Expansion and diversification of KRAB zinc-finger genes within a cluster including Regulator of sex-limitation 1 and 2.

The genomic locus on mouse chromosome 13 called Regulator of sex-limitation (Rsl) accentuates sex differences in hepatic gene expression. Females homozygous for variant rsl alleles express some otherwise male-specific liver proteins, such as sex-limited protein (Slp), major urinary proteins (MUPs), and members of the cytochrome P450 (cyp) 2d subfamily. We recently identified mutations in two genes, Rsl1 and Rsl2, accounting for the rsl phenotype.

The bereft gene, a potential target of the neural selector gene cut, contributes to bristle morphogenesis.

The neural selector gene cut, a homeobox transcription factor, is required for the specification of the correct identity of external (bristle-type) sensory organs in Drosophila. Targets of cut function, however, have not been described. Here, we study bereft (bft) mutants, which exhibit loss or malformation of a majority of the interommatidial bristles of the eye and cause defects in other external sensory organs.