Narrowing the region of candidate genes that control the development of protoscoleces of Echinococcus multilocularis in the mouse liver.

Alveolar echinococcosis is a zoonosis caused by the larval stage of Echinococcus multilocularis. In previous studies, QTL analysis using C57BL/6 N (B6) and DBA/2 (D2) which differ in susceptibility suggested the presence of genes on chromosome 1 that control protoscolex development. In this study, we constructed several congenic mice with different chromosome 1 regions substituted to confirm the presence of responsible genes and to narrow down the regions where the responsible genes exist. Five lines of third-generation congenic strain were constructed and infection experiments were conducted. The results showed that the development of protoscolex was seen in the two lines, resulting to narrow-down the responsible region between 69.4 cM and 70.67 cM. There were 18 genes having different SNPs and 10 genes having amino acid substitutions between B6 and D2 within this region. Infection experiments with third-generation of congenic mice succeeded in narrowing down the chromosomal region determining protoscolex development, resulting to reduce the number of candidate genes. The identification of the gene responsible for protoscolex development will contribute to the control of E. multilocularis infection.