两温度梯度多重PCR鉴别牛早期胚胎性别的技术

稳定、可靠和快速的牛胚胎性别鉴定方法在生产应用中具有重要意义.通过两温度梯度PCR方法对牛基因组、克隆胚胎、胚胎样品进行性别鉴别实验研究,建立了稳定、简便、快速的牛早期胚胎性别鉴别两温度梯度PCR方法,鉴定时间仅为57分钟.采用两温度梯度PCR方法对30枚奶牛胚胎进行了早期性别鉴别,并将鉴别的15枚胚胎(11枚为雌性,4枚为雄性)移植到同期处理的15头受体母牛体内.60天后妊娠检查,有7个受体成功受孕,5头受体怀孕晚期流产,流产犊牛全部为母犊.结果产下1公1母两头犊牛,流产个体与出生个体的性别与PCR鉴别结果完全相符.     

两温度梯度多重PCR鉴别牛早期胚胎性别的技术研究

稳定、可靠和快速的牛胚胎性别鉴定方法在生产应用中具有重要意义。通过两温度梯度PCR方法对牛基因组、克隆胚胎、胚胎样品进行性别鉴别实验研究,建立了稳定、简便、快速的牛早期胚胎性别鉴别两温度梯度PCR方法,鉴定时间仅为57分钟。采用两温度梯度PCR方法对30枚奶牛胚胎进行了早期性别鉴别,并将鉴别的15枚胚胎（11枚为雌性,4枚为雄性）移植到同期处理的15头受体母牛体内。60天后妊娠检查,有7个受体成功受孕,5头受体怀孕晚期流产,流产犊牛全部为母犊。结果产下1公1母两头犊牛,流产个体与出生个体的性别与PCR鉴别结果完全相符。      

试管牛和试管羊胚胎性别的鉴定

奶牛和山羊的卵母细胞经过体外成熟、体外受精和体外发育至桑椹期,在显微操作下,吸取4～6个胚胎细胞,应用巢式PCR技术对其DNA进行SRY基因的测定以进行胚胎性别鉴定。共有27枚转有外源基因的试管牛胚胎和207枚转基因试管羊胚胎进行了SRY基因检测。选取10枚经过性别鉴定的牛胚胎移植于8头受体母牛和124枚已知性别的羊胚胎移植于44头受体母羊,移植后妊娠率分别为37．5％（牛,3/8）和61．4％（羊,27/44）。最后产生1头分娩牛犊和2头流产胎牛以及14头分娩羊羔和2头流产胎羊,它们的性别与胚胎性别鉴定的结果完全相符。 Abstract: The oocytes of bovines and goats were subjected to in vitro maturation,in vitro fertilization(IVF)and in vitro development upto morula stage．4～6 embryonic cells were aspirated with micro-manipulating and the embryo sexes were identified by detecting SRY gene with nested PCR procedure．A total of 27 transgenic IVF bovine and 207 transgenic IVF goat embryos were performed SRY gene detection．10 bovine and 124 goat sexed embryos were selected to be transferred into 8 bovine and 44 goat recipients,respectively,leading to the pregnant rates of 37．5％( in bovine,3/8)and 61．4％(in goat,27/44)．In the end,1 cattle and 14 goatlets were born at term but 2 fetal bovine and 2 fetal goats were miscarried．Their sexes were fully in accordance with the embryonic sex predetermination．     

小鼠早期胚胎性别鉴定的研究

用改进的细胞遗传学方法制备染色体标本,鉴定了小鼠晚期桑椹胚(晚桑)、囊胚和扩展囊胚(扩囊)的性别。在实验中,利用小鼠早期胚胎染色体标本制备的理想实验参数,鉴定了242枚小鼠晚桑、囊胚和扩囊的性别,性别鉴定成功率分别为80.4％、99.0％和94.5％。以细胞遗传学方法鉴定小鼠早期胚胎性别的结果为标准,得出用间接免疫荧光法和PCR(聚合酶链反应)扩增SRY(y染色体的性别决定期)部分序列法分别鉴定100枚和26枚小鼠胚胎性别的准确率相应地为74.0％和92.3％。     

