小尾寒羊高繁殖力候选基因ESR的研究

利用PCR—SSCP技术对高繁殖力绵羊品种（小尾寒羊、湖羊、德国肉用美利奴羊）和低繁殖力绵羊品种（多赛特羊、萨福克羊）的雌激素受体（estrogen receptor,ESR）基因第一外显子部分序列进行单核苷酸多态性研究。结果表明：小尾寒羊、湖羊和德国肉用美利奴羊中存在3种基因型（AA、BB、AB）,而在多赛特羊和萨福克羊中只存在两种基因型（AA、AB）。统计结果表明：湖羊、德国肉用美利奴羊、小尾寒羊、萨福克羊和多赛特羊A等位基因频率分别为0．672、0．786、0．846、0．857和0．867,B等位基因频率分别为0．328、0．214、0．154、0．143和0．133。测序结果表明：BB型和AA型相比在外显子1第363位发生1处碱基突变（C→G）。独立性检验表明：小尾寒羊和湖羊之间基因型分布差异极显著（P〈0．01）,湖羊和多赛特羊之间基因型分布差异显著（P〈0．05）,其他各个绵羊品种之间基因型分布差异均不显著。A8基因型和BB基因型小尾寒羊产羔数比AA基因型分别多0．51只（P〈0．05）和0．7只（P〈0．05）。研究结果表明：ESR基因可能是控制小尾寒羊多胎性能的一个主效基因或与之存在紧密的遗传连锁。     

凉山半细毛羊微卫星标记与羊毛性状的相关分析

利用微卫星技术对凉山半细毛羊核心育种群206个个体第1、2、3、9号染色体上的18个微卫星位点进行研究, 检测其基因型, 利用SAS 程序下的GLM对18个微卫星位点与羊毛性状的关系进行方差分析和多重比较, 结果发现7个微卫星位点对部分羊毛性状存在显著或极显著影响, 同时, 在这些位点上找到对羊毛性状有利的基因型。     

人类原发性高血压候选基因的研究进展

原发性高血压是一种遗传与环境因素相互作用所致的多基因遗传性疾病,其相关或易感研究在近年来非常活跃。利用家系或同胞对,采用基因组扫描结合候选基因策略,迄今已筛选出了数十年原发性高血压的可能相关基因,本从与人体血压生理生化代谢相关的几条途径中,选择介绍了与血压调节密切相关的几个候选基因的研究进展。     

卵巢早衰候选基因的突变研究进展

卵巢早衰病因复杂, 多数病例病因不明。在已知的病因中, 遗传因素非常重要。卵巢早衰不但可导致不孕症, 患者的低雌激素水平还增加了患骨质疏松症和冠心病的危险。目前临床上的主要治疗措施包括激素替代治疗和供卵治疗不孕症等, 但效果都不理想。鉴定卵巢早衰的致病基因是从根本上治疗和预防该病的基础。目前已发现在X染色体上和常染色体上多个基因与之相关, 文章综述了近年来对卵巢早衰候选基因的突变分析情况, 旨在从分子水平分析研究卵巢早衰的发病机制提供基础。     

影响动物肉质性状主要候选基因的研究进展

随着分子生物学在动物遗传育种中的应用,对数量性状主效基因的研究成为必然。本文对影响肉质的脂肪酸结合蛋白基因、肥胖基因、leptin 基因、黑素皮质受体基因、脂蛋白脂酶基因、激素敏感脂酶基因的国内外研究状况加以综述。 Progress in Candidate Genes Influencing Meat Quality Traits in Chickens QIU Xue-mei1,3,LI Ning1,DEND Xue-mei2,WU Chang-xin2 1.The National Laboratories for Agrobiotechnology,China Agricultural University,Beijing 100094,China; 2.College of Animal Science and Technology,China Agricultural University,Beijing 100094,China; 3.College of Animal Science and Technology,Heilongjiang August First Land Reclamation University,Mishan 158308,China Abstract:As the molecular biology has been applied in animal genetics and breeding,it is important that we research major genes on quantitative traits for animal breeding by transgenic technology.In this paper,the research advance of FABP genes,obese gene,leptin gene,MCRs genes,LPL gene,HSL gene affecting meat quality in animals are reviewed. Key words：animal; meat quality; candidate gene     

