食肉目犬型超科(Caniformia)各科間的系統(tǒng)發(fā)育關(guān)系一直是近年來食肉目系統(tǒng)發(fā)育關(guān)系研究的熱點,，至今仍處于眾說紛紜的狀態(tài),，尤其是小熊貓科的系統(tǒng)發(fā)育位置,。小熊貓因其似熊非熊的形態(tài)特征,，使得它的進化地位存在很大的爭議，無法得到解決,。
中國科學(xué)院昆明動物研究所張亞平院士、云南大學(xué)于黎研究員和博士研究生欒鵬濤結(jié)合模式生物基因組信息,，系統(tǒng)篩選獲得了22個新的單拷貝核基因內(nèi)含子片段，將它們用于食肉目科間系統(tǒng)發(fā)育關(guān)系研究,。研究結(jié)果支持小熊貓是浣熊科和鼬科的姐妹群,，不支持形態(tài)學(xué)研究將小熊貓歸于浣熊科，或?qū)⒋?，小熊貓并為熊貓科的觀點，也不支持線粒體基因組研究中認為小熊貓與臭鼬科或由浣熊科,，鼬科和臭鼬科組成的進化枝關(guān)系最近,。
該研究不僅提供了重要的系統(tǒng)發(fā)育信息,，還在新篩選的核基因內(nèi)含子中報道了大數(shù)量的等位基因雜合子(Intra-individual Allele Heterozygotes) 現(xiàn)象,。
這項研究提供了一個使用大規(guī)模內(nèi)含子數(shù)據(jù)進行哺乳動物分子系統(tǒng)學(xué)研究的成功范例,，而且為脊椎動物分子系統(tǒng)學(xué)研究提供了新的核基因標記,。
該研究文章發(fā)表在Systematic Biology上。（生物谷Bioon.com）
生物谷推薦原文出處：
Syst Biol (2011) 60 (2): 175-187. doi: 10.1093/sysbio/syq090
Phylogenetic Utility of Nuclear Introns in Interfamilial Relationships of Caniformia (Order Carnivora)
Li Yu1,2,*?, Peng-Tao Luan1,2,?, Wei Jin1,2, Oliver A. Ryder3, Leona G. Chemnick3, Heidi A. Davis3 and Ya-ping Zhang2,*
Abstract
The monophyletic group Caniformia (dog-like carnivores) in the order Carnivora comprises 9 families. Except for the general consensus for the earliest divergence of Canidae and the grouping of Procyonidae and Mustelidae, conflicting phylogenetic hypotheses exist for the other caniformian families. In the present study, a data set comprising > 22 kb of 22 nuclear intron loci from 16 caniformian species is used to investigate the phylogenetic utility of nuclear introns in resolving the interfamilial relationships of Caniformia. Our phylogenetic analyses support Ailuridae as the sister taxon to a clade containing Procyonidae and Mustelidae, with Mephitinae being the sister taxon to all of them. The unresolved placements of Ursidae and Pinnipeds here emphasize a need to add more data and include more taxa to resolve this problem. The present study not only resolves some of the ambiguous relationships in Caniformia phylogeny but also shows that the noncoding nuclear markers can offer powerful complementary data for estimating the species tree. None of the newly developed introns here have previously been used for phylogeny reconstruction, thus increasing the spectrum of molecular markers available to mammalian systematics. Interestingly, all the newly developed intron data partitions exhibit intraindividual allele heterozygotes (IIAHs). There are 115 cases of IIAHs in total. The incorporation of IIAHs into phylogenetic analysis not only provides insights into the interfamilial relationships of Caniformia but also identifies two potential hybridization events occurred within Ursidae and Otariidae, respectively. Finally, the powers and pitfalls of phylogenetics using nuclear introns as markers are discussed in the context of Caniformia phylogeny.
