Variation in chromosome number among European wild pigs.

Abstract

Peripheral leukocyte cultures from 36 European wild pigs have shown that 73% of the animals possessed 36 chromosomes while 27% had 37. Karyo-types of 36-chromosome individuals differed from those of domestic swine in that they possessed one pair of submetacentric chromosomes not found in domestic pigs and lacked two pairs of the domestic’s telocentrics. The 37-chromo-some animals had one chromosome of each of these three pairs but lacked their homologous members. Matings between animals with 36 and 38 chromosomes have produced fertile offspring with 37. A single litter from a 36 x 37 mating consisted of three pigs with 36 and three with 37 chromosomes, while one from a 37 x 37 mating contained progeny with 36, 37, or 38 chromosomes. The odd number of chromosomes in some wild pigs is postulated to have resulted from the entry of domestic breeding into the wild herd.