Fig. 1. (A) Goosecoid homeodomain sequence alignment. Red and blue residues indicate nonconservative and conservative amino acid substitutions, respectively. The asterisk indicates K50 a residue found in all bicoid-class homeodomain-containing proteins that is essential for binding to cognate cis elements. Vertebrate sequences are contained within the black rectangle. (B) Representative goosecoid proteins are aligned with respect to their homeodomain (HD) sequences. The relative positions of the conserved goosecoid-engrailed homology (GEH) domain that mediates repression are indicated by red boxes. An additional sequence that is similar between SpGsc and Drosophila Gsc is shown in gray. (C) Blot of sperm DNA from two individuals that has been digested with either EcoRI (a) or RsaI (b) and hybridized at reduced stringency with a ³²P-labeled probe representing the homeodomain sequence (see Materials and Methods for details).