Originally published as Genetics Published Articles Ahead of Print on February 3, 2008.

Genetics, Vol. 178, 1445-1456, March 2008, Copyright © 2008
doi:10.1534/genetics.108.086678

The Caenorhabditis elegans PcG-like Gene sop-2 Regulates the Temporal and Sexual Specificities of Cell Fates

* College of Life Sciences, Peking University, Beijing 100871, People's Republic of China, and {dagger} National Institute of Biological Sciences, Beijing 102206, People's Republic of China

2 Corresponding author: National Institute of Biological Sciences, No. 7 Science Park Rd., Zhongguancun Life Science Park, Beijing, People's Republic of China, 102206.
E-mail: zhanghong{at}nibs.ac.cn

How spatial, temporal, and sexual specific cues are integrated to specify distinct cell fates during multicellular organism development is largely unknown. Here we demonstrate that the Caenorhabditis elegans PcG-like gene sop-2 determines the temporal and sexual specificities of a row of hypodermal seam cells, in addition to specifying their positional identities. Loss-of-function of sop-2 causes premature expression of adult fates at larval stages. sop-2 acts upstream of lin-29 in the heterochronic pathway and genetically interacts with other heterochronic genes in specifying the temporal fates of seam cells at different larval stages. We show that the number of ALG-1-containing P bodies is increased in seam cells in sop-2 mutants. Furthermore, the microRNA-mediated repression of a heterochronic gene reporter is enhanced in sop-2 mutants. Mutations in sop-2 also cause partial hermaphrodite-to-male sexual transformations. The homeotic transformations, heterochronic defects, and sexual transformations can occur concomitantly in sop-2 mutants. In summary, our studies reveal that sop-2 integrates spatial, temporal, and sexual cues during C. elegans development.