Immunoglobulin VH genes of the goldfish, Carassius auratus: a re-examination

Abstract

Five VH-related genomic sequences from the goldfish, Carassius auratus, have been characterized. One of these sequences appeared to be a functional gene, and four to be pseudogenes. The main conclusions drawn from this study were that: (1) With minor exceptions, goldfish VH genes conform to the typical pattern of vertebrate VH genes in terms of their structure (they encode an intron-split hydrophobic leader, 3 framework and 2 complementarity-determining regions, and possess a typical 3' recombination signal sequence for VH to D joining) and regulatory sequences (possession of a typical upstream octameric promoter). (2) The sequences indicate that goldfish possess multiple families of VH sequences (at least three). Two of these families contain approximately 6 and 10 members, as judged from Southern blot hybridization experiments. (3) Goldfish VH gene families are distributed throughout the members of the species in the manner typical of that of VH families in other vertebrate species. Thus, this observation corrects the previous conclusion (Wilson et al., Proc. natn. Acad. Sci. U.S.A. 85, 1566-1570, 1988) that VH genes are discontinuously distributed in the goldfish population.