Meiotic differentiation in two allopatric population groups of the tetraploid frog Odontophrynus americanus from Argentina
The Odontophrynus americanus species complex is widely distributed in South America and is formed of diploid and tetraploid cryptic species. We studied the meiotic prophase stages of two allopatric tetraploid population groups from southeastern and northwestern Argentina. These two allopatric population groups showed a bouquet polarization in zigotene and pachytene, and in the latter stage a complete synapsis of quadrivalents and bivalents. In diakinesis, the frequencies of the different elements per cell were recorded and compared with two theoretical distributions for an autotetraploid organism. Both model tests showed the same overall results. The frequency of quadrivalents did not depart significantly from the models in southeastern populations, and must be considered autotetraploid of recent origin. However, northwestern populations have a significantly reduced number of multivalents, which can be explained by diploidization or allotetraploidy. The reduction of quadrivalents is relatively low when compared with one of the models. Additionally, different chiasmatic frequencies were observed between bivalents and quadrivalents in both population groups. The presence of extra chromosomes detected in southeastern populations and the mitotic and meiotic irregularities reported from other populations, not observed in the present study, account for a high cytological variability between populations of the tetraploid frog Odontophrynus americanus, which can be ascribed to polyploidy.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: October 1, 2008
More about this publication?
- The Herpetological Journal is an international scientific journal that publishes papers on the natural history of amphibians and reptiles. Experimental, observational and theoretical studies are published along with reviews and book reviews. Faunistic lists, letters and results of general surveys are not published unless they shed light on herpetological problems of wider significance.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Ingenta Connect is not responsible for the content or availability of external websites