RNAi-mediated Knockdown of Xist Does Not Rescue the Impaired Development of Female Cloned Mouse Embryos     

Mami OIKAWA  Shogo MATOBA  Kimiko INOUE  Satoshi KAMIMURA  Michiko HIROSE  Narumi OGONUKI  Hirosuke SHIURA  Michihiko SUGIMOTO  Kuniya ABE  Fumitoshi ISHINO  Atsuo OGURA 《The Journal of reproduction and development》2013,59(3):231-237

In mice, one of the major epigenetic errors associated with somatic cell nuclear transfer (SCNT) is ectopic expression of Xist during the preimplantation period in both sexes. We found that this aberrant Xist expression could be impeded by deletion of Xist from the putative active X chromosome in donor cells. In male clones, it was also found that prior injection of Xist-specific siRNA could significantly improve the postimplantation development of cloned embryos as a result of a significant repression of Xist at the morula stage. In this study, we examined whether the same knockdown strategy could work as well in female SCNT-derived embryos. Embryos were reconstructed with cumulus cell nuclei and injected with Xist-specific siRNA at 6–7 h after oocyte activation. RNA FISH analysis revealed that siRNA treatment successfully repressed Xist RNA at the morula stage, as shown by the significant decrease in the number of cloud-type Xist signals in the blastomere nuclei. However, blastomeres with different sizes (from “pinpoint” to “cloud”) and numbers of Xist RNA signals remained within single embryos. After implantation, the dysregulated Xist expression was normalized autonomously, as in male clones, to a state of monoallelic expression in both embryonic and extraembryonic tissues. However, at term there was no significant improvement in the survival of the siRNA-injected cloned embryos. Thus, siRNA injection was largely effective in repressing the Xist overexpression in female cloned embryos but failed to rescue them, probably because of an inability to mimic consistent monoallelic Xist expression in these embryos. This could only be achieved in female embryos by applying a gene knockout strategy rather than an siRNA approach.  相似文献   

新疆红花随体染色体及25S rDNA位点分析     

王力军  严兴初 《中国油料作物学报》2012,34(3):245-248

利用荧光原位杂交技术研究我国新疆红花25S rDNA在染色体上的位点数目,同时分析了其随体染色体数目。研究结果显示：新疆红花有2对随体染色体;4对染色体存在25S rDNA位点,其中3对染色体上的杂交信号较强,可稳定检出,有时还可检测到1对染色体上较弱的杂交信号。与国外红花品种相比,新疆红花rDNA位点数目多,表明新疆红花与国外红花品种间核仁组织区结构存在较大差异。这些结果将为研究红花染色体进化及其准确的核型分析提供一定的参考。  相似文献   

甘蓝2号染色体的高分辨率5S rDNA荧光原位杂交   总被引：1，自引：0，他引：1  

王永  朱利泉  荣小营  陈晓丹  唐章林  王小佳 《中国农业科学》2009,42(12):4294-4300

 【目的】羽衣甘蓝5S rDNA 的染色体定位和拷贝数分析,为进一步利用FISH进行2号染色体基因定位和细胞遗传图谱构建奠定基础。【方法】以羽衣甘蓝为材料,采用荧光原位杂交技术将DIG标记的5S rDNA探针定位于不同分辨率的绒毡层细胞中期染色体、粗线期染色体以及伸长DNA纤维上。【结果】在中期染色体和粗线期染色体上,都同时获得3个杂交信号位点（a、b、c）,且位于2号染色体的长臂近着丝粒区域,其信号强度为b＞a＞c;而在伸长DNA纤维上,出现了3种不同长度的念珠状长链（a、b、c）, 其物理大小分别为257、359和134 kb,这3种长链分别与3个信号位点形成一一对应关系。【结论】在羽衣甘蓝2号染色体上存在3个串联重复位点,粗略估算出3个5S rDNA位点的拷贝数分别为510、712和266。  相似文献   

异源三倍体鲫鲂的遗传组成和生殖特性观察     

覃钦博  戴婧  刘少军  刘筠 《水产学报》2014,38(3):356-361

红鲫属鲤亚科,其染色体数目为2n=100;团头鲂属于鲌亚科,其染色体数目为2n=48。在红鲫(♀)×团头鲂(♂)的远缘杂交F1代中获得了异源三倍体鲫鲂和异源四倍体鲫鲂。本研究对异源三倍体鲫鲂进行了染色体核型分析、染色体FISH杂交检测和性腺结构观察,结果表明:1)异源三倍体鲫鲂的染色体数目为3n=124,染色体核型公式为31m+45sm+26st+22t,染色体组由2套红鲫染色体和1套团头鲂染色体组成;2)利用红鲫特有重复序列为探针进行FISH杂交,红鲫的100条染色体均被标记上荧光信号,而团头鲂的染色体均未标记上荧光信号,异源三倍体鲫鲂中有100条染色体被标记上荧光信号,说明异源三倍体鲫鲂含有2套红鲫来源的染色体组;3)异源三倍体鲫鲂的性腺发育异常,其卵巢型和精巢型性腺发育呈现出退化的特征。研究还讨论了异源三倍体鲫鲂的形成机制。实验结果为鱼类远缘杂交和多倍体鱼研究提供了实验数据,在鱼类遗传育种方面具有重要意义。  相似文献   

390份小麦-黑麦种质材料主要农艺性状分析及优异材料的GISH与FISH鉴定   总被引：3，自引：0，他引：3  

罗巧玲  郑琪  许云峰  李立会  韩方普  许红星  李滨  马朋涛  安调过 《作物学报》2014,40(8):1331-1339

将小麦近缘属植物黑麦中的优良基因导入小麦可以拓宽小麦的遗传基础,丰富小麦的遗传变异。本研究调查并分析了390份小麦-黑麦种质材料。在这390份种质材料中,6个主要农艺性状值均有较大的极差,说明其遗传多样性丰富。与10份小麦主栽品种相比,90%以上的材料具有穗长和分蘖数的显著优势,60%以上的材料具有小穗数优势,约30%的材料穗粒数和千粒重显著高于主栽品种。利用基因组原位杂交(genomic in situ hybridization,GISH)和多色荧光原位杂交(multicolor fluorescent in situ hybridization,mc-FISH)技术,对8份农艺性状优良的代表性材料进行染色体组成分析,发现3份为六倍体小黑麦(AABBRR),2份为八倍体小黑麦(AABBDDRR),1份为1RS·1BL易位系,其余2份不具有可见的黑麦染色体或染色体片段。值得指出的是,3份六倍体小黑麦与2份八倍体小黑麦所含的黑麦染色体不完全相同。八倍体小黑麦中有1对来源于黑麦的小染色体,而六倍体小黑麦中没有类似小染色体;并且,不同材料中黑麦4R染色体端部的GISH杂交带有明显差异。本研究结果为这些小麦-黑麦种质材料进一步应用于小麦育种提供了依据。  相似文献   

45S rDNA在7种竹子植物染色体上的定位     

徐川梅  卢江杰  汤定钦 《林业科学》2009,45(12)

编码18-5.8-25S核糖体RNA的45S rDNA基因,是1个简单的多基因家族基因,一般以串联方式相连,对应于核仁组织区(NOR).首次利用荧光原位杂交技术(FISH),研究45S rDNA在散生竹类的毛竹和斑竹,混生竹类的茶秆竹、日本矮竹、菲白竹和铺地竹,以及丛生竹类的白绿竹染色体上的分布.结果表明:本研究所涉及的散生竹和混生竹的几个竹种,只观察到1对随体染色体的次缢痕区域有45S rDNA位点,而丛生竹类的白绿竹除随体染色体具有45S rDNA位点外,某些非随体染色体上也有不同拷贝数的45S rDNA位点存在.  相似文献   

Analysis of radiation-induced W chromosome aberrations in the codling moth, <Emphasis Type="Italic">Cydia pomonella</Emphasis> (L.), by fluorescence in situ hybridization techniques     

