Welcome to Acta Agronomica Sinica,

Acta Agron Sin ›› 2010, Vol. 36 ›› Issue (3): 435-441.doi: 10.3724/SP.J.1006.2010.00435


Cloning and Characterization of Six Oleic Acid Desaturase Pseudogenes of Brassica napus

XIAO Gang1,2,ZHANG Zhen-Qian1,WU Xian-Meng1,TAN Tai-Long1,2,GUAN Chun-Yun1*   

  1. 1 Oil Crops Institute/National Oil Crops Improvement Center, Hunau Agricultural University; 2 Pre-State Key Laboratory for Germplasm Innovation and Resource Utilization of Crops, Changsha 410128, China
  • Received:2009-06-30 Revised:2009-12-08 Online:2010-03-12 Published:2010-01-22
  • Contact: GUAN Chun-Yun,E-mail:guancy2000@yahoo.com.cn
  • About author:XIAO Gang,E-mail: sanjian123@yeah.net; Tel: 0731-4617941


The phenomenon of multi-copy genes is common in plants. Pseudogene is defined as an inactive gene, which can not synthesize functional proteins but share the similar DNA sequences with normal functional genes. In this study, 56 FAD2 DNA clones and 47 FAD2 seed cDNA clones of Brassica napus cv. Xiangyou 15 were investigated, and 6 new copies of FAD2 were detected, designated as FAD2P1-6 respectively. This sequence length of 6 copies ranged from 1 141–1 157 bp and there were no introns in their open reading frames (ORF). These 6 copies share 96.1% identity in nucleotides from one another, and share more than 87% nucleotides identity with AY577313. Deduced amino acid sequences revealed that 112 stop codons occurred in the coding region of six copies which will prevent them from coding for a functional protein. These six copies were investigated in vivo in Saccharomyces cerevisiae through being cloned into yeast expression vector pYES2.0, and the 16:2 and 18:2 fatty acids were determined by gas chromatographic analysis. The results revealed that the products of the six copies were not able to synthesize 16:2 and 18:2 fatty acids, suggesting that they are pseudogenes of FAD2. These multiple pseudogenes of FAD2 within the B. napus genome might result from the duplication of large chromosomal segments simultaneously following mutation. Because of the existence of multiple pseudogenes for FAD2 in B. napus genome, we should be careful in genetic research to identify true and false, to avoid wrong conclusions.

Key words: Brassica napus, FAD2, Oleic acid desaturase, Gene expression, Saccharomyces cerevisiae

[1] Okuley J, Lightner J, Feldmann K, Yadav N, Lark E, Browse J. Arabidopsis FAD2 gene encodes the enzyme that is essential for polyunsaturated lipid synthesis. Plant Cell, 1996, 6: 147-158

[2] Ohlrogge J, Jaworski J G. Regulation of fatty acid synthesis.Plant Mol Biol, 1997, 48: 109-136
[3] Nagahara U. Genome-analysis in Brassica with special reference to the experiments formation of B. napus and peculiar mode of fertilization. Jpn J Bot, 1935, 7: 389-452
[4] Scheffler J A, Sharpe A G, Schmidt H, Sperling P, Parkin I A P, Lühs W, Lydiate D J, Heinz E. Desaturase multigene families of Brassica napus arose through genome duplication.Theor Appl Genet, 1997, 94: 583-591

[5] Lynch M, Conery J S. The evolutionary fate and consequences of duplicate genes. Science, 2000, 290: 1151-1155

[6] Hirotsune S J, Yoshida N, Chen A, Garrett L, Sugiyama F, Takahashi S, Yagami K, Wynshaw-Boris A, Yoshiki A. An expressed pseudogene regulates the messenger-RNA stability of its homologous coding gene. Nature, 2003, 423: 91-96

[7] Frank A C, Amiri H, Andersson S G. Genome deterioration: Loss of repeated sequences and accumulation of junk DNA. Genetica, 2002 115(1): 1-12

[8] Wang G-L(王关林), Fang H-J(方宏筠). Plant Gene Engineering, 2nd edn (植物基因工程·第二版). Beijing: China Science Press, 2002. pp 744-745 (in Chinese)

[9] Wei D S, Li M C, Zhang X X, Ren Y, Xing L J. Identification and characterization of a novel Δ12-fatty acid desaturase gene from Rhizopus arrhizus. FEBS Lett, 2004, 573: 45-50
[10] Romanos M A, Scorer C A, Clare J J. Foreign gene expression in yeast: A review. YEAST, 1992, 8: 423-488

[11] Niu B, Ye H X, Xu Y, Wang S H, Chen P, Peng S M, Ou Y C,Tang L,Chen F. Cloning and characterization of a novel Δ12-fatty acid desaturase gene from the tree Sapium sebiferum.Biotechnol Lett, 2007, 29: 959-964

[12] Guan C-Y(官春云). Advance of high oleic acid in oil seed breeding. Crop Res (作物研究), 2006, 20(1): 1-8 (in Chinese)

[13] Jacq C, Miller J R, Brownlee G G. A pseudogene structure in 5S DNA of Xenopus laevis. Cell, 1977, 13: 109-120

[14] Zhang Z L, Harrison P M, Liu Y, Gerstein M. Millions of years of evolution preserved: A comprehensive catalog of the processed pseudogenes in the human genome.Genome Res,2003,13: 2541-2558

