Table 1.
New “insect specific” degenerate primers designed for the amplification of large homeobox fragments of Dfd, Scr, Ubx, and abd-A Hox genes.
Figure 1.
Alignment of 37 new hexapod Hox gene homeodomains.
The newly isolated sequences of lab, pb, Dfd, Scr, ftz, Antp, Ubx, abd-A and abd-B from the dipluran Campodea fragilis (C.f.), the archaeognath Lepismachilis y-signata (L.y.), the odonates Ischnura elegans (I.e.) and Sympetrum sanguineum (S.s.), the ephemeropteran Baetis sp. (B.sp.), the plecopteran Nemoura cinerea (N.c.) and the dermapteran Forficula auricularia (F.a.) are aligned to their Drosophila melanogaster (D.m.) homolog. Dots indicate identical position.
Table 2.
Hox genes known from the different insect orders.
Figure 2.
Neighbor-Joining tree of the 25 new Hox gene sequences (lab, pb, Dfd, Ubx, abd-A, Abd-B) and known orthologs from other insects (GenBank accession numbers: Folsomia candida AF361326, AF361327, AF361329, AF361333, AF361334, AF361335; Drosophila melanogaster; NM_057265, X63728, X05136, X76210, X54453, X16134; Tribolium castaneum AF231104, AF187068, U81039, AF146649, AF017415, AF227923).
Sequences from this study are in bold. Note that all new sequences group to expected homologs.
Figure 3.
Alignment of Scr and Antp homeodomain fragments.
Shown is the alignment to Tribolium castaneum (AF228509, AF227628) and Drosophila melanogaster (M20705, X05228) sequences. The six new and short Scr and Antp fragments differ in their homeobox sequence but are identical at the amino acid level. Amino acid substitutions between Scr and Antp are shown in green and yellow, respectively.
Figure 4.
The phylogeny is based on information and figures in [56], [57], [58], [59]. Macro-evolutionary events in insect evolution, which are cited as being major Bauplan transitions, are mapped on the phylogeny. Pictures are modified after [60].
Table 3.
Divergence rates of Hox genes.