Genetic analysis of the Caenorhabditis elegans GLH family of P-granule proteins

Caroline Spike, Nicole Meyer, Erica Racen, April Orsborn, Jay Kirchner, Kathleen Kuznicki, Christopher Yee, Karen Bennett, Susan Strome

Research output: Contribution to journalArticlepeer-review

54 Scopus citations

Abstract

The Vasa DEAD-box helicases are widespread markers of germ cells across species, and in some organisms have been shown to be essential for germ-cell formation and development. In contrast to the single Vasa gene in most systems analyzed, Caenorhabditis elegans has four Vasa family members, the germline helicases GLH-1, GLH-2, GLH-3, and GLH-4. Our analysis of deletion alleles of each glh gene demonstrates that GLH-1 is the key member of the family: loss of GLH-1 function causes sterility that is mainly maternal effect, is manifested predominantly at elevated temperature, and is due to reduced germ-cell proliferation and impaired formation of both sperm and oocytes. The other GLHs are not essential. However, GLH-4 serves redundant roles with GLH-1: loss of both genes' function causes glh-1-like sterility at all temperatures. Molecular epistasis analysis demonstrates that GLH-1 and GLH-4 are required for proper association of the PGL family of proteins with P granules, suggesting a pathway of P-granule assembly in which the GLHs are upstream of the PGL proteins and the mRNA cap-binding protein IFE-1. While loss of some P-granule components causes worms to be defective in RNA interference, loss of GLH-1 and GLH-4 does not compromise RNAi. Thus, RNAi likely does not require intact P granules but instead relies on particular P-granule factors. We discuss the evolution of the Vasa/GLH genes and current views of their functions and the assembly and roles of germ granules among species.

Original languageEnglish (US)
Pages (from-to)1973-1987
Number of pages15
JournalGenetics
Volume178
Issue number4
DOIs
StatePublished - 2008

Fingerprint

Dive into the research topics of 'Genetic analysis of the Caenorhabditis elegans GLH family of P-granule proteins'. Together they form a unique fingerprint.

Cite this