Xiaowen Fei1, Yang Zhang1, Lili Ding1, Sha Xiao1, Xiaoqing Xie2,3, Yajun Li2,3, Xiaodong Deng4,5. 1. Department of Biochemistry and Molecular Biology, Hainan Medical College, Haikou, 571101, China. 2. Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, 571101, China. 3. Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou, 571101, China. 4. Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, 571101, China. dengxiaodong@itbb.org.cn. 5. Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou, 571101, China. dengxiaodong@itbb.org.cn.
Abstract
BACKGROUND: Mosquito-borne diseases affect over half of the human population globally. Multiple studies have shown that chemical insecticides are ineffective because of resistance. Therefore, environmentally safe mosquito population control tools need to be developed. Ribonucleic acid interference (RNAi) is a reverse genetic mechanism recently introduced as a new pest control tool. This technique represents a new class of biorational technology that could combat the increased global incidence of insecticide resistance. The technique has the potential of becoming a critical component of integrated vector control programs. METHODS: A 3-hydroxykynurenine transaminase (3-HKT) RNAi expression plasmid was constructed, generated and transformed into Chlamydomonas and Chlorella algae. The transgenic algae were then used to feed Ae. aegypti mosquito larvae. The feeding experiments were conducted on a small and large scale with 10 and about 300 larvae, respectively. The mortality rate of the larvae was calculated over 30 days. In addition, histological examination of the insect tissues was performed to examine the extent of tissue damage. RESULTS: The integumentary system and midguts of larvae fed with transgenic Chlamydomonas were severely damaged. The mortality rate of the larvae fed with transgenic Chlamydomonas ranged from 60 to 100% in small-scale tests. The survival rate of adult mosquitoes was 0.0% in a large-scale feeding experiment when the larvae were fed with transgenic Chlamydomonas. Moreover, when the larvae were fed with transgenic Chlorella, the mortality rate ranged from 6.7% to 43% compared to that fed wild-type Chlorella. CONCLUSIONS: 3HKT RNAi transgenic algae are in some scales lethal to Ae. aegypti. The findings of this study indicate that technology based on microalgae RNAi may provide a new way to control mosquito populations.
BACKGROUND:Mosquito-borne diseases affect over half of the human population globally. Multiple studies have shown that chemical insecticides are ineffective because of resistance. Therefore, environmentally safe mosquito population control tools need to be developed. Ribonucleic acid interference (RNAi) is a reverse genetic mechanism recently introduced as a new pest control tool. This technique represents a new class of biorational technology that could combat the increased global incidence of insecticide resistance. The technique has the potential of becoming a critical component of integrated vector control programs. METHODS: A 3-hydroxykynurenine transaminase (3-HKT) RNAi expression plasmid was constructed, generated and transformed into Chlamydomonas and Chlorellaalgae. The transgenic algae were then used to feed Ae. aegyptimosquito larvae. The feeding experiments were conducted on a small and large scale with 10 and about 300 larvae, respectively. The mortality rate of the larvae was calculated over 30 days. In addition, histological examination of the insect tissues was performed to examine the extent of tissue damage. RESULTS: The integumentary system and midguts of larvae fed with transgenic Chlamydomonas were severely damaged. The mortality rate of the larvae fed with transgenic Chlamydomonas ranged from 60 to 100% in small-scale tests. The survival rate of adult mosquitoes was 0.0% in a large-scale feeding experiment when the larvae were fed with transgenic Chlamydomonas. Moreover, when the larvae were fed with transgenic Chlorella, the mortality rate ranged from 6.7% to 43% compared to that fed wild-type Chlorella. CONCLUSIONS: 3HKT RNAi transgenic algae are in some scales lethal to Ae. aegypti. The findings of this study indicate that technology based on microalgae RNAi may provide a new way to control mosquito populations.
Authors: Ji Chuan Shen; Lei Luo; Li Li; Qin Long Jing; Chun Quan Ou; Zhi Cong Yang; Xiao Guang Chen Journal: Biomed Environ Sci Date: 2015-05 Impact factor: 3.118