猪催乳素受体基因第8内含子多态性及其对产仔性能的影响

Detection of the Polymorphism within Intron 8 of Prolactin Receptor Gene and its Association with Litter Size in Swine

采用PCR-SSCP技术检测了大白猪、长白猪、杜洛克猪、马身猪、山西黑猪和山西白猪等6个品种364头个体催乳素受体基因(prolactin,PRLR)第8内含子的多态性,并分析了多态位点对猪头胎产仔性能的影响。结果表明,猪PRLR基因第8内含子存在多态性,共检测到A、B、C 3个等位基因和AA、AB、AC、BB、BC和CC 6种基因型。在杜洛克猪、长白猪、山西黑猪和山西白猪群体中,A等位基因的频率最高,分别为0.8276、0.5439、0.5345和0.7669;而在大白猪和马身猪群体中,B等位基因的频率最高,分别为0.6894和0.7000;仅在大白猪、山西黑猪和山西白猪中检测到C等位基因,且频率较低,在0.0379～0.1385之间。PRLR基因型对母猪头胎产仔数有显著影响(P<0.05),对产活仔数的影响未达显著水平。AC基因型母猪的头胎产仔数和产活仔数显著高于BC基因型个体,而与AA、AB和BB基因型个体差异不显著。含有A等位基因的母猪的产仔性能优于不带有A等位基因的个体,表明A等位基因是有利于母猪产仔性能提高的等位基因,可应用于标记辅助选择来提高母猪的繁殖性能。

The objective of this study was to detect the polymorphism of porcine prolactin receptor （PRLR） gene and ana- lyze its association with litter size in swine, and to provide the basic knowledge for using PRLR gene as a genetic marker in marker assisted selection （MAS） for improving the reproduction performance in pig production. Polymorphisms of intron 8 of PRLR gene on 364 pigs from 6 breeds including Large White, Landraee, Duroc, Mashen pig, Shanxi Black pig and Shanxi White pig were tested by PCR-SSCP. Three alleles of A, B, C and six genotypes of AA, AB, AC, BB, BC and CC, were ob served in examined populations. The A allele frequency was greater than those of B and C in Duroc （0. 8276）, Landrance （0. 5439） , Shanxi Black pig （0. 5345）, and Shanxi White pig （0. 7669）, whereas the B allele was superior to A and C in Large White （0. 6894） and Mashen pig （0. 7000）. The C allele was in low frequency, ranged from 0. 0379 to 0. 1385, and only pres- ent in Large White, Shanxi Black pig and Shanxi White pig. Statistical analysis showed that PRLR genotype was significantly associated with total number born （TNB） （P%0.05） and was not associated with number born alive （NBA） at first parity. The TNB and NBA of heterozygote AC was significantly different from that of BC, whereas not significantly different from those of AA, AB and BB. The sows with A allele seems to had bigger TNB and NBA than those without allele A, which im- plied that the A allele was the favorable allele for improving sow＇s litter size. The results of this work may provide the poten tial marker for the application in MAS for improving litter size in pig breeding and production.