HAP3 gene family
From Purdue Genomics Database Facility
Zengyan Xie (xiezy@mail.cbi.pku.edu.cn)
Xia Li (lxia@pku.edu.cn)
Beverley J. Glover (beverley.glover@plantsci.cam.ac.uk)
Shunong Bai (shunongb@pku.edu.cn)
Guang-Yuan Rao (rao@pku.edu.cn)
Jingchu Luo (luojc@mail.cbi.pku.edu.cn)
Ji Yang (jiyang@fudan.edu.cn)
Contents |
Gene numbers of HAP3 gene family
There are 5 HAP3 genes (10 alleles) in Selaginella moellendorffii genome. One is LEC1-type, which has been found only in seed plant genomes previously and plays a key role in seed development and maturation (Harada 2001), and the other four are non-LEC1-type (Lee et al. 2003; Kwong et al. 2003). While in Physcomitrella patens and algal genomes, there are only non-LEC1-type HAP3 genes. (Xie et al. 2008)
Gene structures of HAP3 gene family
We classify HAP3 genes into two groups, intron-rich and intron-less/poor, according to their intron numbers (Xie et al. 2008). LEC1-type HAP3 genes belong to the intron-poor/less group. In Chlamydomonas reinhardtii genome, there is only one HAP3 gene which belongs to the intron-rich group. All land plants have two types of HAP3 genes. S. moellendorffii has one intron-rich HAP3 and four (including one LEC1-type HAP3) intron-less HAP3 genes. Obviously, intron-less/poor HAP3 genes derived from intron-rich ones, probably by a mechanism name retroposition (Long 2001). Gene structures and phylogenetic trees can be found on http://mbe.oxfordjournals.org/cgi/content/abstract/msn105
Selaginella LEC1-like gene expression
We use a close relative of S. moellendorffii (S. sinensis) and find its LEC1-like gene (SsLEC1) is expressed under drought stress while not detected under normal conditions (Xie et al. 2008). This implies Selaginella LEC1-like genes may play a role in anti-desiccation, a process similar to seed maturation.
Table of HAP3 gene numbers
| Species | non-LEC1-type HAP3 | LEC1-type HAP3 | Total | |
|---|---|---|---|---|
| intron-rich | intron-less/poor | |||
| Cyanidioschyzon merolae | 1 | 1 | ||
| Chlamydomonas reinhardtii | 1 | 1 | ||
| Physcomitrella patens | 2 | 4 | 6 | |
| Selaginella moellendorffii | 1(2) | 3(6) | 1(2) | 5(10) |
| Arabidopsis thaliana | 3 | 5 | 2 | 10 |
| Oryza sativa | 3 | 5 | 2 | 10 |
References
Kwong RW, Bui AQ, Lee H, Kong LW, Fischer RL, Goldberg RB, Harada JJ. 2003. LEAFY
COTYLEDON1-LIKE Defines a class of regulators essential for embryo development. Plant
Cell. 15: 5-18.
Lee H, Fischer RL, Goldberg RB, Harada JJ. 2003. Arabidopsis LEAFY COTYLEDON1
represents a functionally specialized subunit of the CCAAT binding transcription factor. P.
Natl. Acad. Sci. USA. 100(4): 2152-2156.
Long M. 2001. Evolution of novel genes. Curr. Opin. Genet. Dev. 11: 673-680.
Zengyan Xie; Xia Li; Beverley J. Glover; Shunong Bai; Guang-Yuan Rao; Jingchu Luo; Ji Yang. Duplication and functional diversification of HAP3 genes leading to the origin of the seed-developmental regulatory gene, LEAFY COTYLEDON1 (LEC1), in non-seed plant genomes
Molecular Biology and Evolution 2008; doi: 10.1093/molbev/msn105 (in press)
