小鼠鼻咽部组织相对特异基因调控区的克隆与分析

通过RT－PCR证实PLUNC基因在小鼠鼻咽部具有相对特异性表达。进一步用染色体步移的方法克隆该基因5′端旁侧序列847bp,网上分析结果提示此序列具有调控活性,体外报道基因的研究亦证实这一结果。进一步的研究表明,其核心调控区位于转录起始位点上游200bp之内。这一工作将为构建鼻咽癌转基因动物提供良好的前提。     

鸡催乳素基因序列多态及生物信息学分析

选择繁殖性能具有明显差异的4个鸡品种（莱航鸡、阳山鸡、丝羽乌骨鸡和隐性白洛克鸡）构建品种DNA池,采用测序的方法快速筛查鸡催乳素基因（chicken prolactin,cPRL）5′侧翼调控区、外显子区和部分内含子区约4500 bp范围内可能与产蛋性能相关的序列多态,共检测到13个SNPs和两个短片段（24 bp和15 bp）插入/缺失多态,其中在5′侧翼序列筛查到9个SNPs及两个短片段插入/缺失多态,在第2外显子筛查到1个SNP,在第5外显子筛查到两个SNPs,在第2内含子筛查到1个SNP;进一步利用生物信息学分析cPRL基因的5′侧翼调控序列,发现24 bp短片段的插入使莱航鸡比阳山鸡多出了1个Evi-1可能的结合位点（93分）,C-2402T的变异则使阳山鸡比莱航鸡多出了1个C/EBPbeta可能的结合位点（94分）,这两个结合位点是否影响cPRL基因的表达,影响鸡的就巢性和产蛋性能,还需要进一步研究。Abstract：Four chicken breeds (White Leghorn, Yangshan, Taihe Silkies, White Recessive Rocks) with different reproduction were applied to screen potential SNPs related to laying performance in the 5′flanking region, exon region and partial intron region of chicken prolactin (cPRL) gene. Totally almost 4500 bp were screened rapidly based on DNA pooling and sequencing, and thirteen single nucleotide polymorphisms (SNPs) and two indels (24 bp and 15 bp) were found, including nine SNPs and two indels in the 5′flanking region, one SNP in Exon 2, two SNPs in Exon 5 and one SNP in Intron 2 respectively. Furthermore, 5′flanking region of cPRL gene was analyzed by the website of http://motif.genome.ad.jp/. A possible Evi-1 binding site (score 93) was found in White Leghorn cPRL gene because of the 24 bp insertion, another possible C/EBPbeta binding site (score 94) was found in Yangshan cPRL gene because of the variation of C-2402T. Further studies need to be carried out to verify their effects on the expression of cPRL gene, the broodiness and laying performance of chickens.     

Functional characterization of a putative nitrate transporter gene promoter from rice

Drought is one of the most significant abiotic stresses that influence plant growth anddevelopment.Expression analysis revealed that OsNRT1.3,a putative nitrate transporter gene in rice,wasinduced by drought.To confirm if the OsNRT1.3 promoter can respond to drought stress,a 2019 bpupstream sequence of OsNRT1.3 was cloned.Three OsNRT1.3 promoter fragments were generated by5′-deletion,and fused to the β-glucuronidase (GUS) gene.The chimeric genes were introduced into riceplants.NRT2019::GUS,NRT1196::GUS and NRT719::GUS showed similar expression patterns in seeds,roots,leaves and flowers in all transgenic rice,and GUS activity conferred by different OsNRT1.3 promoterfragments was significantly upregulated by drought stress,indicating that OsNRT1.3 promoter responds todrought stress and the 719 bp upstream sequence of OsNRT1.3 contains the drought response elements.     

Structural feature of sorghum chloroplast psbA gene and regulation effects of its 5'-noncoding region*

Comparative analysis reveals remarkable homology between the sequences of both psbA gene nucleotides and the inferred amino acids of sorghum, a C_4 plant, and those of rice, a C_3 plant. The 5'-noncoding region of sorghum psbA gene contains the conservative promoter elements, "-35" element and "-10" element, like the prokaryote and the promoter element, TATA box, like the eukaryote. As compared with that of the rice, an extra sequence of 7 bp is found in the leader sequence of the mRNA in the former. Using an in vitro system, it has been demonstrated that protein factor exists in sorghum chloroplast protein extract which specifically binds to the 5'-noncoding region of psbA gene. Measurement of the expression of luciferase shows a 2—5 time greater reaction of the expression plasmids pALqs which contain leader region of sorghum psbA gene than that of the expression plasmids pALqr which contain leader region of rice psbA gene in E. coli.     

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.