Expression,structure and function analysis of the sperm-oocyte fusion genes Juno and Izumo1 in sheep(Ovis aries)

Background:JUNO and IZUMO1 are the first receptor-ligand protein pairs discovered to be essential for spermoocyte fusion;their interaction is indispensable for fertilization.Methods:PCR was used to clone the full-length DNA sequence of the Juno gene in sheep.The single nucleotide polymorphism(SNP)loci of Juno were genotyped by Sequenom MassARRAY®.PCR combined with rapid amplification of cDNA Ends were used to clone the full-length cDNA sequence of Juno and Izumo1.Reverse transcriptase-PCR(RT-PCR)and real time-quantitative-PCR(RT-qPCR)were used to analyze the genes’expression in tissues of sheep,and single cell RNA-seq was used to analyze the genes’expression in oocytes,granulosa cells and follicular theca of polytocous and monotocous Small Tail Han ewes.Bioinformatics was used to analyze advanced structure and phylogeny of JUNO and IZUMO1 proteins.Results:The full-length DNA sequence of the Juno gene in sheep was cloned and nine SNPs were screened.We found a significant association between the g.848253 C>A locus of Juno and litter size of Small Tail Han sheep(P<0.05).The full-length cDNA sequence of Juno and Izumo1 genes from Small Tail Han sheep were obtained.We found a new segment of the Izumo1 CDS consisting of 35 bp,and we confirmed the Izumo1 gene has 9 exons,not 8.RT-qPCR showed that Juno and Izumo1 genes were highly expressed in ovarian and testicular tissues,respectively(P<0.01).Single cell RNA-seq showed Juno was specifically expressed in oocytes,but not in granulosa cells or follicular theca,while Izumo1 displayed little to no expression in all three cell types.There was no difference in expression of the Juno gene in oocyte and ovarian tissue in sheep with different litter sizes,indicating expression of Juno is not related to litter size traits.Bioinformatic analysis revealed the g.848253 C>A locus of Juno results in a nonconservative missense point mutation leading to a change from Phe to Leu at position 219 in the amino acid sequence.Conclusions:For the first time,this study systematically analyzed the expression,structure and function of Juno and Izumo1 genes and their encoded proteins in Small Tail Han sheep,providing the basis for future studies of the regulatory mechanisms of Juno and Izumo1 genes.

The Analysis for the Single Nucleotide Polymorphism of TGF-β1 and Its Association with Reproduction in Different Sheep Breeds

A single nucleotide polymorphism （SNP） of 805 bp region in the intron 6 of transfor- ming growth factor β1 （TGF-fll） gene was identified by polymerase chain reaction-single-strand composi- tion polymorphism （PCR-SSCP） in 196 sheep among Small-tailed Han sheep, Tong sheep, Tan sheep and Oula sheep. Comparative sequence analysis of cloned products revealed an AGAC deletion at 294 bases up-stream of exon 7 of the TGF-βI gene （ site 14201 in gi76871756）. Statistical results of the genotype and allele frequencies in different breeds showed that gen- otype AB was dominant in the Small-tailed Han sheep. Genotype BB, however, was in majority in low- fecundity sheep. The results of a Chi-square test indi- cated that all the populations were in Hardy-Weinberg equilibrium.

Study on Changes of Plasma Endothelin-1 in Sheep with Experimental Colonic Obstruction

The present study was designed to determine the relationship between changes of plasma endothelin 1 concentrations and development of colonic obstruction in sleep.Colons were bound in three sheep with sterilized plastic tubes to make pathological model of colonic obstruction.Samples were collected before and after modeling operation on both controls and models.Endothelin 1 concentrations were measured by radioimmunoassay.Plasma ET llevels decreased continually after the modeling operation in the models,it dropped from a basal value of 60 93±18 66 to 34 11±8 22 and 33 54±11 12 pg/mL(P<0 05) on the 3rd and 5 th day,respectively,which were also lower than controls 64 16±12 93 pg/mL(P<0 05).It suggests that colonic obstruction may induce a decrease in plasma endothelin 1 concentrations in sleep.

