999 resultados para Chromosomal number


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Muntjac deer (Muntiacinae, Cervidae) are of great interest in evolutionary studies because of their dramatic chromosome variations and recent discoveries of several new species. In this paper, we analyze the evolution of karyotypes of muntjac deer in the context of a phylogeny which is based on 1,844-bp mitochondrial DNA sequences of seven generally recognized species in the muntjac subfamily. The phylogenetic results support the hypothesis that karyotypic evolution in muntjac deer has proceeded via reduction in diploid number. However, the reduction in number is not always linear, i.e., not strictly following the order: 46-->14/13-->8/9-->6/7. For example, Muntiacus muntjak (2n = 6/7) shares a common ancestor with Muntiacus feae (2n = 13/14), which indicates that its karyotype was derived in parallel with M. feae's from an ancestral karyotype of 2n greater than or equal to 13/14. The newly discovered giant muntjac (Muntiacus vuquangensis) may represent another pa;allel reduction lineage from the ancestral 2n = 46 karyotype. Our phylogenetic results indicate that the giant muntjac is relatively closer to Muntiacus reevesi than to other muntjacs and may be placed in the genus Muntiacus. Analyses of sequence divergence reveal that the rate of change in chromosome number in muntjac deer is one of the fastest in vertebrates. Within the muntjac subfamily, the fastest evolutionary rate is found in the Fea's lineage, in which two species with different karyotypes diverged in around 0.5 Myr.

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Cytogenetic analysis were done on specimens from two populations of Lysapsus limellus limellus. three of L. l. bolivianus and of one of Lysapsus caraya. All animals showed a diploid chromosomal number of 2n=24. The karyotypes of the two L. limellus subspecies were very similar, differing only by the larger amount of telomeric heterochromatin and a small pericentromeric C-band on the short arms of pair 2 in L. l. limellus specimens. The karyotype of L. caraya differed from those of the two L. limellus subspecies in terms of chromosomal morphology, C-banding pattern and location of the main NOR on chromosomes 7 and 6. respectively. The karyotype of the L. l. bolivianus population from Guajara-Mirim/RO differed from those of the other populations of the same subspecies in morphology and heterochromatin pattern of chromosomes 7 and 8. Additional NORs were detected by silver staining and confirmed by FISH in one of the homologues of pairs 1 and 8 in L. l. bolivianus and in pair 7 in L. caraya. These results suggest that a reassessment of the taxonomic status of L. limellus subspecies, especially of the L. l. bolivianus populations, may be necessary. (c) 2005 Elsevier Ltd. All rights reserved.

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The karyotype of Microtus xanthognathus (Leach) is described, based on material from one female and one male vole. The diploid chromosomal number was found to be 54, and the fundamental number 62. The metacentric X-chromosome was of medium size and averaged 6.6% of the haploid complement. The designated Y-chromosome was near acrocentric. The specific distinction of M. xanthognathus and Microtus chrotorrhinus (Miller) was confirmed by the recognition of major differences in karyotype and differences in fundamental number. The distributional history of M. xanthognathus is briefly discussed.

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Recently, the tissue origin of MDA-MB-435 cell line has been the subject of considerable debate. In this study, we set out to determine whether MDA-MB-435-DTP cells shown to express melanoma-specific genes were identical to various other MDA-MB-435 cell stocks worldwide. CGH-microarray, genetic polymorphism genotyping, microsatellite fingerprint analysis and/or chromosomal number confirmed that the MDA-MB-435 cells maintained at the Lombardi Comprehensive Cancer Center (MDA-MB-435-LCC) are almost identical to the MDA-MB-435-DTP cells, and showed a very similar profile to those obtained from the same original source (MD Anderson Cancer Center) but maintained independently (MDA-MB-435-PMCC). Gene expression profile analy-sis confirmed common expression of genes among different MDA-MB-435-LCC cell stocks, and identified some unique gene products in MDA-MB-435-PMCC cells. RT-PCR analysis confirmed the expression of the melanoma marker tyrosinase across multiple MDA-MB-435 cell stocks. Collectively, our results show that the MDA-MB-435 cells used widely have identical origins to those that exhibit a melanoma-like gene expression signature, but exhibit a small degree of genotypic and phenotypic drift.

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Current stocks of the LCC15-MB cell line, which we originally isolated from a human breast-bone metastasis, were found to be genetically matched to the MDA-MB-435 cell line from the Lombardi Cancer Center (MDA-MB-435-LCC) using comparative genomic hybridisation, DNA microsatellite analysis and chromosomal number. LCC15-MB stocks used for our previously published studies as well as the earliest available LCC15-MB cells also showed identity to MDA-MB-435-LCC cells. The original karyotype reported for LCC15-MB cells was considerably different to that of MDA-MB-435 cells, indicating that the original LCC15-MB cells were lost to contamination by MDA-MB-435-LCC cells. Chromosome number is the simplest test to distinguish original LCC 15-MB cells (n ∼ 75) from MDA-MB-435 (n ∼ 52). Collectively, our results prove that LCC15-MB cells currently available are MDA-MB-435 cells and we suggest their re-designation as MDA-MB-435-LCC15 cells. We also review the known misclassification of breast and prostate cancer cell lines to date and have initiated a register maintained at http://www.svi.edu.au/cell_lines_registry.doc.

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本文综合形态学、孢粉学和细胞学以及等位酶分析的实验证据,阐明了中国华中铁角蕨复合体(Asplenium sarelii Hook. Complex)中两个四倍体种的起源问题,并从生物系统学的角度讨论了其中多个种的分类学问题。过去认为的四倍体的“华中铁角蕨”被证明是起源于二倍体华中铁角蕨(A. sarelii Hook.)和二倍体细茎铁角蕨(A. tenuicaule Hayata)的杂交,并被处理为新种:武当铁角蕨(A. wudangense Z.R. Wang et X. Hou, sp. nov.)。 而变异铁角蕨(A. varians Wall., Hook. et Grev.)则被认为起源于二倍体细茎铁角蕨(A. tenuicaule Hayata)和二倍体尖齿铁角蕨(A. argutum Ching)的杂交或二者同源四倍体的杂交。根据原细茎铁角蕨(A. tenuicaule Hayata)和尖齿铁角蕨(A. argutum Ching)在宏观和微观特征上的相似性,以及二者的遗传一致度(0.581~0.705),本文将这两个种处理为细茎铁角蕨(A. tenuicaule Hayata)的两个亚种:细茎亚种(ssp. tenuicaule)和尖齿亚种(ssp. argutum (Ching) Vaine, Rashbach et Reichst., ined.)。依据形态和遗传上的相似性以及各自占有一定部分重叠的分布区域,原云南铁角蕨(A. yunnanense Franch.)、宝兴铁角蕨(A. moupinense Franch.)和云南铁角蕨深裂铁角蕨变种(A. yunnanense Franch. var daraeiforme(Franch.)H. S. Kung)被处理为云南铁角蕨(A. yunnanense Franch.)的三个亚种:云南铁角蕨亚种(ssp. yunnanense)、宝兴铁角蕨亚种(ssp. moupinense (Franch.)Z. R. Wang et X. Hou, st. nov.)和深裂铁角蕨亚种(ssp. daraeiforme(Franch.)Z. R. Wang et X. Hou, st. nov.)。 同时,本文运用孢粉学、细胞学、生态学和形态学的综合手段,处理了中国铁角蕨(Asplenium trichomanes L. s. l.)的种下分类问题,划分了中国该种的四个亚种:原亚种A. trichomanes L. ssp. trichomanes,喜钙亚种A. trichomanes L. ssp. inexpectans Lovis,四倍亚种A. trichomanes L. ssp. quadrivalens D. E. Meyer emend. Lovis,粗轴亚种A. trichomanes L. ssp. pachyrachis (Christ) Lovis et Reichst.,并将一个变种:哈如变种A. trichomanes L. var. harovii Moore emend. Midle,归并入粗轴亚种ssp. pachyrahcis (Christ) Lovis et Reichst.,同时提供了它们在中国的分布情况。查阅研究PE的标本时发现一些定名为为A. trichomanes L. var. centrochinense Christ(中国变种)的模式标本碎片,因在形态上和倍性上均不同于已知分类群,认为应给予种的分类地位。

