To establish an inbred strain, matings are typically done between which relatives?

To establish an inbred strain, matings are typically done between which relatives?

• A. Siblings (brother-to-sister)
• B. First cousins
• C. Unrelated individuals
• D. Parent and offspring

Answer: (A)

Inbred strain establishment aims to make animals genetically uniform by increasing homozygosity across generations. This is best achieved by mating close relatives so that the same alleles are repeatedly passed down from both parents. The typical starting approach is to pair siblings, such as brother to sister, and continue this close-relatives mating for many generations. Repeated sibling matings rapidly raise the inbreeding coefficient, leading to a stable, predictable genetic background after sufficient generations. Choosing first cousins would slow the buildup of homozygosity compared with sibling matings. Mating unrelated individuals wouldn’t increase homozygosity toward an inbred line at all. Parent-offspring matings would also produce inbreeding, but they carry a higher risk of deleterious effects and are less commonly used as the standard method for establishing an inbred strain.

Inbred strain establishment aims to make animals genetically uniform by increasing homozygosity across generations. This is best achieved by mating close relatives so that the same alleles are repeatedly passed down from both parents. The typical starting approach is to pair siblings, such as brother to sister, and continue this close-relatives mating for many generations. Repeated sibling matings rapidly raise the inbreeding coefficient, leading to a stable, predictable genetic background after sufficient generations.

Choosing first cousins would slow the buildup of homozygosity compared with sibling matings. Mating unrelated individuals wouldn’t increase homozygosity toward an inbred line at all. Parent-offspring matings would also produce inbreeding, but they carry a higher risk of deleterious effects and are less commonly used as the standard method for establishing an inbred strain.