloned fragments as a probe for in situ hybridization, 15K transcripts have been localized to a specific region of the male gonad. These studies indicate that the gene for the major sperm protein is regulated by a cell-specific transcriptional control mechanism coincidental with the onset of sexual differentiation in the nematode.