據(jù)4月24日的《科學(xué)》雜志報(bào)道說(shuō),，研究人員現(xiàn)在已經(jīng)完成了對(duì)整個(gè)牛染色體組的測(cè)序,，這一成就對(duì)我們加深了解哺乳動(dòng)物的進(jìn)化、加速牛奶和肉制品的基因改良并由此而更好地了解人類疾病以及對(duì)它們的相關(guān)治療都會(huì)有促進(jìn)作用,。
在2篇獨(dú)立的報(bào)告中,，Richard Gibbs及其同僚重點(diǎn)介紹了Bovine Genome Sequencing and Analysis Consortium的最近的發(fā)現(xiàn)，該項(xiàng)目對(duì)牛的基因組進(jìn)行了分辨率精細(xì)的測(cè)序,；而Bovine HapMap Consortium則將研究焦點(diǎn)放在對(duì)牲畜進(jìn)化和馴養(yǎng)歷史的追蹤工作上,。 對(duì)這2個(gè)項(xiàng)目進(jìn)行研究的工作人員發(fā)現(xiàn)，牛的基因組含有至少2萬(wàn)2000個(gè)基因,，其中大約有1萬(wàn)4345個(gè)基因在7種其它的哺乳動(dòng)物種系中具有對(duì)應(yīng)的基因,。
這些發(fā)現(xiàn)顯示，在牛的進(jìn)化和馴養(yǎng)過(guò)程中,，基因的數(shù)量和構(gòu)成的變化是如何改變牛的生物學(xué)系統(tǒng)并對(duì)它們的繁殖,、免疫能力、乳汁分泌和消化造成了最為顯著的影響的,。 這些研究人員還對(duì)來(lái)自19個(gè)不同地理和在生物學(xué)上混雜繁殖的497頭不同牛只DNA中的3萬(wàn)7470種差異進(jìn)行了調(diào)查,。他們發(fā)現(xiàn)，母牛的進(jìn)化與我們?nèi)祟惐旧淼倪M(jìn)化截然不同,，它們從一個(gè)有著非常大的有效祖先群體到近期發(fā)生的快速的群體下降,，而不是反過(guò)來(lái)的那種一種情形。 文章的作者將這種進(jìn)化歸因于與以往馴化活動(dòng),、因農(nóng)業(yè)專門化所作的選擇以及與動(dòng)物豢養(yǎng)的形成相關(guān)的遺傳學(xué)瓶頸,。 但是，牛品種中的多樣性的現(xiàn)有水平看來(lái)至少與那些在人類群體中的水平一樣地強(qiáng)健有力,。
在一篇Perspective中,，Harris Lewin對(duì)這些發(fā)現(xiàn)進(jìn)行了更為詳細(xì)的探討，并重點(diǎn)介紹了其對(duì)人類健康和可持續(xù)性農(nóng)業(yè)的意義。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 24 April 2009:DOI: 10.1126/science.1169588
The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution
The Bovine Genome Sequencing and Analysis Consortium,* Christine G. Elsik,1 Ross L. Tellam,2 Kim C. Worley3
To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
1 Department of Biology, 406 Reiss, Georgetown University, 37th and O Streets, NW, Washington, DC 20057, USA.
2 CSIRO Livestock Industries, 306 Carmody Road, St. Lucia, QLD 4067, Australia.
3 Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, MS BCM226, One Baylor Plaza, Houston, TX 77030, USA.