[15] Lynch M, Conery J S. The evolutionary fate and consequences of duplicate genes. Science, 2000, 290: 1151-1155
[16] Balakirev E S, Ayala F J. Pseudogenes: Are they “junk” or “functional” DNA.
Annu Rev Genet, 2003, 37: 123-151
[1] CHEN Song-Yu, DING Yi-Juan, SUN Jun-Ming, HUANG Deng-Wen, YANG Nan, DAI Yu-Han, WAN Hua-Fang, QIAN Wei. Genome-wide identification of BnCNGC and the gene expression analysis in Brassica napus challenged with Sclerotinia sclerotiorum and PEG-simulated drought [J]. Acta Agronomica Sinica, 2022, 48(6): 1357-1371.
[2] LI Hai-Fen, WEI Hao, WEN Shi-Jie, LU Qing, LIU Hao, LI Shao-Xiong, HONG Yan-Bin, CHEN Xiao-Ping, LIANG Xuan-Qiang. Cloning and expression analysis of voltage dependent anion channel (AhVDAC) gene in the geotropism response of the peanut gynophores [J]. Acta Agronomica Sinica, 2022, 48(6): 1558-1565.
[3] YUAN Da-Shuang, DENG Wan-Yu, WANG Zhen, PENG Qian, ZHANG Xiao-Li, YAO Meng-Nan, MIAO Wen-Jie, ZHU Dong-Ming, LI Jia-Na, LIANG Ying. Cloning and functional analysis of BnMAPK2 gene in Brassica napus [J]. Acta Agronomica Sinica, 2022, 48(4): 840-850.
[4] HUANG Cheng, LIANG Xiao-Mei, DAI Cheng, WEN Jing, YI Bin, TU Jin-Xing, SHEN Jin-Xiong, FU Ting-Dong, MA Chao-Zhi. Genome wide analysis of BnAPs gene family in Brassica napus [J]. Acta Agronomica Sinica, 2022, 48(3): 597-607.
[5] JIN Rong, JIANG Wei, LIU Ming, ZHAO Peng, ZHANG Qiang-Qiang, LI Tie-Xin, WANG Dan-Feng, FAN Wen-Jing, ZHANG Ai-Jun, TANG Zhong-Hou. Genome-wide characterization and expression analysis of Dof family genes in sweetpotato [J]. Acta Agronomica Sinica, 2022, 48(3): 608-623.
[6] WANG Rui, CHEN Xue, GUO Qing-Qing, ZHOU Rong, CHEN Lei, LI Jia-Na. Development of linkage InDel markers of the white petal gene based on whole-genome re-sequencing data in Brassica napus L. [J]. Acta Agronomica Sinica, 2022, 48(3): 759-769.
[7] QU Jian-Zhou, FENG Wen-Hao, ZHANG Xing-Hua, XU Shu-Tu, XUE Ji-Quan. Dissecting the genetic architecture of maize kernel size based on genome-wide association study [J]. Acta Agronomica Sinica, 2022, 48(2): 304-319.
[8] CHEN Xin-Yi, SONG Yu-Hang, ZHANG Meng-Han, LI Xiao-Yan, LI Hua, WANG Yue-Xia, QI Xue-Li. Effects of water deficit on physiology and biochemistry of seedlings of different wheat varieties and the alleviation effect of exogenous application of 5-aminolevulinic acid [J]. Acta Agronomica Sinica, 2022, 48(2): 478-487.
[9] ZHAO Gai-Hui, LI Shu-Yu, ZHAN Jie-Peng, LI Yan-Bin, SHI Jia-Qin, WANG Xin-Fa, WANG Han-Zhong. Mapping and candidate gene analysis of silique number mutant in Brassica napus L. [J]. Acta Agronomica Sinica, 2022, 48(1): 27-39.
[10] WANG Yan-Peng, LING Lei, ZHANG Wen-Rui, WANG Dan, GUO Chang-Hong. Genome-wide identification and expression analysis of B-box gene family in wheat [J]. Acta Agronomica Sinica, 2021, 47(8): 1437-1449.
[11] WANG Yan-Hua, LIU Jing-Sen, LI Jia-Na. Integrating GWAS and WGCNA to screen and identify candidate genes for biological yield in Brassica napus L. [J]. Acta Agronomica Sinica, 2021, 47(8): 1491-1510.
[12] SONG Tian-Xiao, LIU Yi, RAO Li-Ping, Soviguidi Deka Reine Judesse, ZHU Guo-Peng, YANG Xin-Sun. Identification and expression analysis of cell wall invertase IbCWIN gene family members in sweet potato [J]. Acta Agronomica Sinica, 2021, 47(7): 1297-1308.
[13] LI Jie-Hua, DUAN Qun, SHI Ming-Tao, WU Lu-Mei, LIU Han, LIN Yong-Jun, WU Gao-Bing, FAN Chu-Chuan, ZHOU Yong-Ming. Development and identification of transgenic rapeseed with a novel gene for glyphosate resistance [J]. Acta Agronomica Sinica, 2021, 47(5): 789-798.
[14] TANG Xin, LI Yuan-Yuan, LU Jun-Xing, ZHANG Tao. Morphological characteristics and cytological study of anther abortion of temperature-sensitive nuclear male sterile line 160S in Brassica napus [J]. Acta Agronomica Sinica, 2021, 47(5): 983-990.
[15] ZHOU Xin-Tong, GUO Qing-Qing, CHEN Xue, LI Jia-Na, WANG Rui. Construction of a high-density genetic map using genotyping by sequencing (GBS) for quantitative trait loci (QTL) analysis of pink petal trait in Brassica napus L. [J]. Acta Agronomica Sinica, 2021, 47(4): 587-598.
Full text



No Suggested Reading articles found!