Salinity effects on development of chloride cells in the larvae of ayu (Plecoglossus altivelis)

Abstract

Abstract. Salinity effects on ultrastructure, size and density of chloride cells in the larvae of ayu Plecoglossus altivelis (Temminck and Schlegel) were examined. Ayu larvae hatched in freshwater were reared in seawater and freshwater at the Fisheries Laboratory, University of Tokyo, and the Institute of Zoology, Academia Sinica, between 1984 and 1986. Freshwater-hatched larvae modify the intercellular organization and the junctional structure of skin chloride-cells within 1 h after direct transfer to 30%0 seawater. The gills of seawater-reared larvae develop chloride cells earlier than those of freshwaterreared larvae. Following the development, a more rapid decrease in number of skin chloride-cells occurs in the freshwater group, while a more significant increase in size of skin chloride-cells occurs in the seawater group. These results indicate that chloride cells possibly play a critical role in osmoregulation in the early life stages of ayu as in the adult, and that the skin chloride-cells may perform this function until the development of the gill chloridecells is complete.

Calcium balance in embryos and larvae of the freshwater-adapted teleost, Oreochromis mossambicus

“…The structure and function of these cells have been demonstrated to be similar to that of the gill chloride cells in adults, i.e., the excretion of ions (Hwang and Hirano 1985;Hwang 1990). As described above, the main surface responsible for Ca 2 + flux before the development of gills is the skin, in which only chloride cells showed a typical structure for active transport, i.e., numerous mitochondria, wellbranched tubular system and an apical opening exposed to ambient medium (Hwang and Hirano 1985;Hwang 1989Hwang , 1990. It is reasonable to assume that skin chloride cells are the site which performs the active uptake of Ca 2 + in embryos and larvae.…”

“…Embryos or larvae of teleosts have been found to develop chloride cells in the skin until their gills are fully formed and functioning (Hwang and Hirano 1985;review of Alderdice 1988;Hwang 1989Hwang , 1990. The structure and function of these cells have been demonstrated to be similar to that of the gill chloride cells in adults, i.e., the excretion of ions (Hwang and Hirano 1985;Hwang 1990).…”

“…Embryos or larvae of teleosts have been found to develop chloride cells in the skin until their gills are fully formed and functioning (Hwang and Hirano 1985;review of Alderdice 1988;Hwang 1989Hwang , 1990. The structure and function of these cells have been demonstrated to be similar to that of the gill chloride cells in adults, i.e., the excretion of ions (Hwang and Hirano 1985;Hwang 1990). As described above, the main surface responsible for Ca 2 + flux before the development of gills is the skin, in which only chloride cells showed a typical structure for active transport, i.e., numerous mitochondria, wellbranched tubular system and an apical opening exposed to ambient medium (Hwang and Hirano 1985;Hwang 1989Hwang , 1990.…”

The transcription factor, glial cell missing 2, is involved in differentiation and functional regulation of H+-ATPase-rich cells in zebrafish (Danio rerio)

“…The zgcm2 mRNA signals could not be found in swirl (ectodermal mutants) but were detected in one-eyed pinhead, cloche (mesodermal mutants) and casanova (endodermal mutants) embryos, suggesting that gcm2-expressing cells may originate from nonneural ectoderm cells (16). Ionocytes have also been demonstrated to be derived from nonneural ectoderm (18,23), and functional ionocytes shift from the skin to gills during developmental stages (19,22,33). Furthermore, a shift of gcm2 expression from skin to gill epithelium during 24-to 72-hpf embryonic stages was also found in the present study.…”

Functional classification of mitochondrion-rich cells in euryhaline Mozambique tilapia (Oreochromis mossambicus) embryos, by means of triple immunofluorescence staining for Na+/K+-ATPase,Na+/K+/2Cl- cotransporter and CFTR anion channel

“…Therefore, the discontinuous CFTR staining might indirectly imply type-IV cells as the site not only for Cl -secretion but also that they are involved in paracellular Na + secretion. Previous transmission electron microscopic studies revealed that the interdigitation and leaky junction between chloride and accessory cells appeared within 1-3·h after transfer of larval Ayu Plecoglossus altivelis from freshwater to seawater, and disappeared within 3·h after transfer of juvenile stone flounder Kareius bicoloratus from seawater to freshwater (Hwang and Hirano, 1985;Hwang, 1990). We consider it likely that the development and degeneration of the interdigitation between chloride and accessory cells occurs reversibly in parallel with the appearance and disappearance of CFTR at the apical membrane of MRCs.…”