我国大陆主要少数民族HLA多态性聚类分析和频率分布对中华民族起…

本文是１９９１年１１月６－１３日横滨第１１届国际组织相容性会议（ＩＨＷＣ）协作科研中我国主要少数民族（苗族,布依族,蒙古族,满族,回族,藏族,维吾尔族）和南北汉族样本ＨＬＡⅠ,Ⅱ,Ⅲ类抗原多态性联合报告。聚类分析表明,苗,布依与南方汉族聚类,蒙,满,回,藏与北方汉族集群,提示中华民族包含南北两大群体。维吾尔族非常疏远地区聚于高加索人种,高加索人种起源的ＨＬＡ抗原基因频率（Ａ３,Ｂ８等）由西向东又由     

应用PCR-SSOP技术研究中国汉族、维吾尔族HLA-A基因座基因多态性

人类白细胞抗原（Human Leukocyte Antigen,HLA)基因复合物位于6p21.3,有220多个不同的功能基因,是人类基因组最复杂的遗传多态系统。HLA等位基因的变异在医学、法医学、人类学等领域具有重要的意义。自从1964年以来,HLA分型一直采用经典的微量淋巴细胞毒实验,但该方法是血清学水平的分,不能识别很多特异性的等位基因,而且高质量的抗体也不易获得。从20世纪90年代起,在国家自然科学基金的资助下,首先开展HLAⅡ类位点基因分研究及大规模群体多态性调查,所获得的中国主要民族基因数据已应用于多个领域。相比之下,HLAⅠ类基因数量更丰富,包含了A、B、C、E、F、G和假基因H、J、K、L等10个位点;基因分子结构更复杂,更具多态性。因此,HLAⅠ类DNA分型比HLAⅡ类分型及行多困难。直至目前中国人群HLA－A基因座基因多态性和分布频率的研究尚未充分进行。而任何DNA标记用于遗传分析、法医鉴定等领域之前,必须先进行群体调查,建立不同民族基因数据库,这是不可逾越的基础工作。鉴于此,采用灵敏而非同位素污染的PCR－SSOP基因分型技术,对165个汉族和162个维吾尔族个体的HLA－A基因座多态性进行调查。结果在汉族群体中发现22种等位基因,频率最高的是HLA－A＊1101（19．7％）,其次是＊201（12．72％）;在维族群体中发现22种等位基因,频率最高的是＊2407（17．90％）,等位基因＊0101、＊0201和＊3301的频率均大于10％;HLA－A＊0203、＊0205、＊0302、＊2403和＊3302仅在汉族群体中检出;HLA－A＊0205、＊0211、＊2301、＊2502、＊68012和＊6802仅在维族群体中检出。按照Hardy-Weinberg平衡定律检验,两个民族各等位基因型频率的预期值与实际观察值相吻合（P＞0．05）,证明了所获得汉族、维吾尔族HLA－A位点基因频率具有可靠性;同时也表明各等位基因的遗传特征符合符合孟德尔规律。经计算机统计分析,汉族群体HLA－A基因座杂合度（Heterozygosity,H)、个体识别率（Discrimination Power,DP)和非父排排率（Proba-bility of Paternity Exclusion,EPP)分别为0．9029、0．9776和0．8592;维族群体H、DP和EEP分别为0．9063、0．9379和0．7885。和其他遗传标记（如VNTR、STR、SNP）的单一位点相比,HLA－A具有高度的杂合率、个体识别率和非父排除率。因此,HLA－A等位基因在法医个体识别、亲权鉴定、基因诊断、人类学等领域具有重要的应用价值。     

广东籍人群的HLA调查

人类白细胞抗原（HLA）是迄今最复杂的 多态性遗传系统。HLA的频率分布不但因人 种、民族而异,而且个别抗原还为某些人种所特 有。因此,HLA抗原频率和基因频率已作为人 类遗传学的重要参数被进行了广泛研究。本文 报道广州地区广东籍汉族人群HLA-A, B位 点抗原的调查数据。     

4个HLA等位基因在5个民族中分布的多样性研究

应用ARMS-SSP结合的方法调查与AIDS相关的HLA等位基因,即HLA-A*02,B*35,B*27,B*57四个基因在五个民族群体（云南汉族、彝族、傣族、新疆维吾尔族、广西壮族）中的分布情况,并进行了相应的遗传学分析。结果显示,HLA-A*02在壮族和汉族中检出的阳性样本频率非常高,在另外几个民族中的分布频率偏低;B*35基因在各民族中分布差异不大;B*27在傣族中的分布频率较高,汉族、彝族和壮族中分布的频率差异不大;B*57则在各民族中的分布差异不大;保护性的等位基因即A*02,B*27,B*57的基因型频率在5个民族中有极显著的差异。此课题增进了对我国部分AIDS流行地区AIDS相关HLA等位基因型遗传背景的了解,是对HLA与AIDS相关性研究资料的有益补充。     

中国维、苗、瑶、壮四个少数民族补体C4的遗传多态现象的检测报告

使用国际第四届补体遗传学会议推荐的方法及薄层激光扫描技术,检测了我国维吾尔族、苗族、瑶族、壮族的补体组分4(C4)的多态性,并与我们以往检测过的汉族的C4多态性一起进行了比较。结果发现,在C4A座位上,以C4A3频率最高,以下在汉族、苗族、瑶族、壮族中依C4A2、Q0、4、1次序降低。在C4B座位上,频率最高的均为C4B1。其它基因频率的依次排列,汉与维为2、Q0、3,苗与壮为92、Q0、2、3,瑶为Q0、2、92等。民族间的差异比较集中地存在于C4A2、C4B2、C4AQ0、C4BQ0等4个基因。本文还对中国汉族、日本人、白种、黑种人群的C4同种异型差异进行了对比与讨论。     

中国3个地区汉族人群补体C6的遗传多态性研究

运用聚丙烯酰胺凝胶等电聚焦(PAGIF)和免疫吸引技术,研究了3个地区汉族人群的C6多态性。得到的基因频率如下:漳州市——C6*A:0.4634、C6*B:0.5000、C6*R:0.0366(C6*B2:0.0317);成都市——C6*A:0.4975,C6*B:0.4484,C6*R:0.0545(C6*B2:0.0395);哈尔滨市——C6*A:0.4708,C6*B:0.5219,C6*R:0.0073(C6*B2:0.0073)。蒙古人种的C6*A频率一般都低于0.5,高加索人种的C6*A频率一般都高于0.6。黑人则介于两者之间。蒙古人种与高加索人种的另一个区别在于前者的C6*B2频率在0.03到0.07之间,而后者几乎没有C6*B2。     

中国人免疫球蛋白同种异型的研究:中华民族起源的一个假说

调查了我国24个民族、74个群体的免疫球蛋白同种异型Gm、Km分布。测定了9560例个体的Gm(1,2,3,5,21)因子和9611例个体的Km(1)因子。根据Gm单体型频率计算了遗传距离并绘制了系统树。结果支持作者早前提出的有关中华民族起源于古代两个不同群体的假说。这两个群体大致以北纬30度为界,分别居栖在黄河和长江流域。本文数据和其他主要人种的Gm分布资料相比较,作者认为在人类进化中,尼格鲁人种首先和高加索-蒙古人种分离;然后高加索人种和蒙古人种分离。不同人种间的差异,大于同一人种内不同群体间的差异。蒙古人种明显地被分为南、北两大类型,分别以具有高频率的Gm~(1;21)和Gm~(1,3;5)单体型作为种族的标记。与高加索人种关联的Gm~(3;5)单体型存在于中国西北地区的少数民族中,提示混有高加索人种血缘。很可能来源于中亚地区的高加索人,通过“丝绸之路”进入中国。Km因子在所调查的74个群体中呈随机分布。     

新疆维吾尔族和汉族亚甲基四氢叶酸还原酶基因多态性研究

目的:研究新疆维吾尔族、汉族两民族亚甲基四氢叶酸还原酶(Methyleneterahyofolate reductase MTHFR)基因多态性的分布情况,获取新疆维吾尔族与汉族MTHFR 1298位群体遗传学数据。方法:应用PCR-RFLP技术检测新疆维吾尔族及汉族MTHFR1298位多态性位点基因频率及基因型频率。结果:新疆维吾尔族、汉族MTHFR 1298位C等位基因分布频率分别为12%、23%,P<0.05有统计学差异性,且新疆维吾尔族MTHFR 1298位C等位基因分布频率与现有报道的少数民族贵州苗族、布依族具有统计学差异。结论:MTHFR 1298位多态性在不同民族具有差异性:MTHFR 1298位多态性在新疆维吾尔族和汉族有民族差异;新疆新疆维吾尔族MTHFR 1298位C等位基因频率与贵州苗族、布依族少数民族之间具有民族差异性。     

强直性脊椎炎的遗传模型分析

强直性脊稚炎（ankylosing spondylitis,简称 AS)是一种结缔组织疾病,表现为脊椎和骼骼 关节疼痛以至强直,男性患者约为女性的10 倍。家系调查表明该病的发生有遗传倾向;群 体调查表明,在蒙古种人、高加索种人和尼格罗 种人中AS都与人体白细胞抗原系统中的 HLA-B27抗原有强的关联(association)。目前 多数人认为这是由于存在一个与B27基因连锁 的‘`AS易感基因”(AS susceptibility gene),带 有这个基因的个体容易患病,在群体水平上表 现出与B27关联。Thomson等人E13根据高加索 种人中的调查资料推测这个基因可能是个显性 基因。本文对Thomson方法作了修正,根据国 内调查资料,对AS遗传模型进行了分析。     

中国壮族和裕固族群体HLAⅠ类区域Alu插入多态性及其与HLA-A位点的相关性

近年来研究发现: 位于HLAⅠ类基因区域的Alu插入是研究不同群体HLAⅠ类基因区域祖先单倍型和HLAⅠ类基因多样性产生、进化和重组的理想工具。文章对中国壮族和裕固族群体HLAⅠ类基因区域5个Alu插入多态性(AluMICB、AluTF、AluHJ、AluHG和AluHF)进行研究, 结合HLA基因分型数据, 分析壮族、裕固族、哈尼族、布朗族和傣族5个民族群体中Alu插入与HLA-A等位基因的关系。研究结果显示: (1)壮族和裕固族人群中5个Alu插入频率范围分别为1.5%~35.8%和9.2~34.8%, AluMICB、AluTF和AluHF插入频率在这两个群体中有统计学差异(P<0.05); (2)在5个研究的群体中, AluHG插入与HLA-A*02的不同亚型关联; AluHJ插入与HLA-A*2402在5个群体中都关联, 但AluHJ与HLA-A*1101和HLA-A*2407只在布朗族中关联。表明不同群体HLAⅠ类基因区域内Alu插入具有各自的特征, 且Alu插入与不同的HLA-A等位基因相关联。这种Alu插入及其与HLA-A的关联特征可作为研究群体中HLAⅠ类基因和单倍型系谱变化的重要遗传标记。     

The influence of climatic factors on the distribution of C4 species in Europe

A checklist of the currently-known C4 species which occur in Europe was compiled, and the number of these found in European territories was ascertained. Their contribution to the local floras range from 4.35% in the Azores to 0% in Svalbard. Subsequently, a stepwise multiple regression analysis was used to correlate the relative abundances of four subdivisions of C4 species with climatic variables derived for each territory from meteorological tables. The four subdivisions were: (a) total number of C4 species; (b) number of native C4 species; (c) C4 monocots and (d) C4 dicots. These values were expressed as percentages of either the total flora, (a), or the native flora ((b), (c) and (d)) for the regressions. The abundance of each C4 subdivision was found to be strongly correlated with temperature, and to a lesser extent, negatively with precipitation. Habitat information about the European C4 species was also analysed and it was concluded that their apparent preference for maritime and ruderal habitats indicates some form of competitive advantage of the pathway under saline or disturbed conditions. A small number of European C4 species was identified whose distribution appears to be anomalous with respect to temperature and/or soil moisture content.Nomenclature follows Tutin et al. Flora Europaea.     

Sema4C在神经干细胞中的表达

目的：探讨Sema4C及其相关蛋白在神经干细胞中的表达。方法：利用RT-PCR、WestemI,blot、免疫荧光等方法对神经干细胞中内源性Sema4C及其相关蛋白的表达进行检测。结果：Sema4C及其相关蛋白在神经干细胞中表达,并且Sema4C在神经干细胞终末分化细胞神经元中表达,但在星形胶质中不表达。结论：Sema4C及其相关蛋白在神经干细胞中表达,提示Sema4C及其相关蛋白可能在神经干细胞中起作用。     

北京北部农牧交错区C4植物及其形态功能型和生境分析

根据野外调查和文献资料研究了北京北部农牧交错区C4植物的种类组成、形态功能型组成及其与生境的关系.该区共有野生C4植物68种,分布在7科,40个属,其中禾本科43种,莎草科16种,藜科5种.1年生（ANG和ANF）C4物种占C4植物总数的62%,它们在盐碱地、沙地、弃耕干扰地、湿地均超过这些生境C4植物分布的半数,在草地ANG和ANF超过30%;C4植物数量和C4/total在该地区的生境分布中有两个方向的变化：一是从草地到弃耕干扰地,两者均呈增加趋势,二是从草地到沙地和盐碱地呈现前者减少而后者增加的不同变化趋势,体现了农牧交错区植被退化的复杂性.     

The functional significance of C3-C4 intermediate traits in Heliotropium L. (Boraginaceae): gas exchange perspectives

We demonstrate for the first time the presence of species exhibiting C3-C4 intermediacy in Heliotropium (sensu lato), a genus with over 100 C3 and 150 C4 species. CO2 compensation points (Gamma) and photosynthetic water-use efficiencies (WUEs) were intermediate between C3 and C4 values in three species of Heliotropium: Heliotropium convolvulaceum (Gamma = 20 micromol CO2 mol(-1) air), Heliotropium racemosum (Gamma = 22 micromol mol(-1)) and Heliotropium greggii (Gamma = 17 micromol mol(-1)). Heliotropium procumbens may also be a weak C3-C4 intermediate based on a slight reduction in Gamma (48.5 micromol CO2 mol(-1)) compared to C3Heliotropium species (52-60 micromol mol(-1)). The intermediate species H. convolvulaceum, H. greggii and H. racemosum exhibited over 50% enhancement of net CO2 assimilation rates at low CO2 levels (200-300 micromol mol(-1)); however, no significant differences in stomatal conductance were observed between the C3 and C3-C4 species. We also assessed the response of Gamma to variation in O2 concentration for these species. Heliotropium convolvulaceum, H. greggii and H. racemosum exhibited similar responses of Gamma to O2 with response slopes that were intermediate between the responses of C3 and C4 species below 210 mmol O2 mol(-1) air. The presence of multiple species displaying C3-C4 intermediate traits indicates that Heliotropium could be a valuable new model for studying the evolutionary transition from C3 to C4 photosynthesis.     

Effect of nitrogen nutrition on photosynthesis and growth in C4Panicum species

Abstract. The growth and photosynthetic responses to high and low N nutrition were measured in 2 NADP-malic enzyme and 4 NAD-malic enzyme C₄ subtype Panicum species to evaluate whether differences in C₄ photosynthetic biochemistry result in differences in the N requirement for growth. All species had lower biomass production, photosynthesis rates, and shoot N concentrations at low N, and no consistent differences between the C₄ subtypes were apparent. The assimilation rates (biomass accumulated over the period of growth) for the NADP-malic enzyme species were higher than the NAD-malic enzyme species at high N but not at low N. When assimilation rates were evaluated on a shoot N basis a higher N-use-efficiency was found for the NADP-malic enzyme species at high N. Thus the NADP-malic enzyme Panicum species had a greater amount of growth for a given shoot N concentration, but only above a certain level of shoot N concentrations.     

中国湖北地区汉族家系补体第四成分（C4）单倍型的检测

用我室仿国际标准C4定型程序改进后建立的方法及羧肽酶B处理后C4分型方法对湖北地区93个无血缘关系的汉族家系进行C4单倍型的检测,对310个C4单倍型分析可见,我国汉族以A3B1频率最高(0.4194),A3B2次之(0.1161),A2B1与A4B2均为0.0903。以下依次是AQOB1(0.0645)、A3BQO(0.0548)、AQOBQO(0.0322)、A2B2(0.0256)、A4B1(0.0161)、A2B92(0.0129)等。从连锁不平衡参数(Δ)的卡方数值可见,A4B2、AQOBQO及A2B92具有极显著意义的阳性△值;而A4B1与AQOB2则具有极显著意义的阴性△值。将我们的结果与日本人、美国及德国白人,南非黑人的资料进行了对比,并进行了一些讨论。     

Environmental regulation of photosynthetic metabolism in the amphibious sedge Eleocharis baldwinii and comparisons with related species

The amphibious leafless sedge, Eleocharis baldwinii, expresses C₄ characteristics in the terrestrial form and intermediate characteristics between C₃ and C₄ photosynthesis in the submerged form. This study examined the immunocytochemical localization of C₃ and C₄ enzymes in culms of the two forms to elucidate the regulatory mechanism of photosynthetic metabolism and compared the activities and amounts of C₃ and C₄ enzymes with those in other Eleocharis species, E. vivipara and E. retroflexa, which show C₄ characteristics on land but C₃ and C₄ characteristics under water. The terrestrial form of E. baldwinii exhibited a C₄‐like pattern of enzyme localization. The submerged form exhibited a modified anatomy with well‐developed mesophyll cells and small Kranz cells. The C₄ enzyme levels declined conspicuously in outer mesophyll cells adjacent to the epidermis, whereas Rubisco levels increased throughout the mesophyll in the submerged form. These results suggest that intermediate photosynthesis between C₃ and C₄ photosynthesis in the submerged form results from the predominant operation of the C₃ pathway in the outer mesophyll cells and the C₄ pathway in both the inner mesophyll and Kranz cells. Differences in the degree of C₄ expression in terrestrial forms of Eleocharis species may cause the differences in the expression of photosynthetic modes under water.     

Mesophyll cells of C4 plants have fewer chloroplasts than those of closely related C3 plants

The evolution of C₄ photosynthesis from C₃ ancestors eliminates ribulose bisphosphate carboxylation in the mesophyll (M) cell chloroplast while activating phosphoenolpyruvate (PEP) carboxylation in the cytosol. These changes may lead to fewer chloroplasts and different chloroplast positioning within M cells. To evaluate these possibilities, we compared chloroplast number, size and position in M cells of closely related C₃, C₃–C₄ intermediate and C₄ species from 12 lineages of C₄ evolution. All C₃ species had more chloroplasts per M cell area than their C₄ relatives in high‐light growth conditions. C₃ species also had higher chloroplast coverage of the M cell periphery than C₄ species, particularly opposite intercellular air spaces. In M cells from 10 of the 12 C₄ lineages, a greater fraction of the chloroplast envelope was pulled away from the plasmalemma in the C₄ species than their C₃ relatives. C₃–C₄ intermediate species generally exhibited similar patterns as their C₃ relatives. We interpret these results to reflect adaptive shifts that facilitate efficient C₄ function by enhancing diffusive access to the site of primary carbon fixation in the cytosol. Fewer chloroplasts in C₄ M cells would also reduce shading of the bundle sheath chloroplasts, which also generate energy required by C₄ photosynthesis.     

Desert grassland dynamics estimated from carbon isotopes in grass phytoliths and soil organic matter

Abstract. We document the potential for using carbon isotopes in both soil organic matter (SOM) and grass phytoliths in soil to increase the temporal and taxonomic resolutions of long term vegetation dynamics. Carbon isotope values from both SOM and phytoliths are expected to describe both the age of material through ¹⁴C dating, and the photosynthetic pathway of the source plant material through ratios of ¹²C/¹³C. Taxonomic resolution is increased because the phytoliths examined are specific to grasses, whereas the SOM reflects the contribution of all the vegetation. Temporal resolution is increased because phytoliths are less mobile in the soil profile than SOM, and can therefore provide older dates from the same soil depth. Our results, from a desert grassland site in southwestern North America, largely confirm these expectations, and show that C₄ species have dominated the grass composition for the last 8000 yr, C₃ non‐grass vegetation increased about 100–350 yrBP, and no significant C₃ grass or non‐grass vegetation existed between 350–2000 yr BP.     

人Sema4C重组腺病毒载体的构建及其在小鼠成肌细胞系C2C12中的表达

利用Ad5腺病毒载体系统构建人Sema4C基因重组腺病毒表达载体并在成肌细胞系C2C12中表达,并初步探讨Sema4C基因在成肌发育过程中的可能作用。利用脂质体介导重组腺病毒载体转染HEK293细胞,包装出完整的腺病毒;将重组腺病毒载体感染C2C12成肌细胞后,利用激光共聚焦显微镜观察发现12h即有绿色荧光表达,24h后绿色荧光蛋白表达最强;流式细胞仪检测病毒的感染效率几乎达100%。WB检测结果表明感染重组腺病毒载体组C2C12细胞Sema4C蛋白的表达量明显高于空载体对照组（P<0.01）。为了进一步观察Sema4C基因对C2C12细胞增殖分化的影响,流式细胞仪检测了病毒感染48h后C2C12细胞的增殖指数,并对感染后诱导分化的C2C12细胞的分化情况进行了观察。我们的结果首次表明,过表达外源性人Sema4C基因不仅能使C2C12细胞的G0/G1期比例增加,细胞的增殖指数下降,同时在分化培养条件下还能促进C2C12细胞肌管的形成。