油用向日葵主要农艺性状的遗传分析

对10个油用向日葵品种的主要农艺性状进行遗传分析的结果表明,株高、单株粒数、百粒重、盘径和单株粒重等农艺性状具有较大的遗传率,可以在早代单株选择或直接选择;出苗-现蕾、现蕾-开花、开花-成熟、皮壳率等性状的遗传率较低,应根据各性状间相关关系进行间接选择或将选择推迟到晚期世代进行。遗传变异幅度较大的性状有皮壳率、单株粒数、小区产量、单株粒重等。由于性状的遗传改良效果主要由该性状的遗传率和变异幅度及选择强度所决定,因此,在选择率确定为5%情况下,遗传改良效果较好的性状为单株粒数和单株粒重。 Abstract:The genetic analysis of main agronomic characters was conducted with 10 varieties of oil sunflower(Helianthus annuus L.).The results showed that direct selection can be carried out at early generation for characters with higher heritability such as plant height,grain number pere plant,100-grain weight,diameter of disc and grain weight per plant.For maturity and percentage of shell with lower heritability,indirect selection correlated with other characters or late generation selection can be utilized.The characters showing wide genetic variation were those as percentage of shell,grain number per plant,grain yield per plot and grain weight.Since the successful improvement of a character mainly depends on its heritability,variation of heritability and intensity of selection,we suggest that the characters which may give better genetic improvement are grain number and grain weight per plant under condition of 5% selection pressure.     

神经管畸形相关基因的研究进展

神经管畸形是由遗传和环境因素共同作用而导致的一种常见的出生缺陷。遗传因素中包括细胞增殖因子、转录因子及影响叶酸代谢的关键酶的基因。本文着重从动物模型和群体流行病学调查两方面,简述目前研究的热点基因及特定位点的遗传多态性与神经管畸形的关系,从而揭示多因素作用在神经管畸形病因学研究中的意义。 Progress in Researches on Neural Tube Defects Related the Genes QU Mei,LI Zhu Institute of Reproductive and Child Health of Peking University,National Reference Laboratory on Reproductive Health Research Ministry of Health,Beijing 100083,China Abstract:Neural tube defects are common birth defects which are ascribed to the combination of genetic and environmental factors.The genetic factors include cell growth factors,transformation factors and key enzymic genes involved in folate metabolism.This paper reviews the genes as focus of current investigantion and the relationship between the genetic polymorphism on the specific sites and neural tube defects based on animal model and population epidemiological study.It indicats that the multifactors play an important role in the etiology of neural tube defects. Key words：neural tube defects; genetic polymorphism     

小麦异交群体连续歧化选择的RAPD分析

利用太谷核不育基因构建的遗传变异丰富的基础群体DNS2,进行了连续5轮歧化选择。本论文从不同的世代中,选择了10个子群体进行RAPD分析。采用7个引物扩增出116个位点,从基因频率和表型带两个角度的分析都表明,群体具有丰富的遗传变异。整个群体总的多态位点百分率达88.79,总杂合度为0.3143。子群体内（间）遗传距离的结果显示：子群体内的遗传差异小于子群体间的遗传差异;各选择子群体与未选群体间都有较大的遗传距离;随着选择轮次的增加,株高选择子群体间的遗传距离逐渐增大;对同一性状进行选择的子群体间世代内（间）平均遗传距离小于对不同性状进行选择的子群体内（间）的遗传距离。RAPD分子聚类结果显示出对同一性状进行选择的子群体聚在一起,反映了对株高选高的选择效果比较明显。 Abstract:A base population was established through multi-parent random crossing by using Taigu dominant male-sterile wheat,and then five cycles of 2-way selection for four quantitative characters were conducted.The dynamic changes of genetic structures in the open-pollinated wheat population were examined by RAPD technique.Seven primers in RAPD analysis amplified 116 sites.The results of gene frequencies and phenotypic bands showed abundant genetic variations existed in the population.The percentage of polymorphic loci was 8879,and the average heterozygosity was 0.3143 in the whole population.The genetic distance of RAPD showed as follows :① The genetic distance within a subpopulation was lower than that between every two subpopulations.② Each subpopulation had considerable divergence compared with unselected population.③ The genetic distances between the subpopulations which were selected for plant height gradually increased accompanied with the selection.④The genetic distance between subpopulations which were selected for the same character was lower than that were selected for different characters both in the same generation and among different generations.The cluster results of RAPD genetic distance demonstrated that the subpopulations selected for the same character going to one cluster.It also showed that the selective effect of increasing plant height was obvious.     

