ceh-24, a new NK class homeodomain gene Brian Harfe 1, 2, Pete Okkema 1, and Andy Fire 1 1 Carnegie Institution of Washington, Department of Embryology, 2 Biology Graduate Program, The Johns Hopkins University The NK class of homeodomain proteins are a set of regulatory factors with a broad evolutionary distribution and a variety of expression patterns. Analysis of pharyngeal myosin regulation led to the identification of a member of this family,
ceh-22, which appears to mediate aspects of pharyngeal gene expression (Okkema and Fire, Development 120, 2175). To determine the extent of the NK homeodomain family in C. elegans we have used a degenerate primer based PCR strategy. Among several candidates from the initial PCR, we have so far characterized one gene, denoted
ceh-24. The CEH-24 homeodomain falls into the NK class, but is closer to diverse members of the NK family seen in other species than to CEH-22. In addition to the homeodomain, CEH-24 contains an acid activation domain C-terminal to the homeodomain.
ceh-24 maps (thanks to Alan Coulson) to chromosome V just left of
him-5.