MSTN基因编辑湖羊胫腓肌的转录组分析

[目的]本文旨在探索肌肉抑制素基因(myostatin,MSTN)调控肌肉生长发育的分子机制。[方法]以3月龄MSTN基因编辑湖羊(试验组)和野生型湖羊(对照组)胫腓肌为对象,采用PCR和Western blot方法验证MSTN编辑湖羊编辑形式,在此基础上开展转录组测序和分析,并用real-time PCR方法对差异表达基因进行结果验证。[结果]对照组和试验组共有149个差异表达基因,其中65个基因上调,84个基因下调,GO注释和KEGG富集分析表明,差异表达基因显著富集在氧化磷酸化、果糖和甘露糖代谢、生热作用、FOXO和AMPK信号通路,表明MSTN基因可能通过以上信号通路参与湖羊生长发育调控。[结论]MSTN基因编辑湖羊可能通过FOXO和AMPK、氧化磷酸化、果糖和甘露糖代谢、生热作用等与动物代谢相关的信号通路调控其生长发育。

MSTN^(-/-)牛肌肉miRNA测序及生物信息学分析

为了探寻参与调控动物骨骼肌生长发育的肌肉生长抑制素(myostatin,MSTN)基因的相关miRNA,试验活体采集了5头MSTN基因敲除(MSTN^(-/-))鲁西黄牛(试验组)和5头野生型鲁西黄牛(对照组)的腿臀肌肉,提取肌肉总RNA进行miRNA测序,筛选两组鲁西黄牛肌肉样品间差异表达的miRNA,分析miRNA序列的碱基偏好性,并预测显著差异表达miRNA的靶基因,然后对靶基因进行GO功能和KEGG信号通路富集分析,最后利用实时荧光定量PCR在MSTN基因干扰牛骨骼肌卫星细胞模型上验证miRNA测序数据的准确性。结果表明:miRNA序列第一位碱基的偏好性因长度不同而不同,且不同位置碱基具有偏好性;试验组和对照组样品共鉴定到761个差异表达miRNA,其中有12个显著差异表达miRNA(miR-2285l、miR-496、miR-12006、miR-6533、miR-450b、miR-6524、miR-410、miR-335、miR-2447、miR-147、miR-33a、miR-654),其中试验组有9个较对照组高表达的miRNA(miR-2285l、miR-12006、miR-6533、miR-450b、miR-410、miR-335、miR-147、miR-33a、miR-654)和3个低表达miRNA(miR-496、miR-6524、miR-2447);预测到5969个显著差异表达miRNA的靶基因和9280个靶位点;靶基因主要富集在细胞内部、膜结合细胞器、蛋白结合、生物过程的正向调节等相关功能和卡波氏肉瘤病毒感染、胞吞作用、MAPK信号通路等代谢通路;验证试验中的6个miRNA(miR-6533、miR-450b、miR-2285l、miR-654、miR-12006、miR-496)的表达量变化均与测序结果的变化趋势一致。说明12个显著差异表达miRNA可能参与了MSTN基因调控牛骨骼肌生长发育过程。

牙鲆mstn基因SNPs位点多态性与生长性状的关联分析

为研究牙鲆(Paralichthys olivaceus)肌肉生长抑制基因(mstn)多态性,开发其分子辅助育种新标记,采用重测序方法对120尾牙鲆(3个双克隆杂交家系:60尾;3个雌核发育家系:60尾)的mstn基因进行单核苷酸多态性(Single nucleotide polymorphism,SNP)位点筛选,并对不同基因型个体的生长性状进行多重比较及SNP标记验证。结果显示,共检测到7个SNPs位点,均为颠换型突变;外显子区3个(Exonl 1:G2063A;Exonl 3:C3883T,C4009A),为同义突变;内含子区3个(Intron 1:A2444T;Intron 2:T3816C,A3832C);3'端非编码区1个(3'UTR:C4564A)。SNPs与生长性状关联分析结果表明,A3832C和C4564A标记位点与牙鲆体质量、体长、体高等生长性状显著相关(P<0.05),其中A3832C位点AA基因型和C4564A位点AC基因型在生长上表现出优势,A3832C位点CC和C4564A位点AA、CC基因型在生长上表现出劣势,其他5个SNPs位点对牙鲆生长性状影响不显著(P>0.05)。将A3832C和C4564A标记位点在牙鲆生长快速群体(F:60尾)和生长缓慢群体(S:60尾)中验证,验证结果与多重比对结果一致,表明2个SNPs位点具有较高的稳定性。综上所述,研究筛选出了牙鲆mstn基因中与生长性状显著相关的A3832C和C4564A两个标记位点,为牙鲆分子辅助育种提供了理论参考。

Sequence and Bioinformatics Analysis on MSTN Gene of the Hybrid Grouper Derived from(Epinephelus fuscoguttatus×Epinephelus polyphekadion)

[Objectives]This study aimed to investigate the sequence structure and function of Myostatin(MSTN)gene in the hybrid grouper(Epinephelus fuscoguttatus,♀×Epinephelus polyphekadion,♂).[Methods]Genetic DNA samples were extracted from the caudal fins of the hybrid grouper and its parents to amplify their MSTN genes.Then,MSTN gene sequences were analyzed using bioinformatics tools to predict their protein structures and functions.[Results]The hybrid grouper and its parents shared the same MSTN gene structure,consisting of three exons and two introns.Nucleotide sequence of the gene could be translated into 376 amino acids,including an N-terminal signal peptide,a proteolytic processing site(RXXR motif),and nine conserved cysteine residues at C-terminal,which were the typical features of transforming growth factor beta(TGF-β)superfamily proteins.Alignment of protein sequence showed that MSTN was highly conserved between the hybrid grouper and its parents.Especially,exon 3,an important functional domain,exhibited a sequence similarity of 100%among them.In addition,four variable amino acid residues were detected in exon 2 at positions 141,153,185 and 186 in the hybrid grouper,but they did not affect the secondary structure of the protein.[Conclusion]These results will provide molecular information for future investigation on the growth and heterosis of hybrid grouper species,and on the roles of MSTN gene in regulating the growth traits of the hybrid grouper.

花斑裸鲤MSTN-1基因克隆及表达特性分析

花斑裸鲤是黄河上游重要的冷水性土著鱼类,其生长、发育缓慢,性成熟又较晚,故多年来其种群一直呈下降趋势。MSTN(肌肉生长抑制素)是一种对肌肉生长具有负调控作用的因子,通过克隆花斑裸鲤MSTN-1基因并检测其表达特性,为花斑裸鲤生长缓慢的分子调控机理提供基础资料。采用PCR、5′-RACE和3′-RACE法获得花斑裸鲤MSTN-1基因全长cDNA序列,采用qPCR检测MSTN-1基因在花斑裸鲤不同组织的表达特征和在不同鲤科鱼类肌肉组织中的差异性表达。花斑裸鲤MSTN-1基因的cDNA序列全长为2190 bp,其中ORF长1128 bp,5′UTR长96 bp,3′UTR长966 bp,共编码375个氨基酸。该蛋白是带有一个信号肽、无跨膜结构的不稳定亲水性分泌蛋白,主要分布在细胞核、线粒体和细胞质中。MSTN-1蛋白质二级结构以无规卷曲为主,存在2个TGF-β结构域:即TGF-β前肽区域(37—268 aa)和TGF-β功能区域(281—375 aa),有1个蛋白酶水解位点RIRR和9个位于TGF-β功能区域保守的半胱氨酸残基。氨基酸序列同源性分析表明,花斑裸鲤MSTN-1氨基酸序列与其他鲤科鱼类MSTN-1具有较高的相似性,而与禽类和哺乳动物的相似性较低。系统发育分析显示,花斑裸鲤MSTN-1与其他鲤科鱼类聚于同一进化支。qPCR检测结果表明,MSTN-1在花斑裸鲤的脑、肌肉、鳃、心、肝脏和肾脏组织中均有表达,但在脑和肌肉组织中表达量较高。该基因在不同鲤科鱼类肌肉组织中均有表达,在青海湖裸鲤肌肉组织中的表达量最高,其次在花斑裸鲤和黄河鲤鱼肌肉组织中。通过克隆获得花斑裸鲤MSTN-1基因cDNA序列,进行生物信息学分析和qPCR检测,MSTN-1在这几种土著鱼类肌肉组织中的特征性表达差异有助于进一步了解高原鱼类生长缓慢的分子机理。

