A genetic screen identifies and as pro-apoptotic genes and potential activators of expression.

During development, 1090 somatic cells are generated of which 131 reproducibly die, many through apoptosis. The BH3-only gene is the key activator of apoptosis in somatic tissues, and it is predominantly expressed in 'cell death' lineages i.e. lineages in which apoptotic cell death occurs. expression is regulated at the transcriptional and post-transcriptional level. For example, we previously showed that the miR-35 and miR-58 families of miRNAs repress expression in mothers of 'unwanted' cells by binding to the 3' UTR of mRNA, thereby increasing mRNA turnover. In a screen for RNA-binding proteins with a role in the post-transcriptional control of expression, we identified EIF-3.H (ortholog of human eIF3H) and HRPR-1 (ortholog human hnRNP R/Q) as potential activators of expression. In addition, we demonstrate that the knockdown of the or gene by RNA-mediated interference (RNAi) results in the inappropriate survival of unwanted cells during development. Our study provides novel insight into how expression is controlled to cause the reproducible pattern of cell death observed during development.