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Mass-Rearing and Molecular Studies in Tortricidae Pest Insects
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Reappraising the theme of breeding systems in Echinococcus: is outcrossing a rare phenomenon?
K L Haag1, P B Marin, D A S Graichen
1Programa de Pós Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul Caixa Postal 15053, CEP 91501-970 Porto Alegre, Brazil. karen.haag@unibas.ch
Abstract:
Selfing has been considered the most common mode of reproduction in Echinococcus flatworms. However, population genetic studies on the asexual larval stage involving nuclear co-dominant markers have not always revealed significant heterozygote deficiencies--the expected outcome of a regularly and highly inbred population. In this study, we analysed the genetic structure of Echinococcus granulosus sensu lato populations from Southern Brazil during their adult (sexual) stage using 1 mitochondrial and 1 nuclear marker (cox 1 and mdh, respectively). We show that parasite genetic differentiation is largest among definitive hosts (domestic dogs) from different farms, suggesting that transmission is mostly maintained within a farm. Moreover, we show that heterozygote deficiencies are not significant, and we suggest that outbreeding is the most common mode of reproduction of the parasite in that region.
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