Location and morphology of chloride cells during the post-embryonic development of the european sea bass, Dicentrarchus labrax

Abstract

Location and morphology of chloride cells were studied in the sea bass ( Dicentrarchus labrax) from hatching to the juvenile stage to determine the development of the adult osmoregulatory function as seen in adult fish. During the studied developmental sequence changes were observed in the location, number, size and structure of these cells, that were studied by microscopy (light, scanning electron, transmission electron and confocal) and immunocytochemistry. Chloride cells were found on the tegument and on the gills. They were present on the tegument already at hatching, before the development of the gills. Their density as well as their association in multicellular complexes decreased during the postembryonic development. In old larvae and in juveniles, cutaneous chloride cells were associated with the fins, the developing scales and the lateral line. Gills developed gradually during the prelarval stage and the gill arches were present at mouth opening. At that time chloride cells were already numerous on the gill arches. In older larvae, during the progressive development of the gill filaments, chloride cells were numerous on these structures and formed multicellular complexes. Several stages in the differentiation of these cells were studied, including the development of the tubulovesicular system at the end of the prelarval stage, as well as the stratification appearance of the cytoplasm that was concomitant with the considerable development of the tubular system and its association with the endoplasmic reticulum during the larval period. The involvement of different epithelia in the osmoregulatory process during the postembryonic development of this species, as well as the role of chloride cells during successive developmental stages, is discussed.

Vacuolar-type proton pump in the basolateral plasma membrane energizes ion uptake in branchial mitochondria-rich cells of killifishFundulus heteroclitus, adapted to a low ion environment

“…Since Na + /K + -ATPase is located in the basolateral membrane of MR cells, the antiserum specific for this enzyme serves as a specific marker for their immunocytochemical detection (Ura et al, 1996). In the present study, MR cells were detected by LSM in the whole-mount preparations of gill filaments, as observed in European sea bass by Varsamos et al (2002). Although there were no significant differences in the density of MR cells between the three groups, the distribution of MR cells extended toward the efferent-vascular side in lower NaCl environments.…”

Water calcium concentration modifies whole-body calcium uptake in sea bream larvae during short-term adaptation to altered salinities

“…and A.V.M.C., unpublished results). The identification of extra-branchial MR-cells in these regions, as well as in the trunk and opercular surface, suggests that in gilthead sea bream larvae they may play an important role in extra-intestinal calcium uptake, providing for direct uptake in areas of high calcium demand, as previously suggested (Flik et al, 1995;Hwang et al, 1994;Varsamos et al, 2002).…”

Serotonergic neuroepithelial cells of the skin in developing zebrafish: morphology, innervation and oxygen-sensitive properties

“…A similar redistribution occurs with epithelial ionoregulatory mitochondria-rich cells, as ion regulatory mechanisms shift from the skin to the gills during development and precede the change in respiratory surfaces (Rombough, 2002;Fu et al, 2010). Like NECs, mitochondria-rich cells are numerous in the skin of fish during embryonic and early larval stages, and then decrease in number while they begin to populate the developing gills (van der Heijden et al, 1999;Varsamos et al, 2002;Pan et al, 2005;Jonz and Nurse, 2006).…”

“…In developing fish, the skin is an important site of gas exchange (Rombough, 1988), ion regulation (van der Heijden et al, 1999;Varsamos et al, 2002;Pan et al, 2005) and chemical sensing (Hansen et al, 2002;Northcutt, 2005). In developing zebrafish, cutaneous respiration accounts for nearly all gas exchange and does not become limiting until ~10d.p.f.…”