Microanatomy of the American Malaria Vector Anopheles aquasalis (Diptera: Culicidae: Anophelinae) Midgut: Ultrastructural and Histochemical Observations

J Med Entomol. 2019 Oct 28;56(6):1636-1649. doi: 10.1093/jme/tjz114.

Abstract

The mosquito gut is divided into foregut, midgut, and hindgut. The midgut functions in storage and digestion of the bloodmeal. This study used light, scanning (SEM), and transmission (TEM) electron microscopy to analyze in detail the microanatomy and morphology of the midgut of nonblood-fed Anopheles aquasalis females. The midgut epithelium is a monolayer of columnar epithelial cells that is composed of two populations: microvillar epithelial cells and basal cells. The microvillar epithelial cells can be further subdivided into light and dark cells, based on their affinities to toluidine blue and their electron density. FITC-labeling of the anterior midgut and posterior midgut with lectins resulted in different fluorescence intensities, indicating differences in carbohydrate residues. SEM revealed a complex muscle network composed of circular and longitudinal fibers that surround the entire midgut. In summary, the use of a diverse set of morphological methods revealed the general microanatomy of the midgut and associated tissues of An. aquasalis, which is a major vector of Plasmodium spp. (Haemosporida: Plasmodiidae) in America.

Keywords: Anopheles aquasalis; fluorescent lectin labeling; midgut; ultrastructure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anopheles / anatomy & histology*
  • Anopheles / ultrastructure
  • Digestive System / anatomy & histology
  • Digestive System / ultrastructure
  • Female
  • Malaria / transmission
  • Microscopy
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Mosquito Vectors / anatomy & histology*
  • Mosquito Vectors / ultrastructure