miRNA在调控皮肤和毛囊发育中的作用

表皮发生和毛囊的周期性再生涉及一系列基因的激活和沉默。近年来的研究表明, miRNA的表达谱在表皮和毛囊组织中存在组织特异性, 在毛囊周期性发育中存在阶段特异性。大量miRNA参与表皮和毛囊的发生, 色素的沉着以及毛囊的周期性发育过程, 不同类型细胞中的miRNA通过与信号通路和调控因子相互作用形成了一个全方位、多层次的网络调控系统。文章综述了miRNA调控表皮内稳态和毛囊周期性发育的一些研究 进展, 旨在丰富miRNA参与的基因调控网路的研究, 进而为人工调控miRNA进行疾病治疗和分子育种提供 帮助。     

MicroRNA对多细胞动物复杂性进化的影响

MicroRNA(miRNA)是一种长度约为22个碱基的非编码单链小分子RNA。作为一类重要的转录后基因表达调控因子,miRNA参与了广泛的生物学过程,如发育时程调控、细胞分化、凋亡、肿瘤以及病毒抵抗等。然而,除了在个体发生过程中的重要功能外,越来越多的研究表明,miRNA在系统发生中也扮演着关键的角色。基因表达模式的不同被广泛地认为是物种内和物种间表型差异的根源,动物物种间miRNA的保守性和多样性研究提示miRNA对物种间表型差异以及动物进化起着重要的作用。文章介绍了miRNA产生过程和作用机制,重点探讨了miRNA在动物进化过程中的作用,从miRNA的进化速度、miRNA表达的时空特异性、miRNA作用靶位点变异以及miRNA基因的扩增与丢失4个方面论述miRNA介导的基因调控网络对多细胞动物发育复杂性进化的影响,推测miRNA在多细胞动物进化过程中驱动了复杂性的增加。     

MicroRNAs与疾病和发育

作为模式生物实验系统,线虫可用于研究控制动物发育和人类疾病遗传机制。研究发育缺陷的线虫突变体有助于在动物中发现对发育和生理过程有重要调控作用的基因。其中一些基因编码一类小RNA,如microRNA(miRNA),通过作用于特定基因信使RNA来调控其蛋白质表达。一些在线虫发育过程中有功能的miRNA在人体中也存在。它们参与调控与疾病相关的生物学过程,如癌症、糖尿病和神经退行性疾病。通过分析miRNA在临床样品、哺乳动物细胞和模式生物线虫中的表达,从而揭示miRNA调控途径在相关人类疾病中的功能。     

乳腺发育及泌乳相关miRNA研究进展

MicroRNA(miRNA)是一种重要的转录后调控的非编码RNA, 参与调控哺乳动物乳腺发育和泌乳。文章总结了乳腺发育和泌乳过程中miRNA表达的时空特异性, 综述了个别miRNA对乳腺发育和泌乳的调节作用, 旨在为乳腺miRNA的研究提供指导, 为利用miRNA促进乳腺健康发育和调控高质高效产乳提供理论基础和研究思路。     

植物环状RNA研究进展

环状RNA (circRNA)是一类由mRNA前体经反向可变剪切而来的共价闭合且保守的单链转录本,通过miRNA海绵功能、干扰可变剪切、结合蛋白等方式调控源基因及线性mRNA的表达。测序结果显示,circRNA广泛存在于不同的植物体内,通过细胞类型特异性表达以及组织特异性表达参与花发育、果实成熟、逆境响应等多个生命过程,在植物发育过程中发挥着重要作用。本文综述了植物circRNA的形成机制、鉴定方法、数据库、表达模式以及潜在的生物学功能,通过与动物相关研究结果的比较,概括了植物circRNA的结构特征和调控潜能,以期为植物circRNA研究提供参考。     

