哺乳动物精子发生中减数分裂的起始

生殖细胞的发生、增殖和分化是生命科学领域研究的重要课题之一. 生殖是所有动物赖以生存的基础,精子发生是完成繁殖所必须经历的过程,其最终目的是源源不断地产生单倍体精子.精子发生过程本身是一个复杂特殊的细胞增殖与分化过程,其中减数分裂是精子发生最重要的步骤,但关于减数分裂如何精确起始的分子机制仍知之甚少.已有报道发现,维甲酸（RA）调控Stra8可能是哺乳动物减数分裂起始的机制之一,Nanos2、Boule对RA-Stra8通路具有重要的调控作用. 本文对哺乳动物精子发生中减数分裂起始的相关研究进展进行综述.     

人Boule基因启动子区结合蛋白的生物信息学分析

目的：对精子发生RNA结合蛋白Boule基因启动子区结合蛋白进行生物信息学分析。方法：从基因参考序列数据库获取Boule基因启动子区序列,使用TFSEARCH程序对启动子序列中的转录因子结合位点进行预测。结果：成功获得长度为2kb的人Boule基因启动子区序列。该启动子区Thresholdscore〉90的共有60个转录因子结合位点,涉及sox家族、GATA结合蛋白家族、热休克因子家族、锌指蛋白Kruppel家族、POU家族、runt家族、同源异型框基因家族、TALE类同源结构蛋白家族、转录因子螺旋环螺旋家族、IKAROS家族、FOX家族11个家族的转录因子和3个TATAbox。结论：Boule基因表达的调控是在一定时间或空间上、一种或多种调节蛋白作用的复杂过程。调控Boule基因表达的转录因子绝大部分与胚胎发育、性别决定、个体生长密切相关。     

人类Boule基因在减数分裂时期的生物信息学分析

Boule（boll）基因是DAZ基因家族的一个新成员,含有一个RNA结合域和一个DAZ重复域,是人类精子发生减数分裂过程中主要调控因子。为了研究Boule基因结构及其功能,利用生物信,息学方法对Boule蛋白相关结构、相互作用蛋白及其功能进行分析和预测。结果表明,Boule蛋白存在明显的亲水区、疏水区和卷曲螺旋;不存在信号肽、跨膜结构;主要分布在细胞质、细胞核、线粒体中;二级结构以α-螺旋、延伸链、无规则卷曲所组成,并含有非正规二级结构区;作用蛋白主要为CDC25A蛋白．功能域主要包含RRM保守域。Boule蛋白在精子发生过程中第一次减数分裂的生殖细胞中特异性表达,而在减数分裂完全阻滞的睾丸组织中不表达。因此,Boule蛋白功能可能与雄性生殖细胞减数分裂相关基因表达有关。     

<Emphasis Type="Italic">Ancient Hunters and Their Modern Representatives</Emphasis>: William Sollas’s (1849–1936) Anthropology from Disappointed Bridge to Trunkless Tree and the Instrumentalisation of Racial Conflict

During the first decades of the 20th century, many anthropologists who had previously adhered to a linear view of human evolution, from an ape via Pithecanthropus erectus(today Homo erectus) and Neanderthal to modern humans, began to change their outlook. A shift towards a branching model of human evolution began to take hold. Among the scientific factors motivating this trend was the insight that mammalian evolution in general was best represented by a branching tree, rather than by a straight line, and that several new fossil hominids were discovered that differed significantly in their morphology but seemed to date from about the same period. The ideological and practical implications of imperialism and WWI have also been identified as formative of the new evolutionary scenarios in which racial conflict played a crucial role. The paper will illustrate this general shift in anthropological theory for one particular scientist, William Sollas (1849–1936). Sollas achieved a synthesis of human morphological and cultural evolution in what I will refer to as an imperialist model. In this theoretical framework, migration, conflict, and replacement became the main mechanisms for progress spurred by ‘ ȁ8nature’s tyrant,’ natural selection.     

Expression of miR‐34c in response to overexpression of Boule and Stra8 in dairy goat male germ line stem cells (mGSCs)

Reproduction is required for the survival of all mammalian animals. Spermatogenesis is an essential and complex developmental process that ultimately results in production of haploid spermatozoa. Recent studies demonstrated that Boule and stimulated by retinoic acid 8 (Stra8) played important roles in initiation meiosis in male germ cells. miR‐34c is indispensable in the late steps of spermatogenesis; remarkably, the main function of miR‐34c is to reduce cell proliferation potentiality and promote cellular apoptosis. The objectives of this study were to investigate the expression patterns of Boule, Stra8, P53 and miR‐34c in dairy goat testis and their relationship in male germ line stem cells (mGSCs). The results first revealed the expression patterns of Boule, Stra8, P53 and miR‐34c in 30 dpp, 90 dpp and adult testes of dairy goats. The expression levels of Boule, Stra8, P53 and miR‐34c in adult dairy goat testes were significantly higher than that of 30 dpp. Overexpression of Boule and Stra8 promoted the expression of miR‐34c in dairy goat mGSCs. In our previous study, we showed that miR‐34c was P53 dependent in mGSCs. These results have shown that the up‐regulation of miR‐34c was not due to P53 protein activation but which might be caused by the up‐regulation of Boule and Stra8 promoting the advance of meiosis. In addition, we found retinoic acid would decrease the expression of P53 and miR‐34c, however, did not change the expression of c‐Myc greatly. It suggested that the function of driving differentiation of dairy goat mGSCs by retinoic acid might not be caused by P53. Copyright © 2013 John Wiley & Sons, Ltd.