SNP Genotyping of Myostatin (MSTN) Gene through Taq Man Probe Assay and Association Study between MSTN Genotypes and Growth Traits of Tan Sheep

To establish a rapid, accurate and economical real-time PCR assay system based on TaqMan probe technology for the detection of genetic variations of single nucleotide polymorphisms （SNPs） in myestatin （MSTN） gene, a pair of TaqMan probes were designed on the polymorphism loci of MSTN gene and used in PCR reaction system for SNP genotyping. Meanwhile, an association study was performed between MSTN genotypes and growth traits of Tan sheep, including birth weight, weaning weight, 3-month weight, and 6-month weight. The results showed that rs417816017 locus of MSTN gene in Tan sheep had two genotypes ： YY and XY. The individuals with genotype XY had a growth advantage over the ones with genotype YY. The results indicate that TaqMan probe-based real-time PCR assay can be used to detect the genotype of MSTN gene, which will provide candidate genes for breeding of Tan sheep.

Sequencing Analysis of Myostatin Gene （MSTN） for Meat Cattle in Mongolia

In developed countries, study on special or candidate genes, which are useful for identifying species, breed and productivity of livestock, was conducted at high level and the results have already been used in practice. Such advanced technology and innovation that we are facing is necessary to adopt in Mongolia. In this study, the myostatin gene （MSTN） was investigated as a candidate gene for meat animal in Mongolian breeds of cattle. The conventional phenol-chloroform method and FavorPrepTM tissue DNA extraction kit were used for DNA isolation, and the polymerase chain reaction （PCR） and sequencing analysis were used for further study. The nucleotide sequences of MSTN gene from Selenge, Kazakh white head breeds and Mongolian cattle were sequenced and reported on the DDBJ/EMBL/GenBank database （LC142726, LC146648, LC146649）, and Selenge breed showed the result of single nucleotide mutation in MSTN gene.

Quantitative Study on Expression of MSTN Gene in Different Tissues of Tibetan Sheep at Different Ages

[Objective] The aim was to investigate the difference in MSTN gene expression in different tissues of Tibetan sheep at different ages.[Method] According to the sequence（NM_001009428.1）published in GenBank,a pair of specific primers was designed to amplify part of cDNA sequence of MSTN by using QRT-PCR technique.The relative expression level of MSTN gene in rennet stomach,rumen,leg muscle and cardiac muscle of Tibetan sheep at different ages were analyzed.[Result] After normalization with β-actin gene,the relative expression level of MSTN gene in the 6-month-old Tibetan sheep was the highest and it was 2.52 times than that in 12-month-old Tibetan sheep（P0.05）,the relative expression level of MSTN gene in leg muscle was the highest among all tissues and it was 3 984.78 times than that in rumen（P0.01）.[Conclusion] The results established theoretical foundation for the correct use of MSTN antibody.

