马(Equus caballus)外周血淋巴细胞染色体的三种带型(G带、C带和Ag-NOR_s带)

马驴骡的细胞遗传学研究已有不少报道(Hsu et a1.,1967;Benirschke et al.,1964;Benirschke et al.,1964;Benirschke et al.,1965;Short,1974)。70年代初,用人类染色体显带技术,有学者(Ryder,1978)从进化角度探讨马科种属的起源、进化和杂种不育等问题。在国内除了我们报道了马、驴和他们的杂种马骡和驴骡的核型外(李胜利等,1982),至今尚未见有关于马科动物的细胞遗传学研究报道。本文的目的就马(Equus caballus)染色体的三种带型作初步的介绍,以促进马科动物核型、染色体带型、杂种不育以及进化等方面的细胞遗传学的研究。     

中华绒螯蟹染色体的研究

中华绒螯蟹(Eriocheir sinensis H.Milne Edwards)属甲壳纲(Crustacea)、软甲亚纲(Malacostraca)、十足目(Decapoda)、方蟹科(Grapsidae),俗称河蟹,是我国重要的经济蟹类,其形态解剖、生态习性及生理等方面的研究已有报道(Panning,1939;Koch,1952;堵南山,1954,1957,1958;Bauchau,1960;Leersnyder,1966,1967;Dbainaut et al.,1976;Chevigue,1976;Leeranyder et al.,1977,1978;Pequenx et al.,1982;Chapelle et al.,1982;谈奇坤等,1984.),但至今未见有关细胞遗传学方     

哺乳动物细胞去核产物(胞质体及核体)的结构与功能研究

1967年Carter发现细胞松弛素可以诱发组织培养细胞的自发排核之后,Prescott(1972)借助细胞松弛素存在下的离心处理,使这一排核现象普遍化,从而确立了体外细胞去核的标准方法。经过不断改进(croce et al., 1974;Veomett et al., 1976;Lucas etal., 1976;Wigler et al., 1975),现在,这一技术已广泛应用于细胞学研究的各个重要领域(Mc Burney et al., 1979;Goldman et al., 1974;du Bols et al., 1980)。细胞去核技术及其应用的研究在我国已有初步开展(陈瑞铭等,1979;沈鼎武等,1980)。本实验对二种上皮型传代细胞系进行了去核手术,用扫描电镜和透射电镜对所获得的胞质体     

赤麂(Muntiacus muntjak)细胞株的建立及其生物学特性观察

赤麂(Munliacus muntjak)是迄今已知染色体数目最少的脊椎动物(Wurster,D.H.et al.1970),每条染色体都有明显的个体性,用常规染色方法即可清晰无误地一一加以区开,染色体又特别大。因此,这是比较理想的细胞遗传学实验材料。目前,国外已从印度产的成年印度麂(赤麂)的皮肤、肺、肾等组织建立了细胞株(Altman,P.L etal.1976;Brown,J.A et al.1973;Kato,H et al.1974;Yanagychi,N 1979)并广泛应用于辐射细胞遗传学,进化遗传学,遗传毒理学等许多方面的研究,取得了许多有意义的结果。     

In vivo tunable CRISPR mediates efficient somatic mutagenesis to generate tumor models

Dear Editor, CRISPR/Cas9 has revolutionized genome editing technology due to its simplicity and robustness (Mali et al., 2013). Several inducible CRISPR/Cas9 systems recently developed make spatiotemporal genome editing possible (Kon ermann et al., 2013;Balboa et al., 2015;Dow et al., 2015;Zetsche et al., 2015;Liu et al., 2016;Kleinjan et al., 2017;Maji et al.. 2017;Senturk et al., 2017;Lu et al., 2018).     

Import of Rift Valley fever to China: a potential new threat?

正Several recent studies in Virologica Sinica and other journals have highlighted the enormous international challenge of emerging arboviral diseases,such as Zika virus disease,dengue,and chikungunya(Islam et al.,2015;Maurice et al.,2015;Dai et al.,2016;Deng et al.,2016;Song et al.,2016;Wang et al.,2016;Xu et al.,2016;Zhang et al.,2016;Zhou et     

神农架川金丝猴粪便和尿液中类固醇激素的检测

灵长类动物类固醇激素的研究已经在很多物种间展开(Cariso et al.,1999;Lutz et al.,2000;He et al.,2001;Yan and Jiang,2006;Brandon et al.,2008;Lu et al.,2010;Kim et al.,2012)。特别是对于没有明显发情特征的灵长类动物,类固醇激素的变化可以为它们的繁殖状态提供更多可靠的评估(Fujita et al.,2001)。自然状态下野生动     

Cotton variant genomes—a breakthrough in population genetics analysis

正Cotton is not only an important cash crop for its fiber,but also an excellent model system for studying polyploidization,cell elongation and cell wall biosynthesis(Yang et al.,2014;Fang et al.,2017;Wang et al.,2016;Zou et al.,2016).A focus for scientists is to dissect the genetic basis underlying important agronomic traits(Gong et al.,2018;Huang et al.,2016).The advent of high-throughput sequencing technologies has boosted unveiling the cotton genome(Wang et al.,2012;Li et al.,2014;Li et al.,2015).High-throughput     

