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1.
利用鲤科鱼类线粒体DNA细胞色素b通用引物对分布在新疆的准噶尔雅罗鱼(Leuciscusmerzbacheri)、贝加尔雅罗鱼(L .baicalensis)和高体雅罗鱼(L .idus) 3个鱼种共1 5尾个体的线粒体DNACytb部分核苷酸序列进行了测定,获得1 5条长度为41 3bp的同源基因序列。同源基因序列分析显示,在3种雅罗鱼1 5条mtDNACytb基因片段中,A、T、C、G碱基的平均含量分别是:2 7 4%、2 6 7%、1 7 2 %、2 8 7% ,其中A T含量(5 4 1 % )高于G C含量(4 5 9% ) ;共检测到5 2个突变位点;转换比颠换发生频率高,转换颠换比值(R)是3 5。mtDNACytb的进化速率在3种雅罗鱼间表现出不一致性,贝加尔与高体雅罗鱼、贝加尔与准噶尔雅罗鱼种间遗传距离分别是0 1 2 5 1和0 1 2 61 ,保守性较低;高体与准噶尔雅罗鱼种间的遗传距离是0 0 0 0 7,高度保守。mtDNACytb分子系统树显示,在3种雅罗鱼中贝加尔雅罗鱼独立成一枝,高体雅罗鱼和准噶尔雅罗鱼聚成一类。提示了,在mtDNACytb分子水平上,高体雅罗鱼和准噶尔雅罗鱼的亲缘关系十分相近,贝加尔雅罗鱼与准噶尔雅罗鱼的亲缘关系相距较远。我们对准噶尔、贝加尔和高体雅罗鱼mtDNACytb方面的研究与陈星玉对其骨骼类型的研究结果相吻合。  相似文献   

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用PCR-RFLP技术,对新疆分布的准噶尔雅罗鱼、贝加尔雅罗鱼和高体雅罗鱼的mtDNA D-loop高变区约827bp进行了扩增,用ScaI、HinfI、AluI、DdeI 4种限制性内切核酸酶对56个样本的扩增产物酶切和RFLP分析,共检测到6种单倍型。准噶尔雅罗鱼存在2种单倍型:BDAA和BDBA;贝加尔雅罗鱼存在3种:AAAA、ABAA和ACAA;高体雅罗鱼只有1种。初步认为,准噶尔雅罗鱼、贝加尔雅罗鱼存在较丰富的群体内变异。用6种单倍型及净遗传距离绘制的UPGMA分子系统树,提示准噶尔雅罗鱼有可能是原始种,贝加尔雅罗鱼和高体雅罗鱼是由准噶尔雅罗鱼进化而来。 Abstract:PCR-RFLP technique was employed to amplify about 827bp of mtDNA D-loop hypervariable region of Leuciscus baicalensis,L.merzbacheri and L.idus in Xinjiang.The PCR products of 56 samples with four restriction enzymes were digested:ScaI,HinfI,AluI,DdeI,and RFLP analysis was done then.The study indicates that all of L. species and populations have six haplotypes,L.merzbacheri has two haplotypes:BDAA,BDBA;L.baicalensis has three:AAAA,ABAA,ACAA;L.idus has one:CAAA.It is primarily considered that L.merzbacheri and L.baicalensis have more intra-population mutations.The UPGMA trees with 6 haplotypes and net genetics distance pointed out that L.merzbacheri might be original species,L.baicalensis and L.idus are evolved from L.merzbacheri.  相似文献   