Cloning and Sequence Analysis of IGFBP-1 Gene in Sheep

In this study, using Liangshan semi-fine wool sheep as an experimental material, full-length CDS sequence of IGFBP-1 gene was cloned with RT-PCR method and analyzed with bioinformatics methods. The results showed that the full-length CDS sequence of IGFBP-1 gene in Liangshan semi-fine wool sheep was 792 bp in length, encoding 263 amino acids. The CDS sequence shared 97%, 76% and 74% homology with bovine, human and rat, respectively; the amino acid sequence shared 97% , 69% and 71%, respectively. The GenBank accession number was FJ589639.1. The amino acid molecular weight of IGFBP-1 was 27.8 kD, and the theoretical isoelectric point （pl） was 5.99. The result of phylogenetic analysis showed that IGFBP-1 gene in Liangshan semi-fine wool sheep exhibited close phylogenetic relationships with bovine, goat and other mammals, and distant phylogenetic relationships with chicken and fish. IGFBP-1 gene had obvious hy- drophobic and hydrophilic regions, harboring one signal peptide, one transmembrane region, 16 phosphorylation sites, six N-glycesylation sites and eight O-glycosy- lation sites. The result of secondary structure analysis showed that the random coil, a-helix and 13-sheet regions accounted for 61.98%, 24.33% and 13.69%, re- spectively. The result of tertiary structure analysis showed that IGFBP-1 harbors an IGFBP_N domain and a thyrnglobulin type-1 domain. This study laid a solid foundation for further investigating the function of IGFBP-1 gene in sheep.

CDH1, a Novel Surface Marker of Spermatogonial Stem Cells in Sheep Testis

Spermatogonial stem cells（SSCs） are unique stem cells in adult body that can transmit genetic information to the next generation. They have self-renewal potential and can continuously support spermatogenesis throughout life of a male animal. However, the SSC population is extremely small, isolation and purification of the SSCs is challenging, especially for livestock animals. It has been confirmed that CDH1（cadherin-1, also known as E-cadherin） can be expressed in undifferentiated SSCs of mouse and rats, but it has not been verified in sheep. Here, CDH1 was found as a novel surface marker for sheep SSCs. In this paper, sheep antiCDH1 polyclonal antibodies were prepared and its activity was checked. Using the obtained antibodies and immunohistochemistry analysis, we confirmed that CDH1 can be expressed by SSCs in sheep testis.

Variation of DRB1 Gene in Tibetan Sheep

It reveals that the MHC （major histocompatibility complex） gene product always involved in the control of immune response and disease resistance. Nowadays many studies have indicated the OLA （ovine lymphocyte antigen） DRB1 gene is associated with some sheep diseases. Tibetan sheep is one of the three major shag sheep breeds in China, and also have the largest number of China＇s sheep breeds. But till now no report has been seen on studying DRB1 gene in Tibetan sheep of China. To understand the evolution and provide the basis for sheep disease resistance, polymorphism in the exon2 ofDRB1 gene in Tibetan sheep was analyzed. The PCR-SSCP, cloning and sequencing were used to analyse DRB1 gene variation in 600 Tibetan sheep of China. And the genetic relationship and evolutionary significance of the alleles had also been analyzed. Total of 31 alleles were identified, in which 15 alleles had not been reported before. And there were 70 SNPs （single nucleotide polymorphisms） sites in 31 sheep DRB1 gene haplotypes, the proportion was 29.5% to the whole exort2 sequence. All of this indicated that DRB1 exon2 is highly polymorphic in Tibetan sheep. The variation identified here might have an impact on both the function and level of expression of the OLA-DRB1.

