|
KMID : 0381120120340060637
|
|
Genes and Genomics
2012 Volume.34 No. 6 p.637 ~ p.645
|
|
|
High-mobility-group family genes from Lampetra japonica reveal their early origin and molecular evolution in the vertebrate lineage
|
|
Pang Yue
Xiao Rong
Liu Xin
Li Qingwei
|
|
|
Abstract
|
|
|
|
High-mobility group family (HMG) genes are ubiquitous in vertebrates, including mammals, birds, amphibians and fishes. To elucidate the molecular phylogeny of the HMG genes in the primitive vertebrate, we have cloned three homologues of HMG-box genes, called Lj-HMGB1, Lj-HMGB2 and Lj-HMGBX, from a cDNA library generated from lymphocyte-like cells of the Japanese lamprey (Lampetra japonica), an Agnathan that occupies a critical phylogenetic position between invertebrates and vertebrates. The open reading frames of Lj-HMGB1, Lj-HMGB2 and Lj-HMGBX contained 627 bp, 585 bp and 678 bp, respectively. The analysis of the deduced amino acid sequences indicated that these three putative Lj-HMGB proteins contain four domains: HMG-box A, HMG-box B, an acidic carboxyl-terminal tail and a linker. A phylogenetic analysis revealed that the Lj-HMGB proteins fall outside the vertebrate clade; Lj-HMGBX is descended from a gene ancestral to the mammalian HMGB1/2/3. This discovery implies that there was a gene duplication event in the HMGB1/2/3 gene family that occurred after the divergence of the vertebrates (Cyclostomata) from the Cephalochordata and Urochordata at least 450 million years ago (MYA). The Lj-HMGB1, Lj-HMGB2 and Lj-HMGBX genes were detected in most tissues of the lamprey by RT-PCR. Our findings provide insight into the phylogeny of the HMGB genes in vertebrates.
|
|
|
KEYWORD
|
|
|
HMGB1, Lamprey, Gene duplication, Phylogeny
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
 
|
|