[Relationship of genetic polymorphism of PRLR and RBP4 genes with litter size traits in pig].

The polymorphism of prolactin receptor (PRLR) and retinol-binding protein 4 (RBP4) genes was detected by PCR-RFLP method, and the effects of PRLR and RBP4 genes on litter size traits in pig were analyzed by the least square analysis. Data of total number born (TNB) and number born alive (NBA) from 323 sows, including five Shandong local pig breeds and three foreign pig breeds, were collected. The results showed that the polymorphic sites of both PRLR and RBP4 genes were found in all populations tested. The genotype distribution, however, revealed great differences between Shandong local pig breeds and foreign pig breeds. The effects of genotypes on TNB and NBA were significant (P<0.05). The homozygote AA was the most prolific genotype. For PRLR gene, AA genotypic sows of Shandong local pig breeds and foreign pig breeds produced 1.03 TNB, 0.89 NBA, and 1.26 TNB, 1.11 NBA more than BB genotypic sows, respectively. For RBP4 gene, AA genotypic sows of Shandong local pig breeds and foreign pig breeds produced 0.59 TNB, 0.51 NBA and 0.72 TNB, 0.64 NBA more than BB genotypic sows, respectively.

[Analysis of genetic diversity of Shandong indigenous chicken breeds using microsatellite marker].

Microsatellite marker is one of the frequently used molecular markers. It has been used in the genotype identification, pedigree analysis and estimation of genetic distance. In this paper, five microsatellite markers with high polymorphisms were selected to detect the genetic diversity of seven chicken breeds. The alleles frequencies, polymorphism information content (PIC) and average heterozygosity within each population, and DA genetic distance among breeds were analyzed. The application of microsatellite polymorphisms to the detection of genetic variability and relationship among populations was discussed. Altogether, forty alleles were found in this experiment, and among them the most alleles (10) were detected by ADL0136 and the least (5) were detected by ADL0146. The distribution of alleles was not balanced, each locus having one or more dominant alleles. The average heterozygosity in the Shouguang chicken was the lowest (0.3327), and that in other breeds was also less than 0.4. It can be seen then that microsatellite polymorphisms can be used to reveal the variability within population through calculation of average heterozygosity. The PIC values ranged from 0.6169 (Shouguang chicken) to 0.7027 (Laiwu Black chicken). UPGMA tree was completed through analysis of DA genetic distance. In the tree, the Rizhao Pockmarked and the Jining Hundred chicken were first grouped together with a bootstrap value of 92%, before they were grouped with the Laiwu Black and the Shouguang chickens. The Anoka Yellow and the Guangxi Yellow chicken were grouped together with a bootstrap value of 80%, but the Luxi Fighting chicken had its own branch. In summary, the UPGMA tree well reflected the evolutionary and breeding history of the seven breeds.