| Autor: |
Hjelmen CE; Department of Entomology, Texas A&M University, College Station, TX 77843, USA.; Department of Biology, Texas A&M University, College Station, TX 77843, USA., Parrott JJ; Department of Entomology, Texas A&M University, College Station, TX 77843, USA.; School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306, USA., Srivastav SP; Department of Entomology, Texas A&M University, College Station, TX 77843, USA.; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA., McGuane AS; Department of Entomology, Texas A&M University, College Station, TX 77843, USA.; Harris County Institute of Forensic Sciences, 1861 Old Spanish Trail, Houston, TX 77054, USA., Ellis LL; Department of Entomology, Texas A&M University, College Station, TX 77843, USA.; Department of Biology, Houston Baptist University, Houston, TX 77074, USA., Stewart AD; Department of Biology, Canisius College, Buffalo, NY 14208, USA., Johnston JS; Department of Entomology, Texas A&M University, College Station, TX 77843, USA., Tarone AM; Department of Entomology, Texas A&M University, College Station, TX 77843, USA. |
| Abstrakt: |
Genome size varies widely across organisms yet has not been found to be related to organismal complexity in eukaryotes. While there is no evidence for a relationship with complexity, there is evidence to suggest that other phenotypic characteristics, such as nucleus size and cell-cycle time, are associated with genome size, body size, and development rate. However, what is unknown is how the selection for divergent phenotypic traits may indirectly affect genome size. Drosophila melanogaster were selected for small and large body size for up to 220 generations, while Cochliomyia macellaria were selected for 32 generations for fast and slow development. Size in D. melanogaster significantly changed in terms of both cell-count and genome size in isolines, but only the cell-count changed in lines which were maintained at larger effective population sizes. Larger genome sizes only occurred in a subset of D. melanogaster isolines originated from flies selected for their large body size. Selection for development time did not change average genome size yet decreased the within-population variation in genome size with increasing generations of selection. This decrease in variation and convergence on a similar mean genome size was not in correspondence with phenotypic variation and suggests stabilizing selection on genome size in laboratory conditions. |
