The pattern of phylogenomic evolution of the Canidae
The pattern of phylogenomic evolution of the Canidae
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DOI：
10.1159/000059348
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发表时间：
2001-01-01
期刊：
影响因子：
--
通讯作者：
O'Brien, SJ
中科院分区：
文献类型：
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作者：
Nash, WG;Menninger, JC;O'Brien, SJ
就其染色体组成而言，犬科物种分为两类：具有高编号的主要近端着丝粒核型和其他具有低编号的主要中着丝粒核型。那些具有低编号中心核型的物种源自在高编号物种中作为近端着丝粒染色体发现的染色体片段的多个独立融合。犬科物种内的近端着丝粒染色体臂之间存在广泛的染色体同源性；然而，犬科物种和其他食肉动物科物种之间几乎不存在染色体臂同源性。在这里，我们使用来自日本貉 (Nyctereutes procyonoides) 流式分选染色体的 Zoo-FISH（荧光原位杂交，也称为染色体涂色）探针来检查两种系统发育上不同的犬科动物：北极狐 (Alopex lagopus) 和食蟹狐 (Cerdocyonthous)。结果证实了犬科动物内部染色体同源性，这也与 G 带有关。此外，利用家猫（Felis catus）（代表祖先食肉动物核型（ACK））和大熊猫（Ailuropoda melanoleuca）的绘画探针来定义犬科动物和其他食肉动物科之间明显的原始同源片段。犬科动物染色体在食肉动物中似乎是独一无二的，因为许多犬科动物染色体臂是 ACK 染色体臂的两到四个同源片段的镶嵌体。镶嵌模式显然早于现代犬科动物物种的分化，因为不同犬科动物物种之间保守的同源片段是常见的，即使这些片段相对于祖先食肉动物基因组排列进行了重新排列。结果表明，广泛的中心裂变的祖先事件导致了祖先犬科动物基因组的组织，随后在一些但不是所有犬科谱系中通过多个染色体融合事件进行了重组。版权所有 (C) 2002 S. Karger AG，巴塞尔。
Canidae species fall into two categories with respect to their chromosome composition: these with high numbered largely acrocentric karyotypes and others with a low numbered principally metacentric karyotype. Those species with low numbered metacentric karyotypes are derived from multiple independent fusions of chromosome segments found as acrocentric chromosomes in the high numbered species, Extensive chromosome homology is apparent among acrocentric chromosome arms within Canidae species; however, little chromosome arm homology exists between Canidae species and those from other Carnivore families. Here we use Zoo-FISH (fluorescent in situ hybridization, also called chromosomal painting) probes from flow-sorted chromosomes of the Japanese raccoon dog (Nyctereutes procyonoides) to examine two phylogenetically divergent canids, the arctic fox (Alopex lagopus) and the crab-eating fox (Cerdocyon thous). The results affirm intra-canid chromosome homologies, also implicated by G-banding. In addition, painting probes from domestic cat (Felis catus), representative of the ancestral carnivore karyotype (ACK), and giant panda (Ailuropoda melanoleuca) were used to define primitive homologous segments apparent between canids and other carnivore families. Canid chromosomes seem unique among carnivores in that many canid chromosome arms are mosaics of two to four homology segments of the ACK chromosome arms. The mosaic pattern apparently preceded the divergence of modem canid species since conserved homology segments among different canid species are common, even though those segments are rearranged relative to the ancestral carnivore genome arrangement. The results indicate an ancestral episode of extensive centric fission leading to an ancestral canid genome organization that was subsequently reorganized by multiple chromosome fusion events in some but not all Canidae lineages. Copyright (C) 2002 S. Karger AG, Basel.