首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The present study is aimed at determining some haematological and biochemical parameters in the wild Indian bonnet monkeys as also the microscopic and ultrastructural characteristics of their pancreatic islets. Adult wild Indian bonnet monkeys (Macaca radiata radiata) of both sexes weighing between 2.5 and 4 kg were used in these experiments. Their platelet, reticulocyte and total leukocyte counts and the blood concentrations of hemoglobin and plasma proteins and the serum concentrations of aspartate amino transferase, alanine amino transferase and calcium are similar to the values reported for M. mulatta. Plasma glucose is lower when compared with reported values of M. mulatta and M. fascicularis. Insulin levels are comparable with those of M. mulatta and M. nigra. Histology of islets is similar to that of humans. Ovoid cell collections of islet cells are scattered throughout the pancreas. Ultrastructure of A, B and D cells is similar to humans. These findings suggest that this relatively underutilized macaques may be a suitable model for biomedical research.  相似文献   

2.
Heteroploid cell populations often show narrow peaks of G0/G1 and G2/M DNA content and broadly distributed chromosome numbers. This was originally explained by the selective metaphase arrest of the cells that have non-modal chromosome numbers. To test whether this explanation applies, we have measured the chromosome number distributions, as well as the G0/G1, G2, metaphase (M), and telophase (T) DNA distributions, of the cell lines WCHE-5, MCa-11, and HL-60. The WCHE-5 cells had narrowly distributed chromosome numbers and G0/G1 G2, M, and T DNA peaks. The MCa-11 and HL-60 cells also had narrowly distributed G0/G1 and G2 DNA peaks, but broadly distributed chromosome numbers and M and T DNA peaks. The widths of the MCa-11 and HL-60 M- and T-cell DNA peaks were similar to those of their chromosome number peaks, suggesting that all cells were completing mitosis, regardless of chromosome number or DNA content. Thus, selective metaphase arrest does not seem to be the cause of the narrow G0/G1 and G2 DNA peaks of heteroploid cell populations.  相似文献   

3.
The Cervidae show the largest variation in chromosome number found within any mammalian family. The eight species of deer which are the subject of this study vary in chromosome number from 2n = 70 to 2n = 6. Three species of Bovidae are also included since they belong to a closely related family. Digestion of nuclear DNAs with the restriction endonucleases Hae III, Hpa II, Msp I, Eco RI, Xba I, Pst I and Bam HI reveals that there is a series of highly repetitive sequences forming similar band patterns in the different species. There are two bands (1100 and 550 base pairs) which are common to all species although the two families separated more than 40 million years ago. To obtain information on the degree of homology among these conserved sequences we isolated a Bam HI restriction fragment of approximately 770 base pairs from red deer DNA. This sequence was 32P labeled and hybridized by the Southern blot technique with DNAs cleaved with Bam HI, Eco RI, Hpa II and Msp I. Moreover, the same sequence was cloned in the plasmid vector pBR322 nick translated with 32P and hybridized with the DNAs of 8 species of Cervidae and 3 of Bovidae. The same cloned probe was labeled with 3H and hybridized in situ with the metaphase chromosomes of red deer (2n = 68) and Muntiacus muntjak (2n = 7 male). Homologies are still present between the highly repetitive sequences of the 8 species of Cervidae despite the drastic reorganization that led to extreme chromosome numbers. Moreover, the cloned DNA sequence was found to occupy the same position, in the proximal regions of the arms, in both red deer (2n = 68) and M. muntjak (2n = 7 male) chromosomes. The ribosomal RNA genes and the centromeres in these species have also maintained their main territory despite the drastic chromosome reorganization. These results are experimental confirmation of the chromosome field theory which predicted that each DNA sequence has an optimal territory within the centromere-telomere field and tends to occupy this same territory following chromosome reorganization.  相似文献   

4.
We used reciprocal chromosome painting with both African green monkey (C. aethiops) and human chromosome specific DNA probes to delineate homologous regions in the two species. Probes were derived by fluorescence-activated chromosome flow sorting and then were reciprocally hybridized to metaphase spreads of each species. Segments in the size range of a single chromosome band were identified, demonstrating the sensitivity of the approach when comparing species that diverged more than 20 million years ago. Outgroup analysis shows that the great difference in diploid numbers between the African green monkey (2n = 60) and humans (2n = 46) is mainly owing to fissions, and the direction of change is towards increasing diploid numbers. However, most break points apparently lie outside of the centromere regions, suggesting that the changes were not solely Robertsonian as has been previously assumed. No reciprocal translocations have occurred in the phylogenetic lines leading to humans or African green monkeys. The primate paints established here are a valuable tool to establish interspecies homology, to define rearrangements, and to determine the mechanisms of chromosomal evolution in primate species. Received: 10 December 1998 / Accepted: 18 February 1999  相似文献   

