共查询到20条相似文献，搜索用时 203 毫秒
1.
四川麻鸭染色体组型分析 总被引：1，自引：0，他引：1
本试验分析了四川麻鸭(Anas platyrbynchos domestica)的染色组型。染色体数目2n=80(♂、♀)。染色体基本臂数为86(♂)或85(♀)。性染色体为ZZ(♂)/ZW(♀)型。1号和2号染色体分别属亚中部(sm)和中部(m)着丝粒染色体。Z染色体(4号)属亚端部(st)着丝粒染色体。W染色体(大小相当于8号)和其余常染色体均属端着丝粒(T)染色体。 相似文献
2.
华南野猪的核型及其与家猪的进化关系 总被引：8，自引：0，他引：8
本文报道了分布于云南西双版纳热带丛林的华南野猪(Sus scrofa chirodentus)的染色体组型、G-带、C-带和核仁形成区(NOR)。其结果显示,华南野猪的染色体数目2n=38。与过去报道的欧洲野猪和中亚及远东地区的亚洲野猪各亚种(2n=36)比较,少1对近中着丝粒染色体,而多2对端着丝粒染色体。染色体数目、形态和G-带带型均与过去报道的家猪相同;C-带1号、13—18号染色体着丝粒区结构异染色质显示深染,其余双臂染色体(2—12号和X)着丝粒区均浅染;核仁形成区(NOR)亦定位于8号和10号染色体的次缢痕处,惟8号染色体有的细胞仅出现一个具有活性的NOR。本研究结果表明,华南野猪与欧洲和中亚、远东地区野猪亚种的核型有着明显的差异,而与家猪完全一致。这揭示了华南野猪与家猪在起源和进化方面存在着极为密切的亲缘关系。根据核型进化理论,华南野猪很可能是现代家猪的原始祖先之一。 相似文献
3.
本试验分析了两种家鸭(建昌鸭和北京鸭)和绿头鸭(Anas platyrhynchos的核型及G带带型。结果表明,三种鸭的核型相似。染色体数目2n=80(♂、♀)染色体基本臂数为86(♂)或85(♀)。性染色体为ZZ(♂)/ZW(♀)型。1号和2号染色体分别属亚中部(sm)和中部(m)着丝粒染色体。Z染色体(4号)属亚端部着丝粒染色体,具有明显的短臂。W染色体(大小相当于7-9号)和其余常染色体均属端着丝粒染色体。三种鸭的染色体G带带型显示出很大的同源性。本试验结果从核分类学角度说明了,在起源上家鸭与绿头鸭的亲缘关系密切,绿头鸭很可能是家鸭的祖先。 相似文献
4.
目的探讨口腔鳞癌(OSCC)细胞中的染色体数目异常与结构畸变。方法体外培养OSCC细胞，常规制备染色体，镜下观察。结果OSCC的染色体众数为64～67，并存在多种类型的染色体结构畸变，主要为染色体断裂及染色单体断裂。染色体数目异常有1、7、16、19、20号增加及6、9、10、18、21、22号丢失,结构重排主要累及1、2、4、11号等。结论OSCC的染色体变异研究有助于其相关癌基因或抑癌基因在染色体上的定位。 相似文献
5.
6.
【目的】探讨卢氏绿壳蛋鸡染色体核型和G带带型。【方法】采用骨髓法制备卢氏绿壳蛋鸡染色体标本片,染色后对其染色体核型和G带进行分析。【结果】卢氏绿壳蛋鸡的体细胞染色体数为2n=78,该鸡种的核型中有10对大染色体和29对微小染色体,且微小染色体基本为端着丝粒染色体。公鸡染色体核型由38对常染色体和1对同配型性染色体ZZ组成,母鸡由38对常染色体和1对异配型性染色体ZW组成。1、2号和Z、W均为中央着丝粒(m)染色体,4号和7号均为亚中央着丝粒(sm)染色体,3、6、8、9、10号均为端着丝粒(t)染色体。前10对大染色体(包括Z、W染色体)的G带共可分为32个区,118条带。【结论】卢氏绿壳蛋鸡的染色体数目为:2n=78,公鸡核型78,ZZ;母鸡核型78,ZW。卢氏绿壳蛋鸡与其他品种鸡的G带存在一定的差异。 相似文献
7.
