Aquaporin expression in the alimentary canal of the honey bee Apis mellifera L. (Hymenoptera: Apidae) and functional characterization of Am_Eglp 1

• Published in: PloS one Vol. 15; no. 9; p. e0236724
• Main Authors: Linhares Lino de Souza, Débora, Serrão, Jose Eduardo, Hansen, Immo Alex
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21-09-2020; Public Library of Science (PLoS)
• Subjects: Amino acids; Animals; Apis mellifera; Aquaporins; Aquaporins - genetics; Aquaporins - metabolism; Bees; Bees - genetics; Bees - metabolism; Biology and Life Sciences; Cell membranes; Digestive system; European honeybee; Gametocytes; Gastrointestinal tract; Gastrointestinal Tract - metabolism; Gene expression; Genes; Genes, Insect; Genetic aspects; Genomes; Honey; Ileum; Insect Proteins - genetics; Insect Proteins - metabolism; Insects; Malpighian tubules; Membrane proteins; Midgut; Molecular weight; Oocytes; Organs; Permeability; Physical Sciences; Physiological aspects; Protein transport; Proteins; Rectum; Research and Analysis Methods; Water transport; Water uptake; Workers (insect caste); Xenopus laevis; Brazil
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0236724

Aquaporins (AQP) are a family of plasma membrane proteins responsible for water transport through cell membranes. They are differentially expressed in different parts of the alimentary canal of insects where they regulate water transport. These proteins have been studied in detail in some insects, but few data are available for aquaporins of the honey bee, Apis mellifera. We used quantitative PCR to study the expression of six putative aquaporin genes in forager honey bees. We found differential expression of all putative AQP genes in crop, midgut, ileum, rectum and Malpighian tubules. We found the entomoglyceroporin Am_Eglp 1 expressed at extremely high levels in the midgut. We performed a functional characterization of Am_Eglp 1 using heterologous expression in Xenopus laevis oocyte followed by water uptake assays. Our results confirmed that the Am_Eglp 1 gene encodes a functional water transporter. This study shows that all putative honey bee aquaporin genes have complex expression patterns in the digestive and excretory organs of honey bee workers. Our results suggest that Am_Eglp 1 is the principal water transporter in the midgut of A. mellifera workers.