PLIN1基因InDel位点检测及其与同羊尾脂和生长性状的关联分析

为了探讨同羊PLIN1基因结构及PLIN1基因的插入/缺失(inserted/deletion,InDel)位点对同羊尾脂和体尺性状的影响,试验对PLIN1基因结构进行了生物信息学分析,并测量了166只健康同羊的尾脂和体尺性状;通过测量同羊表型数据、提取基因组DNA,并采用PCR扩增、琼脂糖凝胶电泳和Sanger测序等方法检测PLIN1基因的InDel位点和分型情况,然后对PLIN1基因的InDel位点与同羊尾脂和体尺性状进行关联分析。结果表明:PLIN1基因位于绵羊的18号染色体上,有8个外显子和7个内含子。绵羊、山羊、普通牛、欧亚野猪、智人、小鼠的PLIN1蛋白结构高度保守,原鸡和绿头鸭的PLIN1蛋白结构与其他物种存在差异,以上8个物种的PLIN1蛋白有10个共同基序,2个特定的保守结构域,PLIN1基因在物种进化中相对保守。同羊的PLIN1基因存在1个26 bp(CGATCCTCGGTGCCCCAGAAACATTC)的InDel位点,包含DD、II和ID 3种基因型,I和D等位基因频率分别为0.2018和0.7982,II、ID和DD基因型频率分别为0.0663,0.2711,0.6627,该位点处于中间多态性(0.250.05);该位点对公羊的体尺性状无显著影响(P>0.05);但该位点的II基因型母羊背高显著高于ID和DD基因型(P<0.05)。说明PLIN1基因的InDel位点可被作为母羊育种的有用分子标记。

AP-1对羊毛KRTs的调控研究

滩羊是我国优良的地方绵羊品种,其裘皮形成的机理极为复杂,且是出生后35 d左右特有的性状。综述转录因子AP-1的组成、功能结构、作用机理和结合特点,以及角蛋白的分类及表达特点,并对AP-1对羊毛KRTs基因特异性启动子的结合位点进行预测,为转录因子对羊毛角蛋白基因的调控研究提供有效的参考。

黄淮肉羊IGF 1基因序列特征、组织表达及其与产肉性状的相关性分析

【目的】研究黄淮肉羊胰岛素样生长因子1(insulin like growth factor 1,IGF1)基因序列特征、组织表达规律,并对背最长肌中IGF 1基因的表达量与产肉性状进行相关性分析。【方法】选取3、9、18月龄的黄淮肉羊公羊各3只,屠宰后迅速采集半腱肌、股四头肌、臂三头肌、背最长肌、皮下脂肪、瘤胃、肾脏、脾脏、肝脏、睾丸和小肠组织样品并测定其产肉性能。对黄淮肉羊IGF 1基因进行克隆测序,并进行生物信息学分析,利用实时荧光定量PCR技术检测其在黄淮肉羊同一年龄(9月龄)各组织以及不同年龄阶段(3、9、18月龄)背最长肌中的mRNA水平,利用皮尔逊相关系数分析IGF 1基因的表达量与产肉性状的相关性。【结果】克隆获得黄淮肉羊IGF 1基因CDS序列465 bp,编码154个氨基酸,与山羊的亲缘关系最近。黄淮肉羊IGF1蛋白为亲水性不稳定蛋白,无跨膜结构,存在信号肽,有29个潜在的磷酸化位点。黄淮肉羊IGF1蛋白二级结构主要含有无规则卷曲(54.55%)和α-螺旋(29.87%),三级结构预测结果与二级结构一致。IGF1蛋白与IGF1R、IGFBP3、IGF2等存在蛋白互作关系。实时荧光定量PCR结果显示,IGF 1基因在黄淮肉羊各组织中均有表达,在肝脏组织中表达量最高,在臂三头肌中表达量最低。IGF 1基因在3月龄黄淮肉羊背最长肌中表达量最高,显著高于9和18月龄(P<0.05),而9月龄的表达量又显著低于18月龄(P<0.05)。相关性分析结果表明,IGF 1基因表达量与生长发育和肉品质指标无显著相关(P>0.05);体高、体长、胸围、管围、体重和胴体重之间呈显著或极显著正相关(P<0.05;P<0.01);屠宰率、肉色、大理石纹、眼肌面积之间呈显著或极显著正相关(P<0.05;P<0.01)。【结论】本研究成功克隆了黄淮肉羊IGF 1基因CDS区序列,IGF1蛋白属于亲水不稳定碱性蛋白,主要在肝脏中表达,在背最长肌中的表达趋势表现为随着月龄增长先降后升,与生长发育和肉品质指标无显著相关性。这些结果为进一步探究黄淮肉羊IGF 1基因在肌肉发育与肉品质调控中的作用提供参考。

