中国荷斯坦牛GlyCAM1基因遗传多态性的研究

以273头中国荷斯坦牛为研究对象,利用CRS—PCR、PCR—SSCP及DNA测序技术检测了GlyCAM1基因外显子3、内含子3的遗传多态性。结果表明：GlyCAM1基因分别在外显子3和内含子3的第2081（A／C）、2417（C／T）位存在突变,2个位点的等位基因频率A／B分别为0．7525,0．2475和0．9046,0．0954;经菇。适合性检验,中国荷斯坦牛内含子3的突变达到Hardy—Weinberg平衡状态（P〉0．05）,但其外显子3的突变未达到Hardy—Weinberg平衡状态（P〈0．05）。     

微卫星标记ILSTS011在3个绵羊品种中的遗传多样性分析

为了分析微卫星标记ILSTS011的遗传多态性,研究以河南省地方绵羊品种大尾寒羊、小尾寒羊和豫西脂尾羊为研究对象,采用聚丙烯酰胺凝胶电泳技术分离微卫星标记的带型.结果表明:在3个绵羊品种中均检测到微卫星标记ILSTS011有3个等位基因,微卫星标记ILSTS011的平均杂合度为0.614 1,平均有效等位基因数为2.614 0,平均多态信息含量为0.551 3.说明ILSTS011为高度多态基因座,可作为有效的遗传标记用于大尾寒羊、小尾寒羊和豫西脂尾羊的遗传多样性分析.     

牛肌肉生长抑制素基因单核苷酸多态性分析

应用PCR-SSCP分析方法,对94头肉牛(公牛45头:西门塔尔34头,夏洛来11头;母牛49头:西门塔尔24头,夏洛来25头)的肌肉生长抑制素(MSTN)3个外显子进行了多态性分析.结果显示,第1外显子存在2种基因型,分别为AA型和AB型.经测序发现,第1外显子4 bp处存在C→G的碱基突变,导致编码的氨基酸由谷氨酰胺(Gln)→谷氨酸(Glu).统计结果表明,等位基因B的含量低,而且只在西门塔尔品种内含0.026 6.利用SPSS软件作最小二乘分析,结果表明,B等位基因与西门塔尔牛的成年体质量和犊牛出生体质量呈显著正相关.     

环介导恒温扩增技术在动物病原检测中的应用

环介导恒温扩增技术(LAMP)是一种新型核酸扩增技术,是依赖于靶目标上6个区域的4条引物和一种具有链置换活性的DNA聚合酶Bst的作用,在60 ℃～65 ℃恒温条件下1 h之内即可完成的基因扩增技术.该技术虽然起步较晚,但发展迅速,目前在很多领域的研究和应用已经取得很大进展.论文从技术原理、引物设计、反应机制和特点等方面了介绍了环介导恒温扩增技术,并就该技术在动物细菌性病原微生物、病毒和寄生虫检测中的应用做了介绍.     

微卫星标记BM3413和OB_2在5个绵羊群体中多态性的研究

选萨福克羊、德国美利奴羊、特克塞尔羊、乌珠穆沁羊以及右玉本地绵羊5个绵羊群体共250只,通过耳组织提取基因组DNA,用2对微卫星引物进行PCR扩增,通过电泳分型、凝胶成像系统分析各位点等位基因及全部个体的标记基因型,计算基因频率、多态信息含量(PIC)和杂合度等,从分子水平上分析5个绵羊品种的遗传多态性.结果表明:BM3413和OB2这2个位点的等位基因数分别为7和8,多态信息含量PIC＞0.5,杂合度为0.827 1～0.846 7,均属于高度多态性位点,用于作为与生产性能相关的遗传标记是较理想的.     

哈萨克羊、阿勒泰羊、巴什拜羊遗传多样性的AFLP分析

利用11对AFLP引物组合,检测了哈萨克羊、阿勒泰羊、巴什拜羊池DNA遗传变异,构建了各品种的AFLP DNA 指纹图谱,根据AFLP分析结果,统计了每个引物组合在各品种中检测到的多态性条带,计算了3个品种的遗传相似系数,并据此构建了UPGMA聚类关系图,分析了它们的遗传关系.结果表明:11对AFLP引物组合在3个地方绵羊品种中共检测到310条带,平均每个引物组合产生28.18条带,变化范围在25～34条,其中多态性条带32条,占扩增总带教的10.32%,每对引物平均扩增多态性带2.909条.品种间的遗传相似系数以哈萨克绵羊与阿勒泰绵羊的最高(O.699),哈萨克绵羊与巴什拜绵羊最小(0.592),聚类结果与这些羊的育成史、分化及地理分布一致.     

