Liu Jin Juan, Ran Xue Qin, Li Sheng, Feng Yali, Wang Jia Fu
Guizhou University, Guiyang, China.
Anim Reprod Sci. 2009 Apr;111(2-4):369-75. doi: 10.1016/j.anireprosci.2008.03.004. Epub 2008 Mar 20.
Follicle stimulating hormone (FSH) is a pituitary gonadotropin that plays a key role in the regulation of gonadal function in mammal. The gonadotropic hormones are composed of two subunits, the common alpha subunit and the hormone-specific beta subunit, which determine the binding to specific receptors and induction of biological response. The aim of this study was to investigate the polymorphism of the first intron of FSH-beta gene present in different pig breeds and its influence on the expression of FSH-beta gene. Genomic DNA was isolated from blood of three Chinese local pig breeds and two European pig breeds. The first intron of FSH-beta gene was amplified by polymerase chain reaction (PCR) and the PCR product was then determined by sequencing. The correlation between the expression level of FSH-beta gene and the sequence polymorphism was evaluated by RT-PCR using 29 heterozygous pig breeds. Three patterns of the PCR amplified fragments were observed in five different pig breeds. They are 500bp, 220bp, and 500/220bp in length representing three different genotypes with respect to the size of the first intron of FSH-beta gene. After sequencing the whole intron 1 of FSH-beta, we have found that the different size of the PCR amplified fragments was attributed to an insertion element, which was only found in the larger fragment. The insertion, specific in pig genome, showed high similarity to short interspersed nucleotide elements (SINE). Moreover, The Chinese pig breeds, Xiang, Nuogu and Kele pig, exhibited a statistically significant higher frequency of the allele with this SINE in FSH-beta gene than the European pig breeds did. To elucidate whether the SINE insertion affects the expression of FSH-beta gene, 29 heterozygous Chinese and European pig breeds were tested by RT-PCR. The results confirmed that the major transcript in the heterozygous pigs was from SINE- allele but not detected from SINE+ allele. These data suggested that the SINE insertion negatively regulated the expression of FSH-beta gene and the dominant character related to propagation was gained from the SINE- allele of FSH-beta locus in heterozygous breeds of pigs.
促卵泡激素（FSH）是一种垂体促性腺激素，在哺乳动物性腺功能的调节中起关键作用。促性腺激素由两个亚基组成，即共同的α亚基和激素特异性β亚基，它们决定了与特定受体的结合以及生物反应的诱导。本研究的目的是调查不同猪品种中FSH-β基因第一内含子的多态性及其对FSH-β基因表达的影响。从三个中国地方猪品种和两个欧洲猪品种的血液中分离基因组DNA。通过聚合酶链反应（PCR）扩增FSH-β基因的第一内含子，然后对PCR产物进行测序。使用29个杂合猪品种通过RT-PCR评估FSH-β基因表达水平与序列多态性之间的相关性。在五个不同猪品种中观察到三种PCR扩增片段模式。它们的长度分别为500bp、220bp和500/220bp，代表了FSH-β基因第一内含子大小方面的三种不同基因型。对FSH-β的整个内含子1进行测序后，我们发现PCR扩增片段大小的差异归因于一个插入元件，该元件仅在较大片段中发现。这种在猪基因组中特有的插入与短散在核苷酸元件（SINE）具有高度相似性。此外，中国猪品种香猪、诺古猪和可乐猪在FSH-β基因中具有该SINE的等位基因频率在统计学上显著高于欧洲猪品种。为了阐明SINE插入是否影响FSH-β基因的表达，通过RT-PCR对29个杂合的中国和欧洲猪品种进行了检测。结果证实，杂合猪中的主要转录本来自SINE-等位基因，而未从SINE+等位基因中检测到。这些数据表明，SINE插入对FSH-β基因的表达具有负调控作用，并且在杂合猪品种中与繁殖相关的显性性状来自FSH-β基因座的SINE-等位基因。