AQR is a novel type 2 diabetes-associated gene that regulates signaling pathways critical for glucose metabolism

Type 2 diabetes mellitus(T2 DM) is a common metabolic disease influenced by both genetic and environmental factors. In this study, we performed an in-house genotyping and meta-analysis study using three independent GWAS datasets of T2 DM and found that rs3743121, located 1 kb downstream of AQR,was a novel susceptibility SNP associated with T2 DM. The risk allele C of rs3743121 was correlated with the increased expression of AQR in white blood cells, similar to that observed in T2 DM models. The knockdown of AQR in HepG2 facilitated the glucose uptake, decreased the expression level of PCK2,increased the phosphorylation of GSK-3β, and restored the insulin sensitivity. Furthermore, the suppression of AQR inhibited the mTOR pathway and the protein ubiquitination process. Our study suggests that AQR is a novel type 2 diabetes-associated gene that regulates signaling pathways critical for glucose metabolism.     

Molecular Genetic Variation in a Clonal Plant Population of Leymus chinensis （Trin.） Tzvel.

Randomly amplified polymorphic DNA （RAPD） analysis was used to investigate the genetic variation among populations, between populations, and within populations, relationships between genetic distance and geographic distance, and the molecular variation and population size. The effects of geographic and genetic distances, as well as of genetic differentiation and population size, on genetic variations of Leymus chinensis （Trin.） Tzvel. are discussed. The present study showed that there was significant RAPD variation between the Baicheng region population and the Daqing region population, with a molecular variance of 6.35% （P 〈 0.04）, and for differentiation among area populations of the Daqing region, with a molecular variance of 8.78% （P 〈 0.002）. A 21.06% RAPD variation among all 16 populations among two regions was found （P 〈 0.001）, as well as 72.59% variation within populations （P 〈 0.001）. Molecular variation within populations was significantly different among 16 populations.     

新疆阜康荒漠红砂种群遗传结构及其与生态因子的耦合关系

Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diversity and differentiation were revealed in the population of R. soongorica by 15 random primers. One hundred and thirty-six individuals from seven subpopulations were sampled in the study. Seventy-one loci have been detected, and among them 69 were polymorphic. The mean proportion of polymorphic loci (PPB) was 97.18%. The analyses of Shannon information index (0.307 5), Nei抯 gene diversity (0.312 7) and GST (0.312 0) indicated that there were more genetic variations within the subpopu-lations than those among the subpopulations. The results of AMOVA analysis showed that 61.58% of the genetic variations existed within subpopulations, and 38.02% among the subpopulations. The gene flow among the subpopulations of R. soongorica (Nm = 1.102 8) was much less than that of the common anemophytes (Nm = 5.24), so genetic differentiation among the subpopulations occurred to some extent. Additionally, through the use of clustering and the correlation analyses, we found that the genetic struc-ture of natural population of R. soongorica was related to some ecological factors (soil factors mainly) of the oasis-desert transition zone. The genetic diversity level of R. soongorica had negative correlation with the content of total soil P and Cl- significantly (P＜0.05). On the contrary, it had significant positive correlation with CO32- (P＜0.05), showing that the distribution of the individuals of R. soongorica in the sampled areas correlates with certain soluble salt. Furthermore, the genetic diversity of the natural population of R. soongorica increased with the decreasing of the content of soil organic matters, water, total N and total P in soil. The paper concluded that the microenvironment ecological factors played an important role in the adaptive evolution of R. soongorica population.     

