regA, a Volvox gene that plays a central role in germ-soma differentiation, encodes a novel regulatory protein

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Volvox has two cell types: mortal somatic cells and immortal germ cells. Here we describe the transposontagging, cloning and characterization of regA, which plays a central role as a master regulatory gene in Volvox germsoma differentiation by suppressing reproductive activities in somatic cells. The 12.5 kb regA transcription unit generates a 6,725 nucleotide mRNA that appears at the beginning of somatic cell differentiation, and that encodes a 111 kDa RegA protein that localizes to the nucleus, and has an unusual abundance of alanine, glutamine and proline. This is a compositional feature shared by functional domains of many ‘active’ repressors. These findings are consistent with the hypothesis that RegA acts in somatic cells to repress transcription of genes required for growth and reproduction, including 13 genes whose products are required for chloroplast biogenesis.

This publication has 34 references indexed in Scilit: