The recent origin of the Sdic gene cluster in the melanogaster subgroup

Gene families are composed of closely related genes and are an important part of eukaryotic genomes. In the proximal region of the X chromosome of Drosophila melanogaster there is a cluster of four tandem Sdic genes, located between the gene Cdic and the gene AnnX. Sdic is a chimeric gene that encodes a novel protein with sperm-specific expression. It had been hypothesized that the Sdic gene cluster was formed after the split of D. melanogaster and D. simulans. To study the evolution of this cluster, the sequence of this region was studied in several Drosophilidae species. In all species analyzed, Sdic genes are absent and AnnX and Cdic are adjacent to each other. The results allowed the inference of the ancestral situation and the reconstruction of the evolution of the cluster, and confirm that the Sdic cluster was indeed formed in the lineage that gave rise to D. melanogaster, being one of the youngest gene clusters known. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Formation of chromosome aberrations in androgenetic rainbow trout Oncorhynchus mykiss

Residues of maternal nuclear DNA in the form of chromosome fragments were observed in the healthy and morphologically normal androgenetic rainbow trout Oncorhynchus mykiss. A hypothetical model for formation of chromosome re‐arrangements caused by the incomplete maternal nuclear DNA inactivation in the androgenetic rainbow trout was proposed in the present paper.     

中国地方黄牛的Y染色体遗传多样性及其进化起源

中国黄牛的进化起源与遗传多样性一直是国内外动物遗传学家感兴趣的课题之一.本文主要从Y染色体的形态多样性和Y染色体特异性微卫星标记遗传多态性两个方面对中国地方黄牛的遗传多样性和进化起源进行了综述.中国地方黄牛Y染色体具有中着丝粒、亚中着丝粒和近端着丝粒3种类型,这说明中国地方黄牛起源于普通牛和瘤牛.利用Y染色体特异性微卫星标记对中国地方黄牛Y染色体单倍型分布特征及Y染色体基因流模式的分析表明,北方种群中普通牛单倍型频率最高,瘤牛单倍型在南方种群中占优势;在中国不同地域,瘤牛Y染色体单倍型频率呈现自南而北、自东而西逐渐降低的趋势,这再次证实了中国黄牛主要来源于普通牛和瘤牛,这可能是这两类牛群在长期的历史进化过程中,分别从东南方向和西北方向进入我国,并在中原地区汇合的结果.本文为中国地方黄牛品种资源保护和杂交育种工作提供了参考依据.     

丝裂霉素致小鼠骨髓淋巴细胞遗传损伤及西洋参的干预作用研究

目的:研究西洋参(Panax quinguefolium L)抗突变作用和对细胞增殖的影响.方法:采用小鼠骨髓淋巴细胞有丝分裂指数试验、染色体畸变试验和微核试验,观察西洋参对小鼠骨髓淋巴细胞遗传损伤效应的影响.结果:丝裂霉素(Mitomycin-c MMC)单独作用时,能抑制小鼠骨髓淋巴细胞的增殖(P<0.01),提高小鼠骨髓淋巴细胞的染色体突变(P<0.01)和微核率(P<0.01).西洋参高、中、低剂量组与MMC联合作用时,有丝分裂指数明显比模型组提高(P<0.01),并且均能显著地抑制由于MMC引起的染色体突变,其抑制率分别为68.25%、34.97%和14.29%,同时对MMC诱发的微核率也有明显的抑制效应.结论:西洋参能抑制MMC诱发的染色体畸变率和微核率,促进细胞的增殖能力.     

与男性不育相关基因的研究进展

生殖是所有哺乳动物的生存所需的,基础研究有助于确定这些基因及男性和女性生殖系统发展、功能和调节机制。目前人类已经在生殖领域取得了一些进展,但是将这些科研成果应用于临床的速度也非常缓慢。但总而言之：近年来在对能控制人类生殖的分子基础的理解上的进步是非常巨大的并最终将改善病人的治疗效果。本文就近年来发现的几种常见的基因对男性生育能力的影响。     

Similarities and distinctions in Y chromosome gene pool of Western Slavs

Analysis of Y chromosome Y‐STRs has proven to be a useful tool in the field of population genetics, especially in the case of closely related populations. We collected DNA samples from 169 males of Czech origin, 80 males of Slovakian origin, and 142 males dwelling Northern Poland. We performed Y‐STR analysis of 12 loci in the samples collected (PowerPlex Y system from Promega) and compared the Y chromosome haplotype frequencies between the populations investigated. Also, we used Y‐STR data available from the literature for comparison purposes. We observed significant differences between Y chromosome pools of Czechs and Slovaks compared to other Slavic and European populations. At the same time we were able to point to a specific group of Y‐STR haplotypes belonging to an R1a haplogroup that seems to be shared by Slavic populations dwelling in Central Europe. The observed Y chromosome diversity may be explained by taking into consideration archeological and historical data regarding early Slav migrations. Am J Phys Anthropol 142:540–548, 2010. © 2010 Wiley‐Liss, Inc.     

Phylogeographic analysis of paternal lineages in NE Portuguese Jewish communities

The establishment of Jewish communities in the territory of contemporary Portugal is archaeologically documented since the 3rd century CE, but their settlement in Trás‐os‐Montes (NE Portugal) has not been proved before the 12th century. The Decree of Expulsion followed by the establishment of the Inquisition, both around the beginning of the 16th century, accounted for a significant exodus, as well as the establishment of crypto‐Jewish communities. Previous Y chromosome studies have shown that different Jewish communities share a common origin in the Near East, although they can be quite heterogeneous as a consequence of genetic drift and different levels of admixture with their respective host populations. To characterize the genetic composition of the Portuguese Jewish communities from Trás‐os‐Montes, we have examined 57 unrelated Jewish males, with a high‐resolution Y‐chromosome typing strategy, comprising 16 STRs and 23 SNPs. A high lineage diversity was found, at both haplotype and haplogroup levels (98.74 and 82.83%, respectively), demonstrating the absence of either strong drift or founder effects. A deeper and more detailed investigation is required to clarify how these communities avoided the expected inbreeding caused by over four centuries of religious repression. Concerning haplogroup lineages, we detected some admixture with the Western European non‐Jewish populations (R1b1b2‐M269, ～28%), along with a strong ancestral component reflecting their origin in the Middle East [J1(xJ1a‐M267), ～12%; J2‐M172, ～25%; T‐M70, ～16%] and in consequence Trás‐os‐Montes Jews were found to be more closely related with other Jewish groups, rather than with the Portuguese non‐Jewish population. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.