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丁香属隶属于木犀科,分布于东南欧和东亚至喜马拉雅地区,我国是丁香属的现代分布中心。《中国植物志》(61卷,1992)记录了我国野生丁香种类16种;《Flora of China》(15卷,1996)记录了中国原产丁香种类16种,并认为全世界大约有20种。丁香属属下分类等级划分分歧较大,很多种的划分也存在争议。花叶丁香、四川丁香等种类是根据栽培植物描述的,没有指定模式标本,给分类处理带来了一定困难。另外,丁香属很多分类群的性状变异非常复杂,仅根据有限的标本很难做出合理的分类处理。本研究通过广泛查阅文献和标本,同时进行野外居群取样和性状观察,对各类群的性状在居群内和居群间的变异进行统计学分析,判断其分类价值,并运用多变量分析的方法,为各类群的合理划分提供依据。结合性状分析和地理分布等证据,做出分类处理。 作者查阅了国内外16个标本馆的近2000份标本,其中模式标本约70份。对我国12个省市的40余个居群进行了取样和观察,采集标本500余份,涉及了《中国植物志》61卷收录的除了藏南丁香以外的所有类群。通过对9个复合体的40余个性状在居群内和居群间的变异进行统计分析,发现叶片类型、叶柄长度、花序着生类型、花冠大小、花丝长度、花药颜色在不同类群间差异明显,可以用作划分种的依据;叶片形状、叶片毛被、花序轴毛被、花冠管形状等性状在有些复合体内的居群间呈现连续的变异,只能用作种下等级(亚种)的划分;叶片大小、花序轴形状、花药着生在花冠的位置、蒴果是否被皮孔等性状在不同复合体的居群间呈现间断或连续的变异,视不同情况可以用作种间或种下等级的划分依据,或作种内变异处理;而叶脉、花色、花萼齿裂、花冠裂片形状等性状在居群间差异不大,不适合用作分类依据。 在性状分析和多变量分析的基础上,本文将丁香属划分为2组2系12种13亚种,其中短花冠管组有1种3亚种;长花冠管组的顶生花序系有5种5亚种,侧生花序系有6种5亚种,并指定了各组和系的模式种;编制了属下各组、系、种和亚种划分的检索表,对12种13亚种进行了形态描述、标本引证,给出了地理分布图和生境,并提出了分类处理依据。文中对巧玲花、皱叶丁香、红丁香和云南丁香等复合体内的一些分类群进行了归并,做出4个新组合:S. pubescens ‘Meyer’、S. villosa subsp. wolfii、S. yunnanensis subsp. sweginzowii和S. yunnanensis subsp. tomentella,处理了11个新异名(S. fauriei H. Lév.、S. julianae C. K. Schneid.、S. meyeri var. spontanea M. C. Chang、S. pinetorum W. W. Sm.、S. wardii W. W. Sm.、S. oblata var. donaldii R. B. Clark et J. L. Fiala、S. afghanica C. K. Schneid.、S. protolaciniata P. S. Green et M. C. Chang、S. tibetica P. Y. Bai、S. reflexa C. K. Schneid. 、S. wilsonii C. K. Schneid.)。作者指定了3种4亚种(S. reticulata subsp. reticulata、 S. reticulata subsp. amurensis、S. pubescens subsp. microphylla、S. oblata subsp. dilatata的后选模式,并对其它10个名称指定了后选模式。文中还提出了分类处理原则,对我国丁 香属的分布及各地方植物志的记载进行了评述,并对丁香属的分布格局提出了作者的看法。 作者还对13个分类群的16号材料进行了染色体观察,发现除了毛丁香有染色体2n=48外,其它均为2n=46,其中朝阳丁香的染色体数目为首次报道。对小叶巧玲花不同异名(包括小叶蓝丁香、小叶巧玲花与小叶蓝丁香的杂交种)的材料进行染色体观察时,发现它们之间差异很小,进一步佐证了作者将其合并的合理性。另外野生的花叶丁香(华丁香)与栽培的花叶丁香在染色体数目上也无差异,支持了作者认为二者为同物异名的观点。

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用ACHT处理黑麦萌动种子,对修复前后材料的观察和分析结果表明:1. ACHT操作引起染色体数目变化和染色体断裂损失。在一定 条件和范围内,不同处理引起的这种变化具有显著差异,条件越剧烈,染色体数目变化的范围和频率愈大,断片发生的数量和频率 也愈高,同时修复前后染色体数目的变化范围和频率与断片发生的数量和频率以及它们的修复频率均表现明显的相关性。2. ACHT 操作引起染色体畸变的多样性。经ACHT处理后,胚根细胞染色体有4种断裂方式,包括着丝粒断裂、次溢痕断裂、长臂断裂和短臂 断裂等,其中着丝断裂频率最高;产生6种断片类型,包括有着丝粒和端粒的、有着丝粒而无端粒的、有部分着丝粒和端粒的、有 部分着丝粒而无端粒的、只有端粒的、既无着丝粒也无端粒的断片等。3. ACHT操作引起遗传结构重建的多样性。经ACHT处理后, 对修复24-72小时材料进行核型比较(按Stebbins 和 Levan 标准)和随体分析,处理细胞在染色体数目、大小、形态、位置等方面 均发生显著变化,说明ACHT处理使这些细胞的染色体结构和染色体组型发生了深刻变化。进一步通过Giemsa C— 带分析,观察到 多种重建染色体类型,包括易位型染色体、附加型染色体、无着丝粒染色体、化染色体、增加的m染色体以及某些带型特异的染色 体等。4. RAPD 分析从分子水平上验证了ACHT能有效地引起遗传结构的改变。所用10种引物对处理和对照材料基因组DNA的扩增产 物在条带数目、条带位置及带型特征等方面均有明显差异,其中4种引物出现条带减少,6种引物出现条带增加,后者还包括一个带 位移动。这说明两种材料的基因组DNA具有明显的RAPD反应多态性差异。This paper descripes some results draw on the basis of the observation and analysis on the rye before and after repaired through treating its budding seeds by ACHT in contrast to without ACHT: 1. ACHT manipulation caused the number variation and breakage damage of rye chromosome. Within certain conditions and timits, this phenomenon caused by different treats had signifcant difference: the more the treatment condition is drastie, the more the chageable range and frequence of rye chromosomae number, and so is the produced fragments. Meanwhile, there existed striking relationship among the changeable range and frequence of rye chromosome, the produced number and frequence of fragments and repairing frequence. 2. ACHT manipulafion engendered the diversify of rye chromosomal aberration. Four breakage patterns and six sorts of fragment were observed by watching the chromosome of the rye radicle treated by ACHT, including centric breakage (occuring in the highest frequence), secondary constriction breakage, long arm breakage and short arm breakage to the former, Comprising that with both centromere and telomere, that with centromere and without telomere, that with partial centromere and with telomere, that with partfial ceetromere and without telomere, that only with telomere and that neither with centromere nor with telomere, etc. 3. ACHT manipulation engendered the diversify or rye genetic structs reconstruction. Karureotype analysis(according to Stebbins and Levan) and satellite anaeysis were carried out to rye radicle through 24-72-hour-long recoverage after ACHT manipulation, which showed remarkable change happened on the rye chromosomal number、shape、arm ration and pattern, etc. and also on the satellite number、size、shape and location etc. Those indicated that ACHT manipulation engendered violent changes to rye chromatin structure and chromosome type. Further Giemsa C-banding analysis showed many types of reconstructed chromosome, such as translocation、addition、without centromere、st and other chromosome. 4. RAPD analysis checked the validity of ACHT on changing genetic structure of rye on the level of molecular biology. The treated and recovered rye has different amplifying band pattern by using IO valid arbitary primers selected from 40 comparing with the control.

