鉴定9个新的RHD基因mRNA可变剪接体

为了研究各种RHD基因mRNA可变剪接体的基因结构, 应用逆转录聚合酶链反应(RT-PCR)检测正常人脐血样本RHD mRNA, 对RHD cDNA进行TA克隆和序列分析, 对各可变剪接体的剪接位点进行DNA序列分析, 并将RHD mRNA进行表达序列标签(ESTs)分析。结果在28个阳性克隆中, 除全长RHD cDNA外, 共检测到12种(包括9种新的)RHD可变剪接体, 发现外显子遗漏、5′和3′剪接位点变异3种剪接形式, 涉及外显子2~9, 其中6种新的剪接体同时存在RHD和RHCE基因同源杂交现象。ESTs分析还检索到内含子保留形式的剪接体。研究表明, RHD基因mRNA存在复杂的可变剪接机制, 除已报道的剪接体外, 检测到9种新的RHD可变剪接体, 并发现了可变剪接和同源杂交并存现象。     

应用创造酶切位点法检测单碱基突变

应用引物错配技术结合单碱基突变位点而配合成一个酶切位点,使之成为可用PCR-RFLP方法分析的突变位点,是对单碱基突变位点进行基因型鉴定的有效而简捷的手段。本文以鸡胞外脂肪酸结合蛋白(Extracelluar fatty acid binding protein,EX-FABP)基因单碱基突变的基因型检测为例,探讨了应用创造酶切位点PCR（Created Restriction Site PCR,CRS-PCR）检测单碱基突变基因型的思路、方法和策略。Abstract:Created Restriction Site PCR (CRS-PCR) is a simple and efficient method to identify SNP genotypes.One or more mismatch bases are used in a primer to create a restriction site by combining SNP site after PCR.The CRS-PCR products can be genotyped with a way the same as PCR-RFLP.In the study,Extracelluar fatty acid binding protein (EX-FABP)　gene was served as an example for establishing the CRS-PCR method.Strategy of CRS-PCR was also discussed.     

Phenotypes of HeLa S3 variant cell lines resistant to growth inhibition by sodium butyrate

Summary HeLa cell variants capable of multiplying in the presence of sodium butyrate were used to study the relationship of cell cycle position to human chorionic gonadotropin (hCG) production and regulation of the genes encoding hCG α- and β-subunits. The butyrate-resistant variants exhibit several different stable phenotypes. In wild-type HeLa cells, butyrate arrests cell division and modulates synthesis of α- and β-subunits of glycoprotein hormones by coordinately regulating steady-state levels of their respective mRNAs. Because the variant cell lines replicate, in addition to producing hCG subunits in the presence of butyrate, cell cycle arrest does not seem to be a requirement for expression of glycoprotein hormone genes. Studies of histone modification suggest that neither hyperacetylation of histones H3 and H4 nor dephosphorylation of histones H1 and H2A mediates inhibition of cell replication. In the variants, α-subunit and hCGβ levels are independently regulated, as a consequence of independent regulation of α- and β-hCG mRNA levels. Long-term effects of butyrate include derepression of some genes (hCGβ in the variant AO) and repression of others (hCGα in variant AO). Moreover, hormone production correlates with the steady-state levels of mRNA for each of the subunits, suggesting that regulation occurs before translation. These findings indicate that the butyrate-resistant variant cell lines are valuable for studies of the molecular mechanisms involved in regulation of expression of ectopic hormones.     

基于氨基酸特征序列对人类Rh血型系统的蛋白质结构分析

利用代数学中同态思想和物理中的“粗粒化”思想,以及HP模型,根据a,t,c,g的化学结构分类,提出了DNA序列的特征序列概念（σ-,τ-,σ∩τ-）并推广到蛋白质序列中,从而给出一种数值刻划,将蛋白质序列简化成一个（0,1）序列,基于上述给出特征序列的方法,根据氨基酸分子量与简并度的关系,提出了另外一种DNA序列的特征序列概念（-）并推广到蛋白质序列中,进而给出了另外一种数值刻划,将蛋白质序列简化成一个（0,1,2）序列,通过比较RHD基因和RHCE基因的特征序列的数值刻划图,得出RHD基因和RHCE基因均偏爱使用低分子量且高简并度的氨基酸。     

Allozyme Diversity in Non-social Spiders: Pattern, Process and Conservation Implications

In this article we summarize estimates of genetic variation based on allozymes for 30 non-social spider species. Overall, these species show moderate levels of genetic variability (mean H_o = 6.8%) compared to other invertebrate species surveyed for allozymes, although a number of spiders possess only minimal variation. Fossorial spiders, especially those which are coastal dune dwellers, typically display less variation than other non-social arachnids. In general, differences in heterozygosity estimates between groups of non-social spiders in this article are not confounded by the varying mix of proteins that have been assayed by individual investigators. There is a significant positive relationship between genetic variability and gene flow (Nm), indicating that non-social spider populations which exhibit reduced variability are likely to be genetically isolated. Population bottlenecks, directional selection and environmental homogeneity have all been cited to account for reduced variability in particular non-social spiders. In addition, an analysis using the genus Lutica suggests that low genetic variation may be accompanied by decreased population fitness. Since the potential for evolutionary change is dependent on the existence of genetic variability, our findings indicate that a number of non-social spiders may be at risk in terms of long-term population viability. This conclusion should be verified/extended via a combination of more genetic surveys; genetic and ecological monitoring of populations and their fitnesses in the wild; and experimental studies of the mechanisms underlying fitness differences.     

Metapopulation genetic structure in the water vole, Arvicola terrestris, in NE Scotland

The genetic structure of nine colonies of the water vole, Arvicola terrestris , in one area of NE Scotland was studied. Non-destructive samples from 478 individuals (mostly immature animals) were typed for 12 microsatellites. Cases of Hardy-Weinberg disequilibrium were frequent within all colonies. The five colonies in the inland part of the study area also showed frequent cases of linkage disequilibrium. All colonies showed high levels of genetic diversity (unbiased H = 0.52-0.74). All five colonies sampled in successive years showed significant annual changes in genetic composition. All colonies showed genetic differentiation from each other, whether measured by average 6, pairwise 9 or pairwise Nei's genetic distance. The spatial pattern of genetic differentiation was consistent with either a stepping-stone model over the whole study area or an island model within the coastal and inland parts and an intervening barrier to gene flow. The study suggested that the genetic structure of colonies of A. terrestris often departs from the equilibrium states assumed by traditional mefhods for the study of gene flow, and that a parentage-based approach would be fruitful.     

Short communication: Prevalence of deleterious variants causing recessive disorders in Italian Chianina,Marchigiana and Romagnola cattle

In the last two decades, the molecular cause of six monogenic autosomal recessive disorders has been identified in native Italian beef cattle: two different ATP2A1 variants for the pseudomyotonia congenita, the first in Chianina and Romagnola (PMT1) and the second in Romagnola (PMT2); a KDM2B variant for the paunch calf syndrome (PCS) in Marchigiana and Romagnola; a NID1 variant for the congenital cataract (CC) in Romagnola; a LAMB1 variant for the hemifacial microsomia (HFM) in Romagnola; an ABCA12 variant for the ichthyosis fetalis (IF) in Chianina and a FA2H variant for the ichthyosis congenita (IC) in Chianina. The aim of this study was to evaluate the potential impact of these disorders in the affected Italian populations. For this purpose, 3331 Chianina, 2812 Marchigiana and 1680 Romagnola bulls born in the last 40 years were considered. The allelic frequency (AF) of the variant for PMT1 was 1.0% in Romagnola, 4.6% in Marchigiana and 5.9% in Chianina. The AF of the variant for PMT2 was 3.3% in Romagnola and 0% in the other two breeds. The AF of the variant for PCS was 11.7% in Romagnola, 2.0% in Marchigiana and 0% in Chianina. The AF of the variants for CC, HFM, IF and IC resulted below 3%, being the variants detected only in the breed populations in which they were previously reported. Considering a selected male population in the single breed, Chianina showed carrier prevalence of 11.9% for PMT1, 7.7% for IC and 6.4% for IF. Romagnola showed carrier prevalence of 23.4% for PCS, 6.7% for PMT2, 4.1% for HFM, 3.2% for CC and 2.0% for PMT1. Marchigiana showed carrier prevalence of 9.1% for PMT1 and 4.0% for PCS. With respect to the Romagnola cattle, the concerning presence of a total of five defect alleles in the population hampers a general approach based on the prevention of carriers from artificial insemination. However, identification of carriers may allow conscious mating to prevent the risk of homozygous descendants as well as the spread of heterozygous offspring. Therefore, systematic genotyping for all seven known harmful alleles is recommended to prevent risk mating between carriers, in particular to avoid the occurrence of affected offspring.     

新型p1 基因型肺炎支原体分型方法的建立与应用

【目的】针对肺炎支原体新型p1基因型(V2c型)菌株检测工作的需要,建立相应PCR检测方法并进行评价。【方法】针对新型V2c型肺炎支原体菌株p1基因变异区域序列设计特异性扩增引物,建立对V2c型肺炎支原体菌株进行PCR检测的检测方法并用相关基因测序进行验证。使用所建立的巢式多重PCR对北京地区2008-2011年分离到的214株临床肺炎支原体进行分型分析。【结果】特异引物可有效检测出V2c菌株,在其它型别菌株均无阳性扩增。214株肺炎支原体临床分离株中1型菌株占90.2%(193/214),V2a型菌株占0.9%(2/214),V2c型菌株占8.9%(19/214);未检出2型菌株。【结论】针对V2c型肺炎支原体所建立的基于p1基因的PCR检测方法,能有效区分以往方法无法检测出的新型V2c型肺炎支原体菌株,对开展肺炎支原体流行病学调查和病原分析有重要意义。     

Carboxylesterase-2 in the development of the loach (Misgurnus fossilis L.)

Two esterases splitting -naphthylacetate have been found in the tissues of adult loaches and in embryos. These were identified as arylesterase (E-1) (arylester hydrolase, E.C. 3.1.1.2) and carboxylesterase (E-2) (carboxylic ester hydrolase, E.C. 3.1.1.1.). In unfertilized loach eggs E-1 and E-2 synthesized during oogenesis were found. Active E-2 synthesized under the control of E-2 genes of the embryo appeared in embryos from the stage of 40–50 h of development. Maternal E-2 molecules synthesized in oogenesis or on the stored templates in embryogenesis persisted in larvae up to days 5–6 of development. Two genes controlling the synthesis of two forms of E-2 differing in electric mobility were found in the loach population from the delta of the Danube. The genes for fast and slow E-2 were shown to segregate in meiosis and to be allelic.