| Popis: |
The effects of the dosage of Y chromosomes on some metrical characters in Drosophila melanogaster have been investigated. XO and XYY males were found to be considerably inferior than XY males in regard to mating activity, mating capacity and mating competition ability, while XXY females did not differ from XX females in the studied mating characteristics. Similarly, deviation in the Y chromosome number affected sternopleural bristle number significantly in males but not in females as well as carrying with it an increased developmental instability with respect to intraindividual bristle frequencies. The effect of the differences in mating activity among males with different numbers of Y chromosomes is a strong stabilizing selection for the XY/XX sets of sex chromosomes. |
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