H. Makee  N. Tafesh  F. Marec 《Journal of pest science》2008,81(3):143-151

The structure of the female sex-determining W chromosome was examined in wild-type females and in three mutant female lines of the codling moth, Cydia pomonella. The mutant lines were isolated from progeny of irradiated females using the abnormal appearance of sex chromatin body in female somatic polyploid nuclei as a cytogenetic marker. A detailed cytogenetic analysis was carried out using three different fluorescence in situ hybridization techniques: genomic in situ hybridization (GISH), comparative genomic hybridization (CGH), and fluorescence in situ hybridization (FISH) with the codling moth W-chromosome painting probe. The FISH techniques enabled us to identify the W chromosome and its fragments in mitotic and meiotic chromosome complements and thus helped us to resolve complicated W chromosome aberrations induced by irradiation.  相似文献   

First case of sterility associated with sex chromosomal abnormalities in a jenny          下载免费PDF全文

J Dorado  G Anaya  M Bugno‐Poniewierska  A Molina  A Mendez‐Sanchez  I Ortiz  M Moreno‐Millán  M Hidalgo  P Peral García  S Demyda‐Peyrás 《Reproduction in domestic animals》2017,52(2):227-234

Chromosomal abnormalities are one of the main causes of genetic infertility in horses. Currently, their detection rate is rising due to the use of new diagnostic tools employing molecular markers linked to the sex chromosome pair. Despite genetic similarities, there are no previous reports of sterility associated with chromosomal abnormalities in the domestic donkey (Equus asinus). Hereby, we determined the presence of a chromosomal mosaicism in a female donkey with reproductive problems using molecular methodologies developed for horses. A two‐and‐a‐half‐year‐old jenny characterized by morphological abnormalities of the reproductive tract was cytogenetically analysed using conventional and fluorescent techniques and a group of microsatellite markers (short tandem repeat, STR). At the same time, five ultrasound measures of the reproductive tract were taken and compared with eight contemporary jennies of the same breed. After slaughter, morphological examinations showed that the case study had a blind vaginal vestibule defining an empty pouch that covered the entrance of the cervical os. Histopathological studies demonstrated that this abnormal structure was compatible with a remnant hymen. Molecular markers, STR and fluorescent in situ hybridization determinations revealed that the animal was a 62, XX/61,X mosaic and, therefore, the first case of chromosomal abnormalities in the sex pair reported in donkeys.  相似文献   

蒙古冰草Afa家族串联重复序列克隆及染色体定位     

赵彦  窦全文  云锦凤  王俊杰 《草地学报》2015,23(3):448-452

Afa家族串联重复序列因只出现在小麦及小麦族近缘属物种而得名,本研究从蒙古冰草中克隆得到一个Afa家族序列,长度为233 bp,命名为pAmAfa1,该序列在GENBANK中进行同源序列比对,结果表明该序列与大多数小麦族其他物种的Afa家族串联重复序列存在较高的相似性;系统进化分析表明,蒙古冰草pAmAfa1序列与大赖草pLrAfa3,pLrAfa5序列聚在一起,表明蒙古冰草P染色体组与大赖草的N、X染色体亲源关系较近。为了明确Afa家族串联重复序列在蒙古冰草染色体上的位置,双色荧光原位杂交技术被采用,以pAmAfa1为探针检测到杂交信号出现在染色体的末端或近端部的区域,每条染色体上都有杂交信号,表明Afa家族串联重复序列普遍存在于P染色体组中。  相似文献   

小麦品种绵麦37和绵麦367抗白粉病基因的FISH分析及分子检测     

王洋洋  邱玲  李萌  汤述尧  符书兰  唐宗祥 《麦类作物学报》2015,35(11):1502-1505

为了进一步研究和利用小麦品种绵麦37和绵麦367所携带的白粉病抗性基因,首先以OligopSc119.2-1(可检测小麦染色体结构变异)、Oligo-pTa535-1(可检测小麦染色体结构变异)和pDb12H(可检测簇毛麦染色体)为探针,对这两个小麦品种进行了荧光原位杂交(FISH)分析,然后利用与Pm21基因连锁的分子标记NAU/xibao15对这两个小麦品种进行分子检测。结果表明,绵麦37和绵麦367都含有1对6VS/6AL易位染色体,且均携带Pm21基因。  相似文献