小鼠NPC细胞RFX1ChIP-Seq数据分析

利用NCBI数据库中小鼠Embryonic Stem Cells(ESC)与Neural ProgenitorCells(NPC)的基因芯片结果及NPC时期的RFX1ChIP-Seq数据,进行有关RFX1的分析,结果表明:RFX1结合位点富集在1,2,4,5,7,9,11染色体上,Y染色体上最少,其他染色体上比较均衡;在基因组中结合位点分布区域主要在基因的promoter区域,约有53.2%,其次是intergentic,占22.5%,body区域,占13.1%,enhancer区域,占11.2%.说明RFX1是以结合在基因的promoter区为主要形式对目的基因进行调控.同时在DAVID数据库中用生物信息学方法探索了RFX1靶基因的生物学功能分类.     

土地利用视角下城镇类型区划研究——以黑龙江省为例

充分认识城镇类型及其空间分布特征是推进新型城镇化建设和区域空间规划集约发展的重要依据。基于黑龙江省城镇土地调查数据,综合运用ArcGIS空间分析、密度指数、变异系数、信息熵模型,依据主要土地利用类型组合划分城镇类型,并阐明分布特征。结果表明:(1)黑龙江省镇级城镇共396个,可划分为基础功能性、多功能性和综合性城镇,分别占总量的9.34%、55.56%、35.10%;(2)依据区域城镇密度,全省可划分为城镇高密度区、中密度区、低密度区和微密度区;(3)不同城镇密度区的城镇结构具有明显的区域差异性,城镇高密度区以多功能性城镇为主,城镇类型相对多样;中、低密度区以多功能性或综合性城镇为主,城镇类型多样;微密度区,城镇类型较为单一;(4)多功能性、综合性、基础功能性城镇空间分布的均匀程度依次降低,均主要分布在松嫩、三江平原,其中综合性城镇在大兴安岭分布较多。该研究能够为优化城镇空间布局和完善城镇功能提供依据,进而促进新型城镇化建设。     

赣江中下游浮游动物时空分布特征及水质综合评价

对2010年12月与2011年7月赣江中下游各监测断面中浮游动物类群的结构组成、优势类群进行调查,结果表明:赣江中下游浮游动物有4类41种;种类最多的是轮虫类,共计7科15属25种,占总数的60.98%;枝角类5科6属7种,占17.07%;桡足类与原生动物占21.95%。时间分布上浮游动物丰度丰水期大于枯水期,密度变动范围为100~522个/L,其中丰水期轮虫、枝角类、桡足类与原生动物密度分别占浮游动物密度的61.7%,11.4%,18.9%与7.8%;枯水期轮虫、枝角类、桡足类与原生动物密度分别占浮游动物密度的65.3%,9.5%,16.0%与9.1%。浮游动物密度空间分布上呈现中间大、两端小的特点,最大值出现在4号监测点新干,最小值出现在10号监测点赣州。赣江中下游浮游动物数量结构主要由轮虫和桡足类组成,生物量结构则主要由桡足类和枝角类组成。生物多样性及水质综合评价为轻度污染至中度污染。     

滇西高山峡谷区泥石流危险性评价——以怒江傈僳族自治州为例

滇西高山峡谷区特殊的地理环境特征,使其成为泥石流灾害的高发区.以怒江傈僳族自治州为研究区域,以历史灾害数据为基础,选取地理环境、地质、气候水文、地形和人类活动五个方面,包括地貌类型、土壤类型、植被类型、归一化差分植被指数、岩性、断裂带、河流分布、降雨量、坡度、坡向、土地利用类型以及公路分布12项评价指标,采用统计指标法和层次分析法相结合的方法对该区域的泥石流危险性进行分区和评价.结果显示:泥石流的危险性分区以中低危险区、中危险区和较高危险区为主,分别占总面积的30.96%、25.5%和20.57%,而低危险区和高危险区共占22.94%;不同样本泥石流分布密度与危险性分区具有较高的正相关性,直接印证了分区方法的合理性;评价方法受试者工作曲线下的面积(AUC)为0.756,表明方法具有可行性.     