Split-GFP双分子荧光互补技术在鸡MSTN基因RNAi检测中的应用

【目的】以Split-GFP双荧光互补技术检测鸡肌肉生长抑制素基因(MSTN)RNA干涉(RNAi)效果,并与其他常用检测方法比较,以验证Split-GFP双分子荧光互补技术在RNAi效果评估中的有效性和可行性。【方法】将合成的3个shRNA慢病毒载体(shRNA-a、shRNA-b和shRNA-c)分别转染稳定表达GFP11-MSTN融合蛋白的HEK 293TGFP11-MSTN细胞,经实时荧光定量PCR筛选出最佳shRNA慢病毒载体并包装为慢病毒,然后以慢病毒感染HEK 293TGFP11-MSTN细胞,采用潮霉素B筛选mCherry阳性(mCherry+)细胞,再以实时荧光定量PCR和Western blotting检测RNAi效果;得到的mCherry+细胞再转染pcDNA3.1(+)-GFP1-10质粒,通过荧光显微镜观察和流式细胞术评估RNAi效果。【结果】3个shRNA慢病毒载体对MSTN基因表达均有极显著的抑制作用(P<0.01,下同),其中又以Anti-MSTN shRNA-a慢病毒载体的干涉效果最佳。Anti-MSTN shRNA-a慢病毒感染HEK 293TGFP11-MSTN细胞的最适MOI=3,该条件下MSTN基因相对表达量及GFP11-MSTN融合蛋白表达量均受到抑制;得到的mCherry+细胞再转染pcDNA3.1(+)-GFP1-10质粒,荧光显微镜观察和流式细胞术检测结果表明,GFP+细胞数量明显减少,GFP+细胞百分率由31.1%降至11.5%。Split-GFP检测结果与实时荧光定量PCR及Western blotting检测结果相符,说明Anti-MSTN shRNA-a慢病毒能有效抑制GFP11-MSTN融合蛋白表达,发挥了RNAi作用。【结论】以Anti-MSTN shRNA-a慢病毒对MSTN基因的干涉效果最佳,其感染HEK 293TGFP11-MSTN细胞后MSTN基因表达极显著下调,且再转染pcDNA3.1(+)-GFP1-10质粒后细胞中的GFP+细胞百分率明显下降,与实时荧光定量PCR和Western blotting检测结果相符,证实Slipt-GFP双分子荧光互补技术是一种可靠的可视化RNAi检测方法。

The genetic diversity analysis in the donkey myostatin gene

Myostatin（MSTN）gene negatively controls skeletal muscle development and growth,variations of which play an important role in the regulation of skeletal muscle growth in mammals.However,study on genetic polymorphism of MSTN gene in donkey is limited.In this study,we screened the single nucleotide polymorphsims（SNPs）of MSTN gene in 13 Chinese donkey breeds.Four novel SNPs（g.229T〉C,g.872A〉G,g.2014G〉A,and g.2395C〉G）were detected and genotyped by sequencing and polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP）methods.Six haplotypes（H1–H6）were analyzed,which indicated abundant haplotype diversities in Chinese donkeys.The haplotype H1 was the most dominant and ancient in all breeds.Xinjiang donkey displayed the highest haplotype diversity.The Neighbour-Joining（NJ）tree of MSTN gene among different species was constructed.The clustering result of nine species was consistent with the fact of species differentiation.Our results will provide a reliable theoretical basis for the preservation,exploration and utilization of Chinese donkey genetic resources.

Dietary Methionine Affect Meat Qulity and Myostatin Gene Exon 1 Region Methylation in Skeletal Muscle Tissues of Broilers

Dietary amino acids imbalance will result in stunted broiler performance and deteriorated meat quality, which are involved in various biochemical cycles in vivo. In this study, the effects of dietary methionine on meat quality and methylation of myostatin exon 1 were investigated. Drip loss of the broilers fed with diet of high methionine levels （0.2%） increased from （6.3 ± 0.1）% （control group） to （10.1 ± 1.0）%, and the muscle shearing force increased from （22.8 ± 1.9） N （control group） to （26.3 ±2.3） N. Moreover, many CpG sites were found at the myostatin exon 1 region （nucleotides 2 360-2 540 bp）. To further understand the regulation of broiler myostatin expression, the methylation status of broiler myostatin exon 1 and its mRNA expression were analyzed. At the myostatin exon 1 region where CG enriches （nucleotides 2 360-2 540 bp）, the percentages of methylation were 46 and 84% in low Met and high Met content groups after 55-d feeding, respectively. In skeletal muscle tissues, the exon 1 hypermethylation status of myostatin gene was found to be negatively correlated with the gene expression. These results suggested that methylation of this gene is a dynamic process, which plays a dominant role in regulating gene expression for development of individuals.

