Analysis of female-specific blood feeding mechanisms in hematophagous insects

An aminopeptidase N-like gene (apnl) knockout line (apnl-KO) in Anopheles mosquitoes was done and it was found out that the activity of S6 kinase, a component of the mTOR signaling pathway involved in vitellogenesis, increased in KO females after blood feeding was found to be low. In addition, it was clarified that mRNA expression levels of immune-related genes against malaria parasites were higher in KO females during blood feeding. These results suggested that apnl is involved in both reproduction and malaria parasite susceptibility. A DSXM-deficient strain (DSXM-KO) of Anopheles mosquito was analyzed and confirmed abnormal phenotypes in adult external genitalia maturation and head appendages (antennae and short-whiskers). These effects revealed that DSXM-KO males were infertile. Furthermore, RNA-Seq analysis of DSXM-KO males was done and compared the expression level with wild type using the data, and obtained information on the gene group whose expression level was changed in DSXM-KO. In DSXM-KO males, the expression level of salivary genes related to blood feeding in females was found to be higher than in wild-type males. For two species of sandflies (Phlebotomus papatasi and Lutzomyia longipalpis), male and female cDNAs were prepared, and DSX was cloned in males and females by PCR. cDNA sequences were obtained with different splicing patterns for both males and females, indicating that they have sex-specific exons. From this, it was inferred that DSX produced sex-specific translation products with partially different amino acid sequences in sand flies, as in other insects.

Project details

Vector Control

Apr 2021 — Mar 2024

$35,721

Japan