Generation of marker-free transgenic rice using CRISPR/Cas9 system controlled by ?oral speci?c promoters

Recently, the CRISPR/Cas9 system has been used as a powerful tool for genome editing in many species (Jinek et al., 2012;Cong et al., 2013;Wright et al., 2016;Li et al., 2017;Deng et al., 2018). The CR1SPR/Cas9 system can not only be used as a useful technology to disrupt endogenous genes but also expand numerous other applications, such as precise base editing (Komor et al., 2016;Zong et al., 2017), regulation of gene expression (Gilbert et al., 2013), and gene replacement or insertion (Wang et al., 2017).     

真菌原生质体技术在遗传学和虫生真菌研究领域中的应用

原生质体融合技术自70年代中到80年代末的十几年间有着相当快速的发展过程,从无机试剂诱导的融合(Binding,1974;Ferenczy,1975)到PEG辅助融合(Kao,1974)以至发展到电场诱导原生质体融合(Zimmermann, 1980; Halfmannet al.1983; Call et al. 1984;Broda et al. 1987; Foerster et al.,1986; Fikus et al., 1985; Magae etal., 1986; 汪和睦1986a,b;张博润等,1986;彭卫宪等,1987)反映了原生质体融合方法的演变全貌。随着原生质体融合手段的不断更新,在遗传学研究领域中,利用这项技术进行     

Whole arm inversions of chromosome 4 in Drosophila species

Inversions of genetic segments during the evolution of Drosophila are well documented in the X chromosome and most autosomes, but little attention has been paid to chromosome 4, the smallest autosome or "dot chromosome" present in many Drosophila species. From our previous mapping we have defined probes that mark proximal, intermediate, and distal locations of chromosome 4 in D. melanogaster. In situ hybridizations on salivary gland polytene chromosomes with these probes show that the whole right arm, including genes within cytological region 101EF-102F, is inverted relative to D. simulans. We also used these probes to determine the orientation of the arm of the dot chromosome in nine species of Drosophila, including eight from the melanogaster subfamily. To account for the observed whole arm inversions of chromosome 4 in five of the nine species examined, we propose that three inversion events have occurred during the evolution of these species. These whole arm inversions may explain some of the unusual features of this chromosome.     

Genetics of a Difference in Male Cuticular Hydrocarbons between Two Sibling Species, Drosophila Simulans and D. Sechellia

In seven of the eight species of the Drosophila melanogaster group, the predominant cuticular hydrocarbon of males is 7-tricosene, but in the island endemic species D. sechellia it is 6-tricosene. The phylogeny of the group implies that the novel hydrocarbon profile of D. sechellia is a derived character. Genetic analysis of hybrids between D. sechellia and its close relative D. simulans show that each of the five major chromosome arms carries at least one gene affecting the ratio of the two tricosene isomers, with the right arm of the third chromosome having the largest effect. The species difference in this character is therefore polygenic with the effects of the different chromosome arms generally additive, although there is some epistasis among third-chromosome genes. Observations of courtship by males who have been coated with foreign hydrocarbons suggest that a male's hydrocarbon profile may slightly affect the degree of sexual isolation in one of the reciprocal hybridizations between these species, but that this role is small compared to that played by hydrocarbon differences between females.     

The Y chromosomes of Drosophila simulans are highly polymorphic for their ability to suppress sex-ratio drive

The sex-ratio trait, known in several species of Drosophila including D. simulans, results from meiotic drive of the X chromosome against the Y. Males that carry a sex-ratio X chromosome produce strongly female-biased progeny. In D. simulans, drive suppressors have evolved on the Y chromosome and on the autosomes. Both the frequency of sex-ratio X and the strength of the total drive suppression (Y-linked and autosomal) vary widely among geographic populations of this worldwide species. We have investigated the pattern of Y-linked drive suppression in six natural populations representative of this variability. Y-linked suppressors were found to be a regular component of the suppression, with large differences between populations in the mean level of suppression. These variations did not correspond to differences in frequency of discrete types of Y chromosomes, but to a more or less wide continuum of phenotypes, from nonsuppressor to partial or total suppressor. We concluded that a large diversity of Y-linked suppressor alleles exists in D. simulans and that some populations are highly polymorphic. Our results support the hypothesis that a Y-chromosome polymorphism can be easily maintained by a balance between meiotic drive and the cost of drive suppression.     

A comparative analysis of the rainbow trout genome with 2 other species of fish (Arctic charr and Atlantic salmon) within the tetraploid derivative Salmonidae family (subfamily: Salmoninae).