早老蛋白-1基因突变与Alzheimer病 总被引：1，自引：0，他引：1
Alzheimer病 (AD)的病因非常复杂 ,目前发现与AD相关的基因有 5种 :2 1号染色体上的淀粉样蛋白前体 (APP)基因、1 9号染色体上的ApoE基因、1 4号染色体上的早老蛋白 1 (ps 1 )基因和 1号染色体上的早老蛋白 2 (ps 2 )基因及 1 2号染色体上的α2 巨球蛋白 (α2 MG)基因。在早发型AD(EOAD)家系发现app、ps 1和ps 2基因的突变 ,呈线性常染色体遗传模式 ,此3个基因的突变分别占 2 %～ 3%、70 %～ 80 %和 2 0 %。ps 1基因已成为AD研究的热点。但迄今为止 ,ps 1基因的功能尚未明了。近年来更多的研究发现多数早发型家族性AD(FAD)与p… 相似文献
8.
【目的】探究异染色质纽在玉米、类玉米及其杂种后代染色体上分布的特点及遗传稳定性。【方法】利用组成玉米异染色质纽的180-bp重复序列和TR-1元件对二倍体多年生类玉米（Zea diploperennis, DP）、玉米自交系330及其远缘杂交后代异源种质纯系540的有丝分裂中期染色体进行荧光原位杂交,观察杂交信号在3个材料染色体上的位置、强弱及分布数量。【结果】玉米自交系330的第2、3、5、6、7号染色体长臂的近末端区显示较强杂交信号。DP的第2、3、5、6、7、8、9号染色体的长臂末端检测出异染色质纽,其中2号染色体在短臂的末端也检测到异染色质纽杂交信号。杂交后代540的第2、5、7染色体长臂近末端区检测到较强的杂交信号;3个材料的第6染色体短臂末端的随体上均显示强杂交信号。【结论】玉米大部分异染色质纽成分不能稳定遗传,其表现出来的多态性可以作为鉴定玉米和类玉米杂种后代的细胞学标记。 相似文献
9.
云南龙陵黄山羊的核型及C－带和Ag－NORs研究 总被引：3，自引：0，他引：3
采用外周血淋巴细胞培养及染色体分带技术,分析了龙陵黄山羊的核型,C-带和银染核仁组织区(Ag-NORs),结果表明:龙陵黄山羊染色体数为2n=60,常染色体及X染色体为端部着丝粒染色体,Y染色体最小,为中部着丝粒染色体。常染色体着丝粒区均显示C-带,性染色体未显C-带。雌性银染核仁组织区(Ag-NORs)分布于No.1,2,3,4,5,25号染色体,雄性分布于No.1,2,25号染色体,显示了性别及分布多态性。研究还发现三种不同的联合(ASSOCIATION)。 相似文献
10.
中国原鸡(Gallus gattus) 的染色体研究 总被引：3，自引：0，他引：3
本文报道了产于中国南部原鸡(Gallus gallus)的染色体组型及其 G-带核型。其染色体数目2n=78;性染色体雄性为zz,雌性为 zw。全部常染色体(包括微小染色体)和性染色体经测量分析,计算了双臂染色体的臂比、着丝粒指数和全部染色体的相对长度。分析了1—19号常染色体和性染色体的G-带带型,并绘制了相对长度模式图和G-带模式图。 相似文献
11.
By the combination of cytological analysis and using genomic in situ hybridization technique to identify an alien chromosome in wheat-Haynaldia villosa monosomic addition lines, we studied the meiotic behavior of the alien chromosome. The results indicated that the frequency of bivalent pairing was lower than the value expected in PMCs of two monosomic addition lines, the frequency of wheat chromosomes unpairing increased, and the wheat homologous chromosome pairing was interfered with by the added chromosome 6V at metaphase I. The chromosome 6V lagged in 20.3% -29.3% of PMCs, sister chromatids 6V early divided in 29.0% - 34.1% of PMCs, the single chromosome 6V in 18.2% - 26.1% of PMCs went to a pole randomly,the breakage frequency of chromosome 6V was 1.2% - 2.9%. Meanwhile, it was also found that several wheat chromosomes showed earlier division, lagging and breakage in a few PMCs. It revealed that the added chromosome 6V influenced the behavior of wheat chromosomes at anaphase. It was also found that the translocation was produced between 6V and wheat chromosomes in 1.2% of PMCs. It offered evidence for translocation between wheat and Haynaldia villosa 6V chromosomes. 相似文献
12.
普通小麦─大赖草6N二体异附加系的选育与鉴定 总被引：2，自引：0，他引：2
根据花粉母细胞减数分裂中期Ⅰ染色体配对情况及染色体Ｃ－分带，在中国春－大赖草杂种回交后代中选育出１个稳定的二体异附加系９２Ｇ４６０。通过分析亲本及９２Ｇ４６０的苗期叶片ＧＯＴ同工酶酶谱表型，推测９２Ｇ４６０中临时编为第１１号的大赖草染色体来自Ｎ染色体组，该染色体携有属于第６部分同源群的同工酶结构基因Ｇｏｔ－Ｎ２，故可以将大赖草中临时编为第１１号的染色体命名为６Ｎ。 相似文献
13.