三种舌运动类型遗传方式的研究 Studies of Hereditary Mode on Three Tongue Moving Types

采用Penrose先证者同胞法和分离分析方法对72个家系资料的分析表明：卷舌、尖舌均为常染色体单基因显性遗传,阳性为显性性状;翻舌为常染色体单基因隐性遗传,阳性为隐性性状。虽然环境因素对这类特征的表现也有一定的影响,但遗传因素仍起主要作用。 Abstract:The data of 72 families were analyzed by the method of proband′s sib and the method of segregation analysis.The results showed that the hereditary mode of rolling tongue or pointed tongue is the dominant heredity of single gene of autosome,and the positive type of them is the dominant character;Twisting tongue is the recessive heredity of single gene of autosome,while the positive type is the recessive character.Present study suggested,although environmental might affect these characters,hereditary factors seemed to be dominant.     

蚕豆主要数量性状的遗传主成份和数量分类

对50个蚕豆品种的7个数量性状进行了遗传主成份分析, 初步提出了评选蚕豆品种的遗传主成份标准,并筛选出18个综合性状优良的亲本品种。测定了50个蚕豆品种的遗传距离, 根据遗传距离大小,将50个蚕豆品种聚类为2群、 3类、9组。分类结果指出,蚕豆品种的遗传距离大小与地理差异有些似有一定关系,但在总体上,二者间无必然联系。 Abastract:Analysis of major Genetic component analysis was performed for 7 quantitative characters of 50 faba bean lines and according to the analysis,18 lines were selected as parents.The 50 lines were classified into 2 subpopulations,3 types and 9 groups according to their genetic distance.The results showed that there was seemly a correlation between geographical distribution and genetic distance,nevertheless most lines within the same cluster were close in genetic distance but far in geographic sites.     

Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats

BACKGROUND Despite overt insulin resistance,adipocytes of genetically obese Zucker rats accumulate the excess of calorie intake in the form of lipids.AIM To investigate whether factors can replace or reinforce insulin lipogenic action by exploring glucose uptake activation by hydrogen peroxide,since it is produced by monoamine oxidase(MAO)and semicarbazide-sensitive amine oxidase(SSAO)in adipocytes.METHODS 3H-2-deoxyglucose uptake(2-DG)was determined in adipocytes from obese and lean rats in response to insulin or MAO and SSAO substrates such as tyramine and benzylamine.14C-tyramine oxidation and binding of imidazolinic radioligands[3H-Idazoxan,3H-(2-benzofuranyl)-2-imidazoline]were studied in adipocytes,the liver,and muscle.The influence of in vivo administration of tyramine+vanadium on glucose handling was assessed in lean and obese rats.RESULTS 2-DG uptake and lipogenesis stimulation by insulin were dampened in adipocytes from obese rats,when compared to their lean littermates.Tyramine and benzylamine activation of hexose uptake was vanadate-dependent and was also limited,while MAO was increased and SSAO decreased.These changes were adipocyte-specific and accompanied by a greater number of imidazoline I2 binding sites in the obese rat,when compared to the lean.In vitro,tyramine precluded the binding to I2 sites,while in vivo,its administration together with vanadium lowered fasting plasma levels of glucose and triacylglycerols in obese CONCLUSION The adipocytes from obese Zucker rats exhibit increased MAO activity and imidazoline binding site number.However,probably as a consequence of SSAO down-regulation,the glucose transport stimulation by tyramine is decreased as much as that of insulin in these insulin-resistant adipocytes.The adipocyte amine oxidases deserve more studies with respect to their putative contribution to the management of glucose and lipid handling.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

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     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

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.     

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

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