http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The genome of the mesopolyploid crop species Brassica rapa
Wang, Xiaowu,Wang, Hanzhong,Wang, Jun,Sun, Rifei,Wu, Jian,Liu, Shengyi,Bai, Yinqi,Mun, Jeong-Hwan,Bancroft, Ian,Cheng, Feng,Huang, Sanwen,Li, Xixiang,Hua, Wei,Wang, Junyi,Wang, Xiyin,Freeling, Michael Nature Publishing Group, a division of Macmillan P 2011 Nature genetics Vol.43 No.10
We report the annotation and analysis of the draft genome sequence of Brassica rapa accession Chiifu-401-42, a Chinese cabbage. We modeled 41,174 protein coding genes in the B. rapa genome, which has undergone genome triplication. We used Arabidopsis thaliana as an outgroup for investigating the consequences of genome triplication, such as structural and functional evolution. The extent of gene loss (fractionation) among triplicated genome segments varies, with one of the three copies consistently retaining a disproportionately large fraction of the genes expected to have been present in its ancestor. Variation in the number of members of gene families present in the genome may contribute to the remarkable morphological plasticity of Brassica species. The B. rapa genome sequence provides an important resource for studying the evolution of polyploid genomes and underpins the genetic improvement of Brassica oil and vegetable crops.
Cho, Kwangsoo,O’Neill, Carmel M.,Kwon, Soo-Jin,Yang, Tae-Jin,Smooker, Andrew M.,Fraser, Fiona,Bancroft, Ian Blackwell Publishing Ltd 2010 The Plant journal Vol.61 No.4
<P>Summary</P><P>We conducted a sequence-level comparative analyses, at the scale of complete bacterial artificial chromosome (BAC) clones, between the genome of the most economically important <I>Brassica</I> species, <I>Brassica napus</I> (oilseed rape), and those of <I>Brassica rapa</I>, the genome of which is currently being sequenced, and <I>Arabidopsis thaliana</I>. We constructed a new <I>B. napus</I> BAC library and identified and sequenced clones that contain homoeologous regions of the genome including stearoyl-ACP desaturase-encoding genes. We sequenced the orthologous region of the genome of <I>B. rapa</I> and conducted comparative analyses between the <I>Brassica</I> sequences and those of the orthologous region of the genome of <I>A. thaliana</I>. The proportion of genes conserved (∼56%) is lower than has been reported previously between <I>A. thaliana</I> and <I>Brassica</I> (∼66%). The gene models for sets of conserved genes were used to determine the extent of nucleotide conservation of coding regions. This was found to be 84.2 ± 3.9% and 85.8 ± 3.7% between the <I>B. napus</I> A and C genomes, respectively, and that of <I>A. thaliana</I>, which is consistent with previous results for other <I>Brassica</I> species, and 97.5 ± 3.1% between the <I>B. napus</I> A genome and <I>B. rapa</I>, and 93.1 ± 4.9% between the <I>B. napus</I> C genome and <I>B. rapa</I>. The divergence of the <I>B. napus</I> genes from the A genome and the <I>B. rapa</I> genes was greater than anticipated and indicates that the A genome ancestor of the <I>B. napus</I> cultivar studied was relatively distantly related to the cultivar of <I>B. rapa</I> selected for genome sequencing.</P>
Cheung, Foo,Trick, Martin,Drou, Nizar,Lim, Yong Pyo,Park, Jee-Young,Kwon, Soo-Jin,Kim, Jin-A,Scott, Rod,Pires, J Chris,Paterson, Andrew H,Town, Chris,Bancroft, Ian American Society of Plant Physiologists 2009 The Plant cell Vol.21 No.7
<P>Homoeologous regions of Brassica genomes were analyzed at the sequence level. These represent segments of the Brassica A genome as found in Brassica rapa and Brassica napus and the corresponding segments of the Brassica C genome as found in Brassica oleracea and B. napus. Analysis of synonymous base substitution rates within modeled genes revealed a relatively broad range of times (0.12 to 1.37 million years ago) since the divergence of orthologous genome segments as represented in B. napus and the diploid species. Similar, and consistent, ranges were also identified for single nucleotide polymorphism and insertion-deletion variation. Genes conserved across the Brassica genomes and the homoeologous segments of the genome of Arabidopsis thaliana showed almost perfect collinearity. Numerous examples of apparent transduplication of gene fragments, as previously reported in B. oleracea, were observed in B. rapa and B. napus, indicating that this phenomenon is widespread in Brassica species. In the majority of the regions studied, the C genome segments were expanded in size relative to their A genome counterparts. The considerable variation that we observed, even between the different versions of the same Brassica genome, for gene fragments and annotated putative genes suggest that the concept of the pan-genome might be particularly appropriate when considering Brassica genomes.</P>