家蚕细长蚕（Lan）的染色体研究 总被引：1，自引：1，他引：0
以家蚕突变系统中的细长蚕（Ｌａｎ）卵巢为材料，采用改良今井涂片法制片，Ｇｉｅｍｓａ染色，光学显微镜下观察粗线期染色体，并进行了组型分析。结果表明，细长蚕第１号染色体上有缺失环或瘤状突起，推断其为Ｌａｎ基因的位点。 相似文献
14.
15.
The fragile X site in somatic cell hybrids: an approach for molecular cloning of fragile sites 总被引：17，自引：0，他引：17
Fragile X syndrome is a common form of mental retardation associated with a fragile site on the human X chromosome. Although fragility at this site is usually evident as a nonstaining chromatid gap, it remains unclear whether or not actual chromosomal breakage occurs. By means of somatic cell hybrids containing either a normal human X or a fragile X chromosome and utilizing two genes that flank the fragile site as markers of chromosome integrity, segregation of these markers was shown to be more frequent if they encompass the fragile site under appropriate culture conditions. Hybrid cells that reveal marker segregation were found to contain rearranged X chromosomes involving the region at or near the fragile site, thus demonstrating true chromosomal breakage within this area. Two independent translocation chromosomes were identified involving a rodent chromosome joined to the human X at the location of the fragile site. DNA analysis of closely linked, flanking loci was consistent with the position of the breakpoint being at or very near the fragile X site. Fragility at the translocation junctions was observed in both hybrids, but at significantly lower frequencies than that seen in the intact X of the parental hybrid. This observation suggests that the human portion of the junctional DNA may contain part of a repeated fragility sequence. Since the translocation junctions join heterologous DNA, the molecular cloning of the fragile X sequence should now be possible. 相似文献
16.
LSD and genetic damage 总被引：3，自引：0，他引：3
Of nine studies in vitro, six have indicated some degree of induced chromosomal breakage after exposure to LSD; three failed to confirm these results. The damage, when found, was generally of the chromatid type, arising during or after DNA synthesis. This damage, with one exception, was the result of concentrations of drug and durations of exposure which could not be achieved in humans with reasonable dosages. There did not appear to be a dose-response relation. The magnitude of damage, when found, was in the range encompassing the effects of many commonly used substances. The absence in vitro of excretory and detoxifying systems present in vivo, as well as several negative reports, cast doubt on the relevance of in vitro results. In 21 chromosomal studies in vivo, 310 subjects were examined. Of these, 126 were treated with pure LSD; the other 184 were exposed to illicit, "alleged" LSD. A maximum of only 18 of 126 (14.29 percent) of the subjects in the group exposed to pure LSD showed higher frequency of chromosome aberration than the controls. In contrast, a maximum of 90 of 184 (48.91 percent) of the subjects taking illicit LSD showed an increase in frequency of aberrations. Of all the subjects reported to have chromosome damage, only 18 of the 108 (16.67 percent) were exposed to pure LSD. The frequency of individuals with chromosomal damage reported among illicit drug users was more than triple that associated with the use of pharmacologically pure LSD. We conclude that chromosome damage, when found, was related to the effects of drug abuse in general and not, as initially reported, to LSD alone. We believe that pure LSD ingested in moderate dosages does not produce chromosome damage detectable by available methods. No significant work on carcinogenic potential of LSD has been reported so far. No cause-and-effect relation and no increase in the incidence of neoplasia among LSD users have been demonstrated. Case reports (three in 4.0 years) of leukemia and other neoplasia in this population are rare. The results of early chromosome studies suggested that true genetic damage might be a consequence of LSD exposure. The comprehensive evidence from studies on drosophila indicates no mutagenic effect from 0.28 to 500 microg of LSD per milliliter and a definite mutagenic effect from 2,000 to 10,000 microg/ml; this is consistent with a threshold response or a sigmoid dose-effect relation. We believe that LSD is, in fact, a weak mutagen, effective only in extremely high doses; it is unlikely to be mutagenic in any concentration used by human subjects. Circular dichroism experiments suggested that the specific mechanism of action of LSD on DNA may be a direct interaction resulting in conformational changes in the DNA helix. These changes are unlikely to result in a decrease of internal stability sufficient to cause breakage of chromosomes, but they may be the physical basis of the weak mutagenicity. Early chromosomal studies implicated LSD as a potential cause of congenital malformations, fetal wastage, and germinal chromosome damage. First reports of a teratogenic effect in hamsters and rats have not been confirmed. A review of 15 rodent studies indicated a wide range of individual, strain, and species susceptibility to the effects of LSD. The applicability of such investigations to man is doubtful. In a study of human pregnancies, those exposed to illicit LSD had an elevated rate of spontaneous abortions. There is no reported instance of a malformed child born to a woman who ingested pure LSD; there are six cases of malformation associated with exposure to illicit LSD, four of which have similar limb defects. Given, however, the high frequency of unexplained "spontaneous" birth defects, the rare occurrence of malformed infants born to women who used illicit LSD may be coincidental. While there is no evidence that pure LSD is teratogenic in man, the use of any drug during pregnancy requires that its potential benefits significantly outweigh its potential hazards. From our own work and from a review of the literature, we believe that pure LSD ingested in moderate doses does not damage chromosomes in vivo, does not cause detectable genetic damage, and is not a teratogen or a carcinogen in man. Within these bounds, therefore, we suggest that, other than during pregnancy, there is no present contraindication to the continued controlled experimental use of pure LSD. Note added in proof: A brief review has been brought to our attention. Although based on a sample of only 15 studies the author reached conclusions similar to our own (92). 相似文献
17.
