Searching for new molecules involved in Anopheles mosquitoes’ response to Plasmodium infection

• Published in: Journal of Veterinary Medical Science Vol. 86; no. 5; pp. 485 - 492
• Main Authors: HARAGUCHI, Asako, TAKANO, Makoto, FUJIWARA, Kanta, HAKOZAKI, Jun, NAKAYAMA, Kazuhiko, NAKAMURA, Sakure, YOSHIKAWA, Yasunaga, FUKUMOTO, Shinya, KUSAKISAKO, Kodai, IKADAI, Hiromi
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2024; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Animals; Anopheles; Anopheles - parasitology; Anopheles stephensi; Culicidae; Epithelial cells; Female; Females; Hemocoel; Host-Parasite Interactions; Infections; injection; Malaria - parasitology; Male; Males; Mice; Midgut; molecules; Mosquito Vectors - parasitology; Mosquitoes; Parasites; Parasitology; Plasmodium; Plasmodium berghei; Plasmodium berghei - physiology; Sex differences; Zygotes; Anopheles stephensi; Plasmodium berghei; injection; molecules
• ISSN: 0916-7250; 1347-7439; 1347-7439
• DOI: 10.1292/jvms.24-0008

Plasmodium parasites within mosquitoes are exposed to various physiological processes, such as blood meal digestion activity, the gonotrophic cycle, and host responses preventing the entry of parasites into the midgut wall. However, when in vitro-cultured ookinetes are injected into the hemocoel of mosquitoes, Plasmodium parasites are not affected by the vertebrate host’s blood contents and do not pass through the midgut epithelial cells. This infection method might aid in identifying mosquito-derived factors affecting Plasmodium development within mosquitoes. This study investigated novel mosquito-derived molecules related to parasite development in Anopheles mosquitoes. We injected in vitro-cultured Plasmodium berghei (ANKA strain) ookinetes into female and male Anopheles stephensi (STE2 strain) mosquitoes and found that the oocyst number was significantly higher in males than in females, suggesting that male mosquitoes better support the development of parasites. Next, RNA-seq analysis was performed on the injected female and male mosquitoes to identify genes exhibiting changes in expression. Five genes with different expression patterns between sexes and greatest expression changes were identified as being potentially associated with Plasmodium infection. Two of the five genes also showed expression changes with infection by blood-feeding, indicating that these genes could affect the development of Plasmodium parasites in mosquitoes.