Rosa Florence Mara, Godard Ana Lúcia Brunialti, Azevedo Vasco, Coelho Paulo Marcos Zech
Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Mem Inst Oswaldo Cruz. 2005 Feb;100(1):19-23. doi: 10.1590/s0074-02762005000100004. Epub 2005 Apr 12.
The aim of the present work was to study parasitological, molecular, and genetic aspects in descendants of crossbreedings between a totally resistant Biomphalaria tenagophila strain (Taim, RS) and another one highly susceptible (Joinville, SC) to Schistosoma mansoni. Descendants F1 and F2 were submitted to S. mansoni infection (LE strain). The susceptibility rates for individuals from Group F1 were 0 to 0.6%, and from Group F2 was 7.2%. The susceptible individuals from Group F2 discharged a lower number of cercariae, when compared with the susceptible parental group, and in 2 out of 9 positive snails the cercarial elimination was discontinued. In order to identify genetic markers associated with resistance the genotype of parental snails and their offspring F1 and F2 were analyzed by means of the randomly amplified polymorphic DNA method. Nevertheless, it was not possible to detect any marker associated to resistance, but the results showed that in the mentioned species the resistance character is determined by two dominant genes.
本研究的目的是研究完全抗曼氏血吸虫的嗜卷艾美耳球虫菌株（南里奥格兰德州塔伊姆）与另一个对曼氏血吸虫高度敏感的菌株（圣卡塔琳娜州茹安维尔）杂交后代的寄生虫学、分子和遗传学方面。F1和F2代后代接受了曼氏血吸虫感染（LE株）。F1组个体的易感性率为0至0.6%，F2组为7.2%。与易感亲本组相比，F2组中的易感个体排出的尾蚴数量较少，并且在9只阳性蜗牛中有2只停止排出尾蚴。为了鉴定与抗性相关的遗传标记，通过随机扩增多态性DNA方法分析了亲代蜗牛及其后代F1和F2的基因型。然而，未能检测到任何与抗性相关的标记，但结果表明，在所提及的物种中，抗性特征由两个显性基因决定。