Effects of GH gene polymorphism and sex on carcass traits and fatty acid compositions in Japanese Black cattle

To investigate the effects of bovine growth hormone (bGH) gene polymorphism on carcass traits and fatty acid compositions in Japanese Black cattle caused by nucleotide substitution of CTG (allele A)/GTG (allele B) at codon 127 and of ACG (allele A and B)/ATG (allele C) at codon 172 of bGH, GH genotypes of 135 cattle were determined using allele specific-multiplex polymerase chain reaction (PCR). Allele A gave greater rib thickness and lower melting point of fat (MP) while allele B gave higher C18:1% ( P  < 0.05). Allele C gave higher C18:1, monounsaturated fatty acid (MUFA), unsaturated fatty acid (USFA) percentages ( P  < 0.05). It also gave lower saturated fatty acid (SFA) percentages, higher MUFA/SFA and USFA/SFA ratios, and lower MP ( P  < 0.05). Interactions of sex and GH alleles were analyzed. In heifers, allele A gave higher carcass weight, daily carcass gain, rib eye area, rib thickness, subcutaneous fat thickness, and BMS while allele B gave greater rib eye area and rib thickness ( P  < 0.05). Allele C gave higher C18:1 ( P  < 0.01), MUFA ( P  < 0.01), USFA percentages ( P  < 0.05) and MUFA/SFA and USFA/SFA ratios ( P  < 0.01), and lower C16:0 and SFA percentages ( P  < 0.05) and MP ( P  < 0.01). GH gene polymorphism affected carcass traits and fatty acid compositions although the effects were more pronounced in heifers.     

不同猪种ESR基因多态性的PCR-RFLP分析

运用PCR-RFLP方法,检测了杜洛克、约克夏、长白猪、皮特兰、梅山猪、二花脸猪、枫泾猪、荣昌猪、苏太猪等9个国内外猪种的ESR基因PvuⅡ位点多态性。结果表明,在约克夏猪、二花脸猪、枫泾猪和苏太猪中检测到了AA、AB、BB 3种基因型,在杜洛克猪、皮特兰猪中检测到AB、BB 2种基因型,在长白猪、梅山猪、荣昌猪中只检测到了AB基因型。在本研究中不同品种的A、B基因频率差异显著,总体上在国外猪群体中A等位基因为优势等位基因,而地方猪种中B等位基因为优势等位基因。     

杂种奶牛POU1Fl、GHR、GHRH-R和CSN1S2基因部分序列PCR-SSCP多态性分析

利用PCR-SSCP技术,对荷斯坦公牛冻精改良的93头杂种奶牛的脑垂体转录因子-1（POU1Fl）基因第6外显子、生长激素受体（GHR）基因第10外显子、生长激素释放激素受体（GHRH-R）基因第2外显子和酪蛋白(CSN1S2) 基因第18外显子进行了多态性研究。结果表明,在检测的4个基因位点中,只有POU1Fl基因第6外显子存在2种基因型,AB、BB基因型频率及A、B基因频率分别为0.0323、0.9677和0.0162、0.9838,未发现AA型个体。该群体在此位点上处于Hardy-Weinberg平衡状态,基因杂合度和多态信息含量分别为0.0318和0.0313。测序显示,与普通黄牛POU1Fl基因序列Y15995相比,A等位基因在POU1F1基因第6外显子的第209个碱基处发生了G→C的碱基颠换,导致Thr/Arg替代,其多态的成因及效应需进一步研究。     

Interrelationship of growth hormone AluI polymorphism and hyperketonemia with plasma hormones and metabolites in the beginning of lactation in dairy cows

A polymorphic site of the growth hormone gene (AluI polymorphism) that results in an amino acid change at position 127 of the protein chain (leucine, L to valine, V) has been linked to differences in circulating metabolites and metabolic hormones of calves and bulls and to milk yield traits of lactating cows. Our objective was to investigate the interrelationship of this polymorphism with plasma concentrations of β-hydroxybutyrate, insulin, IGF-I and leptin in postpartum dairy cows. Blood samples were taken from clinically healthy, spring-calving, group-fed Holstein-Friesian cows (n = 257; 7 large-scale farms) 4–13 days after calving. Of all herds, 100 cows had plasma β-hydroxybutyrate levels above 1.2 mmol/l and 157 cows were normoketonemic. The proportion of valine carriers and LL cows was not different within groups of normo- and hyperketonemic animals. Genotype was not associated with plasma β-hydroxybutyrate, insulin, IGF-I and leptin levels either in all of the herds or in the two with the highest proportion of the valine allele carriers (n = 28, 72%). We found significantly lower insulin, IGF-I and leptin concentrations in the presence of hyperketonemia compared to normoketonemic cows. There were strong negative correlations between BHB and the other blood parameters, while insulin, IGF-I and leptin were positively related to each other. In conclusion, in the first two weeks after calving we could not demonstrate any effect of AluI polymorphism on plasma concentrations of β-hydroxybutyrate and metabolic hormones studied. Hyperketonemia was associated with a significant decrease in insulin, IGF-I and leptin blood levels. We infer that cows homozygous for the leucine allele or carrying the valine allele may have a similar endocrine and metabolic response to the challenge of increased nutrient demand early postpartum and that the presence of hyperketonemia is mainly linked to the hormonal and metabolic changes occurring at the onset of lactation.