Cloning and Characterization of Largemouth Bass(Micropterus salmoides) Myostatin Encoding Gene and Its Promoter

Myostatin or GDF-8, a member of the transforming growth factor-β （TGF-β） superfamily, has been demonstrated to be a negative regulator of skeletal muscle mass in mammals. In the present study, we obtained a 5.64 kb sequence of myostatin encoding gene and its promoter from largemouth bass （Micropterus salmoides）. The myostatin encoding gene consisted of three exons （488bp, 371 bp and 1779bp, respectively） and two introns （390bp and 855 bp, respectively）. The intron-exon boundaries were conservative in comparison with those of mammalian myostatin encoding genes, whereas the size of introns was smaller than that of mammals. Sequence analysis of 1.569 kb of the largemouth bass myostatin gene promoter region revealed that it contained two TATA boxes, one CAAT box and nine putative E-boxes. Putative muscle growth response elements for myocyte enhancer factor 2 （MEF2）, serum response factor （SRF）, activator protein 1 （AP1）, etc., and muscle-specific Mt binding site （MTBF） were also detected. Some of the transcription factor binding sites were conserved among five teleost species. This infunnation will be useful for studying the tran- scriptional regulation of myostatin in fish.

Myostatin gene promoter:structure,conservation and importance as a target for muscle modulation

Myostatin(MSTN) is one of the key factors regulating myogenesis. Because of its role as a negative regulator of muscle mass deposition, much interest has been given to its protein and, in recent years, several studies have analysed MSTN gene regulation. This review discusses the MSTN gene promoter, focusing on its structure in several animal species, both vertebrate and invertebrate. We report the important binding sites considering their degree of phylogenetic conservation and roles they play in the promoter activity. Finally, we discuss recent studies focusing on MSTN gene regulation via promoter manipulation and the potential applications they have both in medicine and agriculture.

绵羊MSTN基因多态性及其与肉质性状的关联分析

【目的】探讨绵羊肌肉生长抑制素(myostatin,MSTN)基因多态性及其对绵羊肉质性状的影响,以期为绵羊肉用性能的选育提供有效的遗传分子标记。【方法】利用液相捕获测序技术获取MSTN基因在杜泊羊(D)、滩羊(T)和小尾寒羊(XH)共91只绵羊中的变异位点,并筛选出品种间差异显著的单核苷酸多态性(single nucleotide polymorphism,SNP)位点。针对筛选出的位点,利用飞行质谱检测技术对滩羊、小尾寒羊、杜泊羊和杜滩寒三元杂交羊(DTH)共30只绵羊进行基因分型,并与肉质性状进行关联分析。【结果】试验筛选出的MSTN基因rs129059715位点在4个绵羊群体中共检测到3种基因型,分别为15个CC基因型、9个CA基因型及6个AA基因型,C为优势等位基因(除杜滩寒三元杂交羊外)。在杜泊羊、滩羊和杜滩寒三元杂交羊群体中均处于Hardy-Weinberg平衡状态(P>0.05),在小尾寒羊群体中处于Hardy-Weinberg不平衡状态(P<0.05);在杜泊羊和小尾寒羊群体中均处于低度多态(PIC<0.25);在滩羊和杜滩寒三元杂交羊群体中均处于中度多态(0.25<PIC<0.50)。关联分析发现,rs129059715位点CA基因型个体背膘厚和反亚油酸含量均极显著高于CC基因型(P<0.01),净肉率、肾脏重及脂肪、十一碳酸、十三碳酸和十五碳酸含量均显著高于CC基因型(P<0.05);CC基因型个体肌纤维直径显著高于AA基因型(P<0.05),pH显著高于CA基因型(P<0.05);其他性状各基因型间均无显著差异(P>0.05)。【结论】试验经液相捕获测序技术获得MSTN基因具有差异显著的rs129059715位点,其对绵羊的屠宰性能、肉品质、脂肪酸含量均有显著影响,rs129059715位点可作为产肉性能和肉品质的潜在候选标记。

