Core-SINE blocks comprise a large fraction of monotreme genomes; implications for vertebrate chromosome evolution
Core-SINE blocks comprise a large fraction of monotreme genomes; implications for vertebrate chromosome evolution
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Core-SINE 块包含单孔类动物基因组的很大一部分；
DOI：
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发表时间：
2007
影响因子：
2.6
通讯作者：
J. A. Marshall Graves
中科院分区：
文献类型：
--
作者：
P. Kirby;I. Greaves;E. Koina;P. Waters;J. A. Marshall Graves
产卵鸭嘴兽和针鼹的基因组特别令人感兴趣，因为单孔目动物是最基本的哺乳动物群体。为了更好地了解单孔类动物基因组的组织和进化，对一个古老的短间隔重复序列（SINE）家族（核心SINE）的染色体分布进行了研究。先前的研究已经确定了核心SINE作为鸭嘴兽基因组中的主要SINE，在这项研究中，我们量化，表征和定位亚家族。斑点杂交分析表明，一个非常大的部分（32%的鸭嘴兽和16%的针鼹鼠基因组）是由Mon核心SINE。采用Core-SINE特异性引物对鸭嘴兽和针鼹基因组DNA进行PCR扩增。序列分析表明，鸭嘴兽和针鼹鼠共有一个共同的共有序列Mon 1-B，以及鸭嘴兽特异性Mon 1-C和针鼹鼠特异性Mon 1-D共有序列。FISH映射的Mon核心SINE产品鸭嘴兽中期传播表明，Mon-1C亚家族是负责显着的Mon核心SINE积累在6个大型常染色体对和最大的X染色体的远端区域。这种不寻常的分布突出了单孔类核型中7对大染色体和19对小染色体之间的二分法，这与鸟类和爬行动物的宏观和微观染色体有一些相似性，并表明重复序列的积累可能扩大了祖先脊椎动物的小染色体。在即将公布的鸭嘴兽基因组序列中，仍然存在很大的缺口，并且在6个大型常染色体对的远端区域上广泛的Mon核心-SINE积累可能为这种缺失序列提供一种解释。
The genomes of the egg-laying platypus and echidna are of particular interest because monotremes are the most basal mammal group. The chromosomal distribution of an ancient family of short interspersed repeats (SINEs), the core-SINEs, was investigated to better understand monotreme genome organization and evolution. Previous studies have identified the core-SINE as the predominant SINE in the platypus genome, and in this study we quantified, characterized and localized subfamilies. Dot blot analysis suggested that a very large fraction (32% of the platypus and 16% of the echidna genome) is composed of Mon core-SINEs. Core-SINE-specific primers were used to amplify PCR products from platypus and echidna genomic DNA. Sequence analysis suggests a common consensus sequence Mon 1-B, shared by platypus and echidna, as well as platypus-specific Mon 1-C and echidna specific Mon 1-D consensus sequences. FISH mapping of the Mon core-SINE products to platypus metaphase spreads demonstrates that the Mon-1C subfamily is responsible for the striking Mon core-SINE accumulation in the distal regions of the six large autosomal pairs and the largest X chromosome. This unusual distribution highlights the dichotomy between the seven large chromosome pairs and the 19 smaller pairs in the monotreme karyotype, which has some similarity to the macro- and micro-chromosomes of birds and reptiles, and suggests that accumulation of repetitive sequences may have enlarged small chromosomes in an ancestral vertebrate. In the forthcoming sequence of the platypus genome there are still large gaps, and the extensive Mon core-SINE accumulation on the distal regions of the six large autosomal pairs may provide one explanation for this missing sequence.
影响因子：
--
作者：
G. Pfeifer;A. Riggs
通讯作者：
G. Pfeifer;A. Riggs
影响因子：
7
作者：
Gentles, Andrew J.;Wakefield, Matthew J.;Jurka, Jerzy
通讯作者：
Jurka, Jerzy