Changes in chloride cell morphology were examined in the yolk-sac membrane of Mozambique tilapia (Oreochromis mossambicus) embryos and larvae transferred from fresh water to sea water. By labelling chloride cells with DASPEI, a fluorescent probe specific for mitochondria, we observed in vivo sequential changes in individual chloride cells by confocal laser scanning microscopy. In embryos transferred from fresh water to sea water 3 days after fertilization, 75 % of chloride cells survived for 96 h, and cells showed a remarkable increase in size. In contrast, the cell size did not change in embryos and larvae kept in fresh water. The same rate of chloride cell turnover was observed in both fresh water and sea water. Using differential interference contrast (DIC) optics and whole-mount immunocytochemistry with anti-Na(+)/K(+)-ATPase, we classified chloride cells into three developmental stages: a single chloride cell without an apical pit, a single chloride cell with an apical pit, and a multicellular complex of chloride and accessory cells with an apical pit. DIC and immunofluorescence microscopy revealed that single chloride cells enlarged and were frequently indented by newly differentiated accessory cells to form multicellular complexes during seawater adaptation. These results indicate that freshwater-type single chloride cells are transformed into seawater-type multicellular complexes during seawater adaptation, suggesting plasticity in the ion-transporting functions of chloride cells in the yolk-sac membrane of tilapia embryos and larvae.

REFERENCES

Avella
M.
,
Bornancin
M.
(
1989
).
A new analysis of ammonia and sodium transport through the gills of the freshwater rainbow trout (Salmo gairdneri)
.
J. Exp. Biol
142
,
155
–.
Avella
M.
,
Ehrenfeld
J.
(
1997
).
Fish gill respiratory cells in culture: a new model for Cl-secreting epithelia
.
J. Membr. Biol
156
,
87
–.
Ayson
F. G.
,
Kaneko
T.
,
Hasegawa
S.
,
Hirano
T.
(
1994
).
Development of mitochondrion-rich cells in the yolk-sac membrane of embryos and larvae of tilapia, Oreochromis mossambicus, in fresh water and seawater
.
J. Exp. Zool
270
,
129
–.
Chretien
M.
,
Pisam
M.
(
1986
).
Cell renewal and differentiation in the gill epithelium of fresh-or salt-water-adapted euryhaline fish as revealed by [3H]-thymidine radioautography
.
Biol. Cell
56
,
137
–.
Foskett
J. K.
,
Scheffey
C.
(
1982
).
The chloride cell: Definitive identification as the salt-secretory cell in teleosts
.
Science
215
,
164
–.
Goss
G. G.
,
Laurent
P.
,
Perry
S. F.
(
1992
).
Evidence for a morphological component in acid—base regulation during environmental hypercapnia in the brown bullhead (Ictalurus nebulosu s)
.
Cell Tissue Res
268
,
539
–.
Hirai
N.
,
Tagawa
M.
,
Kaneko
T.
,
Seikai
T.
,
Tanaka
M.
(
1999
).
Distributional changes in branchial chloride cells during freshwater adaptation in Japanese sea bass Lateolabrax japonicus
.
Zool. Sci
16
,
43
–.
Hiroi
J.
,
Kaneko
T.
,
Seikai
T.
,
Tanaka
M.
(
1998
).
Developmental sequence of chloride cells in the body skin and gills of Japanese flounder (Paralichthys olivaceus) larvae
.
Zool. Sci
15
,
455
–.
Hiroi
J.
,
Kaneko
T.
,
Uchida
K.
,
Hasegawa
S.
,
Tanaka
M.
(
1998
).
Immunolocalization of vacuolar-type H+-ATPase in the yolk-sac membrane of tilapia (Oreochromis mossambicus) larvae
.
Zool. Sci
15
,
447
–.
Hootman
S. R.
,
Philpott
C. W.
(
1980
).
Accessory cells in teleost branchial epithelium
.
Am. J. Physiol
238
,
199
–.