新疆8个地域维吾尔族群线粒体DNA V区9 bp缺失频率与Y染色体DYS287位点多态性研究

 为研究新疆8个地域维吾尔族群体的线粒体DNA 9 bp序列缺失频率与Y染色体DYS287位点多态性,分别采用PCR扩增直接测序法和PCR结合琼脂糖凝胶电泳检测法对群线粒体DNA 9 bp缺失频率与Y 染色体DYS287位点多态性进行分析。结果表明在新疆的喀什、和田、库车、且木、哈密、吐鲁番、伊梨和尉梨县的240个无关现代维吾尔族群体中,线粒体DNA 9 bp缺失频率为3.3%,3.3%,6.6%,3.3%,6.6%,3.3%,3.3%,10%。在180个无关现代维吾尔族群男性个体中Y染色体DYS287位点全部显示为YAP-,没有显示为YAP＋。结果提示新疆不同地域现代维吾尔族群体的线粒体DNA 9 bp缺失频率相当低,9 bp缺失不是现代维吾尔族的母系遗传传结构特征,而且不同地域维吾尔族群体线粒体DNA 9 bp缺失频率没有显著性的差异。父系遗传结构单一, YAP+不是现代维吾尔族群体的父系遗传特征。研究获得了新疆不同地域维吾尔族群体的线粒体DNA 9 bp序列缺失频率与Y染色体DYS287位点多态性数据,为不同地域维吾尔族群体遗传关系的分析,法医鉴定及不同地域维吾尔族群体之间的起源关系差异提供了一定的遗传背景资料。     

机场鸟类群落的组成与动态

为了减少机场鸟撞事故的发生,2017年4月至2018年3月,采用样线法对河北南部机场鸟类群落与动态进行了研究.结果显示:共记录鸟类12目29科66种,雀形目(Passeriformes)鸟类的密度、活动频率和Shannon-Weiner多样性指数(H')最高.在空间动态分布上,各样区的鸟类在物种数量、密度、活动频率、多样性指数和Pielou均匀性指数(E)上均存在着显著性差异(P<0.05),其中样区4的鸟类物种数和活动频率最高;样区6的鸟类密度、多样性指数和均匀性指数最大;样区1和样区4的相似性系数(S)最高.在季节动态分布上,各季节的鸟类在物种数量、密度、活动频率和均匀性指数上差异性不显著(P>0.05),但是在多样性指数上存在着显著性差异(P<0.05).春季鸟类物种数最高;春季和秋季鸟类多样性指数、均匀性指数最高;夏季和冬季鸟类密度、活动频率最高;春夏两季的相似性系数最高.因此,根据此特点和机场生境,结合对机场有威胁的29种鸟类,提出有关鸟类防治对策.     

Y-SNP多态性揭示的海南岛黎族、回族和仡隆人群的起源

分析黎族、海南回族、仡隆人群中Y染色体单倍型(Y-SNP)的分布,从遗传学角度研究3个人群的起源。选取部分与东亚人群起源相关的Y染色体非重组区单核苷酸多态性位点,采用PCR-RPLF和geno-typing法分析其多态性,观察由这些多态性位点组成的单倍型在海南3个人群中的分布情况,并将结果与其他人群的分布进行比较。结果在黎族人群中发现4种Y染色体单倍型,其中单倍型O*-175为5个支系所共有,且分布频率都在95%以上。回族人群出现4种单倍型,仡隆人群有2种单倍型。由单倍型种类、频率分布及主成分分析均揭示,黎族与台湾原住民及百越最为接近,可能有共同的起源。海南回族与中国北方回族遗传关系较远;仡隆人群与汉族差异较大,而与百越的仡佬族、水族及黎族遗传关系接近。     

湖侧褶蛙及阿尔泰林蛙的核型、C-带、银带研究

本文报道了产于新疆伊犁的湖侧褶蛙(Pelophylaxridibunda)及阿尔泰地区的阿尔泰林蛙(Ranaaftaica)的核型、C-带、银带。产于中欧的湖侧褶蛙的第8、11号染色体是中部着丝粒染色体,而且几乎每条染色体都有端粒区C 带,在一些染色体上还有居间区C带;而产于新疆伊犁河谷的湖侧褶蛙的第8号染色体是亚端部着丝粒染色体,第11号染色体是亚中部着丝粒染色体,只有着丝粒区C-带,没有端粒区和居间区C-带。本文认为这种染色体核型上的差异是同种不同地域种群的染色体多态现象。阿尔泰林蛙与田野林蛙的第6号染色体均为中部着丝粒染色体,本文认为两者同是欧洲林蛙群2n=26与亚洲2n=24的林蛙群的过渡种类。     

