We use a variety of genetic, molecular, and immunocytochemical approaches to address these questions. Germline proliferation is both positively and negatively regulated. Positive regulation is accomplished via a signal from two somatic cells, the distal tip cells, which is received and transduced by the distal germ line. At present, we study several ego genes whose functions promote germline proliferation and one sog gene whose function restricts germline proliferation. In contrast, sog gene products may limit germline proliferation by promoting meiosis.
Studies are underway to determine how the gene products function at the molecular level.
Molecular analysis of the ego-1 gene has yielded very intriguing results. We found that ego-1 mutants have greatly lowered sensitivity to RNA silencing of many genes in the germ line. This is an intriguing result. We are now investigating the role of EGO-1 in both processes to determine whether there might be a connection between them. For example, RNAi may be used to regulate gene expression during development.