肌内脂肪候选基因的研究

肌内脂肪含量是重要的肉质指标,而脂肪酸结合蛋白在动物体内代谢过程中的作用,已经被认为与肌间脂肪含量等肉 质性状呈显著相关,其中两个编码基因已被列为这些数量性状的候选基因,进行了重点研究。本文通过搜索NCBI Pulmed和 Gene Bank中的文献和有关数据,比较全面地综述了近年来肌内脂肪和两类脂肪酸结合蛋白基因的研究。     

水稻抽穗期QTL定位及候选基因分析

水稻(Oryza sativa)抽穗期是决定产量和品质的重要性状,在育种、制种及引种驯化过程中发挥重要作用。将热研2号(O. sativa subsp. japonica cv.‘Nekken2’)和华占(O. sativa subsp. indica cv.‘HZ’)杂交获得F₁代,经连续多代自交得到120个重组自交系(RILs)群体。在常规水肥管理条件下,对120个RILs株系的抽穗时间进行统计分析。利用已构建好的高密度遗传图谱,对水稻抽穗期相关性状进行QTL定位分析,结果共检测到11个QTLs,分别位于第1、3、4、5、6、8和12号染色体上,其中1个LOD值高达5.75。通过分析QTLs区间内的候选基因,筛选出可能影响两亲本抽穗期的相关基因,并利用实时定量PCR进行基因表达量分析,发现LOC＿Os03g03070、LOC＿Os03g50310、LOC＿Os03g55389、LOC＿Os04g55510、LOC＿Os08g07740和LOC＿Os08g01670共6个基因在双亲间的表达量差异显著,其中LOC＿Os03g50310在Nekken2中的表达量比H...     

BMPR-IB和BMP15基因作为小尾寒羊多胎性能候选基因的研究

以控制BooroolaMerino羊多胎性能的BMPR IB基因 ,以及影响Invedale和Hanna羊排卵数的BMP15基因作为候选基因 ,从分子水平上对小尾寒羊的多胎机制进行研究 ,分析突变位点的特性 ,并通过大规模的群体检测统计推断其遗传效应。实验结果表明 :多胎品种小尾寒羊在BMPR IB基因的相应位置上发生了与BooroolaMerino羊相同的突变 (A74 6G) ,该基因的BB基因型在小尾寒羊群体内为优势基因型 ,且小尾寒羊初产和经产母羊的BB基因型比 ++基因型分别多产 0 97羔 (P <0 0 5 )和 1 5羔 (P <0 0 1) ,推测BMPR IB基因与控制小尾寒羊多胎性能的主效基因存在紧密的遗传连锁。而BMP15基因在小尾寒羊中不存在V31D或Q2 3Ter突变 ,说明小尾寒羊的多胎遗传机制与Romney羊不同 ,因此排除了BMP15突变影响小尾寒羊排卵数的可能性。     

奶牛乳房炎抗性候选基因的研究进展

乳房炎是奶业生产中的一种常见病,发病率很高,每年给世界各国奶牛饲养者造成严重的经济损失。乳房炎的影响因素很多,但遗传因素对其起着重要作用。综述了乳铁蛋白基因、MHC/BoLA基因、ToLL样受体家族基因、趋化性细胞因子受体基因、牛锌指蛋白313基因、β-防御素基因和热休克蛋白70基因等奶牛乳房炎抗性候选基因的研究现状。     

自杀行为候选基因5-HT2A受体基因的核酸及蛋白质分析

为阐明自杀行为的机制,在众多的自杀候选基因中,本文着重对候选基因5-HT2Α受体基因进行了生物信息学分析,结果支持候选基因及其编码蛋白质参与自杀行为的生理生化过程,为自杀行为受基因、环境的共同作用提供了间接证据,也为自杀行为机制的后续研究奠定了基础。     

MyoG基因多态性与优质肉鸡屠宰性状和肉质性状的相关性分析

采用PCR-SSCP分析方法, 对8个品系240只个体的大恒优质肉鸡进行了MyoG基因5′调控区的研究。结果表明, MyoG基因5′调控区存在A、B 2个多态位点, 结合测定的生产资料, 分析了该基因5′调控区两个变异位点产生的基因型之间在屠宰性状和肉质性状的差异并进行了最小二乘分析和显著性检验。表明MyoG基因对鸡的肌纤维生长发育有显著的正相关。     

