57Proc. Arthropod. Embryol. Soc. Jpn. 48, 57 (2017)Ⓒ 2017 Arthropodan Embryological Society of Japan
ISSN 1341–1527

Analysis of Transgenic Anopheline Mosquitoes Overexpressing an
Antimicrobial Peptide in Their Salivary Glands*1, *2
Daisuke S. YAMAMOTO1), Naoki WATANABE1), Megumi SUMITANI2),
Takashi SUZUKI3) and Hiroyuki MATSUOKA1)
Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, 3311–1, Yakushiji, Shimotsuke,Tochigi 329–0498, Japan2)
Genetically Modified Organism Research Center, National Institute of Agrobiological Sciences, 1–2, Owashi, Tsukuba, Ibaraki
305–8634, Japan
3)
Division of Public Health, Department of International Health Development, Graduate School of Tokyo Medical and Dental
University, Tokyo 113–8510, Japan
E-mail: daisukey@jichi.ac.jp (DSY)1)

Anopheline mosquitoes transmit malaria parasites. The
mosquito has an innate immune system to prevent infection
by various pathogens; however, malaria parasites escape fromthis immune system and develop. It remains unclear how thisoccurs. Transgenesis in anopheline mosquitoes has beenutilized for the analysis of mosquito-malaria parasite
interaction and a new strategy of malaria control (Terenius etal. 2008). The insect antimicrobial peptide defensin is one of
the effector molecules against Gram-positive bacteria in theinnate immune system (Cirimotich et al. 2010). Overexpressed
defensin showed a certain inhibitory effect against the malaria
parasite in mosquito midgut or hemolymph using transgeniclines (Kim et al. 2004; Kokoza et al. 2010). Mosquito salivary
glands have been shown to be effective tissue for inactivating
malaria sporozoites using transgenesis (Sumitani et al. 2013);
however, the overexpression of defensin has not been
examined in these salivary glands.
The aim of this study was to investigate the effect ofoverexpressed defensin in Anopheles stephensi salivary glands
against the malaria parasite. Moreover, we chose defensin
derived from the tsetse fly, Glossina palpalis (gpdef), andaimed to examine the effect of this immune system moleculeof a non-malaria vector species against the malaria parasite.
We cloned the gpdef gene, and produced a transgenic mosquito
expressing gpdef fused to monomeric DsRed gene (mDsRedgpdef) under the control of anopheline antiplatelet protein(aapp) gene promoter, which drives the salivary gland-specificexpression in adult females (Yoshida and Watanabe 2006). The
transgenic mosquitoes showed female salivary gland-specificexpression of the mDsRed-gpdef gene. The mDsRed-gpdef

protein in female salivary glands was detected at least 13 days
after blood feeding, at which time sporozoites begin to invade
into the salivary glands. We are now beginning to investigate
the effect of the mDsRed-gpdef protein in the salivary glandagainst sporozoites using a rodent malaria model.
References
Cirimotich, C. M., Y. Dong, L. S. Garver, S. Sim and G. Dimopoulos(2010) Mosquito immune defenses against Plasmodium infection.
Developmental Comparative Immunology, 34, 387–395.
Kim, W., H. Koo, A. M. Richman, D. Seeley, J. Vizioli, A. D. Klocko and
D. A. OʼBrochta (2004) Ectopic expression of a cecropin transgenein the human malaria vector mosquito Anopheles gambiae(Diptera: Culicidae): effects on susceptibility to Plasmodium.
Journal of Medical Entomology, 41, 447–455.
Kokoza, V., A. Ahmed, S. Woon Shin, N. Okafor, Z. Zou and A. S.
Raikhel (2010) Blocking of Plasmodium transmission bycooperative action of Cecropin A and Defensin A in transgenic
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Sumitani, M., K. Kasashima, D. S. Yamamoto, K. Yagi, M. Yuda, H.
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*1 Abstract of paper read at the 49th Annual Meeting of the Arthropodan Embryological Society of Japan, June 7–8, 2013 (Tsukuba-san, Ibaraki).
*2 This article, which was accepted in 2013 and should have been published in 2014, was printed in 2017 being much delayed due to various circumstances.