PUBLICATION
Evolution of glutamine synthetase in vertebrates: multiple glutamine synthetase genes expressed in rainbow trout (Oncorhynchus mykiss)
- Authors
- Murray, B.W., Busby, E.R., Mommsen, T.P., and Wright, P.A.
- ID
- ZDB-PUB-030715-8
- Date
- 2003
- Source
- The Journal of experimental biology 206(9): 1511-1521 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Blotting, Southern
- Chromosome Mapping
- DNA Primers/genetics
- Gene Expression Profiling*
- Genes, Duplicate/genetics
- Glutamate-Ammonia Ligase/genetics*
- Likelihood Functions
- Molecular Sequence Data
- Oncorhynchus mykiss/genetics*
- Oncorhynchus mykiss/metabolism
- Phylogeny*
- PubMed
- 12654890 Full text @ J. Exp. Biol.
Citation
Murray, B.W., Busby, E.R., Mommsen, T.P., and Wright, P.A. (2003) Evolution of glutamine synthetase in vertebrates: multiple glutamine synthetase genes expressed in rainbow trout (Oncorhynchus mykiss). The Journal of experimental biology. 206(9):1511-1521.
Abstract
Glutamine synthetase (GSase) is a key enzyme in nitrogen metabolism and encoded by a single gene in mammals. Using PCR cloning techniques, including RT-PCR from total RNA and PCR from a cDNA library, we find evidence of four expressed GSase mRNAs for the tetraploid rainbow trout. For two of these mRNAs (Onmy-GS01, -GS02) we characterize the full-length coding regions, and for two others (Onmy-GS03, -GS04), we describe partial sequences. Northern analysis of Onmy-GS01, -GS02, -GS03 and -GS04 indicates that (1) Onmy-GS02 is expressed at higher levels relative to the other transcripts in most adult tissues, with the exception of brain and gill, where Onmy-GS01 is at the highest level, and (2) the tissue with the highest level of expression of all four transcripts is the brain, with decreasing levels in the intestine, liver, red muscle, gill/kidney, white muscle and heart. Clearly, rainbow trout possess multiple GSase genes with differing levels of tissue expression, implying manifold potential routes of regulation for this octameric enzyme. Our data also indicate that caution should be taken when interpreting mRNA expression data of a single gene, unless multiple genes have been ruled out. Consistent with a southern blot, phylogenetic and intron sequence analyses imply that the trout genes are encoded by at least four separate loci, belonging to two distinct evolutionary branches. Our data on rainbow trout, together with those from two full-length zebrafish Danio rerio GSase genes compiled from GenBank ESTs, support the idea that fish GSases are polyphyletic and that gene duplications have occurred at multiple points and in independent lineages throughout the evolution of bony fishes.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping