TY - JOUR
T1 - Nannochloropsis Genomes Reveal Evolution of Microalgal Oleaginous Traits
AU - Wang, Dongmei
AU - Ning, Kang
AU - Li, Jing
AU - Hu, Jianqiang
AU - Han, Danxiang
AU - Wang, Hui
AU - Zeng, Xiaowei
AU - Jing, Xiaoyan
AU - Zhou, Qian
AU - Su, Xiaoquan
AU - Chang, Xingzhi
AU - Wang, Anhui
AU - Wang, Wei
AU - Jia, Jing
AU - Wei, Li
AU - Xin, Yi
AU - Qiao, Yinghe
AU - Huang, Ranran
AU - Chen, Jie
AU - Han, Bo
AU - Yoon, Kangsup
AU - Hill, Russell T.
AU - Zohar, Yonathan
AU - Chen, Feng
AU - Hu, Qiang
AU - Xu, Jian
PY - 2014/1
Y1 - 2014/1
N2 - Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains) and one time-series transcriptome dataset for triacylglycerol (TAG) synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2) in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels.
AB - Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains) and one time-series transcriptome dataset for triacylglycerol (TAG) synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2) in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels.
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U2 - 10.1371/journal.pgen.1004094
DO - 10.1371/journal.pgen.1004094
M3 - Article
C2 - 24415958
AN - SCOPUS:84893754953
SN - 1553-7390
VL - 10
JO - PLoS genetics
JF - PLoS genetics
IS - 1
M1 - e1004094
ER -