猪AMPD1基因的克隆与变异位点分析

腺苷一磷酸脱氨酶基因(AMPD1)在嘌呤代谢过程中起着重要的作用。AMPD1基因主要在骨骼肌中高水平表达, 与肌肉中肌苷酸代谢有关。还发现AMPD1与猪的胴体性状有关。对AMPD1基因CDS进行了克隆、测序, 获得2 195 bp的CDS序列, 并利用PCR-SSCP方法对其进行分子扫描, 寻找多态位点, 分析不同基因型在不同猪种间的分布规律。χ2独立性检验表明, 民猪、大白猪、杜洛克间不同基因型的分布存在着极显著的差异(P<0.01)。     

Climatic adaptation in recently shorn merino sheep

Heart rates, respiratory rates, body temperatures, ad libitum ‘day’ and ‘night’ food consumption and body weight changes have been examined in 15 mature Merino wethers shorn in moderate environmental conditions. All sheep showed a depression in food consumption for two days after shearing. Sheep that gained weight during the next three weeks then increased their food consumption at night by approximately 30% although the average daily consumption was only increased by 5%. Sheep that lost weight showed a depressed food consumption throughout the three week period after shearing. Marked increases in the temperature difference between ear skin and air as well as thermal tachypnoea during the warmest period of the day were recorded in all sheep 14–16 days after shearing. This indicated that the critical temperature for all sheep had decreased by about 10°C. These signs of acclimatisation appeared at similar times in all sheep, suggesting that increased resistance to body cooling developed at similar rates in weight gain and weight loss sheep and independent of the origin of body heat production. The results of the investigations are discussed in relation to the concept that the initial response to cold stress includes a depression in food intake and that the duration of this depression is a function of the cold stimulus and the strain it induces in the sheep.     

秦川牛IGF2基因SNPs检测及其与胴体、肉质性状的相关性

采用PCR-SSCP方法对186头24月龄秦川牛IGF2基因进行了SNPs多态性检测, 并将其与部分胴体和肉质性状进行关联分析。在IGF2基因120碱基处发现C→T 突变, 在279碱基处发现 A→G 突变。方差分析结果表明: BB、DD 两个位点与胴体性状中与宰前活重、胴体重、胴体长、胴体胸深、眼肌面积显著相关(P<0.05), 其中背部皮下脂肪厚达到差异极显著(P<0.01); 与肉质性状大理石花纹、嫩度、pH24 (牛肉排酸24 h后的酸度值)显著相关(P<0.05)。但是在胴体深、系水力指标中差异不显著(P>0.05)。A、D 等位基因是群体中的优势等位基因, AA、DD 基因型是优势基因型, 而含有B、D 等位基因的个体的胴体和肉质性状优于其他个体, 尤其有着极强脂肪沉积能力     

Candidate gene analysis in primary lymphedema

BACKGROUND: Primary lymphedema, the accumulation of protein-rich fluid in the interstitial space, is the clinical manifestation of mutations involved in lymphatic development and function. Mutations in three genes, VEGFR3, FOXC2, and SOX18, cause primary lymphedema. However, mutations in these three genes only account for a fraction of primary lymphedema. To identify other genes mutated in primary lymphedema, we resequenced twenty-five biologically plausible candidate genes for lymphedema in a large collection of primary lymphedema families. METHODS AND RESULTS: Candidate genes were selected on the basis of gene expression in lymphatic endothelial cells, differential antigenic expression in lymphatics, and mouse studies of lymphatic development. The gene sequence was downloaded from GenBank and sequence primers designed to amplify 1 Kb of the 5' sequence, exons and flanking intron-exon boundaries, and 500 bp of the UTR of each gene. No common causative mutations were observed among the 25 genes screened. Single mutations were observed in elastin microfibril interfacer (EMILIN1), lymphocyte cytosolic protein 2 (LCP2), fatty acid binding protein 4 (FABP4), protein tyrosine kinase SYK (SYK), neuropilin-2 (NRP2), SpSRY-box 17 (SOX17), vascular cell adhesion molecule 1 (VCAM1), ROR orphan receptor C (RORC), and vascular endothelial growth factor B (VEGFB). Among these, the mutations in EMILIN1, RORC, LCP2, SYK, and VEGFB failed to segregate with lymphedema. The mutations in FABP4 (2), NRP2, SOX17, and VACM1 are consistent with being causative mutations, but occur in families too small to convincingly confirm cosegregation of mutation and phenotype. CONCLUSION: We excluded mutation in 21 biological candidate genes as a common cause of primary lymphedema. Mutations in FABP4, NRP2, SOX17 and VCAM1 are consistent with causality and follow up of these four genes are warranted. The evidence for FABP4 harboring lymphedema mutations is discussed.     