澳湖杂交F_(1)代生长性能试验研究

为了研究澳洲白与湖羊的杂交效果,2023年5月以湖羊为母本、澳洲白为父本进行杂交试验研究,选择澳湖杂交F1以及湖羊纯繁一代的羔羊初生、2月龄、4月龄、6月龄进行体重、体长、体高测量。结果表明:(1)澳湖F1平均体重比湖羊纯繁一代分别提高13.06%、25.44%、24.83%和21.31%;(2)平均体长分别提高7.75%、7.61%、10.55%和11.86%;(3)平均体长分别提高5.9%、6.13%、8.05%和13.19%。研究认为,澳湖杂交代生长性能优于湖羊,优先选为嘉峪关市肉羊产业发展的杂交繁育组合。

绵羊防御素(sBD1)mRNA在不同发育阶段的组织分布和定量分析

为确定绵羊防御素(Sheep beta defensin-1,sBD1)mRNA在组织器官中的分布和不同发育阶段的表达是否存在差异。利用RT-PCR(Reverse Transcription PCR)方法检测绵羊防御素sBD1 mRNA在组织器官的分布情况,通过荧光定量RT-PCR(Fluorescence quantitative RT-PCR)检测不同发育阶段绵羊防御素的表达差异。结果表明:在胎羊的舌、皱胃、十二指肠、空肠、盲肠检测到绵羊防御素sBD1 mRNA,在羔羊和成年羊消化道的舌、食道、瘤胃、皱胃、十二指肠、空肠、回肠、盲肠、直肠和呼吸道的气管、肺均检测到绵羊防御素sBD1 mRNA,在各发育阶段的心、肝、肾以及羔羊、成年羊的淋巴结和体外培养的羔羊肺泡巨噬细胞均未检测到sBD1 mRNA;实时定量PCR比较表明,sBD1 mRNA在不同发育阶段皱胃、十二指肠和空肠表达量的高低为sBD1 mRNA表达量(羔羊)>sBD1 mRNA表达量(成年羊)>sBD1 mRNA表达量(胎羊)。绵羊防御素sBD1 mRNA主要分布在消化道和呼吸道,且在整个发育过程中是持续表达的,其在消化道表达量高低为sBD1 mRNA表达量(羔羊)>sBD1 mRNA表达量(成年羊)>sBD1 mRNA表达量(胎羊)。

日粮不同蛋白质水平对绵羊IGF-1和GH分泌及基因表达的影响

本研究旨在探讨不同蛋白质水平日粮对绵羊胰岛素样生长因子-1(IGF-1)和生长激素(GH)分泌及基因mRNA表达量的影响,为科学配置肉羊饲料及研究肉羊生长发育提供基础。选择6月龄体重相近的多胎萨福克公羔18只,随机分为3组,分别饲喂不同蛋白质水平的日粮(低蛋白日粮、中蛋白日粮和高蛋白日粮)。采用ELISA方法和SYBR Green Real-time PCR方法检测日粮不同蛋白质水平对不同生长发育阶段(30、60、90和120d)羔羊外周血中IGF-1、GH浓度和皮肤组织中基因表达的影响。结果显示,日粮蛋白质水平显著影响绵羊平均日增重、外周血中IGF-1和GH的浓度以及皮肤组织IGF-1基因的表达丰度,而未显著影响GH基因的表达丰度。结果提示,随着日粮蛋白质水平的升高,绵羊生长发育快,外周血中IGF-1浓度增加,GH浓度降低,IGF-1基因表达量增加。

