PhD thesis
PhD thesis
PhD thesis
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68 Submitted manuscript<br />
Chapter IV<br />
Fig. 2 Characterisation of the Cdx sequence of Terebratalia transversa. (A) Cdx<br />
homeodomain sequence alignment. The accession numbers for the EMBL/GenBank databases<br />
are given in brackets: Terebratalia transversa (Ttr, brachiopod, XXXXXXX), Nematostella<br />
vectensis (Nve, cnidarian, DQ500749), Patella vulgata (Pvu, gastropod, AJ518062.1), Capitella<br />
teleta (Cte, annelid, AAZ95508.1), Drosophila melanogaster (Dme, fruit fly, NM_057606.4),<br />
Tribolium castaneum (Tca, flour beetle, NM_001039409.1), Ciona intestinalis (Cin, tunicate,<br />
NP_001071669), Saccoglossus kowalevskii (Sko, hemichordate, NP_001158415), and Mus<br />
musculus (Mmu, mouse, NM_009880.3). The following alternative species and Hox protein<br />
sequences were chosen as outgroups: Drosophila simulans, Abdominal B (DsiAbdB, fruit<br />
fly, XP_002103136), Drosophila melanogaster, Proboscipedia (DmePb, fruit fly, CAA45272),<br />
Drosophila virilis, Antennapedia (DviAnt, fruit fly, AAQ67266.1), Mus musculus, HoxA9<br />
(MmuHoxA9, mouse, NP_034586.1), Neanthes virens, Engrailed (NviEng, annelid, DQ366680).<br />
Dots represent amino acid identity with the amino acid sequence of the T. transversa Cdx<br />
protein shown at the top of the alignment. (B) Alignment tree based on the 49 amino acid<br />
sequences is shaded in Fig. 2A. Algorithm = UPGMA; Bootstrap = 10.000 replicates. Bootstrap<br />
values are given for each node. Due to the small number of residues used in the analysis, the<br />
phylogenetic signal of the tree is limited. The tree shows, however, that TtrCdx clusters with all<br />
other Cdx/caudal protein sequences and thus is a true Cdx protein.<br />
RESULTS<br />
Characterization of the Terebratalia<br />
Not and Cdx genes<br />
The PCR-amplified region of the TtrNot<br />
homeobox encodes for a 45 amino<br />
acids long peptide which is largely<br />
similar to the NveNot sequence of the<br />
cnidarian Nematostella vectensis (82%<br />
sequence identity). This peptide has<br />
clear affinities to the HvuNot protein<br />
of the cnidarian Hydra vulgaris (69%<br />
sequence identity, Fig. 1). The TtrNot<br />
segment cloned by RACE-PCR was<br />
667 base pairs long and is deposited<br />
in GenBank under the accession<br />
number XXXXXX. The transcribed<br />
region downstream of the homeobox<br />
ends with a poly-A stretch and shows<br />
no similarity to other known gene<br />
sequences.<br />
The conserved protein sequence of the<br />
TtrCdx homeobox identified in this study