Elymus sibiricus, E. nutans 和 E. burchan-buddae 的形态学鉴定及其染色体组亲缘关系的研究

为了进一步研究Elymus sibiricus L.、E．nutans Griseb．和E．burchan-buddae(Neuski)Tzelev [＝Roegneria nutans(Keng)Keng]的外部形态差异及其系统学关系,本文对这三种植物的6个穗部形 态性状进行了观测和比较,并对这三个Elymus种进行了种间杂交及杂种F1的减数分裂染色体配对行 为的分析研究。结果表明：这三个Elymus种的穗长及颖长等性状均变异很大,而内稃的长、宽则变异 不大并具有明显的种间差异。E. nutans×E．barchan-buddae及E.nutans×E．sibiricus的杂种F1均完 全不育,减数分裂不规则。E．nutans×E．burchan-buddae杂种F1的减数分裂构型为：7.70I+13.40 Ⅱ+0.06Ⅲ+O.08 Ⅳ,而E．sibiricus×E．nutans杂种F1的构型为11.98 Ⅰ+9.61Ⅱ+O.64Ⅲ+0.39 Ⅳ+0.01V。由本实验的形态学和细胞学的研究结果得出以下结论：1．利用内稃形态性状结合穗部 其它性状的差异能对这三个物种进行较准确的鉴定;2．E．nutans与E.burchan-buddae的亲缘关系较 近,而E．nutans与E．sibiricus的亲缘关系则较远;3. E,burchan-buddae×E．nutans的杂种Fl中存在着染色体配对控制因子。     

利用ISSR标记研究野大豆居群内遗传变异及其取样策略

为了有效地保护野大豆(Glycine soja Sieb.et Zucc.)并制定合理的居群取样策略,对上海江湾机场的一个人然野大豆居群进行了 100个单株(个体)的随机取样,并用ISSR分子标记对其进行了遗传多样性分析.利用筛选出的15条ISSR引物在这个居群中检测到较高的遗传变异,样本内个体间的相似系数变化在0.17～0.89之间.居群内平均每个位点的平均预期杂合度(He)为0.171 4,香农指数(I)为0.271 4.PCA分析显示,江湾野大豆居群内的遗传变异不是呈均匀分布,而是呈从状分布.该野大豆居群遗传多样性和样本内个体数量间的相关性分析显示:在个体数少于40的情况下,遗传多样性随个体数的增加而迅速增加;当样本中的个体数大于40时,遗传多样性的增加减慢并很快趋于饱和.研究表明:对野大豆居群进行异地保护时,对各居群的采样植株数不应当低于35～45;在居群内采样时,所采集的个体之间最好相隔一定的空间距离.     

Statures in Han populations of China

<正>Dear Editor,Shortly after initiating thePhysical Anthropological Research on Han Chineseresearch project,we applied uniform sampling methods as well as methods and instruments of measurement to obtain a complete set of measurements of physical anthropological indicators among Han populations across China.Among these measurements,body stature was a key indicator.Currently,there should be reliable     

The β-alanyl-monoamine synthase ebony is regulated by schizophrenia susceptibility gene dysbindin in Drosophila

The Drosophila homolog of schizophrenia susceptibility gene dysbindin(Ddysb)affects a range of behaviors through regulation of multiple neurotransmitter signals,including dopamine activity.To gain insights into mechanisms underlying Ddysb-dependent regulation of dopamine signal,we investigated interaction between Ddysb and Ebony,the Drosophilaβ-alanyl-monoamine synthase involved in dopamine recycling.We found that Ddysb was capable of regulating expression of Ebony in a bi-directional manner and its subcellular distribution.Such regulation is confined to glial cells.The expression level of ebony and its accumulation in glial soma depend positively on Ddysb activity,whereas its distribution in glial processes is bound to be reduced in response to any alterations of Ddysb from the normal control level,either an increase or decrease.An optimal binding ratio between Dysb and Ebony might contribute to such non-linear effects.Thus,Ddysb-dependent regulation of Ebony could be one of the mechanisms that mediate dopamine signal.     

哺乳动物的核移植

哺乳动物的核移植陆长富卢光（湖南医科大学人类生殖工程研究室,长沙４１００７８）ＮｕｃｌｅａｒＴｒａｎｓｐｌａｎｔａｔｉｏｎｉｎＭａｍｍａｌｉａｎＬＵＣｈａｎｇｆｕＬＵＧｕａｎｇｘｉｕ（ＨｕｍａｎＲｅｐｒｏｄｕｃｔｉｖｅＥｎｇｉｎｅｒｉｎｇＬａｂｏｒ...     

Glycosyl phosphatidylinositol myristoylation in African trypanosomes. New intermediates in the pathway for fatty acid remodeling

Glycosyl phosphatidylinositol (GPI) anchors in the bloodstream form of Trypanosoma brucei are unusual in that their two fatty acids are myristate. The myristates are added in the final stages of GPI biosynthesis in a remodeling reaction. Remodeling occurs first at the sn-2 position of glycerol, involving removal of a longer fatty acid and subsequent attachment of myristate. The second myristate is then incorporated into the sn-1 position, but the mechanism has been unclear due to the unavailability of a reliable cell-free system supporting complete remodeling. Here, we first refined the cell-free system (by removing Mn(2+) ions), thereby allowing efficient production of the dimyristoylated GPI precursor. Using this improved system, we made three new discoveries concerning the pathway for fatty acid remodeling. First, we discovered a monomyristoylated GPI (known as glycolipid theta') as an intermediate involved in remodeling at the sn-1 position. Second, we found an alternative pathway for production of glycolipid theta, the first lyso intermediate in remodeling. The alternative pathway involves an inositol-acylated GPI known as glycolipid lyso-C'. Finally, we found that there is significant breakdown of GPIs during remodeling in the cell-free system, and we speculate that this breakdown has a regulatory role in GPI biosynthesis.     

Single-seeded InDel fingerprints in rice:An effective tool for indica-japonica rice classification and evolutionary studies

Asian cultivated rice(Oryza sativa L.),an important cereal crop worldwide,was domesticated from its wild ancestor 8000 years ago.During its long-term cultivation and evolution under diverse agroecological conditions, Asian cultivated rice has differentiated into indica and japonica subspecies.An effective method is required to identify rice germplasm for its indica and japonica features,which is essential in rice genetic improvements.We developed a protocol that combined DNA extraction from a single rice seed and the insertion/deletion(InDel) molecular fingerprint to determine the indica and japonica features of rice germplasm.We analyzed a set of rice germplasm,including 166 Asian rice varieties,two African rice varieties,30 accessions of wild rice species,and 42 weedy rice accessions,using the single-seeded InDel fingerprints(SSIF).The results show that the SSIF method can efficiently determine the indica and japonica features of the rice germplasm.Further analyses revealed significant indica and japonica differentiation in most Asian rice varieties and weedy rice accessions.In contrast,African rice varieties and nearly all the wild rice accessions did not exhibit such differentiation.The pattern of cultivated and wild rice samples illustrated by the SSIF supports our previous hypothesis that indica and japonica differentiation occurred after rice domestication under different agroecological conditions.In addition,the divergent pattern of rice cultivars and weedy rice accessions suggests the possibility of an endoferal origin(from crop)of the weedy rice included in the present study.     

广州地区106例汉族人群MICA和MICB微卫星基因座 单体型研究 The Study on the Haplotype of MICA and MICB Microsatellite Locus In Guangzhou Han Population

利用聚合酶链反应和荧光（6－FAM）自动化检测技术对广东地区汉族106例无亲缘关系样本进行MICA基因外显子5和MICB基因内含子1微卫星基因座多态性及其单体型分布调查。根据群体资料估算两者间的单体型频率、连锁不平衡参数、相对连锁不平衡参数。结果显示，广州地区汉族人群MICA和MICB微卫星基因座基因型分布符合Hardy-Weinberg平衡法则，共检出MICA微卫星基因座 5个等位基因， MICB微卫星基因座14个等位基因。其中MICA A5基因频率最高（0.2877），A4基因频率最低（0.1321）。MICB CA14等位基因频率最高（0.3255），CA19、CA28等位基因频率最低（0.0047），未检出CA27。21种MICA－MICB单体型频率大于1%(连锁不平衡参数>0), 其中单体型A5－CA14 (16.73%), A5.1－CA18 (8.75%), A4－CA26(3.76%)，A9－CA15(3.66%)和A6－CA21(2.61%)为强连锁常见单体型（χ2>3.84, P<0.05）。广州地区汉族人群MICA和MICB微卫星基因座多态性和单体型分布有其自身特点，MICA和MICB微卫星基因座适合做为遗传标志，用于人类学、遗传疾病基因连锁分析、法医学亲子鉴定和个体识别等研究领域。Abstract: This study is to investigate genetic polymorphisms and haplotypes of microsatellite locus in the exon 5 of the MICA gene and intron 1 of the MICB gene based on 106 samples of Guangzhou Han Population by polymerase chain reaction and fluorescent technique (6-FAM). The corresponding haplotype frequencies, linkage disequilibria values and relative linkage disequilibria values were estimated based on population data. The results show that the genotype distributions of MICA and MICB microsatellite meet Hardy-Weinberg equilibrium in Guangdong Han population. In total, 5 alleles of MICA microsatellite locus and 14 alleles of MICB microsatellite locus were observed. MICA A5 was the most common allele (0.2877), whereas A4 was the least popular one (0.1321). MICB CA14 was the most common allele (0.3255), and CA19 and CA28 were the least popular ones (0.0047). CA27 was not observed. Twenty-one kinds of MICA-MICB haplotypes occurred at frequencies of more than 1% (linkage disequilibria value>0). The common MICA-MICB haplotypes were A5-CA14（16.73％）, A5.1- CA18 (8.75%), A4- CA26(3.76%)，A9-CA15(3.66%) and A6-CA21(2.61%)（χ2>3.84, P<0.05）, and they were strong linkage disequilibria. The polymorphisms and haplotypes distributions of MICA and MICB microsatellite locus in Guangzhou Han population have their own genetic characteristics. The microsatellite locus of the exon5 of the MICA gene and intron 1 of the MICB gene could be used as the genetic markers in the studies of anthropology, linkage analysis of genetic disease genes, individual identification and paternity test in forensic medicine.