贵州杂交黄牛MSTN基因cDNA克隆、生物信息学及多态性分析

为比较贵州杂交黄牛肌肉生长抑制素(Myostatin,MSTN)性质、结构和多态性与本地黄牛的差别,该研究先通过RT-PCR克隆MSTN基因cDNA并进行生物信息学分析,再通过PCR-SSCP结合直接测序法筛查贵州本地黄牛和杂交黄牛MSTN基因外显子多态性。结果在贵州杂交黄牛MSTN基因CDS区序列发现4个突变位点,其中3个为错义突变:76 bp处G/A替换,引起天冬酰胺变为天冬氨酸;79 bp处G/A替换,引起丝氨酸变为甘氨酸;1066 bp处G/A替换,引起谷氨酸变为赖氨酸。267 bp处G/A替换与525 bp处A/G替换,为同义突变。MSTN蛋白基本理化性质和结构与普通牛基本一致,但有细微的差别;通过基因同源性和系统进化树,结合motif、蛋白保守域和结构域分析,可知MSTN基因在哺乳动物中高度保守,但也存在遗传多样性。贵州本地黄牛外显子发现3个SNP位点,分别为g.6279107 G>C、g.6281238 T>C和g.6283933 A>C,贵州杂交黄牛中未发现多态位点。单倍型分析共发现6种单倍型和14种双倍型,双倍型H3H5频率最高,且杂交牛的双倍型均为H3H5,之后可一步将此与生长性状进行关联分析研究。

Study on the Polymorphisms of Porcine Myostatin Gene in Promoter Region by PCR-RFLPS

In order to further study functions of the porcine myostatin gene, we analyzed the polymorphisms of porcine myostatin gene in promoter region among different breeds including Yorkshire, Landrace, Duroc, Junmu, Min pig and Sanjiang white pig by PCR-RFLPs. The allele T dominated in the imported lean-type pig breeds such as Yorkshire, Landrace and Duroc. No allele A was detected in Junmu and Sanjiang white pig, and the frequencies of three genotypes were about equal in Min pig. The result using X2 analysis showed that the distribution of three genotypes was related to pig breeds.

Cloning and Sequence Analysis on 3′ Coding Region of Wild Boar and Cross Bred Pig Myostatin Gene

Myostatin, with a highly conservative gene among breeds is a negative regulator of muscle. The 3′ coding regions of wild boar and crossbred pig myostatin were cloned by RT-PCR and sequenced respectively. The homology of the nucleotide sequence between wild boar and crossbred pig was 100% and there was no difference in this region compared with pig myostatin gene of Genbank. This indicated that there was not change of gene sequence in this region during the evolution processes.

Polymorphisms of the CAPN1, CAST and MSTN Genes,and Their Association with Histological and TexturalParameters of Beef from Polish Holstein-Friesian Cattle

The purpose of this study was to analyse polymorphisms of the CAPN1, CAST and MSTN genes and their association with the microstructure of the Musculus longissimus thoracis (MLT) and textural parameters in bulls of the Holstein-Friesian breeds, black-and-white variety. The polymorphisms at the three loci: in position 6536 of the 3’UTR region of the CAPN1 gene, in position 230 of intron 5 in CAST gene, and in position 371 of the promoter region of the MSTN gene were analysed. Given the inconsequential genetic diversity at the analysed CAPN1 and MSTN loci in the animal sample, it was considered unreasonable to perform further statistical analyses aimed at determining associations between polymorphisms in these positions and meat characteristics. Based on an analysis of the CAST gene polymorphism, a significant association with certain histological and textural parameters was identified.