5.
Threshold mechanisms of activity for mutagenic agents have been debated for some time, especially for those substances which induce aneuploidy by inhibiting mitotic spindle function. No observed effect levels (NOELs) or "practical thresholds" have been demonstrated for several aneugens both in vitro and in vivo generally by either counting chromosomes in metaphase preparations or by observing micronuclei. Recently, fluorescence in situ hybridization (FISH) has proven to be a sensitive and useful technique for the assessment of aneuploidy at low concentrations. Using binucleate human lymphocytes coupled with FISH, we have been able to characterize a threshold mechanism of action for two spindle inhibitors, benomyl and its active metabolite, carbendazim. Test chemicals were added 24 h following culture initiation. After a further 20 h, cytochalasin B was added, and cells were harvested 28 h later (72 h post initiation). The distribution of chromosomes between the nuclei of binucleate cells was evaluated by fluorescence microscopy for the simultaneous detection of centromeres labeled with FITC (green) or Cy-3 (red). Six human chromosomes were investigated in pairs (1 and 8, 11 and 18, and X and 17). Abnormalities were classified as chromosome loss (including centromeric positive micronuclei), chromosome gain, non-disjunction, or polyploidy. Dose-response data were generated over a range of closely spaced concentrations at 100 ng/ml intervals. The threshold, defined as the lowest "effect" concentration using statistical methods, was determined for each chromosome. Non-disjunction proved to be the most sensitive endpoint for the detection of aneuploidy occurring at higher frequencies and lower concentrations. Results for the six chromosomes demonstrated similar dose-response data which included a series of concentrations with no statistically significant increase above background, followed by a second range of higher concentrations with a statistically significant, concentration-dependent increase. Nearly equimolar threshold concentrations were determined for benomyl- and carbendazim-induced non-disjunction.  相似文献   

6.
7.
Cross-amplification of 15 human microsatellites was performed successfully in cynomolgus (Macaca fascicularis) and rhesus (M. mulatta) macaques and 11 other Cercopithecidae species of biomedical and conservation relevance. To allow for quick, efficient, and high-throughput genotyping to assess intra- and interspecific genetic variation, we performed three multiplex sets, each comprised of five markers from different parts of the genome (i.e., autosomes, the MHC region, and the X-chromosome). These multiplex sets are likely to reveal allelic divergence between taxa, which could be used for their discrimination. Population studies on three regional populations of M. fascicularis and one of M. mulatta revealed that most of the loci, with the exception of one monomorphic locus, displayed polymorphisms (the expected heterozygosities were 0.48-0.91 for M. fascicularis, and 0.61-0.93 for M. mulatta), which makes them useful for population genetics. For the multiplex set M1, including the nonlinked autosomal markers, low probabilities of identity were observed: P(ID) values ranged from 8 x 10(-7) to 3 x 10(-5). This multiplex set is reliable for forensic applications, such as individual identification, parentage testing, and kinship analysis, in wild and captive populations.  相似文献   

8.
The distribution of the G-bands in chromosomes of bone marrow cells of Cercopithecus aethiops was studied by means of differentail staining with the Romanovsky - Gimsa dye. All the homologous chromosome pairs were identified and morphometric parameters were detected. The comparison of C. aethiops karyotypes with those of Macacca mulatta has shown that they are different in numbers and in the character of banding pattern of the most chromosomes. Both species revealed 12 pairs of chromosomes similar in their morphology and parameters.  相似文献   

9.
A species complex in Spirogyra consists of the series of filament morphotypes of various ploidal levels arising from an original morphotype within a clonal culture or in nature. A clonal culture of filaments identified as Spirogyra maxima (Hassall) Kützing produced several morphotypes, i.e. filament types of distinctly different widths and ploidal levels. Banding patterns and satellites were visible on chromosomes stained at mitotic prophase and metaphase. The original culture of S. maxima contained filaments averaging 127 μ wide. Vegetative cells of the original culture contained six large chromosomes (>4 μ long), identifiable as three distinct pairs based on banding patterns and presence of satellites: (1) one pair of short chromosomes (ca. 5.0 μ); (2) one pair of long chromosomes (ca. 8.0 μm); and (3) a second pair of long chromosomes (ca. 9.0 μm) including a nucleolar organizing region and satellite. A larger morphotype averaging 175 μm in width contained 12 chromosomes, with two pairs of short chromosomes and four pairs of long chromosomes (satellites were usually indistinct). Aneuploid chromosome numbers ranging from 5 to 13 were observed in a few cells. Binucleate and trinucleate cells were also observed. A twobanded chromosome fragment was observed in a few cells with 6 chromosomes and a few cells with 12 chromosomes. The variety of morphotypes derived in this study could be identified as four different species of Spirogyra by conventional taxonomic criteria. The banding patterns and satellites on chromosomes suggest that three pairs of homologous chromosomes are present in filaments of the original clonal culture and that these filaments are themselves autopolyploid (diploid) descendants of ancestral form with a base chromosome number of x = 3.  相似文献   