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采用线粒体Cyt b基因序列对额尔齐斯河流域的青河(QH,18尾)、哈巴河(HBH,21尾)、185团(185T,18尾)和乌伦古湖(WLG,20尾)4个贝加尔雅罗鱼(Leuciscus leuciscus baicalensis)群体进行了遗传结构的比较分析。在片段长度为1 109 bp的同源序列上,77尾个体共检测到54种单倍型,其中共享单倍型7个,总单倍型多样性指数(Hd)、总核苷酸多样性指数(π)和平均核苷酸差异数(K)分别为0.981 9、0.008 21和9.091,且185团群体单倍型多样性指数和核苷酸多样性指数最高、青河群体最低。4个群体间遗传距离在0.006~0.011之间,基于Kimura 2-parameter法构建的单倍型邻接关系树分为3支,群体间遗传关系和地理分布没有明显的相关性。AMOVA分析显示额尔齐斯河流域贝加尔雅罗鱼遗传差异极显著(P0.01)。青河和乌伦古湖群体基因流(Nm)远高于其他群体间,推测乌伦古河或许是二者进行基因交流的渠道。尽管单倍型核苷酸不配对分布呈双峰,但偏差平方和(Q)与粗糙指数(r)均不显著(P0.05),且Tajima′s D和Fu′s Fs检验也均显著偏离中性,结合群体呈现高单倍型多样性和低核苷酸多样性的特点,推测贝加尔雅罗鱼经历了群体扩张事件。参考已校正的鲤科鱼类Cyt b基因0.76%/Ma的进化速率,估算群体扩张的时间大约在1.97 Ma前的更新世中晚期,推测该时期阿尔泰山地区发生的冰川作用和频繁的古地震造成的地理隔离和融合可能是贝加尔雅罗鱼发生群体扩张的重要原因。  相似文献   

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采集黄河上游厚唇裸重唇鱼(Gymnodiptychus pachycheilus)甘肃玛曲群体,测定其线粒体DNA控制区序列,并从GenBank中下载青海玛多和贵德等3地2个群体的同源序列,分析该物种的遗传多样性、遗传结构及其演化历史.从81条729 bp序列中,检测到26个变异位点(占3.57%),碱基序列总的单倍型多样性为0.844,核苷酸多样性为0.0054,界定了34个单倍型,有1个广布单倍型H2,占所有样品的38.27%.单倍型网络图图显示单倍型没有明显的亲缘地理格局,H2处于中心,呈星状发散,系统发育分析没有显示出单倍型与地理位置的对应关系.AMOVA分析显示变异主要来自地理区内群体间,歧点分布和中性检测显示厚唇裸重唇鱼近期经历了种群扩张.分析表明黄河上游3地种厚唇裸重唇鱼种群未出现分化,建议应作为一个整体进行保护.  相似文献   

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目的测定云南猕猴线粒体DNA控制区全序列,对其进行鉴定及进化分析。方法利用PCR技术扩增猕猴线粒体DNA控制区全序列,结合GenBank中下载的猕猴参考序列(AY612638),采用多个生物学软件对序列碱基组成、同源性、转换/颠换比等遗传信息进行分析,并基于邻接法(NJ)和最小进化法(ME)构建系统进化树。结果云南猕猴线粒体DNA控制区全长为(1084-1089)bp,A、T、G和c四种碱基平均含量分别为29.9%、26.9%、12.3%和30.9%,A+T含量(56.8%)高于G+C含量(43.2%)。所分析序列间的同源性为91.5%-99.5%,平均核苷酸变异率为4.5%,变异类型包括转换、颠换、插入和缺失4种形式,转换/颠换比值平均为26.1。进化树显示云南猕猴存在两个平行进化的姐妹分支。结论本研究获得了云南猕猴mtDNA控制区全序列,为猕猴进化关系研究及mtDNA控制区功能研究奠定基础。  相似文献   

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美丽硬仆骨舌鱼mtDNA D-loop区遗传变异特征   总被引:2,自引:0,他引:2  
采用直接测序法分析美丽硬仆骨舌鱼(Scleropages formosus)3个种群(金龙鱼、红龙鱼和青龙鱼)共24个个体的线粒体D-loop区的遗传变异特征。经序列比对、分析,金龙鱼、红龙鱼和青龙鱼的D-loop序列不仅在个体间存在位点序列的变异(17个简约性信息位点),而且还存在序列长度的多态性(长度为915-924 bp),这种长度的差异在于存在不同碱基长度的微卫星序列。3种龙鱼碱基组成基本一致,G含量偏低。定义了10种单倍型,但金龙鱼、红龙鱼和青龙鱼间没有共享单倍型,单倍型多样度较高(0.667-1.00),核苷酸多样度较低(0.001 09-0.003 23)。AMOVA分析显示,变异主要来自地理区内不同群体间,个体间遗传距离为0-0.008 7,显示遗传变异仍处于种内水平。NJ、MP和Bayesian构建的分子系统树拓扑结构基本一致,但不能有效地反映金龙鱼、红龙鱼和青龙鱼间的亲缘关系。  相似文献   

