在11月13日的《美國科學(xué)院院刊》網(wǎng)站上公示了來自美國新澤西大學(xué)的華裔學(xué)者王清華（Qinghua Wang，音譯，文章第一作者）和Hugo K. Dooner的有關(guān)玉米基因組結(jié)構(gòu)變異的最新研究成果,。
玉米可能是所有農(nóng)作物中最多樣化的物種,。通過比較兩種不同的玉米自交系McC和B73的（inbred lines）bz基因組區(qū)域,，研究人員以外地發(fā)現(xiàn)了大量的單模標(biāo)本差異,。
構(gòu)成了玉米中多數(shù)DNA成分的反轉(zhuǎn)錄轉(zhuǎn)座子簇在構(gòu)成上有明顯的變化并且在基因中的相對位置也有明顯變化。
這些Corn Belt自交系的等位bz區(qū)域只具占所有序列的少數(shù),。為了進(jìn)一步分析由反轉(zhuǎn)錄轉(zhuǎn)座子,、helitrons和其他插入形式，研究人員分析了另外5種品系玉米中的bz基因組區(qū)域,。這五種分別為自交系A(chǔ)188,、CML258和I137TN以及l(fā)and races Coroico和NalTel。
這種垂直比較揭示出存在幾種新的helitrons,、反轉(zhuǎn)錄轉(zhuǎn)座子,、每個DNA轉(zhuǎn)座子超家族成員、大量的微笑成分和新的插入成分——TAFT(TA-flanked transposons),。
通過垂直比較和成對比較,，研究人員推測共有基因空間的重組極大地增加了玉米祖先中反轉(zhuǎn)錄轉(zhuǎn)座擴增產(chǎn)生的變異性，從而創(chuàng)造出現(xiàn)代玉米中基因組構(gòu)成異質(zhì)性特征,。
部分英文原文：
Unprecedented Haplotype Variability In The Maize bz Genomic Region
A comparison of the bz genomic regions of lines McC and B73, the selected standard for sequencing the maize genome, showed unexpected polymorphisms in the size and make-up of retrotransposon clusters at “allelic” positions, in the pattern of interspersion of genes and retrotransposons in the region, and in the gene content of the bz genomic region. Four genes, all members of small gene families, are located next to each other in line McC, but are missing from the corresponding location in line B73. Those four genes, either in one or two fragments, appear to be present elsewhere in the B73 genome. Additional sequencing of the bz genomic region from other inbred lines has identified common haplotypes and chimeric haplotypes. Chimeric haplotypes have retrotransposon clusters found in different haplotypes. Recombination in the gene space shared by different haplotypes shuffles retrotransposon clusters, creating huge heterogeneity in genome organization among modern maize lines. The observed intraspecific violation of genetic colinearity has potential implications regarding the breeding behavior of maize inbreds and hybrids.