10.
A method is described for visualizing three nucleic acid sequences simultaneously by in situ hybridization using a new blue immunofluorescent label, amino methyl coumarin acetic acid (AMCA), in combination with green and red fluorescing FITC and TRITC. Three chromosome-specific repetitive probes labeled with either amino acetyl fluorene (AAF), mercury, or biotin were hybridized simultaneously to metaphase chromosomes prepared from human blood lymphocytes or to interphase tumor nuclei. Conditions for the combined use of three immunocytochemical affinity systems as well as the optimal spectral separation of the three fluorescing labels have been determined. Three-color in situ hybridization was applied to the study of numerical chromosome abnormalities as occur in human solid tumors. Further applications of this method in prenatal diagnosis for the detection of aneuploidy of the most frequently involved autosomes, as well as for the quantification of gene copy number and mRNA expression, are discussed.  相似文献   

11.
12.
Summary Treatment of metaphase PtK1 cells with 0.2 M to 0.5 M sucrose and anaphase cells with 0.5 M sucrose has previously been shown to stop chromosome motion probably due to a significant alteration in the functional attachment of kinetochore microtubules (kMTs) with the kinetochore lamina. The work presented here examines the effects of 0.15 M to 0.25 M sucrose on PtK1 metaphase and anaphase cells with a focus on the ultrastructural changes in the kinetochore and rates of chromosome motion. Metaphase PtK1 cells treated with 0.15 M and 0.20 M sucrose from 5 to 15 min showed spindle elongation with sister chromatids remaining at the metaphase plate; these cells failed to enter anaphase. Ultrastructural analysis revealed MTs did not insert directly into the kinetochore lamina but rather associated tangentially with an amorphous material proximal to the kinetochore region much like that described previously with higher concentrations of osmotica. Treatment of metaphase cells with 0.25 M sucrose arrested the cell in metaphase and ultrastructural analysis revealed novel osmiophilic spherical structures approximately 0.50 m in diameter located proximal to kinetochores. MTs appeared to stop just short of. or associate laterally with, these spherical structures. Anaphase PtK1 cells treated with 0.15 M and 0.20 M sucrose showed reduced rates of chromosome segregation during 5 min treatments, suggesting they retained functional kinetochore/kMT interactions. However, treatment of anaphase cells with 0.25 M sucrose blocked anaphase A chromosome motion and produced electron dense spherical structures approximately 0.50 m in diameter, identical to those observed in similarly treated metaphase cells. Removal of 0.25 M sucrose in treated anaphase cells resulted in normal chromosome segregation within 1 min. Cells released from sucrose treatment showed the absence of spherical structures and reformation of normal kinetochore/MT interactions which was temporally correlated with the resumption of chromosome motion.Abbreviations DIC differential interference contrast - kMT(s) kinetochore microtubule(s) - MT(s) microtubule(s) - nkMT(s) non-kinetochore microtubule(s)  相似文献   

13.
Chromosomes of Bombyx mori (n = 28) and of Bombyx mandarina (n = 27) were studied cytogenetically to resolve the origin of the large M chromosome in the Japaneses type of B. mandarina. In the F1 progeny from the reciprocal cross between B. mandarina and B. mori, the mitotic chromosome number was 2n = 55, and a chromosome configuration of 26 bivalents plus 1 trivalent was observed at metaphase I of germ cells. The trivalent chromosome consisted of the M chromosome from B. mandarina and two chromosomes from B. mori. When males of B. mori were mated to the F1 females, nuclei with two types of chromosome number (2n = 55 and 2n = 56) and two sets of chromosome pairs (26 bivalents plus 1 trivalent versus 28 bivalents) were observed in the metaphase I stage. Linkage analysis showed that the 14th chromosome of B. mori was involved in these two types of chromosome segregation. This result indicates that the M chromosome in B. mandarina arose from a fusion between a chromosome corresponding to the 14th linkage group and another, yet unidentified linkage group.  相似文献   

