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[Exon and Intron Variability in Salmonidae Growth Hormone Genes]
D N Kamenskaya1,2, M V Pankova3, V A Brykov1,3
1Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, 690041 Russia.
Molekuliarnaia Biologiia
|December 4, 2020
Summary
Gene duplication in salmon, including the growth hormone gene, leads to relaxed selection and new functions. Salmon growth hormone genes gh1 and gh2 show higher variability in introns than exons, with gh2 exhibiting greater exon variability due to ongoing subfunctionalization.
Area of Science:
- Evolutionary genetics
- Molecular evolution
- Genomics
Background:
- Gene duplication is a primary driver of evolutionary innovation, creating new genetic material.
- Duplicated genes experience relaxed selection, facilitating mutation accumulation and functional divergence.
- Salmon possess numerous duplicated genes due to polyploidization events, including growth hormone genes.
Purpose of the Study:
- To investigate nucleotide diversity in paralogous salmon growth hormone genes (gh1 and gh2).
- To understand the evolutionary pressures and functional significance shaping variability in these duplicated genes.
Main Methods:
- Analysis of nucleotide diversity within exons and introns of gh1 and gh2 genes.
- Comparison of variability levels across gene regions and between paralogs.
Main Results:
- Introns of gh1 and gh2 genes exhibited higher nucleotide diversity than their corresponding exons.
- Exon variability showed a weak correlation with exon length, suggesting functional constraints.
- The gh2 gene displayed higher exon variability than gh1, indicative of ongoing subfunctionalization.
Conclusions:
- Gene duplication in salmon, exemplified by growth hormone genes, provides raw material for evolution.
- Differential variability patterns in gh1 and gh2 reflect distinct evolutionary trajectories and functional specialization.
- Functional significance of protein regions, rather than length, primarily dictates exon variability in these duplicated genes.
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