Laboratory Animal and Comparative Medicine

• XXXX XXXX •    

Screening and Analysis of Microsatellite Genetic Markers in Commonly Used Inbred Rat Strains

TANG Jianping1,2(), ZHAO Liya2, ZHAO Ying1()()   

  1. 1.Shanghai Laboratory Animal Research Center, Shanghai 201203, China
    2.Shanghai BK/KY Biotechnology Co. , Ltd. , Shanghai 201203, China
  • Online:2026-03-03
  • Contact: ZHAO Ying

Abstract:

Objective To screen a set of Short Tandem Repeats(STR) markers covering rat chromosomes 1-20 (autosomes) and the X chromosome (2-4 markers per chromosome), and establish a dedicated marker panel for genetic background detection, genetic contamination detection, and inter-strain identification of five commonly used inbred rat strains (F344, BN, DA, Lewis, and PVG). Methods 6 samples were collected from each strain (half male and half female). Genomic DNA was extracted from each sample. A total of 61 STR markers were selected, including 27 from national standards and 34 from reference. Singleplex STR PCR amplification combined with capillary electrophoresis was used for genotyping of the five inbred rat strains, and genotype data were analyzed using GeneMapper ID v3.2 software. Based on the STR genotyping results, genetic distances between strains were calculated with GenAlEx 6.51b2 software, and a phylogenetic tree of the inbred rat strains was constructed using MEGA7 software. Results Among the 61 STR markers, non-specific amplification was observed for D15mit3, while no specific amplification product was obtained for D3wox7, resulting in 59 usable STR markers. The success rate of specific amplification for these 59 markers reached 100% across 5 inbred strains. Additionaly, the genotyping results of each sample were homozygous, and the average homozygosity of the 5 inbred strains reached 100%, which meets the requirements for genetic quality control of inbred strains. The phylogenetic tree showed that the number of STR allelic differences between BN and F344 strains was 49, with a genetic distance of 1.775, both of which were the highest among all strain pairs. This indicated that the two strains exhibited the highest level of genetic differentiation and the farthest genetic relationship. In addition, F344, DA, and PVG clustered into one clade, suggesting that they originated from a common ancestor, while BN and Lewis formed another clade, implying a shared ancestral origin. The genetic relationships among the 5 strains were largely consistent with previous reports. Among the genotyping results of the 59 STR markers, LCA, AGT, and D5Hmgc2 exhibited no inter-strain polymorphism across the 5 inbred strains, while the remaining 56 markers possessed inter-strain polymorphism. These 56 markers covered rat 20 autosomes and the X chromosome (2-4 markers per chromosome). Thus, these 56 markers can serve as a panel for genetic background detection of inbred rat strains. A subset of 42 markers selected from the 56 polymorphic ones can be employed for genetic contamination detection. Additionally, The amplified product lengths of D7wox14, D15rat123 and D20wox3 exhibited inter-strain differences among the 5 strains, which can be used for the rapid identification of 5 commonly used inbred rat strains. Conclusion This study successfully screened out of a set of STR markers for genetic testing of 5 commonly used inbred rat strains, and established dedicated marker panels for genetic contamination detection and inter-strain identification, respectively.

Key words: Inbred rats, Short tandem repeats, STRs, Genetic detection, Evolutionary tree, Screen

CLC Number: