恒河猴与食蟹猴微卫星DNA多态性的比较分析

目的分析恒河猴和食蟹猴群体间的遗传多样性,确立一种对恒河猴和食蟹猴种群个体的遗传鉴别方法。方法利用聚合酶链反应（PCR）扩增技术采用15个多态性微卫星DNA位点对50只恒河猴和50只食蟹猴个体进行了DNA多态性的分析,对比两群体间等位基因数目差异。结果筛选的15个具有显著多态性的微卫星DNA位点对恒河猴和食蟹猴种群可以进行DNA多态性分析,其等位基因数目均在7个以上,且两群体间有11个位点的等位基因数存在一定的差异。结论利用这些多态性微卫星DNA位点建立一种有效鉴别恒河猴和食蟹猴种群遗传背景的方法具有一定的可行性。     

食蟹猴微卫星DNA标记遗传监测及多态性分析

目的研究国内食蟹猴种群的遗传背景特性,建立食蟹猴种群遗传质量监测方法。方法采用微卫星DNA遗传标记技术对50只食蟹猴种群个体进行遗传质量监测及DNA多态性分析。结果从100个微卫星DNA位点中筛选出20个多态性高的位点,其食蟹猴种群个体的等位基因数目为5-10条,个体间均呈现高度的多态性;其观察等位基因数（Na）为5.0～10.0,有效等位基因数（Ne）为4.6118～8.3404,基因多样性（H）为0.7832～0.8801和香隆信息指数（I）为1.5651～2.1592。结论本实验有效地分析了食蟹猴种群的遗传多态性,为今后筛选特异性微卫星位点来建立食蟹猴种群遗传质量监测方法提供了理论依据。     

梅花鹿3个种群遗传多样性的微卫星标记分析

利用16个微卫星标记对黑龙江省部分地区(兴凯湖农场、大庆市银浪牧场、五大连池大庆农场鹿苑)的3个梅花鹿(Cervus nippon)群体进行了遗传多样性检测.统计了3个鹿群的等位基因组成、平均有效等位基因数(Ne)、平均遗传杂合度(h)和多态信息含量(PIC).结果表明,除5个位点外,其余11个微卫星位点均表现出不同的多态信息含量,其中高度多态位点5个,中度多态位点4个.这说明本研究所选用的微卫星位点可较准确地评估3个梅花鹿群体的遗传多样性,并为今后相关研究筛选出了有价值的引物.3个梅花鹿群体的平均h在0.454～0.636之间变动,其中兴凯湖梅花鹿群体最高,为0.636,具有较大的遗传潜力.     

中国7个地方绵羊品遗传多样性的微卫星分析

利用26个微卫星标记分析了中国7个地方绵羊（Ovis aries）品种的遗传多样性。通过计算基因频率,平均杂合度（H）、多态信息含量（PIC）及有效等位基因数（Ne）,并根据Nei氏标准遗传距离,利用UPGMA法进行了聚类分析,评估其种内遗传变异和品种间遗传关系。结果表明：26个微卫星位点共检测到278个等位基因,Ne在2.1288-13.3924之间;26个位点均为高度多态位点,PIC在0.6628-0.8712之间,聚类分析表明哈萨克羊、阿勒泰羊和巴音布鲁克羊遗传关系最近;然后与白藏羊,黑藏羊聚为一类,湖羊和晋中羊聚为一类,各绵羊各种的聚类关系与其来源,育成史及地理分布基本一致。     

利用微卫星遗传标记对恒河猴进行遗传同质性分群的探索

目的探索建立利用微卫星遗传标记对中国恒河猴免疫遗传学同质性分群的方法。方法根据已报道的中国恒河猴和印度恒河猴微卫星标记和与MHC基因高度连锁的微卫星遗传标记,对52只恒河猴进行了微卫星检测和遗传同质性分群。结果依据判断标准,可以将检测的恒河猴分为印度恒河猴,中国恒河猴和无法判定来源的恒河猴3个地理类别,并根据MHC附近的微卫星遗传标记将其分为若干MHC基因相同的同质性群体。结论此方法的建立将有利于恒河猴参与的实验分组,也为恒河猴繁殖管理提供了参考。     

恒河猴群微卫星DNA多态性的分析

目的　确立一种对恒河猴群个体的遗传物质进行准确可靠、快速简便的遗传检测方法。方法　利用聚合酶链反应 (PCR)扩增技术对 2 0只恒河猴群个体间进行了DNA多态性的分析。结果　筛选出 9个微卫星DNA位点具有显著多态性 ,4个微卫星DNA位点没有多态性 ,还有 2个位点等位基因数目较少。结论　利用这些多态性微卫星位点建立一种对恒河猴群个体进行有效、准备可靠、快捷简便的遗传背景监测方法。     