Protein synthesis in kidneys of merino sheep in postnatal ontogenesis

By evaluating parameters of activity of the nucleolar organizers (AgNORs), patterns of protein synthesis in cells of the right and left kidneys of merino sheep were examined in dependence of their age, sex, and the organ position. Depending on these parameters, the number of AgNORs in the kidney of merino sheep varies from 2 to 7. The total area of AgNORs in cells was within 0.50 +/- 0.03-2.22 +/- 0.05 mcm2. In different structure of nephrons, regions of nuclear organizers differ in both the quantity and total area. The obtained data testify that in kidney of 3 month old males and females of merino sheep the synthesis of 18S- and 28S-classes of ribosomal RNA and, accordingly, proteins occurs most actively.     

Effects of growth hormone administration on wool growth in merino sheep

The effects of daily administration of 10 mg of highly purified ovine growth hormone (GH) for a period of 4 weeks on wool growth have been measured in 12 Merino ewes fed either a calculated maintenance energy intake or 1.6 times this amount (six on each ration). Concentrations of hormones, glucose, urea, alpha-amino N and amino acids in the blood were monitored and faeces and urine collected for measurement of nitrogen balance. Wool growth rate decreased by 20% during the 4 weeks of GH treatment in sheep fed the high energy diet, largely because of reduced wool fibre diameter. This was followed by restoration of normal growth and then an increase of up to 20% above control levels, a response which persisted for 12 weeks following cessation of GH administration, and which was due to increases in both fibre length and diameter. GH administration caused marked increases in plasma concentrations of GH, insulin and somatomedin C, glucose and free fatty acids, all of which returned to basal levels following cessation of GH administration. No consistent changes in plasma concentration of T3, T4, cortisol, prolactin or alpha amino N were detected. Plasma urea and methionine levels decreased during GH treatment and returned to, or were raised above, basal levels after the GH treatment period. GH injection also resulted in a net retention of N during treatment, followed by a transient period of net N loss. The GH-induced changes in wool growth may be caused by a change in the partitioning of amino acids between the muscle mass and the skin. No other contributing factor(s) were identified.     

Candidate gene microsatellite variation is associated with parasitism in wild bighorn sheep

The loss of genetic variation in host populations is thought to increase host susceptibility to parasites. However, few data exist to test this hypothesis in natural populations. Bighorn sheep (Ovis canadensis) populations occasionally suffer disease-induced population declines, allowing us to test for the associations between reduced genetic variation and parasitism in this species. Here, we show that individual mean heterozygosity for 15 microsatellite loci is associated with lungworm abundance (Protostrongylus spp.) in a small, recently bottlenecked population of bighorn sheep (linear regression, r2=0.339, p=0.007). This association remains significant for seven microsatellites located in genes (p=0.010), but not for eight neutral microsatellites (p=0.306). Furthermore, heterozygotes at three of four microsatellites located within disease-related genes had lower lungworm burdens. This study corroborates theoretical findings that increased parasitism and disease may be a consequence of reduced heterozygosity in wild populations, and that certain individual loci influence parasite resistance. The results illustrate the usefulness of using genomic information, strong candidate genes and non-invasive sampling for monitoring both genetic variation and fitness-related traits, such as parasite resistance, in natural populations.     

Candidate gene markers for sperm quality and fertility of boar

Candidate genes gonadotropin releasing hormone receptor (GNRHR), prolactin (PRL), prolactin receptor (PRLR), follicle-stimulating hormone beta (FSHB), luteinizing hormone beta (LHB), follistatin (FST), inhibin alpha (INHA), inhibin beta A (INHBA) and inhibin beta B (INHBB) were investigated for their association with sperm quality traits of sperm concentration (SCON), motility (MOT), semen volume per ejaculate (VOL), plasma droplets rate (PDR), abnormal sperm rate (ASR) and fertility traits of non return rate (NRR) and number of piglets born alive (NBA). The experimental material included 356 boars of Pietrain (PI) and Pietrain x Hampshire (PI x HA). Analysis of variance revealed significant association of GNRHR with MOT (P = 0.0161), PDR (P = 0.0048) and ASR (P = 0.0201), INHBA was found to have significant effects on PDR (P = 0.0318) and ASR (P = 0.0067), INHBB was significant (P = 0.0360) for SCON trait. FSHB, FST, INHA, PRL, PRLR and LHB had no significant effects on any trait in this experiment.