奉节县村庄发展潜力评价与类型识别

从地形、交通、规模和资源4个维度构建指标体系,借助TOPSIS评价、SOFM网络模型和系统聚类等方法,对重庆市奉节县332个行政村（不含社区）进行综合评价和类型识别,并对各类型村庄特征与发展路径进行分析．结果表明:1）各村庄地形本底和交通区位值总体呈现中部高、南北低分布格局,村庄规模和资源禀赋分布特征不明显,二者具有负向对应关系,各村庄维度值空间聚集不显著,以中、中低等级为主;2）各村庄接近度值呈现中部高、南北低以及沿梅溪河线状高值聚集分布格局,各等级数量呈正态分布,总体以中、中低等级为主;3）利用SOFM模型法将研究区村庄划分为24种类型,各类型村庄具有大分散、小聚集的分布特性．基于发展水平和4个维度,运用系统聚类法,将村庄类型合并为6种类型,数量上以Ⅱ、Ⅳ、Ⅴ和Ⅵ为主,占总数的78.92%;面积上以Ⅳ、Ⅴ和Ⅵ为主,占70.05%．综合来看,研究区村庄总体上在近年来得到了不同程度的发展,但今后仍需针对不同类型,采取发挥优势、补足短板、有序推进的策略促进村庄发展．研究结果可为研究区村庄分类发展、脱贫攻坚与乡村振兴战略有效衔接提供决策依据．      

江西省非物质文化遗产时空特征与影响因素分析

以江西省567项国家级和省级非物质文化遗产为研究对象,运用EXCEL、SPSS20.0和ArcGIS10.5分析其类型结构特征、空间分布类型、市域分布特征、空间聚集分布特征、时间演变特征和相关影响因素,结果显示:江西省非物质文化遗产在结构类型上主要以传统技艺类、民俗类、传统舞蹈类为主;数量上主要分布于赣南、赣北地区;空间分布类型趋于集中分布,有1个极核密度区、1个高度密度区、3个次级密度区;各市认定的国家级和省级非物质文化遗产时空分布由分散式团状向非均衡扩散式演化并趋于稳定;经济水平越高的地区非物质文化遗产数量也越多,且非物质文化遗产多分布于丘陵地区,邻近河流水系。     

NPY基因SNPs与鸡屠体性状的关联分析

利用PCR-SSCP法对AA肉鸡、仙居鸡(兼用型)和罗曼蛋鸡神经肽Y(NPY)基因全序列进行了单核苷酸多态(SNPs)检测.在基因内含子2中发现了5个紧密连锁的碱基变异位点:T2623C,C2704T,T2776G,T2787C和A2821G,这5个位点以单倍型的方式在突变基因型个体中遗传;各品种间NPY 基因AA野生型、AB杂合型和BB突变型基因及基因型频率分布差异极显著(P<0.01);基因型对鸡腹脂率、腿肌率及肝重有显著影响,BB基因型个体的腹脂率、腿肌率显著高于AA型和AB型,AB型个体的肝重显著高于AA型和BB型.因此,NPY基因可能是影响鸡脂肪沉积和屠体性状的主效基因或与主效基因相连锁.     

Population structure of the human pseudoautosomal boundary

The mammalian sex chromosomes are composed of two genetically distinct segments: the pseudoautosomal region, where recombination occurs between the X and Y chromosomes, and the sex chromosome-specific parts. Between these two segments the human sex chromosomes differ by the insertion of an Alu element on the Y chromosome. We have surveyed the sequence variation in the boundary region using the polymerase chain reaction. Fifty seven Y and sixty X chromosomes from ten different human populations were analysed. The X chromosomes were found to be polymorphic at five positions in a 300-base-pair region. By contrast, all Y chromosomes were identical except for one distal polymorphism shared with the X chromosome.     

牦牛(Bos Grunniens)染色体高分辨G带带型的研究

由麦洼牦牛(公26,母8)颈静脉采血,经Brdu处理,结合胰酶G显带法,制备牦牛染色体高分辨G带标本,绘制出牦牛染色体高分辨G带模式图,并进行染色体区带划分和命名。结果是牦牛常染色体均为近端点着丝粒染色体,X、Y染色体为亚中部着丝粒染色体。单套染色体的G带数(含X、Y染色体)为641条,划分为108个区,牦牛染色体高分辨G带带型同普通牛染色体G带带型以及高分辨R带带型相比较,其X染色体基本相似,而Y染色体和常染色体有较大差异,这对今后深入探讨牦牛的雄性不育是有意义的。     

一种新的分子标记--单核苷酸多态(SNP)

单核苷酸多态(SNP)为同一物种不同个体间染色体上遗传密码单个碱基的变化，是继限制性片段长度多态性(RFLP)、微卫星标记(SSR)之后的又一种新的分子标记，通常呈双等位基因多态。在此从SNP的特点、SNP的搜寻、SNP的确认与检测、SNP数据库、SNP作图、SNP的研究前景等方面对其研究进展进行综述。     

Closely related sequences on human X and Y chromosomes outside the pairing region

