检索结果-南通市图书馆

Sporophytic nondisjunction of the maize B chromosome at high copy numbers

Journal of Genetics and Genomics 2010年第1期37卷 79-84页

作者： Rick E.Masonbrink James A.Birchler Division of Biological Sciences University of Missouri

It has been known for decades that the maize B chromosome undergoes nondisjunction at the second pollen *** in-situ hybridization （FISH） was used to undertake a quantitative study of maize plants with differing numbers of B chromosomes to observe if instability increases by increasing B dosage in root tip tissue.B chromosome nondisjunction was basically absent at low copy number,but increased at higher B ***,B nondisjunction rates are dependent on the dosage of B＇s in the *** in nondisjunction were also documented between odd and even doses of the *** plants that have inherited odd numbered doses of the B chromosome,B loss is nearly twice as likely as B gain in a somatic *** comparing plants with even doses of B＇s to plants with odd doses of B＇s,plants with even numbers had a significantly higher chance to increase in ***,the B＇s nondisjunctive capacity,previously thought to be primarily restricted to the gametophyte,is present in sporophytic cells.

关键词： maize Zea mays B chromosome nondisjunction odd-even effect

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of age on segregation of the X and Y chromosomes in cultured lymphocytes from Chinese men

引用

Journal of Genetics and Genomics 2009年第8期36卷 467-474页

作者： Yaxian Song Qian Chen Zhen Zhang Heli Hou Ding Zhang Qinghua Shi Laboratory of Molecular and Cell Genetics Hefei National Laboratory for Physical Sciences at Microscale School of Life Sciences University of Science and Technology of China Hefei 230027 China Department of Science of Biology Bengbu Medical Collage Bengbu 233000 China

Chromosome malsegregation in binucleated lymphocytes is a useful endpoint to evaluate age effect on genetic stability. However, the investigations on chromosome malsegregation in binucleated lymphocytes from Chinese are scarce. In this study, peripheral blood lym- phocytes were collected from 14 old （60-70 years） and 10 young （22-26 years） healthy Chinese men. To detect malsegregation of the sex chromosomes, multi-color fluorescence in situ hybridization （FISH） was performed on binucleated lymphocytes, cytokinesis-blocked by cytochalasin B at the first mitosis after phytohaemagglutinin stimulation. Compared with that in young men, a significant increase in frequencies of loss of chromosome X （9.2± 3.2‰ vs. 1.1 ± 0.9‰, P 〈 0.001） and Y （2.5 ± 1.9‰ vs. 0.2± 0.3‰, P 〈 0.001） was found in old men. Similarly, nondisjunction of chromosome X （16.5± 3.4‰ vs. 3.5 ± 1.1‰, P 〈 0.001） and Y （7.2 ± 2.6‰ vs. 2.4 ± 1.3‰, P 〈 0.001） occurred more frequently in old men than in young men. Regardless of donor＇s age, nondisjunction is more prevalent than loss for both chromosome X and Y. The frequencies of observed simultaneous malsegregation were relatively higher than the expected, suggest- ing an association between malsegregation. These results indicated that in Chinese men, malsegregation of the sex chromosomes increases with age in an associated fashion, and nondisjunction accounts for the majority of spontaneous chromosome malsegregation.

关键词： chromosome loss nondisjunction chromosome X chromosome Y lymphocyte Chinese men

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Maize centromeres:where sequence meets epigenetics

引用

Frontiers in Biology 2011年第2期6卷 102-108页

作者： Wenchao YIN James A.BIRCHLER Fangpu HAN State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Division of Biological Sciences University of Missouri-ColumbiaColumbiaMO 65211USA Graduate Universtiy of the Chinese Academy of Sciences Beijing 100039China

The centromere is a highly organized structure mainly composed of repeat sequences,which make this region extremely difficult for sequencing and other *** plays a conserved role in equal division of chromosomes into daughter cells in both mitosis and ***,centromere sequences show notable *** a dicentric chromosome,one of the centromeres can become inactivated with the underlying DNA ***,formerly inactive centromeres can regain activity under certain *** addition,neocentromeres without centromeric repeats have been found in a wide spectrum of *** evidence indicates that epigenetic mechanisms together with centromeric sequences are associated with centromere specification.

关键词： centromere centromere inactivation centromere reactivation nondisjunction maize

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Study of Apolipoprotein E4 Allele Distribution in Parents of Down’s Syndrome Children as a Risk Factor in Khorasan Razavi Province, Iran

引用

Open Journal of Genetics 2016年第4期6卷 87-95页

作者： Elmira Iranifar Tayebeh Hamzehloie Department of Human Genetics Mashhad University of Medical Science Mashhad Iran

Backgrounds: Down syndrome (DS) is the most common chromosomal abnormality. The most important factor in DS is increased maternal age so after the age of 35, the risk of Down syndrome in pregnancy increases. Down syndrome can be diagnosed during pregnancy by prenatal screening. nondisjunction in cell divisions is the main cause of the DS. Apo lipoprotein E is a 317 amino acid glycoprotein that plays an essential role in metabolism and cholesterol transport. Alzheimer’s disease (AD) is one of the symptoms of adults with DS. The apoE allele e4 has been identified as a risk factor for AD and also, played a main role in nondisjunction. An increased risk of AD in mothers of adults with DS has been reported. We hypothesized that young mothers of DS children (Methods: In this case-control study, 33 DS children and their parents were compared in case of age with 90 families without any history of DS. Genotyping was performed by ARMS-PCR technique. Statistical analysis was performed by SPSS v.21 software. Results: It indicated that there is a significant difference in allele distribution between case and control groups. The C allele for 112 codon of APOE gene and the C allele for 158 codon of APOE gene may associate with nondisjunction. In 112 codon of APOE gene, it seems having T allele reduces the risk of nondisjunction and in contrast C allele may be a risk factor in happening of nondisjunction. (p-value = 0.000006, OR = 2.66, 95% CI = 1.74 - 4.06). In 158 codon of APOE gene, it seems having T allele reduces the risk of nondisjunction and in contrast C allele may be a risk factor in happening of nondisjunction. (p-value = 0.0000, OR = 3.89, 95% CI = 2.38 - 6.34). E4 allele frequency in mothers of DS is about 14% more than those in control group. According to results of this study the C allele in 158 codon of APOE gene and the C allele in 112 codon of APOE gene could be considered as susceptibility genetic factors for nondisjunction in Northeast of Iran.

关键词： Down Syndrome nondisjunction ApoE Allele e4 Polymorphism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：