雌二醇对蒙古绵羊输卵管上皮细胞内β-防御素(sBD-1)表达的影响

为了探索雌二醇与β-防御素（sBD-1）表达量的关系,体外模拟蒙古绵羊（Ovis aries）生理周期,用添加雌二醇浓度10-11、10-10、10-9、10-8、10-7、10-6mol/L的培养液及不添加雌二醇的培养液（即对照组）分别培养蒙古绵羊输卵管上皮细胞,作用24 h、48 h、72 h后,提取细胞总RNA,应用SYBR GreenⅠ荧光定量RT-PCR法进行定量分析。结果显示,添加不同浓度雌二醇培养的输卵管上皮细胞中sBD-1的相对表达量0.000 740~0.001 758,与对照组0.000 190之间差异显著（P〈0.05）,且小于10-8mol/L雌二醇添加浓度与sBD-1基因相对表达量变化基本呈正相关。此结果为进一步研究雌激素参与机体防御功能奠定了基础。

多浪羊MHC-DRB1基因多态性与包虫病抗性分析

通过PCR扩增122只包虫病(细粒棘球蚴病)阴性和70只包虫病阳性多浪羊的MHC-DRB1第2外显子,产物经SacⅠ、Hin1Ⅰ和HaeⅢ3种限制性内切酶酶切后进行RFLP多态性分析。结果表明,多浪羊MHC-DRB1基因第2外显子在SacⅠ、Hin1Ⅰ和HaeⅢ酶切位点存在丰富的多态性,分别检测出了2、2和6种等位基因,出现了3、3和18种基因型。将包虫病阴性和阳性多浪羊的等位基因频率和基因型频率分别进行比较分析,发现等位基因HaeⅢa对包虫病感染具有一定的易感性(P<0.05),SacⅠab和Hin1Ⅰaa 2个基因型对包虫病具有一定的抗性(P<0.05),HaeⅢbe和HaeⅢef这2个基因型对包虫病具有较强的易感性(P<0.01)。

酿酒酵母甘露聚糖对绵羊瘤胃上皮细胞β-防御素-1(S BD-1)表达的影响

为探究酿酒酵母菌细胞壁成分甘露聚糖对绵羊瘤胃上皮细胞(RECs)β-防御素-1(SBD-1)表达的影响,本研究用不同浓度的甘露聚糖刺激RECs 8 h后,利用荧光定量PCR (qPCR)和ELISA方法分别检测RECsSBD-1 mRNA的转录水平和蛋白表达变化,确定甘露聚糖诱导SBD-1表达量最高的刺激浓度。然后用该浓度甘露聚糖对RECs进行不同时间的刺激,同样利用qPCR和ELISA方法对SBD-1 mRNA转录水平和蛋白的表达变化进行检测,确定甘露聚糖诱导SBD-1表达的最佳时间。qPCR和ELISA结果显示:不同浓度甘露聚糖刺激RECs8 h后,SBD-1 mRNA转录水平和蛋白的表达量均有所增加,但随着甘露聚糖浓度的增加,SBD-1表达量呈现先升高后降低的趋势,且当甘露聚糖浓度为50μg/mL时SBD-1表达量达到最大,并与对照组相比差异极显著(p<0.01)。当用50μg/mL的甘露聚糖分别刺激RECs不同时间后,SBD-1 mRNA转录水平和蛋白的表达量先是随着刺激时间的延长而呈上升趋势,刺激时间为4 h时SBD-1表达量达到峰值,且极显著高于对照组(p<0.01),之后呈下降趋势。结果表明甘露聚糖能够提高绵羊RECs SBD-1的表达,且甘露聚糖浓度为50μg/mL刺激RECs 4h时,SBD-1 mRNA转录水平和蛋白表达量达到最高。本研究为甘露聚糖在体内如何发挥先天性免疫提供了一种新解释,也为更好的开发利用甘露聚糖制剂提供实践指导。

绵羊UCP1基因碱基突变与其蛋白结构和功能

【目的】检测两个绵羊群体中解偶联蛋白1(uncoupling protein 1,UCP1)基因的单核苷酸多态性(single nucleotide polymorphism,SNP),预测和分析碱基改变对蛋白结构和功能的影响。【方法】利用PCR-SSCP结合测序的方法检测UCP1基因编码区的SNPs,用生物信息学方法分析UCP1蛋白的理化性质和结构。【结果】UCP1基因编码区存在4个SNPs,其中c.214G>A(Val72Met)和c.273C>T位于外显子2,c.624C>T和c.757G>A(Ala253Thr)位于外显子5。进一步分析导致氨基酸改变的c.214G>A和c.757 G>A突变发现,此两个突变只对UCP1蛋白的理化性质和转录因子结合位点有细微改变,未引起UCP1蛋白空间构象的变化,对蛋白表达的影响不大。【结论】基于对人类中两个与肥胖相关的外显子突变型蛋白结构的比较说明,UCP1蛋白结构的改变可能影响其功能。