During meiosis the human X and Y chromosomes form a synaptonemal complex which covers most of Yp and the terminal 30% of Xp (ref. 1). By analogy with the autosomes, this is presumed to reflect DNA sequence homology. It has been suggested that these regions of the X and Y chromosomes contain either related or identical loci which are distal to a site of cross-over, and support for these ideas has come from the finding that an X-linked cell-surface antigen controlling gene MIC2 is related to a gene on the Y chromosome. A number of DNA sequences have been shown to occur either on the X and Y chromosomes or on the X, Y and autosomes. We have now isolated a sequence from the Y chromosome which is present on Xq and Yq. This region lies well outside the pairing segments, and sequence analysis reveals no base change in 1 kilobase pair (kb). This high degree of similarity between the X and Y chromosomes near the tips of the long arms is a strong indication that interchange can occur in this region.     

The DNA sequence of the human X chromosome

The human X chromosome has a unique biology that was shaped by its evolution as the sex chromosome shared by males and females. We have determined 99.3% of the euchromatic sequence of the X chromosome. Our analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and Y, and the extent of subsequent degradation of the Y chromosome. LINE1 repeat elements cover one-third of the X chromosome, with a distribution that is consistent with their proposed role as way stations in the process of X-chromosome inactivation. We found 1,098 genes in the sequence, of which 99 encode proteins expressed in testis and in various tumour types. A disproportionately high number of mendelian diseases are documented for the X chromosome. Of this number, 168 have been explained by mutations in 113 X-linked genes, which in many cases were characterized with the aid of the DNA sequence.     

A primitive Y chromosome in papaya marks incipient sex chromosome evolution

Many diverse systems for sex determination have evolved in plants and animals. One involves physically distinct (heteromorphic) sex chromosomes (X and Y, or Z and W) that are homozygous in one sex (usually female) and heterozygous in the other (usually male). Sex chromosome evolution is thought to involve suppression of recombination around the sex determination genes, rendering permanently heterozygous a chromosomal region that may then accumulate deleterious recessive mutations by Muller's ratchet, and fix deleterious mutations by hitchhiking as nearby favourable mutations are selected on the Y chromosome. Over time, these processes may cause the Y chromosome to degenerate and to diverge from the X chromosome over much of its length; for example, only 5% of the human Y chromosome still shows X-Y recombination. Here we show that papaya contains a primitive Y chromosome, with a male-specific region that accounts for only about 10% of the chromosome but has undergone severe recombination suppression and DNA sequence degeneration. This finding provides direct evidence for the origin of sex chromosomes from autosomes.     

染色体的空间分布

本文主要就细胞分裂周期中的同一个染色体组内染色体的空间分布,二倍体或导源多倍体中同源染色体组间的空间分布,同源多倍体中同源染色体组间的空间分布,异源多倍体中部分同源染色体组间的空间分布以及这些分布的机制进行述评,并对研究这个问题的方法和意义进行讨论。     

Genetic evidence that a Y-linked gene in man is homologous to a gene on the X chromosome

The mammalian sex chromosomes are thought to be related to each other by sharing a common origin. That is, the X and Y chromosomes originally evolved from a pair of chromosomes that only differed at the locus determining sexual differentiation. For example, this evolutionary relationship is reflected during meiosis in chromosomal pairing between the tip of the human X chromosome short arm and the Y chromosome which presumably implies sequence homology. However, compelling genetic evidence for functional homology between the mammalian X and Y chromosome is lacking. We describe here the localization of a gene to the tip of the short arm of the human X chromosome and evidence for a related gene on the Y chromosome.     

Low variability in a Y-linked plant gene and its implications for Y-chromosome evolution

Sex chromosomes have evolved independently in several different groups of organisms, but they share common features, including genetic degeneration of the Y chromosome. Suppression of recombination between ancestral proto-X and proto-Y chromosomes is thought to have led to their gradual divergence, and to degeneration of the Y chromosome, but the evolutionary forces responsible are unknown. In non-recombining Y chromosomes, deleterious mutations may be carried to fixation by linked advantageous mutations ("selective sweeps"). Occurrence of deleterious mutations may drive "Muller's ratchet" (stochastic loss of chromosomes with the fewest mutations). Selective elimination of deleterious mutations, causing "background selection" may accelerate stochastic fixation of mildly detrimental mutations. All these processes lower effective population sizes, and therefore reduce variability of genes in evolving Y chromosomes. We have studied DNA diversity and divergence in a recently described X- and Y-linked gene pair (SLX-1 and SLY-1) of the plant Silene latifolia to obtain evidence about the early stages of Y degeneration. Here we show that DNA polymorphism in SLY-1 is 20-fold lower than in SLX-1, but the pattern of polymorphism does not suggest a selective sweep.