Objective: To cultivate inbred guinea pig strains and establish microsatellite molecular markers for detecting the genetic structure of guinea pigs.
Methods: The methods of inbreeding and backcrossing, single-line and optimal breeding, selection and elimination were used to cultivate Zmu-1:DHP outbred guinea pigs into Zmu-1:DHP inbred guinea pigs. PCR was performed on the DNA samples of the inbred line and the reference Zmu-1:DHP outbred line and Zmu-2:DHP inbred line guinea pig DNA samples using 15 pairs of guinea pig polymorphic microsatellite primers that had been screened (reported separately). The genetic structure of related strains was analyzed by product electrophoresis bands, and the genetic homozygosity of each strain was evaluated. The same method was used to study the genetic structure of guinea pigs of each lineage of Zmu-1:DHP inbred line, and to evaluate the genetic homozygosity of each lineage.
Result: After 13 years of cultivation, 8 inbred guinea pig branches (litters) with more than 20 generations were obtained, and each branch had 1-3 guinea pigs. After identification, the gene frequency of Zmu-1:DHP inbred line 2 reached 86.7%, which was higher than 6.7% of Zmu-1:DHP outbred line and 66.7% of Zmu-2:DHP inbred line respectively; The number of genes was 1.13, which were lower than 2.47 of Zmu-1:DHP outbred line and 1.33 of Zmu-2:DHP inbred line; the genotype frequency of Zmu-1:DHP inbred line was also higher than other lines. The genotypes of the Zmu-1:DHP inbred line are all contained in the genes of the Zmu-1:DHP outbred line, but lack the two characteristic genes carried by the Zmu-2:DHP inbred line. The gene homozygosity rates of the 8 lines of Zmu-1: DHP inbred line were not equal, and the gene homozygosity rates of the 2nd and 8th lineages were higher.
Conclusion: Zmu-1:DHP inbred line and Zmu-1:DHP outbred line have both homology and specificity. The second branch of Zmu-1:DHP inbred line is basically cultivated into a new inbred line. For inbred guinea pigs, the formation of multiple inbred lines is beneficial to the screening of lines with dominant traits. Zmu-2: DHP black inbred lines carry microsatellite markers not found in white lines, and may carry genes for superior traits associated with coat color traits.