We updated the genetic map of rainbow trout (Oncorhynchus mykiss) for 2 outcrossed mapping panels, and used this map to assess the putative chromosome structure and recombination rate differences among linkage groups. We then used the rainbow trout sex-specific maps to make comparisons with 2 other ancestrally polyploid species of salmonid fishes, Arctic charr (Salvelinus alpinus) and Atlantic salmon (Salmo salar) to identify homeologous chromosome affinities within each species and ascertain homologous chromosome relationships among the species. Salmonid fishes exhibit a wide range of sex-specific differences in recombination rate, with some species having the largest differences for any vertebrate species studied to date. Our current estimate of female:male recombination rates in rainbow trout is 4.31:1. Chromosome structure and (or) size is associated with recombination rate differences between the sexes in rainbow trout. Linkage groups derived from presumptive acrocentric type chromosomes were observed to have much lower sex-specific differences in recombination rate than metacentric type linkage groups. Arctic charr is karyotypically the least derived species (i.e., possessing a high number of acrocentric chromosomes) and Atlantic salmon is the most derived (i.e., possessing a number of whole-arm fusions). Atlantic salmon have the largest female:male recombination ratio difference (i.e., 16.81:1) compared with rainbow trout, and Arctic charr (1.69:1). Comparisons of recombination rates between homologous segments of linkage groups among species indicated that when significant experiment-wise differences were detected (7/24 tests), recombination rates were generally higher in the species with a less-derived chromosome structure (6/7 significant comparisons). Greater similarity in linkage group syntenies were observed between Atlantic salmon and rainbow trout, suggesting their closer phylogenetic affinities, and most interspecific linkage group comparisons support a model that suggests whole chromosome arm translocations have occurred in the evolution of this group. However, some possible exceptions were detected and these findings are discussed in relation to their influence on segregation distortion patterns. We also report unusual meiotic segregation patterns in a female parent involving the duplicated (homeologous) linkage group pair 12/16 and discuss several models that may account for these patterns.     

部分菊属植物及其种间杂种减数分裂异常现象观察

对不同倍数性菊属植物及其部分种间杂种的减数分裂异常现象进行观察统计,并分析其形成机制以及在菊属系统演化中的作用。结果表明,菊属减数分裂异常现象包括分裂不同步、二价体提前解离、二价体互锁、染色体桥、落后染色体等。减数分裂不同步现象普遍存在于菊属植物减数分裂过程。二倍体的菊花脑、甘菊、异色菊的部分二价体在终变期提前解离为单价体。菊花脑及其部分杂种中观察到了互锁二价体。四倍体菊花脑、南京野菊、‘黄英’、‘滁菊’在AI和AII都出现了染色体桥,毛华菊有1.5%的PMC在AI出现染色体桥。四倍体菊花脑AI、AII期出现落后染色体的频率分别为10.6%和7.3%;毛华菊AI期出现落后染色体的频率为4.4%;栽培菊‘黄英’和‘滁菊’在AI、AII期出现落后染色体的频率高于毛华菊。杂种出现染色体桥及落后染色体的频率普遍高于亲本。倒位以及由其引起的各种染色体结构变异可能在菊属系统演化过程中起着重要作用。     

Chromosome pairing in haploids of Brassica campestris

Summary The maximum chromosome pairing observed in haploids of Brassica campestris was two bivalents plus one trivalent but differences were observed in the chromosome pairing frequencies of the four haploids studied. This pairing supports the theorem that the species is hexasomic for one chromosome, tetrasomic for two and disomic for three others but it is emphasized that some of the observed pairing might be explained by a phenomenon other than homology.     

Puff expression in relation to genotype]

The studies of genotype influence on puff size in salivary gland chromosomes of Drosophila virilis (stocks 9, 101, 142, 151) and D. texana (the stock 123) reveal significant differences between the species concerning the structure of puff in the 3-C-6 region at the stage of puparium formation. In reciprocal F1 hybrids the size of the puff was intermediate in comparison with parental forms having a slight maternal effect. The differences in puff size in the 5th chromosome between interspecific hybrids and the special stock of D. virilis carrying a region of D. texana 5th chromosome in heterozygous condition (inserted into D. virilis 5the chromosome by double crossing-over) were observed. The transfer of the region of the third chromosome to near centrimetric heterochromatic of the 5th chromosome by translocation resulted in the increase in the 3-B-2 puff size. However, the transposition of the 3-B1 region in the proximal direction with respect to chromocenter did not affect the puff size.     

Distribution of the retrotransposable element 412 in Drosophila species

Copy numbers of sequences homologous to the Drosophila melanogaster retrotransposable element 412, their distribution between the chromosome arms and the chromocenter, and whether they contain full- size copies were analyzed for 55 species of the Drosophila genus. Element 412 insertion sites were detected on the chromosome arms of D. melanogaster, Drosophila simulans, and a few species of the obscura group, but the chromocenter was labeled in almost all species. The presence of element 412 sequences in the majority of species shows that this element has a long evolutionary history in Drosophilidae, although it may have recently invaded the chromosomes in some species, such as D. simulans. Differences in copy number between species may be due to population size or specific endogenous or environmental factors and may follow the worldwide invasion of the species. Putative full-length copies were detected in the chromocenters of some species with no copies on the chromosome arms, suggesting that the chromocenter may be a shelter for such copies and not only for deleted ones.