Telomeres in the chicken: Genome stability and chromosome ends
Telomeres in the chicken: Genome stability and chromosome ends
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DOI：
10.1093/ps/82.6.917
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发表时间：
2003-06-01
期刊：
影响因子：
4.4
通讯作者：
Taylor, HA
中科院分区：
文献类型：
--
作者：
Delany, ME;Daniels, LM;Taylor, HA
端粒是位于线性染色体末端的复杂核蛋白结构。端粒DNA由高度保守的六核苷酸串联重复序列组成。端粒酶是逆转录酶家族中的一种核糖核蛋白，它决定端粒DNA的序列并维持端粒序列的长度。在模式生物中的大量研究确立了端粒结构和功能在调节基因组稳定性、细胞衰老和肿瘤发生中的重要性。我们的总体研究目标是了解在这种高等脊椎动物基因组的不寻常的组织和专业化特征（包括紧凑的基因组，众多的微染色体和高重组率）的背景下，在鸡的端粒阵列的组织，并阐明端粒在影响细胞功能和寿命的基因组稳定性中发挥的作用。最近的研究发现，鸡基因组包含三个重叠的端粒阵列大小类别，其在位置和年龄相关的稳定性方面不同：I类0.5至10 kb，1110至40 kb和11140 kb至2 Mb。鸡端粒生物学的一些显著特征是，鸡基因组含有比人类基因组多十倍的端粒DNA，并且III类端粒阵列是任何脊椎动物物种中描述的最大的。在体内，鸡端粒（11类）缩短与年龄相关的方式和端粒酶活性是高的早期胚胎和发育器官，但在胚胎发生后期或出生后在大多数体细胞组织下调。在体外，鸡细胞下调端粒酶活性，除非转化。鸡端粒生物学的知识有助于信息相关的现在和未来的生物技术应用的鸡在体内和鸡细胞在体外。
Telomeres are the complex nucleoprotein structures at the termini of linear chromosomes. Telomeric DNA consists of a highly conserved hexanucleotide arranged in tandem repeats. Telomerase, a ribonucleoprotein of the reverse transcriptase family, specifies the sequence of telomeric DNA and maintains telomere array length. Numerous studies in model organisms established the significance of telomere structure and function in regulating genome stability, cellular aging, and oncogenesis. Our overall research objectives are to understand the organization of the telomere arrays in chicken in the context of the unusual organization and specialized features of this higher vertebrate genome (which include a compact genome, numerous microchromosomes, and high recombination rate) and to elucidate the role telomeres play in genome stability impacting cell function and life span. Recent studies found that the chicken genome contains three overlapping size classes of telomere arrays that differ in location and age-related stability: Class I 0.5 to 10 kb, Class 1110 to 40 kb, and Class 11140 kb to 2 Mb. Some notable features of chicken telomere biology are that-the chicken genome contains ten times more telomeric DNA than the human genome and the Class III telomere arrays are the largest described for any vertebrate species. In vivo, chicken telomeres (Class 11) shorten in an age-related fashion and telomerase activity is high in early stage embryos and developing organs but down-regulates during late embryogenesis or postnatally in most somatic tissues. In vitro, chicken cells down-regulate telomerase activity unless transformed. Knowledge of chicken telomere biology contributes information relevant to present and future biotechnology applications of chickens in vivo and chicken cells in vitro.