14.
应用双色荧光原位杂交技术检测克氏综合征   总被引:2,自引:1,他引:2  
刘永章  吴雪昌  金龙金  董杰影 《遗传》2003,25(3):271-275
探讨用双色荧光原位杂交技术(dual-color fluorescence in situ hybridization,D-FISH)检测性染色体数目异常克氏综合征的应用价值,建立常规分裂期染色体和间期细胞FISH技术的实验方法。以Biotin标记的X染色体α-卫星DNA(pBamX7)探针和以Digoxigenin标记的Y染色体长臂末端重复序列(pY3.4)探针对19例克氏综合征标本同时进行外周血染色体及其间期细胞核的原位杂交,分别用Avidin-FITC和Rhodamine-FITC及其Anti-avidin进行信号的检测与放大,DAPI复染。于Olympus AX-70型荧光显微镜下,分别通过WIB、WIG及其WU滤光镜观察杂交信号及其染色体或间期核背景,并统计外周血中期染色体及其间期细胞核的杂交信号颗粒数量。在显微镜下可见以Biotin标记的pBamX7探针显示2个绿色杂交信号,以Digoxigenin标记的pY3.4探针显示1个红色杂交信号,染色体或间期核背景经DAPI复染显示蓝色;18例出现XXY杂交信号的细胞,染色体及其间期细胞核杂交平均出现率分别为95.89%和95%,明显大于正常对照标准值2.75%,证实核型为47,XXY,与染色体检测的结果一致;其余1例染色体核型检测为嵌合体,XXY杂交信号细胞出现率为92%,同时检出6.7%的XY杂交信号细胞(>正常对照标准值4.17%)。用FISH 技术检测性染色体数目异常克氏综合征具有快速、敏感度高、信号强、背景低、多色等优点,故FISH 技术在产前诊断检测领域中显示其重要的应用价值和发展前景。 Abstract:The objective of the work is to study the technique of dual-color fluorescence in situ hybridization(D-FISH) and its application value in the diagnosis of sex chromosomal count abnormality Klinefelter syndrome and establish an experimental approach to metaphase chromosome and interphase nucleus FISH technique.Biotin labeled alpha satellite X-chromosome DNA(pBamX7) probe and Digoxigenin labeled Y-chromosome long arm terminal repetitive sequence (pY3.4) probe were hybridized with pre-treated slides of peripheral blood chromosome and interphase nucleus in 19 cases of Klinefelter syndrome specimens.After being washed,the slides were treated with Avidin-FITC,Rhodamine-FITC and Anti-avidin,amplified with an additional layer and counter-stained with DAPI in an antifade solution.The hybridization signals,chromosomal or interphase nucleus settings were observed respectively with WIB,WIG and WU filters under fluorescence microscope Olympus AX-70,and the number of metaphase chromosome and interphase nucleus in the peripheral blood was counted.It was observed under the microscope that the Biotin labeled pBamX7 probe showed 2 green hybridization signals and that the Digoxigenin labeled pY3.4 probe showed 1 red hybridization signal.Chromosome or interphase nucleus counter-stained with DAPI showed blue.The average signal rate of chromosome and interphase nucleus hybridization was 95.89% and 95% respectively,significantly higher than the normal control (2.75%).Karyotype 47,XXY was confirmed,which agrees with the chromosomal findings.One case showed mosaic nuclei.XXY chromosome hybridization signal rate was 92% and XY hybridization signal rate was 6.7%,higher than the normal control rate of 4.17%.FISH is a valuable technique in diagnosing sex chromosomal count abnormality Klinefelter syndrome with the merits of fast speed,high sensitivity,strong signal,low background and multiple color.Therefore,FISH technique can find wide application and potential in prenatal diagnosis.  相似文献   

15.
四倍体鲫鲤、三倍体湘云鲫染色体减数分裂观察   总被引:10,自引:0,他引:10  
用精巢细胞直接制片法观察了异源四倍体鲫鲤、三倍体湘云鲫和二倍体红鲫、湘江野鲤精母细胞染色体第一次减数分裂中期配对情况 ;作为对照 ,观察了上述四种鱼肾细胞的有丝分裂中期染色体。在精母细胞第一次减数分裂中 ,异源四倍体鲫鲤同源染色体两两配对 ,形成 10 0个二价体 ,没有观察到单价体、三价体和四价体 ;三倍体湘云鲫精母细胞形成 5 0个二价体和 5 0个单价体 ;红鲫和湘江野鲤精母细胞分别形成 5 0个二价体。肾细胞检测表明异源四倍体的染色体数目为 4n =2 0 0 ;湘云鲫为 3n =15 0 ;红鲫和湘江野鲤分别为 2n =10 0。减数分裂时染色体分布情况与肾细胞染色体检测结果相吻合。具有四套染色体的异源四倍体鲫鲤在减数分裂中只形成 10 0个二价体 ,而不形成 2 5个四价体或其它形式 ,为产生稳定一致的二倍体配子提供了重要的遗传保障 ,也为人工培育的异源四倍体鲫鲤群体能够世世代代自身繁衍下去提供了重要的遗传学证据。三倍体湘云鲫在减数分裂过程中出现二价体、单价体共存 ,同源染色体在配对和分离中出现紊乱 ,导致非整倍体生殖细胞的产生 ,为湘云鲫的不育性提供了染色体水平上的证据  相似文献   

