Figure 2.

An alignment of hexapod engrailed-family protein sequence obtained in this study, and for comparison data from Hui et al. (1992), Peterson et al. (1998) and Marie & Bacon (2000). Encompassed EH2 (C-terminal end), EH3 and EH4 (N-terminal end of homeodomain). The number of RT-PCR clones obtained for each sequence is shown in brackets after the genus/species name. In cases where there are two numbers, the second indicates the number of clones recovered that contain a splice variant lacking the hexanucleotide encoding the RS-motif. Residues that are 100% conserved across hexapod species are boxed. A putative polymorphic residue in Harmonia axyridis engrailed is shown in bold; a proline may in some cases replace this serine. The Oncopeltus fasciatus clones were obtained from an RT-PCR experiment using a gene specific primer targeted to sequence encoding EH1. An asterisk is positioned above serine/threonine residues that we hypothesize, in some contexts, might be targets for phosphorylation (see §4).