Mechanisms underlying parallel reductions in aerobic capacity in non-migratory threespine stickleback (Gasterosteus aculeatus) populations
| Autor: | Michelle Ou, Anne C. Dalziel, Patricia M. Schulte |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Mitochondrial enzymes
Physiology Ecology Pectoral muscle Oxygen transport VO2 max Zoology Stickleback Gasterosteus Aquatic Science Biology biology.organism_classification Smegmamorpha Oxygen Oxygen Consumption Pyruvate kinase activity Insect Science Dominance (ecology) Animals Animal Science and Zoology Animal Migration Muscle Skeletal Molecular Biology Ecology Evolution Behavior and Systematics |
| Zdroj: | The Journal of experimental biology. 215(Pt 5) |
| ISSN: | 1477-9145 |
| Popis: | SUMMARY Non-migratory, stream-resident populations of threespine stickleback, Gasterosteus aculeatus, have a lower maximum oxygen consumption (ṀO2,max) than ancestral migratory marine populations. Here, we examined laboratory-bred stream-resident and marine crosses from two locations (West and Bonsall Creeks) to determine which steps in the oxygen transport and utilization cascade evolved in conjunction with, and thus have the potential to contribute to, these differences in ṀO2,max. We found that West Creek stream-resident fish have larger muscle fibres (not measured in Bonsall fish), Bonsall Creek stream-resident fish have smaller ventricles, and both stream-resident populations have evolved smaller pectoral adductor and abductor muscles. However, many steps of the oxygen cascade did not evolve in stream-resident populations (gill surface area, hematocrit, mean cellular hemoglobin content and the activities of mitochondrial enzymes per gram ventricle and pectoral muscle), arguing against symmorphosis. We also studied F1 hybrids to determine which traits in the oxygen cascade have a genetic architecture similar to that of ṀO2,max. In West Creek, ṀO2,max, abductor and adductor size all showed dominance of marine alleles, whereas in Bonsall Creek, ṀO2,max and ventricle mass showed dominance of stream-resident alleles. We also found genetically based differences among marine populations in hematocrit, ventricle mass, pectoral muscle mass and pectoral muscle pyruvate kinase activity. Overall, reductions in pectoral muscle mass evolved in conjunction with reductions in ṀO2,max in both stream-resident populations, but the specific steps in the oxygen cascade that have a genetic basis similar to that of ṀO2,max, and are thus predicted to have the largest impact on ṀO2,max, differ among populations. |
| Databáze: | OpenAIRE |
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