西藏小型猪胚胎成纤维细胞的分离培养及性别鉴定

目的探索和建立西藏小型猪胚胎成纤维细胞体外分离培养及性别鉴定的技术方法。方法取35d的西藏小型猪胚胎分离胚胎成纤维细胞,进行体外原代培养及传代培养,观察细胞成纤维细胞的形态和生长状况。根据猪Y染色体上性别决定基因SRY设计引物进行性别鉴定,同时以β珠蛋白作为内参基因,建立PCR反应体系鉴别胚胎的性别。结果西藏小型猪胚胎成纤维体外分离后,呈贴壁生长,快速增殖。PCR性别鉴定结果表明雄性胚胎细胞可扩增出一特异性SRY基因条带,而雌性则没有。该法可快速鉴定胚胎的性别,可用于体细胞克隆动物早期性别鉴定。结论研究结果表明利用胶原酶消化法所获得的西藏小型猪胚胎成纤维细胞可在体外稳定培养并传代,利用PCR鉴定猪胎儿性别具有简单、快速、准确的特点,可应用于克隆猪研究中体细胞系的早期性别鉴定。     

山羊体外受精胚性别鉴定不同取样方法的研究

为了不断完善山羊早期胚胎性别鉴定技术,实现奶山羊雌性胚胎的体外生产与商业化,本研究对胚胎性别鉴定的两种采样方法进行比较。结果表明,两种取样方法性别鉴定结果的准确性没有差异,桑椹胚经打孔法采样后胚胎妊娠率(36．84％)明显高于切割法(31．25％),囊胚经切割法采样后胚胎妊娠率(31．58％)明显高于打孔法(23．53％),综合比较,胚胎性别鉴定应以打孔法采集早期桑椹胚为宜。     

乙醇对着床前小鼠胚胎体外发育的影响

用含不同浓度乙醇的Whitten氏培养液对小鼠2细胞、4细胞、8细胞和桑椹期胚胎分别进行体外培养,研究了乙醇对小鼠不同发育时期胚胎体外发育的影响。首先利用含0、0．1％、0．5％、1．0％、1．5％、2．0％、3．0％、5．0％和10．0％乙醇的Whitten氏培养液对2细胞胚胎进行培养,发现小鼠2细胞胚胎对培养液中乙醇浓度的耐受极限在1．5％左右。然后又用含1％和3％乙醇的Whitten氏培养液分别对小鼠2细胞、4细胞、8细胞和桑椹期胚胎进行培养。结果发现：含1％乙醇的培养液对于8细胞胚胎和桑椹胚的囊胚形成有促进作用,而在2细胞和4细胞胚胎中则影响不明显。3％乙醇则对各期胚胎均有不同程度的抑制作用,但随着胚胎发育其对乙醇的耐受力逐渐增强。     

小鼠早期胎在6℃不同贮液中的保存研究

低温能抑制哺乳动物植入前胚胎的代谢和发育,从而可使胚胎在体外进行短期贮存。本文利用三种不同贮存液：Ｗｔｈｉｔｔｅｎ＇ｓ,ＰＢＳ和ＣＭＲＬ－１０６６对小鼠２－和８－细胞胚胎进行贮存研究。结果表明,贮于上述三种贮液中的小鼠２－细胞胚胎,在６℃贮２４小时后,经３７℃培养,成活率分别为４２．８％、０％和０％;贮７２小时后的８－细胞胚胎的成活率分别为４３．３％、２０．０％和０％。还证实,培养液中丙酮酸钠和乳     

小鼠早期胚胎在6℃不同贮液中的保存研究

低温能抑制哺乳动物植入前胚胎的代谢和发育，从而可使胚胎在体外进行短期贮存。本文利用三种不同贮存液：Ｗｈｉｔｔｅｎ′ｓ、ＰＢＳ和ＣＭＲＬ－１０６６对小鼠２－和８－细胞胚胎进行贮存研究。结果表明，贮于上述三种贮液中的小鼠２－细胞胚胎，在６℃贮２４小时后，经３７℃培养，成活率分别为４２．８％、０％和０％；贮７２小时后的８－细胞胚胎的成活率分别为４３．３％、２０．０％和０％。还证实，培养液中丙酮酸钠和乳酸钠的存在对小鼠胚胎的体外发育是至关重要的。     

绵羊胚胎性别鉴定试剂盒的研究

根据绵羊Y-染色体的特异序列和常染色序列分别设计了确定公羊Y-染色体特异序列的3对特异性引物和内标基因的4对特异性引物。单重PCR扩增绵羊基因组DNA,筛选出了3对Y-染色体特异引物和3对羊DNA特异内标引物。将不同的绵羊Y-染色体特异引物与内标引物组合,利用多重PCR扩增绵羊基因组DNA,筛选出了1个可用于羊早期胚胎性别鉴定的PCR引物组合:A0/C1。按照最优PCR扩增DNA条件配制了绵羊PCR性别鉴定试剂盒并成功应用于绵羊血液、已知性别的绵羊成纤维细胞和胚胎,表明本研究建立的体系完全可用于绵羊早期的胚胎性别鉴定。     

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.