Abstract: Striped Hamster (Cricetulus barabensis) is one of the main functional groups in the regulation of cropland ecosystems. Litter size is one of the main factors affecting the population fluctuation of Striped Hamster, and prolactin receptor (PRLR) is the main effective gene controlling the litter size of animals. However, how the PRLR works on the population fluctuation of Striped Hamster is still unclear. In this study, ninety Striped Hamster individuals with the records of litter size were taken as the test materials to detect the SNP of the 5′ end of PRLR, analyze the haplotype structure, and examine the expression quantity of PRLR in ovaries during the oestrum, aimed to understand the correlations of the haplotype structure of the 5′ end of PRLR and the expression quantity of PRLR in ovaries during the oestrum with the litter size. A total of 3 polymorphic loci and 5 haplotypes (H1, H2, H3, H4, and H5) were detected in the 5′ end of the PRLR. Among the 5 halotypes structure, there existed significant difference in the litter size. Except between H1 and H2 and between H4 and H5, the expression quantity in the PRLR in ovaries during the oestrum had significant difference among the other haplotypes, and this expression quantity was significantly positively correlated with litter size (r= 0.982). Therefore, the polymorphic loci detected in the 5′ end of PRLR significantly affected the litter size, which could provide theoretical basis at molecular level for the effective control of Striped Hamster population.

Key words: carbon, Loess Plateau., nitrogen, plantation age, Robinia pseudoacacia, phosphorus