MicroRNA在哺乳动物精子发生中的作用

MicroRNAs(miRNAs)是一类长20~24 nt的单链非编码调控RNA序列。miRNA作为基因转录后表达调控分子,通过碱基互补配对的方式与靶mRNA结合,从而导致靶mRNA的降解或抑制其翻译过程。从最早发现存在于秀丽隐杆线虫Caenorhabditis elegans中的miRNA lin-4和let-7至今20多年里,研究人员已陆续从不同的种属中发现了大量的miRNA。近年来随着基因克隆、表达和功能研究技术的应用和发展,通过分析不同动物物种睾丸组织中miRNA的变化表明miRNA与精子发生过程密切相关。此外,miRNA相关的Dicer、Drosha等蛋白在初级精母细胞减数分裂粗线期所发挥的调控功能通过大量啮齿动物基因敲除模型得到证实。本文从miRNA的合成、作用机制和精子发生过程中的调控作用进行综述。     

MicroRNA参与调控睾丸支持细胞的增殖与粘附功能

精子发生过程需要生精细胞及睾丸体细胞的共同参与,这两种细胞也决定着睾丸的发育及雄性生育力。支持细胞是生精小管中唯一的体细胞,在正常精子发生过程中发挥重要的作用。支持细胞增殖与粘附功能的异常将导致精子发生异常,进而引发雄性不育。近年来研究发现,microRNA (miRNA)可调控支持细胞的增殖与粘附功能,其表达水平在激素、内分泌干扰素和营养状况等多种因素作用下发生特异性变化。本文总结了与睾丸支持细胞增殖与粘附功能相关的miRNA及其作用机制,以期发现并鉴定更多与支持细胞相关的miRNA,进而为探索与支持细胞相关不育症的病因提供理论依据。     

猪microRNA组学研究进展

MicroRNA(miRNA)是一类长约22 nt的非编码小RNA,广泛存在于各种生物中,调节生物体生长、发育和凋亡等过程。研究表明,miRNA在猪肌肉、脂肪、生殖系统以及免疫系统等的发育过程中发挥着重要的调控作用。此外,高通量的新一代测序技术在猪miRNA的挖掘和差异表达研究中发挥着巨大的作用。文章综述了高通量的新一代测序技术在挖掘猪miRNA中的应用以及一些miRNA在猪脂肪代谢、肌肉发育、卵母细胞成熟和B、T淋巴细胞发育中的调控作用,旨在为猪miRNA的研究提供参考,为利用miRNA调控和改善猪肉品质、生长性能、繁殖性能以及免疫机能提供理论基础和研究思路。     

急性呼吸窘迫综合征中miRNAs的生物标记作用与调控机制

MiRNAs作为非编码单链RNA分子,具有时空特异性和较高的保守性。近年来,许多实验数据证明,miRNA对细胞基因表达、细胞分化和组织发育等过程有着重要的调控作用,特别是在一些疾病的发生与发展中,miRNAs会异常表达且通过某些机制促进或抑制疾病的恶化。急性呼吸窘迫综合征(acute respiratory distress syndrome, ARDS)的发生由多种因素造成,主要临床表现为肺泡-毛细血管损伤。在ARDS发病过程中,一些miRNAs表达异常,且通过调控mRNA转录和表达,参与整个发病过程。在ARDS发病过程中明显上调或下调且具有特异性的miRNA分子可能为ARDS的预前及预后提供新的标志物,同时研究其调控机制也为诊疗提供新靶点。     

泛素?蛋白酶体途径在精子生成中的作用

泛素?蛋白酶体途径(Ubiquitin–proteasome pathway,UPP)是真核细胞内蛋白质主要降解途径,通过调节蛋白质相互作用、蛋白活性、蛋白定位及信号转导,进而在细胞周期进程、细胞凋亡、应激反应及机体生长发育等过程发挥重要作用。研究表明,UPP在人和动物精子生成中的顶体生物合成及精子尾部形成过程起着关键的调控作用,精子变态过程中UPP调控异常导致精子畸形及精子活力降低,并引发少精子症、不育及睾丸肿瘤等生殖系统疾病。本文综述了UPP在动物精子生成过程中的信号传导及调节机制,以期为后续相关研究提供参考。     

