Hox and ParaHox genes are groups of key developmental transcription factors that are highly conserved throughout the Metazoa. Their order of expression along the body axis of an animal is not only highly conserved between different organisms, but is also collinear to the arrangement of individual genes along the chromosome. Studies of these developmental control genes can give valuable insights into the evolution of body plans. A total of 7 homeobox containing genes (<I>dpl1-dpl7</I>) were isolated form the <I>D. listerianum </I> genome. Four of these were members of the <I>Hox</I> gene family and of the <I>ParaHox </I>gene family. Initial fragments were isolated using the method of degenerate PCR with primers designed from the highly conserved amino acid sequence of the 1<sup>st</sup> and 3<sup>rd</sup> helix of the homeodomain. Short fragments limit gene characterisation and as such, regions flanking the degenerate PCR products were isolated, using inverse PCR, 3' and 5' RACE PCR. Phylogenetic relationships of the genes are also examined. <I>Dpl1</I> exhibited high identities with the arthropod <I>Antennapedia</I> and the vertebrate <I>Hox6 </I>and <I>Hox 7</I> paralogue groups. Phylogenetic analysis showed dpl1 to be more closely related to the Hox6 than to the Hox7 group genes. <I>Dpl2 </I>shares high identity with members of the <I>Hox5/Scr </I>paralogous group. <I>Dpl3</I> has a high level of homology to the <I>C. intestinalis</I> gene <I>CiIPF1</I>. The <I>Dpl3 </I>homeodomain shared high identity with the ascidian <I>H. roretzi</I> and <I>H. curvata </I>cdx genes (<I>Hr-cad</I> and <I>Hec-cdx</I>, respectively), however differences in the hexapeptide regions, indicated high divergence of these genes in the ascidians. <I>Dpl5</I> possessed features characteristic of posterior Hox genes and was most closely related to the <I>C. intestinalis</I> <I>CiHbox5</I> gene. <I>Dpl6</I> shared features common to the Hox 4 paralogous group Gsx ParaHox groups.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:367481 |
| Date | January 2001 |
| Creators | Goostrey, Anna |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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