Larger Daphnia at lower temperature: a role for cell size and genome configuration?
| Autor: | Dag O. Hessen, Marwa Jalal, Marcin W. Wojewodzic, Carl M M Laane |
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| Rok vydání: | 2013 |
| Předmět: |
Daphnia magna
DNA condensation Daphnia Daphnia pulex chemistry.chemical_compound Genome Size Species Specificity Genetics medicine Animals Propidium iodide Molecular Biology Genome size Cell Size Fluorescent Dyes Cell Nucleus Genome Microscopy Confocal biology General Medicine DNA biology.organism_classification Flow Cytometry Cold Temperature medicine.anatomical_structure chemistry Biophysics Ethidium bromide Nucleus Biotechnology |
| Zdroj: | Genome. 56(9) |
| ISSN: | 1480-3321 |
| Popis: | Experiments with Daphnia magna and Daphnia pulex raised at 10 and 20 °C yielded larger adult size at the lower temperature. This must reflect increased cell size, increased cell numbers, or a combination of both. As it is difficult to achieve good estimates on cell size in crustaceans, we, therefore, measured nucleus and genome size using flow cytometry at 10 and 20 °C. DNA was stained with propidium iodide, ethidium bromide, and DAPI. Both nucleus and genome size estimates were elevated at 10 °C compared with 20 °C, suggesting that larger body size at low temperature could partly be accredited to an enlarged nucleus and thus cell size. Confocal microscopy observations confirmed the staining properties of fluorochromes. As differences in nucleotide numbers in response of growth temperature within a life span is unlikely, these results seem accredited to changed DNA–fluorochrome binding properties, presumably reflecting increased DNA condensation at low temperature. This implies that genome size comparisons may be impacted by ambient temperature in ectotherms. It also suggests that temperature-induced structural changes in the genome could affect cell size and for some species even body size. |
| Databáze: | OpenAIRE |
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