16.
玉兰减数分裂观察及染色体构型分析   总被引:2,自引:1,他引:1  
采用去壁低渗方法,观察研究了玉兰Magnolia denudata有丝分裂和减数分裂的细胞学特征。实验结果证实玉兰存在两种染色体倍性,即2n=4x=76和2n=6x=114。通常,在木兰属甚至整个木兰科每个物种只具有一种染色体数目。玉兰有丝分裂间期核为复杂染色中心型,其中期染色体较小。玉兰在减数分裂中期I的构型表现出多样性,其中最主要的特点是比同源多倍体预期的二价体出现的频率更高些,其次是在减数分裂中期I可以观察到1或2个环状和(或)链状六价体。这些特征与同源异源六倍体或部分的异源六倍体种北美红杉Sequ  相似文献   

17.
The experiments were carried out on human leucocytes cultured in vitro. We studied the distribution of silver grains over metaphase chromosomes after pulse-labeling of cells with H3-lysine in S- and G2 phases. It was found that the grain number per chromosome of the pairs No. 1–3, 13–15 is proportional to their lengths. The probability of incorporation of labeled proteins into each of the homologous chromosomes of the first pair is equal to 0.5 found from the results of statistical analysis of silver grain counts. In cells with karyotype XXX labeled in late-S, the grain number per chromosome in the subgroup 6-X-7 is uniform. In these cells there is no difference in labeling densities among chromosomes of the group A. The data obtained suggest that the formation of the protein component in autosomes of different groups as well as in homologous autosomes and sex-chromosomes proceeds simultaneously and at equal rate.  相似文献   

18.
Using a Giemsa C-banding procedure three chromosome pairs (3, 6 and 7) have been identified in meiosis of the F1 of a cross between two rye inbred lines. Two of these chromosome pairs (3 and 7) were heterozygous for a prominent telomeric heterochromatic band. The comparison between the frequencies of the different meiotic configurations at metaphase I, anaphase I and metaphase II presented by these two chromosome pairs has allowed the estimation of the chiasma frequency and the genetic length of the chromosome arms 3 short and 7 long.  相似文献   

19.
The properties of DNA in situ as reflected by its staining with acridine orange are different in quiescent nonstimulated lymphocytes as compared with interphase lymphocytes that have entered the cell cycle after stimulation by mitogens. The difference is seen after cell treatment with buffers at pH 1.5 (1.3-1.9 range) followed by staining with acridine orange at pH 2.6 (2.3-2.9). Under these conditions the red metachromatic fluorescence of the acridine orange-DNA complex is higher in quiescent cells than in the cycling lymphocytes while the orthochromatic green fluorescence is higher in the cycling, interphase cells. The results suggest that DNA in condensed chromatin of quiescent lymphocytes (as in metaphase chromosomes) is more sensitive to acid-denaturation than DNA in dispersed chromatin of the cycling interphase cells. The phenomenon is used for flow cytometric differentiation between G0 and G1 cells and between G2 and M cells. In contrast to normal lymphocytes the method applied to neoplastic cells indicates the presence of cell subpopulations with condensed chromatin but with DNA content characteristic not only of G1 but also of S and G2 cells. The possibility that these cells represent quiescent (resting) subpopulations, arrested in G1, S and/or G2, is discussed.  相似文献   

20.
一个小黑麦附加—双代换花粉株系(M16)的创制与鉴定   总被引:5,自引:0,他引:5  
张相岐  王献平 《遗传学报》1999,26(4):391-396
报道了一个遗传组成复杂的小麦/小黑麦杂种花粉株系M16的创制,形态性状,遗传稳定性,染色体组成以及抗白粉病的鉴定结果,M16植株形态为普通小麦型,染色体数目为2n=44,具有很高的遗传稳定性,有丝分裂和减数分裂的染色体稳定性分别为91.05%和93.23%,接种鉴定表明M16高抗小麦白粉病,原位杂交,C-分带和同工酶标记分析证明M16有3对黑麦染色体,是一个4R附加,3R(3D)和6R(6D)代换  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号