采用淋巴细胞培养和染色体Ｃ─分带方法，测定了二花脸、大约克纯种猪Ｎｏ．１３和Ｎｏ．１６染色体Ｃ─带的长度、面积和异染色质的量，以图揭示家猪染色体Ｃ─带的品种差异．结果表明，二花脸、大约克纯种猪在Ｎｏ．１６染色体上Ｃ─带的长度、面积和异染色质的量存在着显著差异，以此可以作为区分两品种的重要依据． 相似文献
18.
硫酸锰对大蒜根尖细胞有丝分裂的影响 总被引：1，自引：0，他引：1
采用不同浓度硫酸锰分别处理大蒜根尖,通过常规染色体压片技术,观察大蒜根尖细胞有丝分裂。结果表明,随着处理液中硫酸锰浓度的升高(1.0、2.0、3.0、4.0、5.0 mmol/L),有丝分裂指数呈现M形曲线变化;随着处理时间的延长(12、24、48h),有丝分裂指数逐渐下降,说明硫酸锰具有细胞分裂抑制剂的作用,不同浓度的硫酸锰在不同处理时间内均能诱使大蒜根尖细胞发生染色体畸变,表现为染色体断裂、染色体桥、微核等。 相似文献
19.
辐照大麦M1代损伤效应与M2代变异频率的关系 总被引：2，自引：0，他引：2
本试验以鲁啤一号大麦为材料,用~(60)Co-γ射线分0、93.3、186.6、279.9、373.2、559.8Gy 6个剂量进行辐照处理,着重分析了M_1代植株损伤和细胞学损伤与M_2代叶绿素突变和农艺性状变异之间的相关关系。M_1代根尖细胞的染色体畸变率、微核率、黄叶尖率、苗高和不育率与M_2代性状变异频率以及与M_2代叶绿素突变率之间呈显著或极显著指数函数关系;M_1代出苗率与M_2代性状变异率和叶绿素突变率之间相关不明显。同时,M_1代各种损伤与吸收剂量之间呈显著或极显著直线相关关系;M_2代叶绿素突变及农艺性状变异与剂量之间呈显著或极显著指数函数关系。 相似文献
20.
用６０Ｃｏ射线２００Ｇｙ、２５０Ｇｙ、３００Ｇｙ的剂量对３个小麦品种的风干种子进行辐射处理，从芽长、出苗率、成株率、畸变苗（株）率和植株致矮性等方面研究了Ｍ１代的辐射效应；从早熟性、矮秆及穗型变异等方面研究了Ｍ２代的诱变效果。结果表明，随着辐射剂量的增加，Ｍ１代各供试材料的田间出苗率，成株率及株高均呈下降趋势，而畸变苗（株）率呈上升趋势。３个供试材料对辐射的敏感性有显著差异，其敏感顺序为：荷兰１号＞永良４号＞永良１２号。在Ｍ２代中，３个品种总的突变率分别为荷兰１号（０．６２％）、永良４号（０．５４％）、永良１２号（０．５０％）。各处理中诱发突变频率高低的剂量顺序为２５０Ｇｙ＞３００Ｇｙ＞２００Ｇｙ＞。用６０Ｃｏ射线处理小麦干种子，可以在短期内改变品种的早熟性和穗部性状。 相似文献