应用RNA-seq数据开展鸭基因组可变剪接的鉴定与分析

可变剪接是畜禽增加转录组和蛋白质结构与功能多样性的一种重要机制。研究应用前期测定的不同发育时期(2、4、6周龄)北京鸭胸肌和皮脂RNA-seq数据,挖掘北京鸭胸肌和皮脂内可变剪接及其功能注释。结果显示:1 6个样品中共鉴定出30 465个可变剪接,这些事件发生在7 587个基因上,可变剪切类型以外显子跳跃、内含子滞留、可变的5′剪接位点和可变的3′剪接位点等为主;2可变剪接的发生具有组织和发育阶段特异性;3共有可变剪接的基因主要富集于物质合成、物质结合及酶活性相关的GO条目中,胸肌特有可变剪接基因显著富集到骨骼肌发育相关的GO条目中,而皮脂特有的可变剪接基因富集到油脂合成的GO条目中。研究系统鉴定了北京鸭胸肌和皮脂内的可变剪接和基因,为北京鸭分子育种提供理论基础。     

肌肉发育相关基因的可变剪接研究进展

可变剪接是生物体内的一个重要机制,它能够利用同一mRNA前体产生不同的mRNA转录本,从而丰富蛋白质组的多样性。肌肉发育是一个复杂的过程,受到多种相关基因的调控。当可变剪接出现在肌肉发育相关基因时,这些基因则会产生不同功能的蛋白质。文章对近年来动物肌肉发育相关基因可变剪接的研究情况进行了综述,重点阐述这些基因的不同异构体之间功能的差异情况。     

可变剪接在反刍动物中的研究进展

可变剪接发生在前体mRNA成熟过程中,通过该过程可使单个基因产生多个mRNA异构体和蛋白质亚型,造成蛋白质表达多样性,是调节反刍动物基因表达的关键机制.许多研究表明,剪接因子、剪接位点对蛋白质的多样性表达起着十分重要的作用.可变剪接机制可特异性地调节反刍动物的繁殖性状,参与机体生长发育的各种生理及病理过程.文章对可变剪...     

可变剪接及其在畜禽育种中的研究与应用

可变剪接是指个体发育或者细胞分化时有选择地越过某些外显子或某个剪接点进行变位剪接,从而产生组织或发育阶段特异性mRNA的过程。通过可变剪接,生物体可以由单个基因产生多个不同的蛋白质异构体,从而导致大量的蛋白质变异。因此,可变剪接在动物生长发育和生理代谢等过程中发挥重要的调控作用。本文对可变剪接的类型、鉴定方法及其对畜禽各种经济性状的影响进行了总结,并展望了其在畜禽育种中的应用前景,以期为畜禽育种改良进行提供新思路。     

可变剪接在农业动物中的研究进展

可变剪接(alternative splicing, AS)是由单个前体mRNA形成多个成熟mRNA的过程,从同一基因产生多个转录本,增加转录组和蛋白质组的多样性,此过程是调节基因组表达和产生蛋白组多样性的重要机制。同种生物经可变剪接产生不同表型,在不改变基因序列的情况下调控蛋白质的生物学功能,对于理解生命活动的调控过程有重要意义。文章对可变剪接的发生机制及其在农业动物中的研究进展进行了综述,以期为在农业动物中进一步研究可变剪接奠定基础。     

鸡Lmbr1基因一种异常可变剪接的克隆和表达分析

根据人Lmbr1/C7orf2基因的一种缺失外显子4的可变剪接与Acheiropodia(ACHP)疾病的关联,本研究拟根据可变剪接在物种间的保守性,进行鸡Lmbr1这种相似可变剪接的鉴定和表达分析。设计跨越Lmbr1外显子4的引物可同时检测这2种转录产物的表达,本研究成功地从鸡的心脏组织获得了缺失外显子4的Lmbr1异常剪接(Lmbr1-β)。在白来航初生雏鸡及5～6胚龄胚的组织表达分析显示,2种转录产物均可在所检测的组织中表达,与包含外显子4的转录产物(Lmbr1-α)相比,可变剪接Lmbr1-β为一种次要表达产物,表达量较弱。对多趾的丝羽乌骨鸡和四趾的白来航鸡胚组织间2种转录产物表达进行进一步分析,在2个品种3～11胚龄(E3～E11)的胚胎发育期间均可同时检测到Lmbr1-α和Lmbr1-β的表达,Lmbr1-α为主要表达产物,Lmbr1-β为次要表达产物,Lmbr1-β表达量微弱。在2个品种的胚胎发育期间未见2种转录产物明显的表达差异。结果显示,包含外显子4的Lmbr1-α为鸡Lmbr1基因的主要转录产物,广泛而稳定地在雏鸡和发育鸡胚各组织中表达,丝羽乌骨鸡多趾表型的发育与常见转录产物Lmbr1-α和异常可变剪接Lmbr1-β的表达无直接的相关。     

肉鸡肌肉与脂肪组织基因组差异剪接基因分析

旨在鉴定和分析肉鸡肌肉和脂肪组织基因组差异剪接基因(differential splicing gene,DSG)。本研究采用Illumina Hiseq 2500测序平台对AA肉鸡胸肌和腹部脂肪组织各3个样品进行转录组测序,使用rMATS软件检测样品中可变剪接事件(alternative splicing,AS)和组织间的DSG,并对DSG进行GO功能富集和KEGG通路分析。结果表明,在肉鸡肌肉和脂肪组织中分别检测到(5 966.00±111.66)和(6 757.00±156.51)个可变剪接事件(P=0.002)。5种可变剪接类型中以外显子跳跃(skipped exon,SE)为主,分别占肌肉和脂肪组织中可变剪接事件总数量的54.92%和52.67%。肌肉和脂肪组织基因组间检测到513个显著的DSGs。GO基因富集分析发现,93个DSGs显著富集于细胞组分和分子功能中。信号通路分析发现,31个DSGs富集在肌动蛋白细胞骨架调节、焦点粘连、丙酮酸代谢和细胞内吞作用信号通路中,其中14个DSGs在肌肉和脂肪组织基因组中的表达水平未发生显著变化。本研究通过对肉鸡肌肉和脂肪组织基因组中DSG的鉴定与分析,为研究可变剪接及其调控机制、组织间差异剪接的多样性提供理论依据。     

可变剪接的表观遗传学调控机制及其在脂肪代谢中的作用研究进展

可变剪接是指从1个mRNA前体中通过不同的剪接方式产生不同的mRNA剪接异构体,并使得最终的蛋白产物表现出不同或者相互拮抗的功能和结构特性的过程。基因通过可变剪接在组织发育和疾病中起着至关重要的作用,是高等真核生物蛋白质多样性的主要来源之一。剪接过程受多种因素调控,其中表观遗传学现象是可变剪接过程中重要的影响因素,多项研究表明多种表观遗传学现象对于可变剪接存在调控作用。可变剪接对于脂肪细胞的分化以及脂质的代谢也起到不可或缺的作用。本文综述了表观遗传学修饰对可变剪接的调控及其在脂肪代谢调控中的研究进展,以期为可变剪接的进一步研究提供参考依据。     

关于肌细胞生成素基因的初步探讨

肌肉调节因子(MRF)基因家族编码4种明显不同的肌肉特异性转录因子,分别称为生肌决定因子(MoyD)、肌细胞生成素(MyoG)基因、生肌因子5(Myf5)和生肌调节因子4(MRF4),这些蛋白质代表控制骨骼肌生成很多方面的关键调节因子。MyoG基因为近年来人们发现的一种与肌纤维数目有关的基因。本文对肌细胞生成素(Myogenin)基因的位置结构、遗传多态性、多态性的检测及与经济性状关系进行了初步探讨。     

关于肌细胞生成素基因的初步探或

肌肉调节因子（MRF）基因家族编码4种明显不同的肌肉特异性转录因子,分别称为生肌决定因子（MoyD）、肌细胞生成素（MyoG）基因、生肌因子5（Myff3）和生肌调节因子4（MRF4）,这些蛋白质代表控制骨骼肌生成很多方面的关键调节因子。MyoG基因为近年来人们发现的一种与肌纤维数目有关的基因。本文对肌细胞生成素（Myogenin）基因的位置结构、遗传多态性、多态性的检测及与经济性状关系进行了初步探讨。     

Research Progress of Alternative Splicing and Its Application in Livestock and Poultry Breeding

Alternative splicing(AS) refers to the process of selective splicing across exons or splice junctions during individual development or cell differentiation to produce tissue-or development-stage specific mRNA. Through AS process, organisms can produce many different protein isomers from a single gene and finally increase the proteome diversity. Therefore, AS plays an important role in the regulation of animal growth, development and physiological metabolism. This article not only summarized the types and the detection methods of alternative splicing, but also highlighted its impact on various economic traits of livestock and poultry, and prospected its application prospects in livestock and poultry breeding. This article could provide new ideas for the improvement of livestock and poultry breeding.     

Molecular cloning and tissue distribution of a short form chicken leptin receptor mRNA

In mammals, alternative splicing of the leptin receptor (LEPR) produces several C-terminal truncated isoforms that are believed to play a role in the transport, cellular internalisation and degradation of the hormone leptin. The chicken leptin receptor (chLEPR) is similar to its mammalian counterparts in terms of its intron/exon structure and conserved motifs. However, it is unknown whether the chLEPR also undergoes alternative splicing. To test this, structural analysis of intron 19 of the chLEPR, equivalent to the intron in which alternative splicing occurs in mammals, was combined with 3'-rapid amplification of cDNA ends (3'-RACE) to search for chLEPR splice variants. A 44-amino acid alternative exon 20 was identified that is spliced to generate a short isoform of the chLEPR (chLEPR-SF). Comparative sequence analysis of intron 19 identified two regions that are highly conserved between the chicken and mammals, indicating their possible importance as intronic elements in the regulation of alternative splicing of the LEPR in vertebrates. Tissue expression of the chLEPR-SF was lower and more restricted than that of the chLEPR long isoform. Collectively these data demonstrate that the chLEPR is alternatively spliced to produce at least one short isoform, as is the case in mammals.     

