ARS | Publication request: Structural assessment of backcrossing using microsatellite markers

Submitted to: South African Journal of Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 15, 2008
Publication Date: October 1, 2008
Citation: Tshipuliso, N.O., Alexander, L.J., Kotze, A., Ehlers, K., Leesburg, V.L., Macneil, M.D. 2008. Structural assessment of backcrossing using microsatellite markers. South African Journal of Science 38(4):290-292.

Interpretive Summary: Backcrossing plays an important role in introducing new genetic material into established breeds or lines of livestock and poultry. When coupled with marker or gene assisted selection, it can be used to move a specific gene or chromosomal region from one population into another. It is often intended that the remainder of the genome remain unaffected when using these technologies. Our objective was to assess the genomic structure of cattle produced by backcrossing for loci that are unlinked to a specific locus that was being moved from a donor breed to a recipient breed in when the particular genetic variant was not otherwise present. Genotypes of the two parental populations, their F*1 progeny, and two subsequent backcross generations of animals were determined at 34 independent loci. There was little evidence to suggest any systematic genome-wide departure from pedigree derived expectation as a result of the breeding system. These data validate the desired intention of a backcrossing program that progressive generations migrate genotypically toward one of the parental types.

Technical Abstract: Backcrossing, coupled with marker or gene assisted selection, can be used to introgress a specific gene or chromosomal region from one population into another. The objective of this study was to assess the genomic structure of cattle produced by backcrossing for loci that are unlinked to a locus that was being introgressed. Genotypes of the two parental populations, their F1 progeny, and two subsequent backcross generations of animals were determined at 34 microsatellite loci that were not linked to a locus being introgressed. There was little evidence to suggest any systematic genome-wide departure from pedigree derived expectation as a result of the breeding system. These data validate the desired intention of a backcrossing program that progressive generations migrate genotypically toward one of the parental types.