Chromosomal aberrations in cultured leukocytes from pigs derived from X-irradiated semen

Abstract

Fresh semen from swine was exposed to 600 r of X-irradiation and used to inseminate sows. The chromosomes of the resultant liveborn progeny were studied through the use of leukocyte cultures. Of the 31 pigs studied, 4 had consistent large aberrations in all of the 30 cells studied per animal. Three of these aberrations were translocations; the other was a pericentric inversion. These were thought to be attributable to immediate effects of X rays. An interesting mosaic condition was seen in three of the pigs studied. It was apparently inherited, at least in two of them. All of the pigs had a breakage-deletion condition for the same chromosome. Among the delayed effects of X-irradiation were chromosome alterations including aneuploidy, fragments, chromosome breaks, chromatid breaks and chromosome gaps. Other traits studied were chromatid gaps, secondary constrictions, pericentric inversions and sister chromatid fusions. The independent variables included in the analyses of variance were X-irradiation, breed, sex, irradiation × sex interaction and breed × sex interaction. The effects of these independent variables were not lucid, but there were some conclusions drawn. X-irradiation had a threshold effect, with the effect being a suppression of aberrations. Females, when interacting with the irradiation or breed effects, had higher frequencies of aberrations than males. Breed effects were not consistent, and no trend was apparent. Of the nine dependent variables studied, only fragments and chromosome breaks were noticeably correlated.

Chromosomal mutations in pigs derived from X-irradiated semen

“…Currently, gene mapping of swine chromosomes is under investigation using family analysis and somatic cell hybrid ization. -Numbers in parenthesis Include the poorly identified cases detected by Zartman et al (1969).…”