title: Morphophysiological study of digestive system litter-feeding termite Cornitermes cumulans (Kollar, 1832).
abstract: Termites are the major decomposers of lignocellulosic biomass on Earth and are commonly considered as biological reactor models for lignocellulose degradation. Despite their biotechnological potential, few studies have focused on the morphophysiological aspects of the termite digestive system. We therefore analyze the morphology, ultrastructure and gut luminal pH of the digestive system in workers of the litter-feeding termite Cornitermes cumulans (Blattodea: Termitidae). Their digestive system is composed of salivary glands and an alimentary canal with a pH ranging from neutral to alkaline. The salivary glands have an acinar structure and present cells with secretory characteristics. The alimentary canal is differentiated into the foregut, midgut, mixed segment and hindgut, which comprises the ileum (p1), enteric valve (p2), paunch (p3), colon (p4) and rectum (p5) segments. The foregut has a well-developed chewing system. The midgut possesses a tubular peritrophic membrane and two cell types: digestive cells with secretory and absorptive features and several regenerative cells in mitosis, both cell types being organized into regenerative crypts. The mixed segment exhibits cells rich in glycogen granules. Hindgut p1, p4 and p5 segments have flattened cells with a few apical invaginations related to mitochondria and a thick cuticular lining. Conversely, the hindgut p3 segment contains large cuboid cells with extensive apical invaginations associated with numerous mitochondria. These new insights into the morphophysiology of the digestive system of C. cumulans reveal that it mobilizes lignocellulose components as a nutritional source by means of a highly compartmentalized organization with specialized segments and complex microenvironments.
authors.affiliation: Laboratório de Bioquímica de Insetos e Parasitos (Labip), Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Prédio do CCS, Bloco D, Sala 13, Rio de Janeiro, RJ, Brazil, 21941-590.
authors.forename: Géssica
authors.initials: G
authors.lastname: de Sousa
authors.affiliation: Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Vânia Cristina
authors.initials: VC
authors.lastname: Dos Santos
authors.affiliation: Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Nelder
authors.initials: N
authors.lastname: de Figueiredo Gontijo
authors.affiliation: Laboratório de Termitologia, Departamento de Zoologia, Universidade de Brasília, Brasília, Brazil.
authors.forename: Reginaldo
authors.initials: R
authors.lastname: Constantino
authors.affiliation: Laboratório de Bioquímica de Artrópodes Hematófagos, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Gabriela
authors.initials: G
authors.lastname: de Oliveira Paiva E Silva
authors.affiliation: Laboratório de Bioquímica de Insetos e Parasitos (Labip), Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Prédio do CCS, Bloco D, Sala 13, Rio de Janeiro, RJ, Brazil, 21941-590.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Bahia
authors.affiliation: Laboratório de Bioquímica de Insetos e Parasitos (Labip), Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Prédio do CCS, Bloco D, Sala 13, Rio de Janeiro, RJ, Brazil, 21941-590.|Laboratory of Malaria and Vector Research, National Institutes of Health, Bethesda, Md., USA.
authors.forename: Fabio Mendonça
authors.initials: FM
authors.lastname: Gomes
authors.affiliation: Laboratório de Bioquímica de Insetos e Parasitos (Labip), Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Prédio do CCS, Bloco D, Sala 13, Rio de Janeiro, RJ, Brazil, 21941-590. ednildo.machado@gmail.com.|Diretoria de Metrologia Aplicada às Ciências da Vida, Instituto Nacional de Metrologia Qualidade e Tecnologia, Rio de Janeiro, Brazil. ednildo.machado@gmail.com.
authors.forename: Ednildo
authors.initials: E
authors.lastname: de Alcantara Machado
mesh_terms: D000818:Animals; D004064:Digestive System / Q000033:anatomy & histology; D005247:Feeding Behavior; D006863:Hydrogen-Ion Concentration; D020049:Isoptera / Q000033:anatomy & histology* / Q000502:physiology / Q000648:ultrastructure; D012469:Salivary Glands / Q000033:anatomy & histology / Q000648:ultrastructure
keywords: Gut morphology; Insects; Intestinal pH; Regenerative crypts; Salivary glands