β2-Microglobulin (β2m) is related to major histocompatibility complex class I alpha chains, and forms cell-surface glycoproteins that mediate a variety of functions in immune defense. In general, β2m has no isoforms and is not polymorphic in higher vertebrates, but polymorphisms between different alleles have been found in some fish species. In this study, full-length β2m cDNA and genomic sequences were cloned from the miiuy croaker (Miichthys miiuy).
Twelve polymorphic microsatellites from the (AG)13 and (CA)13 enriched genomic libraries of Miichthys miiuy were isolated and characterized in a test population; the number of alleles ranged from two to nine. The observed and expected heterozygosities ranged from 0.1923 to 1.0000 and from 0.2633 to 0.8337, respectively. Three loci deviated from Hardy-Weinberg equilibrium, and linkage disequilibrium between five pairs of loci was significant.