The XXXX Hand gene controls embryogenesis and early gonadogenesis.

@entity72524 @entity2199 @entity72523 @entity3392
The @entity2199 genome encodes a single Hand bHLH transcription factor. Either @entity72523 or a @entity72523 deletion causes partially penetrant defects in viability and gonadogenesis. Dead embryos and young larvae are often misshapen at the posterior end. Our primary focus has been the role of @entity72523 in gonadogenesis. Wild-type @entity2199 has two somatic gonadal precursors and two primordial germ cells in stereotyped positions within its four-celled gonadal primordium. The @entity72523 gene affects the presence and position of both the somatic gonadal precursors and primordial germ cells within the primordium, but does not appear to have any role in later gonadogenesis. @entity72523 probably acts within the somatic gonadal precursors or their mesodermal predecessors; defects in primordial germ cells and germ line appear to be secondary. In @entity72523 mutants, somatic gonadal precursors are generated normally, but are not maintained properly and sometimes die. A similar role in controlling the maintenance of precursor fates has been described for other genes governing early organogenesis, including the @entity3392 Hand gene hands off. We also report the discovery of two genes, ehn-1 and @entity72524 , that have overlapping functions with @entity72523 in embryogenesis and gonadogenesis.
