Assay 2: Extracts were prepared from three temperature-sensitive mutant strains that are defective in different aspects of germline development. At the permissive temperature (15 Centigrades) in all three strains, OMA-1 was expressed. At the nonpermissive temperature (25 Centigrades),
glp-4(
bn2) mutant worms do not produce a germline and do not express OMA-1.
fem-3(
e2006) mutant worms produce only oocytes and no sperm at 25 C and express OMA-1. Semidominant mutants
fem-3(
q20sd) at 25 C produce only sperm and no oocytes and do not express OMA-1. Thus, OMA-1 protein is expressed primarily in adult oocytes but not in sperm, consistent with the functional assay.