Comparative ultrastructure of cells and cuticle in the anterior chamber and papillate region of Porcellio scaber (Crustacea, Isopoda) hindgut

Abstract

Isopod hindgut consists of two anatomical and functional parts, the anterior chamber, and the papillate region. This study provides a detailed ultrastructural comparison of epithelial cells in the anterior chamber and the papillate region with focus on cuticle ultrastructure, apical and basal plasma membrane labyrinths, and cell junctions. Na+/K+-ATPase activity in the hindgut epithelial cells was demonstrated by cytochemical localisation. The main difference in cuticle ultrastructure is in the thickness of epicuticle which is almost as thick as the procuticle in the papillate region and only about one sixth of the thickness of procuticle in the anterior chamber. The apical plasma membrane in both hindgut regions forms an apical plasma membrane labyrinth of cytoplasmic strands and extracellular spaces. In the papillate region the membranous infoldings are deeper and the extracellular spaces are wider. The basal plasma membrane is extensively infolded and associated with numerous mitochondria in the papillate region, while it forms relatively scarce basal infoldings in the anterior chamber. The junctional complex in both hindgut regions consists of adherens and septate junctions. Septate junctions are more extensive in the papillate region. Na+/K+-ATPase was located mostly in the apical plasma membranes in both hindgut regions. The ultrastructural features of hindgut cuticle are discussed in comparison to exoskeletal cuticle and to cuticles of other arthropod transporting epithelia from the perspective of their mechanical properties and permeability. The morphology of apical and basal plasma membranes and localisation of Na+/K+-ATPase are compared with other arthropod-transporting epithelia according to different functions of the anterior chamber and the papillate region.

The gut barrier and the fate of engineered nanomaterials: a view from comparative physiology

“…117 Beneath the epithelial cells typically lays the basal lamina, which can have a thickness from 100-300 nm in isopods (being regarded as outstandingly thick for invertebrates). 116 The basal lamina is supposed to act like a charged sieve, in which the passage of macromolecules depends on its charge and porosity. In insects, for example, it has been shown that the basal lamina of the midgut prevented the passage of 6-15 nm gold nanoparticles.…”

Formation and remodelling of septate junctions in the epidermis of isopod Porcellio scaber during development

“…The ultrastructure of SJs in tergite epidermis of intermoult adult P. scaber was characterised and compared with SJs in the hindgut epithelium of the same species ( Bogataj et al 2018 ) and with pleated SJs in different ectodermal epithelia of adult specimens of other arthropod species ( Happ and Happ 1970 ; Lane and Skaer 1980 ; Noirot-Timothée and Noirot 1980 ).…”

Description of the larval and adult hindgut tract of the common spider crab Maja brachydactyla Balss, 1922 (Brachyura, Decapoda, Malacostraca)

“…The adult epithelial cells show abundant mitochondria in the apical region, and infolded membranes with lateral junctions. Such features are associated with the reabsorption of water and ions in several arthropods, including insects, crustaceans and millipedes (Mykles 1979;Phillips et al 1987;Nardi et al 2006;Nardi et al 2009;Nardi et al 2016;Bogataj et al 2018). Moreover, the fibres structures of the epithelial cells are more developed in adults than in larvae, and have also been proposed to be involved in the intracellular transport of water and ions in different crustacean groups (Komuro and Yamamoto 1968;Witkus et al 1969;Vernon et al 1974).…”

“…Since the fibres structures have two potential roles (intracellular transport and mechanical connection), it raises one question: are both roles inclusive or mutually exclusive? Bogataj et al (2018) suggested both roles for the hindgut epithelial cells of the woodlouse. In our opinion, the hindgut epithelial cells of the larvae and adults probably are tendon cells, connecting the muscular action with the cuticle, but in adults the same cells also develop a sophisticated transport system for osmoregulation.…”

“…Little information is available regarding the sub-cellular structure of the hindgut, even if higher taxa are considered. In this sense, the cuticle and epithelial cells have been described in crabs and lobsters (Mykles 1979), woodlouses (Bogataj et al 2018), and the strange mystacocarids (Herrera-Alvarez et al 2000); and the rosette glands were described in the ghost shrimps (Felder and Felgenhauer 1993).…”