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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

Mean condition factor (± SD) for each cross at each time point (145, 234, and 327 days post-fertilization).Results from PERMANOVA tests are shown (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in condition factor between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross (Rbt x F1), F1-Rbt = F1 hybrid with Rbt maternal lineage, F1-Yct = F1 hybrid with Yct maternal lineage, bc-Yct = first generation Yct backcross (Yct x F1), and Yct = Yellowstone cutthroat trout.
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pone.0141373.g001: Mean condition factor (± SD) for each cross at each time point (145, 234, and 327 days post-fertilization).Results from PERMANOVA tests are shown (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in condition factor between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross (Rbt x F1), F1-Rbt = F1 hybrid with Rbt maternal lineage, F1-Yct = F1 hybrid with Yct maternal lineage, bc-Yct = first generation Yct backcross (Yct x F1), and Yct = Yellowstone cutthroat trout.

Mentions: Weight and length were highly correlated across individuals (r = 0.947, P < 0.001), but neither length nor weight differed significantly among crosses within each time point following the B-Y FDR adjustment procedure for 9 simultaneous tests (critical value α = 0.0177) (S1 Fig). Condition factor differed among crosses at each time point (Fig 1). Rbt had higher condition factor than Yct within each time point. Condition factor differed between bc-Rbt and bc-Yct at 234 and 327 days post-fertilization, but neither backcross differed from their respective backcrossing parent. Family effects within cross were significant at 234 days (weight, pseudo-F = 4.101, P = 0.001; length, pseudo-F = 3.018, P = 0.008; condition factor, pseudo-F = 3.054, P = 0.007), but were non-significant at 145 and 327 days.


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)

Mean condition factor (± SD) for each cross at each time point (145, 234, and 327 days post-fertilization).Results from PERMANOVA tests are shown (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in condition factor between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross (Rbt x F1), F1-Rbt = F1 hybrid with Rbt maternal lineage, F1-Yct = F1 hybrid with Yct maternal lineage, bc-Yct = first generation Yct backcross (Yct x F1), and Yct = Yellowstone cutthroat trout.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0141373.g001: Mean condition factor (± SD) for each cross at each time point (145, 234, and 327 days post-fertilization).Results from PERMANOVA tests are shown (pseudo-F and P-value) and lowercase letters indicate significant differences (P < 0.05) in condition factor between crosses in post-hoc tests. Rbt = rainbow trout, bc-Rbt = first generation Rbt backcross (Rbt x F1), F1-Rbt = F1 hybrid with Rbt maternal lineage, F1-Yct = F1 hybrid with Yct maternal lineage, bc-Yct = first generation Yct backcross (Yct x F1), and Yct = Yellowstone cutthroat trout.
Mentions: Weight and length were highly correlated across individuals (r = 0.947, P < 0.001), but neither length nor weight differed significantly among crosses within each time point following the B-Y FDR adjustment procedure for 9 simultaneous tests (critical value α = 0.0177) (S1 Fig). Condition factor differed among crosses at each time point (Fig 1). Rbt had higher condition factor than Yct within each time point. Condition factor differed between bc-Rbt and bc-Yct at 234 and 327 days post-fertilization, but neither backcross differed from their respective backcrossing parent. Family effects within cross were significant at 234 days (weight, pseudo-F = 4.101, P = 0.001; length, pseudo-F = 3.018, P = 0.008; condition factor, pseudo-F = 3.054, P = 0.007), but were non-significant at 145 and 327 days.

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