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Considering an estimated number of millipedes of approximately 80,000, cytogenetic studies on these animals are rare, as only a total of 70 species have their karyotypes described. The present study reports on the chromosomal number of four Brazilian diplopods of the family Spirostreptidae: Urostreptus atrobrunneus with 2n = 24, XY; Gymnostreptus olivaceus 2n = 12, XY and Alloporus araraquarensis and A. principes, 2n = 18, XY. The C-banding pattern and NOR staining of U. atrobrunneus, G. olivaceus and A. araraquarensis are described. (C) 2008 Elsevier Ltd. All rights reserved.

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The aim of this study was to compare wild boar (chromosomal number 2n = 36) to phenotypically similar animals of 2n = 37 and 2n = 38 chromosomes (crossbreeds) with respect to live weight, carcass yield, meat yield, fat and weight of inner organs. All animals were born and raised on the same farm and slaughtered at 39 weeks. The final live weight of wild boar 2n = 36 was significantly lower (47.2 kg) as compared to crossbreeds (80.0 kg). Animals 2n = 36 had more carcass yields (65.5%) than 2n = 37 karyotype (64.9%) and 2n = 38 (64.4%). Wild boar had the highest yields for the cuts with bones and boneless cuts compared to crossbreeds. Therefore, variations in karyotype are accompanied by differences in some carcass quantitative traits, i.e., 2n = 36 grow and fatten slower than crossbreeds 2n = 37 and 2n = 38. (c) 2008 Elsevier Ltd. All rights reserved.

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The majority of chromosomes in Oreochromis niloticus, as with most fish karyotyped to date, cannot be individually identified owing to their small size. As a first step in establishing a physical map for this important aquaculture species of tilapia we have analyzed the location of the vertebrate telomeric repeat sequence, (TTAGGG)n, in O. niloticus. Southern blot hybridization analysis and a Bal31 sensitivity assay confirm that the vertebrate telomeric repeat is indeed present at O. niloticus chromosomal ends with repeat tracts extending for 4-10 kb on chromosomal ends in erythrocytes. Fluorescent in situ hybridization revealed that (TTAGGG)n is found not only at telomeres, but also at two interstitial loci on chromosome 1. These data support the hypothesis that chromosome 1, which is significantly larger than all the other chromosomes in the karyotype, was produced by the fusion of three chromosomes and explain the overall reduction of chromosomal number from the ancestral teleost karyotype of 2n=48 to 2n=44 observed in tilapia.

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The Diplopoda have received little attention from cytogeneticists owing mostly to technical difficulties in obtaining mitotic chromosomes, restricting the studies to meiosis and eventual spermatogonial metaphases, which limits the use of modern cytogenetical techniques. A literature search shows that only about 0.1% of all known species have been cytogenetically studied. There are 80,000 species estimated for this group, making it the 3rd. larger class in Arthropoda, after Insecta and Arachnida. The diploid chromosomal number in diplopods varies from 2n=8 to 2n=30 and the sex determination mechanism commonly found is XY/XX. In meiotic prophase, the bouquet formation and the diffuse state in pachytene are typical events. The few works performed on Brazilian fauna add up to 16 species, out of an estimated number of 2000 to 3000 species. The present review reports all the species of diplopods that have been cytogenetically studied so far, each with its chromosome number and sex determination system.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)