數(shù)千年來,，家蠶只以桑葉作為唯一的食物。為了探索二者之間的聯(lián)系,，日前,，《自然—通訊》雜志在線發(fā)表了西南大學(xué)家蠶基因組生物學(xué)國家重點實驗室完成的桑樹全基因組測序成果。
據(jù)了解,，桑樹基因組測序由中國工程院院士向仲懷,、西南大學(xué)家蠶基因組生物學(xué)國家重點實驗室牽頭，集合了浙江省農(nóng)業(yè)科學(xué)院,、廣東省農(nóng)業(yè)科學(xué)院,、中國林業(yè)科學(xué)研究院等單位，歷時3年完成,。
向仲懷介紹說,，早在2008年，家蠶的基因組就已經(jīng)被解析,，但在西南大學(xué)發(fā)布之前,，全世界對桑樹基因的研究為零。實際上,，以桑樹和家蠶為典型代表的植物和植食性昆蟲之間在分子水平上存在相互作用,。為此，他們開展了桑樹基因組測序,。
據(jù)了解,，測序采用的材料為川桑。此前文獻均將桑樹染色體基數(shù)定為14,，而此次課題組經(jīng)過深入研究后判明,，川桑染色體基數(shù)為7。這是桑樹學(xué)科百余年來最重要的貢獻之一,。
研究人員采用第二代Illumina測序技術(shù)進一步發(fā)現(xiàn),，相比首個完成基因測序的木本植物——楊樹，桑樹的基因組更小,，在過去的1億年中沒有經(jīng)歷全基因組加倍事件,，桑樹基因的進化速度大約是薔薇目其他物種的3倍，且存在一系列新的多倍體類型,。
向仲懷表示,，桑樹基因組測序的完成,，不僅能促進桑樹改良，也能調(diào)控蠶的基因表達,，對蠶桑產(chǎn)業(yè)的創(chuàng)新變革以及現(xiàn)代桑樹學(xué)的建立都有巨大作用（生物谷Bioon.com）,。
生物谷推薦的英文摘要
Nature Communications doi:10.1038/ncomms3445
Draft genome sequence of the mulberry tree Morus notabilis
Ningjia He，Chi Zhang,，Xiwu Qi,，Shancen Zhao，Yong Tao,，Guojun Yang,，Tae-Ho Lee，Xiyin Wang,，Qingle Cai,，Dong Li，Mengzhu Lu,，Sentai Liao,，Guoqing Luo，Rongjun He,，Xu Tan,，Yunmin Xu，Tian Li,，Aichun Zhao,，Ling Jia，Qiang Fu
Human utilization of the mulberry–silkworm interaction started at least 5,，000 years ago and greatly influenced world history through the Silk Road. Complementing the silkworm genome sequence,， here we describe the genome of a mulberry species Morus notabilis. In the 330-Mb genome assembly， we identify 128,？Mb of repetitive sequences and 29,，338 genes， 60.8% of which are supported by transcriptome sequencing. Mulberry gene sequences appear to evolve ~3 times faster than other Rosales,， perhaps facilitating the species’ spread worldwide. The mulberry tree is among a few eudicots but several Rosales that have not preserved genome duplications in more than 100 million years,； however， a neopolyploid series found in the mulberry tree and several others suggest that new duplications may confer benefits. Five predicted mulberry miRNAs are found in the haemolymph and silk glands of the silkworm,， suggesting interactions at molecular levels in the plant–herbivore relationship. The identification and analyses of mulberry genes involved in diversifying selection,， resistance and protease inhibitor expressed in the laticifers will accelerate the improvement of mulberry plants.