秦川母牛群体遗传特性的微卫星标记研究

为了从DNA分子水平揭示秦川牛群体遗传多态性和群体遗传结构,寻找可用于秦川牛的微卫星标记,本研究选择了12个普通牛（Bos taurus）微卫星标记检测了90头秦川母牛各微卫星位点的遗传变异及多态性。结果表明,在秦川母牛群体中,12个微卫星位点共检测到了247个等位基因,各位点的等位基因数在13（INRA005）～33个（HEL13）之间,平均每个微卫星位点的等位基因数为21个;总有效等位基因数和平均每个位点平均有效等位基因数（Ne）分别分为142．6229和11．8852。各位点平均基因频率取样方差（V（pij））为2．6036×10^-4。12个微卫星位点平均观察杂合度（Ho）和平均期望杂合度（He）在0．7842（INRA005）～0．9775（BM315）和0．7952（BM315）～0．9446（HEL13）之间。12个位点平均多态信息含量（PIC）在0．7653（INRA005）～0．9420（HEL13）之间,平均为0．8965．12个微卫星位点均属于高度多态位点,这表明秦川母牛群体中所检测各微卫星位点具有丰富的遗传多态性,具备较大的选择潜力。12个微卫星位点的平均固定指数（F）为-0．0076,即各位点杂合子的缺陷度不高,即偏离Hardy—Weinberg平衡的程度不大。     

微卫星座位对实验动物beagle犬的遗传分析

目的对美国进口、广州自养beagle犬基因组中存在的微卫星结构进行分析,研究其群体的微卫星多态性,以此探索在分子水平上对作为实验动物的beagle犬进行检测。方法通过微卫星分子标记技术进行遗传背景分析,并结合微卫星位点测序结果,研究DNA分子特征。结果在研究位点上共发现6个复等位基因,进口犬群体共有6个等位基因片段,自养犬群体共有5个等位基因片段,根据基因型计算各群体等位基因频率,由相关公式计算杂合度、群体多态信息含量(PIC)、基因纯合率、基因分化系数。结论两群体的杂合度、PIC值均较高(分别为0.7010、0.6747和0.7876、0.7515),基因分化系数很低(0.021),表明两群体没有形成明显的独立群。     

吉丽罗非鱼(尼罗罗非鱼♀×萨罗罗非鱼♂)及其两亲本遗传变异的微卫星分析

吉丽罗非鱼是由耐盐性较强的萨罗罗非鱼做父本与生长速度较快的尼罗罗非鱼做母本进行杂交、杂交后代自交产生,2009年全国水产原良种审定委员会审定为养殖新品种。为了分析吉丽罗非鱼及其两亲本遗传特性,选择有代表性的6对微卫星引物,对这3种罗非鱼遗传变异进行研究分析。研究结果表明:(1)6对微卫星引物扩增产物片段大小为180～350bp,共发现21个等位基因,鱼类群体间、微卫星座位间及等位基因间都存在极显著差异。(2)有效等位基因数(Ne)、Nei's基因多样指数(H)和多态信息含量(PIC)值等群体遗传多样性指标都是吉丽罗非鱼>尼罗罗非鱼>萨罗罗非鱼,吉丽罗非鱼PIC值达到了0.657,属于高度多态性。(3)吉丽罗非鱼与萨罗罗非鱼的遗传距离要比与尼罗罗非鱼的近,萨罗罗非鱼对吉丽罗非鱼的遗传影响要大于尼罗罗非鱼。     

利用17个微卫星标记分析鳙鱼的遗传多样性

选用本实验室克隆的17个鳙鱼微卫星分子标记分析四川泸州和江西鄱阳湖的两个种群鳙鱼的遗传多样性及种质特性,计算和统计了杂合度、多态信息含量（PIC）、有效等位基因数、等位基因频率、遗传距离、遗传相似系数、Hardy-Weinberg平衡偏离指数等方面内容。结果表明：选择使用17个微卫星标记,其中有4个为单态标记,13个为多态标记。江西和四川鳙鱼群体每个微卫星位点的平均等位基因数分别为3.325及3.882,平均有效等位基因数分别为3.531及2.676,多态位点百分率分别为82.4及70.5, 17个微卫星标记共有等位基因71个,多态微卫星位点的PIC在0.114~0.960之间变动,平均为0.417 ,两群体位点平均观测杂合度为0.385和0.452,平均期望杂合度为0.360和0.422,两个群体间的遗传相似系数为0.897,群体间的遗传距离为0.109。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细