白来航笼养蛋鸡胰岛素样生长因子Ⅰ限制性片断多态性与骨质疏松症

Restrictive fragment length polymorphism of insulin-like growth factor Ⅰ and osteoporosis in White Leghorn cage layers

目的:了解白来航笼养蛋鸡胰岛素样生长因子Ⅰ限制性片断多态性与骨质疏松症的关系。方法:实验于2006-01/04在南京农业大学畜禽骨骼研究实验室完成。随机选取83周龄白来航蛋鸡180羽,应用PCR扩增鸡胰岛素样生长因子Ⅰ启动子上游7kb处基因片断,用PstⅠ限制性内切酶消化产生限制性片断长度多态性,分析胰岛素样生长因子Ⅰ多态性与胫骨、股骨、肱骨骨放射密度及其皮质骨厚度、髓质骨和小梁骨体积、体质量、骨代谢标志物(钙、磷、骨钙素及碱性磷酸酶)、雌二醇等的关系。结果:180羽蛋鸡PP、Pp、pp基因型频率分别为0.0389、0.35、0.611,P、p等位基因频率分别为0.214、0.786。方差分析(ANOVA)显示,pp基因型肱骨骨放射密度及皮质骨厚度显著大于Pp、PP基因型(P<0.05)、pp基因型的胫骨皮质骨厚度极显著大于PP基因型(P<0.01),pp基因型胫骨骨骺骨小梁体积极显著大于Pp、PP基因型(P<0.01)。结论:白来航笼养蛋鸡胰岛素样生长因子Ⅰp等位基因具有一定的骨质指针作用,pp基因型蛋鸡呈现骨质强的优势,提示从分子水平探讨骨质丢失以及对骨质疏松症的基因诊断和抗性基因选育具有一定的意义。

AIM： To study the association between restrictive fragment length polymorphism （RFLP） of insulin-like growth factor [ （IGF- Ⅰ） and osteoporosis in White Leghorn cage layers. METHODS： The experiment was performed in the research laboratory of animal bone, Nanjing Agricultural University from January to April 2006. 180 hens of 83-week-old were randomly selected. The IGF-Ⅰ gene fragments were detected by means of PCR-RFLP, and the gene fragments were digested with Pst Ⅰ . The association between genetic polymorphism and tibial, femora＇l, and humeral bone radiographic density, cortical width, cancellous bone volume and medullary bone volume, body mass, estradiol, and bone metabolic markers such as calcium, phosphonium, osteocalcin, and alkalinephosphatase was analyzed. RESULTS： The frequencies of PP, Pp and pp genetypes in 180 hens were 0.038 9, 0.35, and 0.611, respectively. And the overall gene frequencies for P and p alleles were 0.214 and 0.786. Analysis of variance showed that the humeral bone radiographic density and cortical width of pp genetype were significantly higher than those of the other genetypes （P 〈 0.05）, and the tibial cortical width of pp genetype was extremely higher than that of PP genetype （P 〈 0.01）; the cancellous bone volume （epiphysis in approximal tibia） of pp genetype was significantly higher than that of other genetypes （P 〈 0.01）. CONCLUSION： IGF-Ⅰ p allele may be a marker of osteoporosis and pp genotype is the characteristic of White Leghorn cage layers with high bone quality, indicating it is very important to probe into the bone loss, gene diagnosis of osteoporosis and selection of resistant osteoporosis for layers at molecule level.