酿酒酵母菌对绵羊瘤胃上皮细胞β-防御素-1(SBD-1)基因表达的影响

【目的】探索益生性酿酒酵母菌对绵羊瘤胃上皮细胞β-防御素-1(sheep beta-defensin-1,SBD-1)表达的调节作用,为在分子水平上揭示益生菌对防御素的调控机理提供一定的理论基础及依据。【方法】首先将新鲜的绵羊瘤胃组织用PBS和抗生素处理后进行瘤胃上皮细胞原代培养,当原代细胞数量长到细胞培养瓶的85%以上时,将细胞传于12孔板用于细胞刺激试验。同时将活化并纯化后的酿酒酵母菌25℃、180 r/min有氧培养48 h后,进行5次平行平板计数试验,根据平板计数的数据处理方法,得到浓度为5.2×108CFU·m L-1的酿酒酵母菌液,再通过倍比稀释把所得菌液依次稀释成浓度为5.2×107、5.2×106、5.2×105、5.2×104CFU·m L-1的菌液,用以上不同浓度(5.2×104—5.2×108CFU·m L-1)的酿酒酵母菌对体外培养的绵羊瘤胃上皮细胞分别进行不同时间(2、4、8、12、24 h)的刺激,并设置对照组用DMEM/F12培养基代替酿酒酵母菌。然后提取总RNA,逆转录为c DNA后,利用实时荧光定量PCR技术和酶联免疫吸附测定(ELISA)法检测瘤胃上皮细胞中SBD-1表达差异。最后用SAS 9.2软件对数据进行相关差异性分析。【结果】荧光定量PCR结果表明,在各时间组内SBD-1 m RNA的表达量随着菌液浓度的增加均呈先升高后降低的趋势,当菌液浓度为5.2×107CFU·m L-1时表达量达到最大,并与对照组和其他浓度组相比差异极显著(P<0.01)。当菌液浓度一定时,SBD-1 m RNA的表达量先是随着刺激时间的延长而呈上升趋势,刺激时间为12 h时SBD-1 m RNA表达量达到峰值,之后呈下降趋势。因此,当浓度为5.2×107CFU·m L-1的菌液刺激瘤胃上皮细胞12 h后,SBD-1基因的表达量达到最高,且与此浓度下其他时间组的表达量相比差异极显著(P<0.01)。ELISA检测结果显示,SBD-1蛋白表达趋势与SBD-1 m RNA检测结果基本一致。不同浓度的菌液分别刺激绵羊瘤胃上皮细胞2、4、8、12、24 h后均能提高共培养上清中SBD-1蛋白的表达,且与对照组相比存在极显著差异(P<0.01)。在菌液浓度为5.2×107CFU·m L-1刺激瘤胃上皮细胞12 h后SBD-1蛋白分泌水平达到最高,与此浓度下各时间组相比差异极显著(P<0.01)。【结论】酿酒酵母菌能够提高绵羊瘤胃上皮细胞SBD-1的表达,且菌液浓度为5.2×107CFU·m L-1刺激瘤胃上皮细胞12 h后,SBD-1的表达量达到最高。

