三疣梭子蟹渔业生物学的初步调查

三疣梭子蟹(Portunus trituberculata)简称梭子蟹,俗称蓝蟹、枪蟹或蠘,是我国北部产量最高的一种著名的海产食用蟹类。梭子蟹的个体较大,最大的怀母蟹平均一只重达1斤2两,个别可达1斤半左右。最大的公蟹平均一只也都在1斤1—2两左右。梭子蟹的肉质饱满,味道鲜美,营养丰富,是人们喜食的一种水产品,每年也有一定的数量出口国外。它在我国的分     

miR-139555及其靶基因PtNBC在三疣梭子蟹适应盐度胁迫中的表达调控

为研究miR-139555及其潜在靶基因PtNBC(碳酸氢钠协同转运基因)在三疣梭子蟹(Portunus tritu-berculatus)适应盐度胁迫中的表达调控分析,利用RACE技术克隆了PtNBC基因,该基因全长5308 bp,开放阅读框(ORF)3570 bp,共编码1189个氨基酸.利用RT-PCR技术分析m...     

三疣梭子蟹的形态与习性

三疣梭子蟹Portunus trituberculatus(Miers)是我国北方沿海主要的经济蟹类,壳薄肉多、营养丰富、味美适口,其卵可加工为蟹子豆腐。甲壳除作饲料和肥料外,还可制成合成纤维。三疣梭子蟹属于节枝动物门、甲壳纲、软甲亚纲Malacostraca、十足目Decapoda、短尾派Brachyura、梭子蟹科Portunidae。一、外部形态蟹体前后短,两侧宽,呈梭形。体表为一层很厚的外骨骼所包被。外骨骼系由几丁质和石灰盐类所组成。雄蟹体长75—88毫米,体宽     

三疣梭子蟹不同月龄形态性状的主成分分析

利用三疣梭子蟹(Portunus trituberculatus)在1-5月龄的生长数据, 对其全甲宽、甲宽、体长、体高、大螯长节长、大螯不动指长、第一步足长节长及体重8个性状进行主成分分析。结果表明: 1-3月龄各性状间相关系数均达到极显著水平(P<0.01), 4、5月龄部分性状间不显著(P>0.05)。各月龄三疣梭子蟹的主成分有所不同: 1月龄三疣梭子蟹的第一主成分为长度因子, 第二主成分为宽度因子; 2月龄三疣梭子蟹的第一主成分为宽度因子, 第二主成分为长度因子, 第三主成分为体重因子; 3月龄三疣梭子蟹的第一主成分为宽度因子; 4-5月龄三疣梭子蟹的第一主成分均为体重因子, 第二主成分均为长度因子。不同月龄三疣梭子蟹各性状的生长速率存在一定差异。1-3月龄形态性状的增长优先于体重, 4-5月龄体重增长优先于形态性状的增长。     

三疣梭子蟹UHRF1基因在胚胎、幼体和性腺发育过程中的表达分析

为探讨泛素样含PHD和环指域蛋白1(UHRF1)基因在三疣梭子蟹(Portunus trituberculatus)发育过程中的作用, 实验采用SMART RACE方法, 克隆了三疣梭子蟹UHRF1(PtUHRF1)基因。该基因cDNA全长为2849 bp, 开放阅读框(ORF)为2298 bp, 预测其编码1个含有765个氨基酸的蛋白质。结构域分析显示, 该蛋白质包含UBL、PHD、TTD、SRA、RING finger 5个功能结构域。同源分析表明, 三疣梭子蟹PtUHRF1的氨基酸序列与其他物种有较高的同源性。qRT-PCR结果显示, PtUHRF1基因在三疣梭子蟹所有组织中均有表达, 但在精巢中表达量显著高于其他组织。该基因在胚胎和幼体发育不同时期表达差异显著, 在受精卵中的表达量最高, 并显著高于胚胎发育其他时期, 是多细胞时期表达量的2.5倍。PtUHRF1基因在性腺发育不同时期表达存在显著差异, 在卵巢II期表达量达到峰值, 之后逐渐下降; 在精巢Ⅰ期的表达量最高, 随着精巢发育逐渐下降。实验结果表明, PtUHRF1参与了三疣梭子蟹胚胎、幼体和性腺发育调控, 为进一步深入研究该基因在三疣梭子蟹及甲壳动物生长发育中的作用提供参考。     

