Literaturdatenbank
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Girondot, M., Servan, J., & Pieau, C. (1994). Détermination du sexe sensible à la température chez une tortue (emys orbicularis): importance du composant génétique. Bulletin de la société d'écophysiologie, 19(1-2), 5–17.
Added by: Sarina Wunderlich (27 Nov 2011 14:28:04 UTC) |
| Resource type: Journal Article BibTeX citation key: Girondot1994 View all bibliographic details  |
Categories: General Keywords: Emydidae, Emys, Emys orbicularis, Schildkröten = turtles + tortoises, Zeitigung = incubation Creators: Girondot, Pieau, Servan Collection: Bulletin de la société d'écophysiologie |
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| Abstract |
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Temperature-dependent sex determination in a turtle (Emys orbicularis): importance of genetic component. Two mechanisms of sex determination are generally distinguished in reptiles: genotypic sex determination (GSD) and temperature-dependent sex determination (TSD). In TSD, the sensitivity to temperature shows genetic variability. However, many authors consider that this variability has little influence in natural conditions. The turtle Emys orbicularis exhibits TSD. Sex ratio has been analyzed, clutch by clutch, at three incubation temperatures (28.3, 28.5 et 28.7°C) in the transitional range of temperature (TRT). This analysis clearly reveals a polymorphic genetic component of sex determination. However, sex ratio varies significantly at each of these temperatures, thus indicating that in TRT, sex determination remains sensitive to temperature and is not strictly genetic. In order to find a molecular marker of the genetic component, a new strategy of analysis of the polymorphism of tandem repeats DNA has been carried out. Reference profiles are obtained by hybridization of a synthetic oligonucleotide probe with a mixture of DNA from several male individuals or from several female individuals. Then, individual profiles are compared to these reference profiles. Different bands in males and in females have been obtained with (GATA)5 and (GGAT)5 probes. However, these bands correspond to rare alleles which, by chance, were more represented in one sex than in the other. With the (GGCT)5 probe, two bands were significantly more present in males than in females, a sexual difference not due to a different methylation of DNA.
Added by: Sarina Wunderlich |