Allozyme Expression in Hybrids between Diploid and Tetraploid Races of Spinous Loach, Cobitis biwae and Loach, Misgurnus anguillicaudatus

Abstract

Allozyme expression in PGM, IDHP-2, LDH-1, and AAT-1 enzyme-coding loci was electrophoretically examined in hybrids between diploid and tetraploid races of spinous loath, Cobitis biwae and in intergeneric hybrids between the two races of spinous loath and common diploid loath, Misgurnus anguillicaudatus. The interracial hybrids showed asymmetrical expression of allelic products, indicative of heterozygous triploid genotypes including two alleles of the tetraploid race and one allele of the diploid race at the diagnostic loci. The intergeneric hybrids between tetraploid spinous loath and common diploid loath also exhibited similar electrophoretic phenotypes demonstrating triploid hybrid nature. On the other hand, those between diploid spinous loath and loath had phenotypes showing equal expression of two different alleles and were confirmed as diploid hybrids.