三疣梭子蟹nm23基因克隆及在卵巢发育中的表达分析

Nm23基因编码的核苷二磷酸激酶(NDPK)参与调控生物体的多项生理功能,包括生长、发育、分化和肿瘤转移等。根据三疣梭子蟹(Portunus trituberculatus)转录组数据库中的nm23同源序列,利用c DNA末端快速扩增技术(RACE)首次克隆获得了三疣梭子蟹nm23基因的全长c DNA序列(Gen Bank登录号:KP027331)。该序列全长777 bp,编码一个151个氨基酸的蛋白,该蛋白包含一个典型的核苷二磷酸激酶(NDPK)区域,具有NDPK活性位点和多肽结合位点。推导的氨基酸序列与已知甲壳动物的nm23一致性达到90%以上,与脊椎动物第一类nm23的一致性也达到70%以上。系统进化树分析发现第一类nm23与第二类nm23分别聚为一支,甲壳动物nm23属于第一类,且与nm23-1和nm23-2亲缘关系较近。采用实时荧光定量PCR(q PCR)技术分析了三疣梭子蟹nm23的组织差异表达及其在卵巢发育过程中的表达水平变化,结果表明nm23在三疣梭子蟹各组织内均有表达,其表达水平在眼柄、肌肉和Y器中最高,卵巢和肝胰腺次之。在三疣梭子蟹卵巢发育过程中,卵巢中nm23的表达水平在Ⅰ期最高,之后随着卵巢发育的进行,其表达水平逐渐下降,并在成熟期降至最低,这表明nm23可能参与调控三疣梭子蟹的卵巢发育。     

两种不同产地养殖三疣梭子蟹肌肉中营养成分比较分析

目的：评价不同产地养殖三疣梭子蟹（Portunus trituberculatus）肌肉的营养品质及其风味物质含量差异性。方法：采用生化分析方法,对浙江省台州市和山东省日照市三疣梭子蟹肌肉中的基本营养成分,以及氨基酸、脂肪酸、核苷酸及矿物质元素等营养物质的含量进行检测和对比分析。结果：山东省日照市养殖雌性三疣梭子蟹肌肉中脯氨酸含量显著高于浙江省台州市养殖雌性三疣梭子蟹（P＜0.05）;山东省日照市养殖三疣梭子蟹肌肉中SFA、MUFA和PUFA含量均显著高于浙江省台州市养殖三疣梭子蟹（P＜0.05）;山东省日照市养殖三疣梭子蟹肌肉中肌苷酸（IMP）和腺苷酸（AMP）含量均显著高于浙江省台州市养殖三疣梭子蟹（P＜0.05）;山东省日照市养殖雌性三疣梭子蟹肌肉中甜菜碱含量显著高于浙江省台州市养殖雌性三疣梭子蟹（P＜0.05）。结论：不同产地养殖三疣梭子蟹肌肉中营养成分含量存在一定差异,并对其风味及营养价值产生影响,可能与水域环境、遗传基因等因素有关。本研究可为三疣梭子蟹的品质评价及养殖繁育工作提供科学依据。     

饥饿对三疣梭子蟹初孵幼体(Z1)存活及主要生化成分的影响

研究了饥饿对三疣梭子蟹(Portunus trituberculatus)初孵幼体(Z1)存活及主要生化组成的影响,同时分析饥饿期间的能量变化和能量来源。结果表明,1.三疣梭子蟹初孵幼体Z1的TI(初次死亡时间)、T50(50%死亡时间)和T100(100%死亡时间)的时间分别为2.5 d、6.0 d和9.5 d,饥饿第3 d,幼体活力显著下降;2.饥饿期间,幼体的蛋白质和脂肪含量显著下降,水分含量略有上升,脂肪/蛋白的值表现为高-低-高-低的变化趋势;3.饥饿期间,初孵幼体Z1体内的总能量显著下降,最初24 h的能量消耗最快,整个饥饿期间脂类、蛋白质供能比例分别为42.71%、57.05%。     

三疣梭子蟹HMGBa基因克隆及其应答不同病原入侵的表达特征

为研究三疣梭子蟹(Portunus trituberculatus)高迁移率族蛋白B (High-mobility group box protein, HMGB)在其先天免疫中发挥的功能, 利用RACE技术首次克隆得到了三疣梭子蟹HMGBa基因, 命名为PtHMGBa。其cDNA序列全长1030 bp, 其中5′端非编码区(UTR)为94 bp, 3′端非编码区(UTR)为255 bp, 开放阅读框(ORF)为681 bp, 编码一个含有227个氨基酸, 分子量25.82 kD, 理论等电点为5.94的蛋白质。PtHMGBa蛋白包含2个HMG盒结构域和一个酸性尾部结构域。分析表明, 三疣梭子蟹HMGBa氨基酸序列与凡纳滨对虾(Litopenaeus vannamei) HMGBa相似度最高。实时荧光定量PCR结果显示, PtHMGBa基因在血细胞和肝胰腺的表达量最高, 在眼柄中表达量最低。在副溶血弧菌和WSSV感染过程中, PtHMGBa基因在肝胰腺和血细胞中均出现了表达上调。其中, 经副溶血弧菌感染后, 该基因在上述2种组织中分别于48h和6h达到表达量的峰值; 经WSSV感染后, 该基因在2种组织中均在12h达到表达量的峰值。结果表明PtHMGBa基因参与了三疣梭子蟹抵御外来病原的免疫响应, 研究为深入开展三疣梭子蟹和其他甲壳动物的免疫调控机理提供了科学依据。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

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     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.