Fig. 7.

Models of FBF and PUF-2 subfamily evolution. (A) Cladogram of Elegans group Caenorhabditis [based on published data (Kiontke et al., 2004; Woodruff et al., 2010)] and summaries of knockdown phenotypes for FBF and PUF-2/1.2 subfamilies from this study: GD, germline degeneration; Mog, masculinization of germ line; Fog, feminization of germ line. Because of lineage-specific subfamily loss, some species-subfamily combinations have no data. (B) Genetic model for regulatory interactions between fbf, puf-2 and other sex determination factors in the hermaphrodite germ line of C. elegans and C. briggsae. The weight of the repression bars downstream of fbf and Cbr-puf-2/1.2 is indicative of the relative significance of the interaction for sex determination. Note that C. elegans gld-1 promotes spermatogenesis by directly regulating tra-2 (Jan et al., 1999), but this is not shown here.