Hwang
P. P.
(
1989
).
Distribution of chloride cells in teleost larvae
.
J. Morph
200
,
1
–.
Hwang
P. P.
,
Hirano
R.
(
1985
).
Effects of environmental salinity on intercellular organization and junctional structure of chloride cells in early stages of teleost development
.
J. Exp. Zool
236
,
115
–.
Karnaky
K. J. J.
,
Degnan
K. J.
,
Garretson
L. T.
,
Zadunaisky
J. A.
(
1984
).
Identification and quantification of mitochondria-rich cells in transporting epithelia
.
Am. J. Physiol
246
,
770
–.
Karnaky
K. J. J.
,
Kinter
L. B.
,
Kinter
W. B.
,
Stirling
C. E.
(
1976
).
Teleost chloride cell. II. Autoradiographic localization of gill Na,K-ATPase in killifish Fundulus heteroclitus adapted to low and high salinity environments
.
J. Cell Biol
70
,
157
–.
Kultz
D.
,
Somero
G. N.
(
1995
).
Osmotic and thermal effects on in situ ATPase activity in permeabilized gill epithelial cells of the fish Gillichthys mirabilis
.
J. Exp. Biol
198
,
1883
–.
Lasker
R.
,
Threadgold
L. T.
(
1968
).
‘Chloride cells’ in the skin of the larval sardine
.
Exp. Cell Res
52
,
582
–.
Laurent
P.
,
Dunel
S.
(
1980
).
Morphology of gill epithelia in fish
.
Am. J. Physiol
238
,
147
–.
Li
J.
,
Eygensteyn
J.
,
Lock
R. A. C.
,
Verbost
P. M.
,
van der Heijden
A. J. H.
,
Wendelaar Bonga
S. E.
,
Flik
G.
(
1995
).
Branchial chloride cells in larvae and juveniles of freshwater tilapia Oreochromis mossambicus
.
J. Exp. Biol
198
,
2177
–.
Morgan
I. J.
,
Potts
W. T. W.
,
Oates
K.
(
1994
).
Intracellular ion concentrations in branchial epithelial cells of brown trout (Salmo trutta L.) determined by X-ray microanalysis
.
J. Exp. Biol
194
,
139
–.
Ohtani
R.
,
Kaneko
T.
,
Kline
L. W.
,
Labedz
T.
,
Tang
Y.
,
Pang
P. K. T.
(
1989
).
Localization of calcitonin gene-relatedJ. HIROI, T. KANEKOANDM. TANAKA3495 Sequential changes in chloride cell morphology peptide in the small intestine of various vertebrate species
.
Cell Tissue Res
258
,
35
–.
Perry
S. F.
(
1997
).
The chloride cell: structure and function in the gills of freshwater fishes
.
Annu. Rev. Physiol
59
,
325
–.
Philpott
C. W.
(
1980
).
Tubular system membranes of teleost chloride cells: osmotic response and transport sites
.
Am. J. Physiol
238
,
171
–.
Pisam
M.
,
Auperin
B.
,
Prunet
P.
,
Rentier-Delrue
F.
,
Martial
J.
,
Rambourg
A.
(
1993
).
Effects of prolactin onand chloride cells in the gill epithelium of the saltwater adapted tilapia Oreochromis niloticus
.
Anat. Rec
235
,
275
–.
Pisam
M.
,
Caroff
A.
,
Rambourg
A.
(
1987
).
Two types of chloride cells in the gill epithelium of a freshwater-adapted euryhaline fish: Lebistes reticulatus; their modifications during adaptation to saltwater
.
Am. J. Anat
179
,
40
–.
Pisam
M.
,
Rambourg
A.
(
1991
).
Mitochondria-rich cells in the gill epithelium of teleost fishes: An ultrastructural approach
.
Int. Rev. Cytol
130
,
191
–.
Potts
W. T. W.
(
1994
).
