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Hybridization between Yellowstone Cutthroat Trout and Rainbow Trout Alters the Expression of Muscle Growth-Related Genes and Their Relationships with Growth Patterns.

Ostberg CO, Chase DM, Hauser L - PLoS ONE (2015)

Bottom Line: Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions.Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change.Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

View Article: PubMed Central - PubMed

Affiliation: U.S. Geological Survey, Western Fisheries Research Center, Seattle, Washington, United States of America.

ABSTRACT
Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroat trout (O. clarkii) produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L) and the relationship of these genes with growth traits (length, weight, and condition factor) in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout). Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

No MeSH data available.


Related in: MedlinePlus

Transcript abundance (± SD) of eight muscle growth-related genes among crosses at 145, 234, and 327 days post-fertilization.Significant PERMANOVA tests are indicated (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in expression between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross, F1-Rbt = F1 hybrid with Rbt maternal lineage, Yct = Yellowstone cutthroat trout, bc-Yct = first generation Yct backcross, and F1-Yct = F1 hybrid with Yct maternal lineage.
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pone.0141373.g003: Transcript abundance (± SD) of eight muscle growth-related genes among crosses at 145, 234, and 327 days post-fertilization.Significant PERMANOVA tests are indicated (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in expression between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross, F1-Rbt = F1 hybrid with Rbt maternal lineage, Yct = Yellowstone cutthroat trout, bc-Yct = first generation Yct backcross, and F1-Yct = F1 hybrid with Yct maternal lineage.

Mentions: Four genes were differentially expressed among crosses following the B-Y FDR adjustment procedure for 24 simultaneous tests (critical value α = 0.0132) (Fig 3). Family effects within cross were not significant. Parental species differed significantly in transcript abundance for MyoD1b at 145 days, IGF-2 and MyoD1b at 234 days, and for MSTN-1a and MSTN-1b at 327 days. Yellowstone cutthroat trout produced more transcripts than Rbt, with the exception of MyoD1b at 145 days. Genes that were differentially expressed between parental species tended to be expressed in hybrids at levels that were intermediate to the parental species, with the exception of MyoD1b, MSTN-1a and MSTN-1b in bc-Rbt, IGF-2 in bc-Yct, MyoD1b in F1-Yct, and MSTN1a in F1-Rbt. We found that bc-Rbt expressed fewer MSTN-1a and MSTN-1b transcripts than both parental species at 327 days. Transcript abundance differed between F1 hybrid crosses for MyoD1b at 145 days. Transcript abundance differed between backcrosses for MyoD1b at 145 days and for MSTN-1a and MSTN-1b at 327 days. Each backcross and their backcrossing parental species differentially expressed at least two genes.


Hybridization between Yellowstone Cutthroat Trout and Rainbow Trout Alters the Expression of Muscle Growth-Related Genes and Their Relationships with Growth Patterns.

Ostberg CO, Chase DM, Hauser L - PLoS ONE (2015)

Transcript abundance (± SD) of eight muscle growth-related genes among crosses at 145, 234, and 327 days post-fertilization.Significant PERMANOVA tests are indicated (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in expression between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross, F1-Rbt = F1 hybrid with Rbt maternal lineage, Yct = Yellowstone cutthroat trout, bc-Yct = first generation Yct backcross, and F1-Yct = F1 hybrid with Yct maternal lineage.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4612777&req=5

pone.0141373.g003: Transcript abundance (± SD) of eight muscle growth-related genes among crosses at 145, 234, and 327 days post-fertilization.Significant PERMANOVA tests are indicated (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in expression between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross, F1-Rbt = F1 hybrid with Rbt maternal lineage, Yct = Yellowstone cutthroat trout, bc-Yct = first generation Yct backcross, and F1-Yct = F1 hybrid with Yct maternal lineage.
Mentions: Four genes were differentially expressed among crosses following the B-Y FDR adjustment procedure for 24 simultaneous tests (critical value α = 0.0132) (Fig 3). Family effects within cross were not significant. Parental species differed significantly in transcript abundance for MyoD1b at 145 days, IGF-2 and MyoD1b at 234 days, and for MSTN-1a and MSTN-1b at 327 days. Yellowstone cutthroat trout produced more transcripts than Rbt, with the exception of MyoD1b at 145 days. Genes that were differentially expressed between parental species tended to be expressed in hybrids at levels that were intermediate to the parental species, with the exception of MyoD1b, MSTN-1a and MSTN-1b in bc-Rbt, IGF-2 in bc-Yct, MyoD1b in F1-Yct, and MSTN1a in F1-Rbt. We found that bc-Rbt expressed fewer MSTN-1a and MSTN-1b transcripts than both parental species at 327 days. Transcript abundance differed between F1 hybrid crosses for MyoD1b at 145 days. Transcript abundance differed between backcrosses for MyoD1b at 145 days and for MSTN-1a and MSTN-1b at 327 days. Each backcross and their backcrossing parental species differentially expressed at least two genes.

Bottom Line: Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions.Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change.Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

View Article: PubMed Central - PubMed

Affiliation: U.S. Geological Survey, Western Fisheries Research Center, Seattle, Washington, United States of America.

ABSTRACT
Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroat trout (O. clarkii) produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L) and the relationship of these genes with growth traits (length, weight, and condition factor) in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout). Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

No MeSH data available.


Related in: MedlinePlus