Systematic identification and characterization of miRNAs and piRNAs from porcine testes

microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs) execute important regulatory roles in testis development and spermatogenesis, while previous studies mainly focus on the expression profiles in immature and mature porcine testes, which may cause a bottleneck for further understanding their complex physiological processes in porcine testes development and spermatogenesis. Thus, we presented the expression and characterization of miRNAs and piRNAs in DS (60-day-old), DN (90-day-old), DT (120-day-old) and DF (150-day-old) pig testes. In total, 12,834,628, 13,359,726, 12,851,249 and 12,938,601 clean reads were generated from these libraries, respectively. 293 mature and 36 novel miRNAs as well as 4923 piRNA clusters were identified from pig testes, and they showed an age-dependent manner. GO enrichment analysis of miRNA target genes and piRNA generated genes showed that they participated widely in regulating the pig spermatogenesis process. In addition, 12 differentially expressed miRNAs were randomly selected to validate using qRT-PCR. Our results provided novel comprehensive expression profiles of miRNAs and piRNAs in pig testes at different stages of sexual maturity, which will promote our knowledge of them in regulating the pig testes development and spermatogenesis process.     

Immunoexpression of Tyro 3 family receptors--Tyro 3, Axl, and Mer--and their ligand Gas6 in postnatal developing mouse testis.

Tyro 3 family receptors contain three members-Tyro 3, Axl, and Mer-that are essential regulators of mammalian spermatogenesis. However, their exact expression patterns in testis are unclear. In this study, we examined the localizations of Tyro 3, Axl, Mer, and their ligand Gas6 in postnatal mouse testes by immunohistochemistry. All three members and their ligand were continuously expressed in different testicular cells during postnatal development. Tyro 3 was expressed only in Sertoli cells with a varied distribution during testis development. At day 3 postnatal, Tyro 3 was distributed in overall cytoplasmic membrane and cytoplasm of Sertoli cells. From day 14 to day 35 postnatal, Tyro 3 appeared on Sertoli cell processes toward the adlumenal compartment of seminiferous tubules. A stage-dependent Tyro 3 immunoexpression in Sertoli cells was shown by adulthood testis at day 56 postnatal with higher expression at stages I-VII and lower level at stages IX-XII. Axl showed a similar expression pattern to Tyro 3, except for some immunopositive Leydig cells detected in mature testis. In contrast, immunostaining of Mer was detected mainly in primitive spermatogonia and Leydig cells, whereas a relative weak signal was found in Sertoli cells. Gas6 was strongly expressed in Leydig cells, and a relative weak staining signal was seen in primitive spermatogonia and Sertoli cells. These immunoexpression patterns of Tyro 3 family receptors and ligand in testis provide a basis to further study their functions and mechanisms in regulating mammalian spermatogenesis.     

家蚕Fox转录因子在精巢中的表达特征及BmFoxL2在精巢发育中的功能初探

Fox家族蛋白广泛存在于植物以外的物种中,是一类与发育相关的重要转录因子.但是不同Fox基因在鳞翅目昆虫家蚕Bombyx mori精巢中的表达特征,以及BmFoxL2亚家族蛋白在精巢发育中的功能未知.本文检测了家蚕12个BmFox基因在家蚕精巢中的表达量,发现BmFoxL2-2的表达量最高,BmFoxL2-1次之.Bm...     

Expression and localization of nerve growth factor (NGF) in the testis of alpaca (llama pacos)

During alpaca testis development and spermatogenesis, nerve growth factor (NGF) may play an important role. The main aim of this study was to determine the expression and localization of NGF in the alpaca testis, and to discuss the important role of NGF in alpaca reproductive characteristics. Immunohistochemical staining technique and real-time PCR were used. The expression of NGF in the same cells one-month old (newborn) alpacas 12-month, and 24-month old alpacas showed significant differences (p < 0.05); 12- and 24-month old alpacas showed no significant differences (p > 0.05); NGF at different cell stages showed no significant differences (p > 0.05). It suggests that NGF may be involved in the regulation of spermatogenesis, which provides direct evidence for NGF action in the alpaca testis during postnatal development and spermatogenesis.