PRPF8蛋白在真核生物可变剪切中的作用

可变剪切是真核生物转录过程中的重要调控机制,剪切体是可变剪切过程中的关键元素.PRPF8是可变剪切组分U5中的关键蛋白,在剪切过程中具有重要的作用.为此,文章介绍了PRPF8蛋白在可变剪切5'和3'位点的作用方式及其参与调控可变剪切因子的途径,总结了PRPF8蛋白可变剪切在动物生产和肿瘤研究中的应用,得出了PRPF8蛋...     

Translation from the internal ribosome entry site of bovine viral diarrhea virus is independent of the interaction with polypyrimidine tract-binding protein

Translation of the pestiviral polyprotein is initiated cap independently at an internal site of the viral RNA, the internal ribosome entry site (IRES). We investigated the translation from the IRES of bovine viral diarrhea virus (BVDV) and the possible interaction of the unconventional cellular RNA-binding proteins, particularly of polypyrimidine tract-binding protein (PTB). The BVDV IRES is translationally active in rabbit reticulocyte lysate (RRL), and it is translated most efficiently at low concentrations of Mg(2+)- and K(+)-ions. In the UV cross-link assay, several proteins from RRL bind to the BVDV IRES, including proteins of 50, 65 and 72kDa, but no protein of 57kDa possibly corresponding to PTB, although PTB is endogenously present in RRL. However, the BVDV IRES can bind PTB weakly under certain conditions. Interestingly, in a functional depletion and add-back translation system, PTB does not enhance translation of BVDV, although PTB enhances translation of a picornavirus in this translation stimulation assay. These results indicate that PTB can bind the BVDV IRES RNA, but translation is independent of the action of PTB.     

Messenger ribonucleic acid expression of the MyoD gene family in muscle tissue at slaughter in relation to selection for porcine growth rate

Livestock meat production capacity is related to muscle fiber numbers and growth. Muscle fibers develop during early embryonic development from proliferating and differentiating myoblasts. Post-natal muscle growth requires satellite cell proliferation and differentiation. Myoblast and satellite cell proliferation and differentiation is regulated by the genes of the MyoD gene family (myogenin, myf-5, myf-6, and MyoD1). Our aim was to study the mRNA expression of these genes in postnatal muscle tissue in relation to porcine selection for growth rate or leanness. Five boars from a line selected for fast growth (F-line) and five boars from a line selected against backfat thickness (L-line) were slaughtered, and biopsies were taken from 12 muscles. Between-line effects, within-line effects in relation to the performance of the pigs, and muscle-specific effects were studied. Comparing the F-line with the L-line revealed significantly greater myogenin, myf-5, and MyoD1 mRNA expression in some muscles of the F-line. The expression of myf-6 showed a tendency for the opposite effect in some muscles. Muscles were ordered by their muscle-specific growth rate (b-value). Within-line evaluation of the data revealed a systematic muscle effect for the myf-6 expression level in the F-line because higher b-values correlated with increased myf-6 expression level. Backfat thickness was negatively related to myogenin expression in the F-line. A relationship was found between myogenin:MyoD1 mRNA expression ratio and meat color/muscle fiber type composition in the L-line. Furthermore, the myogenin:MyoD1 ratio was greater in muscles from F-line boars than in muscles from L-line boars, which relates to the difference between the lines in muscle fiber type. We conclude that the mRNA levels of the MyoD genes in porcine muscle tissue at slaughter showed different relationships to selection for growth rate when evaluated between selection lines and within selection lines.     

HuR的功能及其对肌肉生长发育的调控作用

RNA结合蛋白HuR(human antigen R)，又被称为类胚胎致死性异常视觉基因1(ELAV like RNA binding protein 1, ELAV1)，是一种在机体各组织中广泛表达的重要RNA结合蛋白，其通过调控mRNA前体剪接、多聚腺苷酸化，以及mRNA稳定性与翻译效率等方式参与机体各项生命活动。研究表明，RNA结合蛋白参与了肌肉生长发育调控，其中HuR主要通过影响靶mRNAs的稳定性和翻译参与调控肌生成与肌肉疾病的发生。本文结合近年来HuR的相关研究，从HuR的生物学特性、主要功能与作用方式、在肌肉生长发育及肌肉疾病中的调控作用等方面展开综述，以期为进一步研究HuR在肌肉生长发育调控中的作用提供参考。