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对红鲫19尾个体的线粒体tRNA-Thr基因、tRNA-Pro基因和部分控制区的核苷酸序列进行了测定.获得19条长度为836~837bp的同源基因序列,共发现18个变异位点.定义了4种单元型.在红鲫4种单元型中确认了DNA复制终止相关的序列TAS、中央保守区序列(CSB-F、CSB-E和CSB-D)和保守序列CSB1.在18个变异位点中,除一个缺失外,序列变异全部为转换,无颠换发生.4种单元型之间的序列差异在0.1%。1.7%之间.结果显示,红鲫群体具有较高的遗传多样性水平,因而暗示了它具有较强的适应外界环境变化的能力,同时说明它是鱼类遗传育种的较好实验材料.  相似文献   

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丁小雷  何毛贤  邓凤姣  张锡元 《遗传》2004,26(3):319-324
测定了双壳纲不同科、属、种及种内共11个个体的核糖体RNA 18S-ITS1序列。结果表明,该序列在种间存在很高的多态性,长度从558bp到784bp不等,碱基差异百分比在10.7%~61.7%之间,ITS1序列同源性很低,有片段的插入与缺失。种间18S部分序列碱基差异百分比在0.9%~23.7%之间,变化主要是碱基的转换。用邻接法(NJ)构建了8个种的18S部分序列(约240bp)的系统发育树,与传统形态学分类结果相符。马氏珠母贝(Pinctada martrtensi)4个不同地域个体间的序列差异百分比在0.6%~1.9%之间。分析指出:18S基因可以作为双壳纲动物高阶元系统发育的分子标记;ITS1序列种间变化很大,可以应用于该纲物种的分类及鉴别.在亲缘关系相近种及种内变异相对较小,但核苷酸变异位点信息量丰富,可用于属内种间、亚种和群体间的遗传多样性研究。  相似文献   

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淋巴细胞存在有δ阿片肽受体的分子证据   总被引:1,自引:1,他引:0  
以小鼠的成神经细胞瘤和大鼠神经胶质瘤的杂交细胞δ阿片肽受体的基因外显子Ⅲ序列为依据合成引物,应用RT-PCR方法扩增人外周血淋巴细胞mRNA的一片段cDNA,扩增产物经纯化后进行核苷酸序列测定.测序结果表明该片段与杂交瘤细胞的δ阿片肽受体基因序列相比有5个同源区,其中碱基的同源性达63%.实验结果从分子水平表明了人淋巴细胞表面存在有阿片肽受体的可能性.  相似文献   

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准噶尔雅罗鱼β-肌动蛋白基因启动子克隆及序列分析   总被引:1,自引:0,他引:1  
利用PCR方法克隆了准噶尔雅罗鱼(Leuciscus merzbacheri)的β-actin基因启动子片段SZ21,大小是2398bp。对克隆的启动子序列进行了转录调控元件的生物信息学预测分析,同时,基于启动子中包含的开放阅读框和内含子序列,探讨了准噶尔雅罗鱼与鲤鱼(Cyprinus carpio)、草鱼(Ctenopharyngodon idella)、青鱼(Mylopharyngodon piceus)、团头鲂(Megalobrama amblycephala)、泥鳅(Misgurnus mizolepis)间的系统进化关系。结果显示,该启动子序列的3个核心启动子转录元件:CAAT-box、CArGmotif和TATA-box分别在转录起始位点(+1)上游的-89、-59、-26处,序列中还含有MEF2、SATB、CHRF、INRE、MTEN、E-box、RU49、ZBPF、CREB、Enhance region、CEBP位点等多种转录调控元件。在剪接体内含子中,剪接位点遵循GT…AG法则。启动子SZ21序列含有3个内含子和155个氨基酸。内含子1、内含子2、内含子3的系统发育分析表明,团头鲂与草鱼和青鱼的亲缘关系要比与准噶尔雅罗鱼的更近一些,这与传统分类中的亲缘关系显示不一致,其原因尚需探讨。  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

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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  相似文献   

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