Affiliation:
1. Departamento de Parasitologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG 31 270-901, Brazil
2. Centro de Pesquisas René Rachou (CPqRR) – Fiocruz Minas, Belo Horizonte, MG 30 190-009, Brazil
Abstract
ABSTRACT
Aedes aegypti is one of the most important disease vectors in the world. Because their gut is the first site of interaction with pathogens, it is important to understand A. aegypti gut physiology. In this study, we investigated the mechanisms of pH control in the midgut of A. aegypti females under different nutritional conditions. We found that unfed females have an acidic midgut (pH ∼6). The midgut of unfed insects is actively maintained at pH 6 regardless of the ingestion of either alkaline or acidic buffered solutions. V-ATPases are responsible for acidification after ingestion of alkaline solutions. In blood-fed females, the abdominal midgut becomes alkaline (pH 7.54), and the luminal pH decreases slightly throughout blood digestion. Only ingested proteins were able to trigger this abrupt increase in abdominal pH. The ingestion of amino acids, even at high concentrations, did not induce alkalinisation. During blood digestion, the thoracic midgut remains acidic, becoming a suitable compartment for carbohydrate digestion, which is in accordance with the higher alpha-glucolytic activity detected in this compartment. Ingestion of blood releases alkalising hormones in the haemolymph, which induce alkalinisation in ex vivo preparations. This study shows that adult A. aegypti females have a very similar gut physiology to that previously described for Lutzomyia longipalpis. It is likely that all haematophagous Nematocera exhibit the same type of physiological behaviour.
Funder
Fundação de Amparo à Pesquisa do Estado de Minas Gerais
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Publisher
The Company of Biologists
Subject
Insect Science,Molecular Biology,Animal Science and Zoology,Aquatic Science,Physiology,Ecology, Evolution, Behavior and Systematics
Cited by
24 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献