关岭牛MSTN基因3'-UTR与bta-miR-27b的靶向验证

【目的】明确关岭牛bta-miR-27b与肌肉生长抑制素基因(MSTN)的结合位点及靶向调控关系,为通过调控miRNA改良关岭牛产肉量提供理论依据,也为贵州地方黄牛分子遗传改良工作提供新的切入点。【方法】通过TargetScan预测牛MSTN基因3'端非翻译区(3'-UTR)的潜在miRNA结合区域及互作miRNA,对比关岭牛与不同关岭牛杂交品种的生理表型及MSTN基因和3'-UTR端miRNA表达差异,并分析bta-miR-27b在不同关岭牛杂交群体中的靶位点特异性。将MSTN基因3'-UTR序列野生型(WT)和3'-UTR序列突变型(MUT)分别克隆至pMIR-REPORT Luciferase(H306)载体构建重组双荧光素酶报告基因载体,与bta-miR-27b共转染293T细胞以验证bta-miR-27b与MSTN基因的作用关系,并利用实时荧光定量PCR验证bta-miR-27b对MSTN基因表达的影响。【结果】在牛MSTN基因3'-UTR端发现7个miRNA结合位点;关岭牛各系杂交品种的3个miRNA(bta-miR-27a-3p、bta-miR-27b和bta-miR-128)相对表达量均极显著高于关岭牛(P<0.01,下同),MSTN基因相对表达量极显著低于关岭牛,体质量、体高、体斜长、胸围等生长指标却明显优于关岭牛。关岭牛及其杂交牛MSTN基因3'-UTR端的bta-miR-27b结合区域均无突变、无缺失;MSTN-3'-UTR(WT)与bta-miR-27bmimics共转染293T细胞后其相对荧光值下降53.80%,极显著低于MSTN-3'-UTR(MUT)+bta-miR-27bmimics共转染;转染bta-miR-27b mimics后,bta-miR-27b在关岭牛原代成肌细胞株(N2)中成功超表达,而MSTN基因相对表达量呈极显著下调趋势,表明bta-miR-27b能抑制MSTN基因表达。【结论】bta-miR-27b与MSTN基因的结合区域位于3'-UTR端第62~69位碱基处,且靶位点保守性较高。bta-miR-27b对MSTN基因有很强的靶向调控作用,表现为bta-miR-27b能抑制MSTN基因表达。

贵州白山羊肌肉生长抑制素(MSTN)基因生物信息学预测与系统进化分析

本研究旨在解析贵州白山羊肌肉生长抑制素(MSTN)基因的结构特性,为该基因功能探究提供理论依据。基于生物信息学及比较基因组学方法,对NCBI数据库中已登录的贵州白山羊MSTN基因完整编码区序列(CDS)核苷酸组成特性及编码蛋白的相关结构开展预测及分析,构建了15个物种MSTN基因系统进化树。结果表明,贵州白山羊MSTN基因CDS长度为1128bp,共编码375个氨基酸,由3个外显子和2个内含子构成,其AT含量均高于GC。贵州白山羊MSTN蛋白属混合型二级结构,存在无规则卷曲、延伸链和α-螺旋,为弱碱不稳定亲水蛋白质;包括1个18个氨基酸的潜在信号肽,无跨膜区,形成5对二硫键,含有16个磷酸化位点;278~375位氨基酸为转化生长因子-β样结构域。贵州白山羊MSTN基因与绵羊、牛等牛科动物的亲缘关系较近,与鸡形目原鸡和绿头野鸭的亲缘关系较远。本研究可为贵州白山羊MSTN基因分子遗传学及其表达调控研究奠定理论基础。