Chromosomal mutations in pigs derived from X-irradiated semen

Area of Science:

• Genetics
• Radiation Biology
• Animal Science

Background:

• Semen irradiation is a method used for genetic modification in livestock.
• Understanding the effects of radiation on pig chromosomes is crucial for breeding programs.
• Previous studies have documented spontaneous chromosomal mutations in pigs.

Purpose of the Study:

• To investigate the frequency and types of chromosomal mutations induced by semen irradiation in pigs.
• To determine the threshold dose for inducing detectable chromosomal mutations in porcine semen.
• To identify specific chromosomes prone to rearrangements in the Suidae family.

Main Methods:

• Semen from domestic pigs was irradiated at doses of 600 and 800 rads.
• The irradiated semen was used for artificial insemination to produce offspring.
• Chromosomal analysis (karyotyping) was performed on phenotypically normal pigs derived from the irradiated semen.

Main Results:

• Chromosomal mutations were detected in 8 out of 30 pigs (26.7%) derived from semen irradiated at 800 rads.
• The observed mutations included eight translocations, two pericentric inversions, and one paracentric inversion.
• No chromosomal mutations were found in pigs derived from semen irradiated at 600 rads.
• Analysis of spontaneous and induced mutations in Suidae suggested chromosomes 1 and 15 are frequently involved in rearrangements.

Conclusions:

• Semen irradiation at 800 rads can induce significant chromosomal mutations in pigs.
• A dose of 600 rads appears to be below the threshold for inducing detectable chromosomal mutations in this study.
• Chromosomes 1 and 15 are potentially hotspots for chromosomal aberrations in pigs, warranting further investigation.