湖羊Lrh-1基因cDNA序列及组织表达谱分析

本研究以湖羊肝脏为材料对肝受体类似物-1(Liver receptor homolog-1,Lrh-1;NR5A2)基因序列进行RT-PCR和RACE测定,并用DNAman、Tmpred、Signal P 3.0、Expasy等生物信息学分析软件和在线工具,对Lrh-1cDNA序列及其蛋白的理化特性、跨膜结构、信号肽和二级结构进行生物信息学分析,同时采用实时荧光定量PCR方法检测湖羊Lrh-1基因的组织表达谱。结果表明,湖羊Lrh-1基因cDNA序列全长1 488bp,与牛的核酸序列相似度最高,为98%,编码区共编码495个氨基酸,氨基酸序列与牛、人、马、猴、犬、小鼠、褐鼠的氨基酸同源性分别为98%、97%、96%、97%、97%、86%和86%;Lrh-1mRNA在湖羊脑、消化及生殖系统组织中均有表达且具有组织特异性,其中在下丘脑组织中的表达量相对最高。

半胱胺对羊毛生长及皮肤中GH受体、IGF-1和IGF-1型受体基因表达的影响

罗米丽×中国美利奴 (新疆军垦型) 杂交一代断奶母羔 214只, 随机分成两组, 在日粮中分别添加 3 5 (试验组) 和 0g·kg-1 (对照组) 生长调节剂CT2000 (半胱胺盐酸盐), 实验期为 120d。于试验前和试验结束时称重, 采毛和皮肤样品, 测定母羔生长速度, 羊毛长度、细度、强度、弯曲度和羊毛油汗颜色, 并用反转录多聚酶链式反应 (RT PCR) 方法, 定量分析绵羊皮肤中生长激素受体 (GHR)、胰岛素样生长因子 1 (IGF 1) 和胰岛素样生长因子 1型受体(IGF 1R)mRNA的相对丰度。实验结果显示, 与对照组相比较, 试验组平均日增重提高 12 77% (P<0 01), 羊毛平均日增长提高 24 01% (P<0 01), 羊毛纤维直径平均日增长提高 217 31% (P<0 01), 羊毛纤维强度没有显著的差异(P>0 05), 羊毛油汗颜色和羊毛弯曲度的正常百分率显著提高 (P<0 05); 皮肤中GHRmRNA表达量增加 110 57%(P<0 01), IGF 1、IGF 1RmRNA表达量无明显变化。结果表明, 半胱胺 (CT2000 ) 能够显著提高羔羊生长性能, 促进羊毛生长, 其机制可能与提高皮肤中GHR水平有关。

绵羊皮肤中GHR、IGF-1和IGF-1R基因表达的发育性变化及品种特点

采用相对定量反转录多聚酶链式反应（RT-PCR）方法，以18S rRNA作内标，研究了罗米丽（Romilly Hillys）×中国美利奴（新疆军垦型）杂交一代优质细毛羊和哈萨克粗毛羊皮肤中生长激素受体（GHR）、胰岛素样生长因子1（IGF-1）和胰岛素样生长因子1受体（IGF-1R）mRNA发育性变化并进行了品种间比较。分别于30、60、90、135、180和255日龄称重、采毛样，并于30、90、135和255日龄采皮样。结果表明：粗毛羊和细毛羊体重、羊毛生长的发育模式没有明显的差异，30-135日龄体重迅速增加，135～255日龄增重十分缓慢；30-135日龄羊毛日增长逐渐增加，135-180日龄羊毛生长十分缓慢，而180-255日龄又上升到较高水平。粗毛羊皮肤中GHRmRNA在30～90曰龄显著增加（P〈0．05），90日龄达到高峰，此后显著下降（P〈0．05）；细毛羊在135日龄时GHR mRNA极显著地升高（P〈0．01），此后又极显著地下降。粗毛羊皮肤中IGF-1、IGF-1R mRNA30—90日龄上升，90日龄之后极显著下降（P〈0．01）：细毛羊皮肤中IGF—1、IGF-1R mRNA出生时较高，然后逐渐下降。品种之间比较，细毛羊GHR mRNA出现高峰晚于粗毛羊，135日龄高峰时显著地高于粗毛羊；粗毛羊IGF—1、IGF-1RmRNA在90日龄出现高峰，并极显著或显著地高于细毛羊；粗毛羊90日龄前GHR、IGF-1和IGF-1RmRNA高于细毛羊，之后低于细毛羊。结果提示：绵羊皮肤中GHR，IGF-1和IGF-1R基因表达有特定的发育模式，并存在品种差异。