The embryonic expression patterns of zfh-1 and zfh-2, two Drosophila genes encoding novel zinc-finger homeodomain proteins.

The zfh-1 and zfh-2 genes of D. melanogaster encode novel proteins containing both homeodomain and C2-H2 zinc-finger DNA-binding motifs. Antisera against these proteins were used to investigate their expression patterns during embryonic development. The zfh-1 gene is expressed in the mesoderm of early embryos and in a number of mesodermally-derived structures of late embryos, including the dorsal vessel, support cells of the gonads, and segment-specific arrays of adult muscle precursors. In addition, zfh-1 is expressed in the majority of identified motor neurons of the developing CNS. The mesodermal zfh-1 expression requires the products of the twist and snail genes. The zfh-2 gene displays a more limited expression pattern, largely restricted to the CNS of late embryos. Ubiquitous zfh-1 expression in transgenic flies bearing an hsp70-zfh-1 construct has specific developmental consequences, including embryonic CNS defects as well as adult eye and bristle abnormalities. The expression patterns of zfh-1 and zfh-2 suggest that both genes may be involved in Drosophila neurogenesis and that zfh-1 may have additional functions in mesoderm development.