ISSN : 1225-3480
Hox genes are expressed along the anterior-posterior body axis in a collinear fashion in the majority of bilaterians. Contrary to polyplacophorans, gastropods including abalone deviate from this pattern by expressing Hox genes in distinct morphological structures and not in a staggered fashion. However, the molecular developmental understandings remain unknown. In the present study, we isolated DNA sequence of Hox gene from genome database and investigated its mRNA expression in early developmental stages of abalone, Haliotis discus hannai. The H. discus hannai Hox gene (HDH-HoxA2) showed 36% and 37% amino acid identities with with HoxA2 of Crassostrea gigas and Mixuhopecten yessoensis, respectively. The 62 amino acids sequence of homeodomain was conserved well in HDH-HoxA2. The qRT-PCR detected HDH-HoxA2 at the first day after hatching (trocophore larvae stage), but the expression of HDH-HoxA2 mRNA decreased after two days post-hatching. The present study is the first to report on the molecular cloning, characterization and expression analysis of Hox gene in H. discus hannai. The results might provide new insights into the regulation of early developmental stages of abalone.
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