Isolation, characterization and comparison of Atlantic and Chinook salmon growth hormone 1 and 2
Date
2008-11-03
Authors
Von Schalburg, Kristian R
Yazawa, Ryosuke
De Boer, Johan
Lubieniecki, Krzysztof P
Goh, Benjamin
Straub, Christopher A
Beetz-Sargent, Marianne R
Robb, Adrienne
Davidson, William S
Devlin, Robert H
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
Background: Growth hormone (GH) is an important regulator of skeletal growth, as well as other adapted processes
in salmonids. The GH gene (gh) in salmonids is represented by duplicated, non-allelic isoforms designated as gh1 and gh2.
We have isolated and characterized gh-containing bacterial artificial chromosomes (BACs) of both Atlantic and Chinook
salmon (Salmo salar and Oncorhynchus tshawytscha) in order to further elucidate our understanding of the conservation
and regulation of these loci.
Results: BACs containing gh1 and gh2 from both Atlantic and Chinook salmon were assembled, annotated, and
compared to each other in their coding, intronic, regulatory, and flanking regions. These BACs also contain the genes
for skeletal muscle sodium channel oriented in the same direction. The sequences of the genes for interferon alpha-1,
myosin alkali light chain and microtubule associated protein Tau were also identified, and found in opposite orientations
relative to gh1 and gh2. Viability of each of these genes was examined by PCR. We show that transposon insertions have
occurred differently in the promoters of gh, within and between each species. Other differences within the promoters
and intronic and 3'-flanking regions of the four gh genes provide evidence that they have distinct regulatory modes and
possibly act to function differently and/or during different times of salmonid development.
Conclusion: A core proximal promoter for transcription of both gh1 and gh2 is conserved between the two species of
salmon. Nevertheless, transposon integration and regulatory element differences do exist between the promoters of gh1
and gh2. Additionally, organization of transposon families into the BACs containing gh1 and for the BACs containing gh2,
are very similar within orthologous regions, but much less clear conservation is apparent in comparisons between the
gh1- and gh2-containing paralogous BACs for the two fish species. This is consistent with the hypothesis that a burst of
transposition activity occurred during the speciation events which led to Atlantic and Pacific salmon. The Chinook and
other Oncorhynchus GH1s are strikingly different in comparison to the other GHs and this change is not apparent in the
surrounding non-coding sequences.
Description
BioMed Central
Keywords
Citation
Von Schalburg et al.: Isolation, characterization and comparison of Atlantic and Chinook salmon growth hormone 1 and 2. BMC Genomics 2008, 9:522.