“云杉基因组项目”联合课题组在本期Nature上发表了第一种裸子植物的基因组草稿，即一种挪威云杉(Picea abies)的基因组草稿。该基因组来自最初于1959年在瑞典中部的东J?mtland获得的一棵树，大小为20千兆碱基对，比模型植物“拟南芥”的基因组大100倍，但二者所含基因数量差不多。这个基因组之所以大，是由于可转位元素的积累。对另外五个裸子植物基因组所做的比较测序表明，可转位元素多样性也见于现存针叶树。该基因组的序列数据可以在ConGenIE网站(http://congenie.org/)上公开获取。（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature doi:10.1038/nature12211
The Norway spruce genome sequence and conifer genome evolution
Bjorn Nystedt, Nathaniel R. Street, Anna Wetterbom, Andrea Zuccolo, Yao-Cheng Lin, Douglas G. Scofield, Francesco Vezzi, Nicolas Delhomme, Stefania Giacomello, Andrey Alexeyenko, Riccardo Vicedomini, Kristoffer Sahlin, Ellen Sherwood, Malin Elfstrand, Lydia Gramzow, Kristina Holmberg, Jimmie Hallman, Olivier Keech, Lisa Klasson, Maxim Koriabine, Melis Kucukoglu, Max Kaller, Johannes Luthman, Fredrik Lysholm, Totte Niittyla et al.
Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinus sylvestris, Abies sibirica, Juniperus communis, Taxus baccata and Gnetum gnemon reveals that the transposable element diversity is shared among extant conifers. Expression of 24-nucleotide small RNAs, previously implicated in transposable element silencing, is tissue-specific and much lower than in other plants. We further identify numerous long (>10,000 base pairs) introns, gene-like fragments, uncharacterized long non-coding RNAs and short RNAs. This opens up new genomic avenues for conifer forestry and breeding.