Kinetics of sodium uptake in freshwater animals: a comparison of ion-exchange and proton pump hypotheses
.
Am. J. Physiol
266
,
315
–.
Sardet
C.
,
Pisam
M.
,
Maetz
J.
(
1979
).
The surface epithelium of teleostean fish gills
.
J. Cell Biol
80
,
96
–.
Sasai
S.
,
Kaneko
T.
,
Hasegawa
S.
,
Tsukamoto
K.
(
1998
).
Morphological alteration in two types of gill chloride cells in Japanese eel (Anguilla japonica) during catadromous migration
.
Can. J. Zool
76
,
1480
–.
Shelbourne
J. E.
(
1957
).
Site of chloride regulation in marine fish larvae
.
Nature
180
,
920
–.
Shiraishi
K.
,
Kaneko
T.
,
Hasegawa
S.
,
Hirano
T.
(
1997
).
Development of multicellular complexes of chloride cells in the yolk-sac membrane of tilapia (Oreochromis mossambicus) embryos and larvae in seawater
.
Cell Tissue Res
288
,
583
–.
Silva
P.
,
Solomon
R.
,
Spokes
K.
,
Epstein
F. H.
(
1977
).
Ouabain inhibition of gill Na—K-ATPase: Relationship to active chloride transport
.
J. Exp. Zool
199
,
419
–.
Sullivan
G. V.
,
Fryer
J. N.
,
Perry
S. F.
(
1995
).
Immunolocalization of proton pumps (H+-ATPase) in pavement cells of rainbow trout gill
.
J. Exp. Biol
198
,
2619
–.
Sullivan
G. V.
,
Fryer
J. N.
,
Perry
S. F.
(
1996
).
Localization of mRNA for the proton pumps (H+-ATPase) and Cl/HCO3 exchanger in the rainbow trout gill
.
Can. J. Zool
74
,
2095
–.
Uchida
K.
,
Kaneko
T.
(
1996
).
Enhanced chloride cell turnover in the gills of chum salmon fry in seawater
.
Zool. Sci
13
,
655
–.
Uchida
K.
,
Kaneko
T.
,
Yamauchi
K.
,
Hirano
T.
(
1996
).
Morphometrical analysis of chloride cell activity in the gill filaments and lamellae and changes in Na+,K+-ATPase activity during seawater adaptation in chum salmon fry
.
J. Exp. Zool
276
,
193
–.
Ura
K.
,
Soyano
K.
,
Omoto
N.
,
Adachi
S.
,
Yamauchi
K.
(
1996
).
Localization of Na+,K+-ATPase in tissues of rabbit and teleosts using an antiserum directed against a partial sequence of the-subunit
.
Zool. Sci
13
,
219
–.
van der Heijden
A. J. H.
,
Verbost
P. M.
,
Eygensteyn
J.
,
Li
J.
,
Wendelaar Bonga
S. E.
,
Flik
G.
(
1997
).
Mitochondria-rich cells in gills of tilapia (Oreochromis mossambicus) adapted to fresh water of sea water: quantification by confocal laser scanning microscopy
.
J. Exp. Biol
200
,
55
–.
Watanabe
S.
,
Kaneko
T.
,
Watanabe
Y.
(
1999
).
Immunocytochemical detection of mitochondria-rich cells in the brood pouch epithelium of the pipefish, Syngnathus schlegeli: structural comparison with mitochondria-rich cells in the gills and larval epidermis
.
Cell Tissue Res
295
,
141
–.
Wendelaar Bonga
S. E.
,
van der Meij
C. J. M.
(
1989
).
Degeneration and death, by apoptosis and necrosis, of the pavement and chloride cells in the gills of the teleost Oreochromis mossambicus
.
Cell Tissue Res
255
,
235
–.
Wood
C. M.
,
Pärt
P.
(
1997
).
Cultured branchial epithelia from freshwater fish gills
.
J. Exp. Biol
200
,
1047
–.
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