The zelbirafish vitronectin Receptor:: Characterization of integrin αV and β3 expression patterns in early vertebrate development

alpha V beta 3 is a receptor for vitronectin and other extracellular matrix ligands, and it has been implicated in angiogenesis and osteoclast function in mammals. We have cloned full-length cDNAs of zebrafish integrin alpha V (itg alpha V), and two paralogous zebrafish beta 3 integrins (itg beta 3.1 and itg beta 3.2). Whole-mount in situ hybridization analysis revealed that alpha V and beta 3.1 share overlapping expression domains in apical ectodermal ridge, ventricular myocardium, hypothalamus, posterior tuberculum, medial tectal proliferation zone, and in the odontogenic field of the bilateral pharyngeal dentitions. In contrast to beta 3.1, beta 3.2 is transiently expressed throughout the developing embryo. In situ hybridization profiles and heterologous expression of proteins in tissue culture cells suggest that beta 3.1 is the major beta 3 paralog that associates with alpha V in zebrafish. Furthermore, when beta 3.1 expression profiles are compared to those of other potential aV partners (beta 1, beta 5, and 08), pharyngeal dentitions appear to represent a unique expression field for alpha V and beta 3.1.