Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Intermediate-size filaments in a germ cell: Expression of cytokeratins in oocytes and eggs of the frog Xenopus.
Franz JK
,
Gall L
,
Williams MA
,
Picheral B
,
Franke WW
.
???displayArticle.abstract???
Vitellogenic oocytes and eggs of the frog Xenopus laevis contain intermediate-size filaments that are resistant to extractions in high-salt buffers and Triton X-100 and are specifically stained with antibodies to cytokeratins. Gel electrophoresis of cytoskeletal proteins from Xenopus oocytes shows a specific enrichment of three polypeptides designated components 1 [Mr, 56,000; IEP (pI obtained by two-dimensional gel electrophoresis in the presence of 9.5 M urea), ca. 5.9], 2 (Mr, 46,000; IEP, 5.38), and 3 (Mr, 42,000; IEP, ca. 5.3). The same three cytoskeletal polypeptides are found in eggs and early embryos, in intestinal mucosa of adult frogs, and in cultured kidney epithelial cells. They are different from amphibian vimentin and desmin and from the keratins present in the epidermis of adult frogs. Peptide mapping and immunoblotting experiments indicate that Xenopus cytokeratin component 1 is related to cytokeratin A of higher vertebrates but is different from the two smaller cytoskeletal polypeptides 2 and 3. Incorporation of [35 S]methionine shows that all three polypeptides are synthesized in both oocytes and embryos. Our observations show that maternal storage is not only restricted to proteins serving basic cellular functions but also can extend to proteins related to a specific form of cell differentiation (i.e., epithelial formation) in the early embryo. The data suggest that mechanisms of epithelial differentiation in Xenopus embryogenesis are different from those of early mammalian embryos in which no such intermediate-size-filament storage pool has been detected.
FIG. 1. Immunofluorescence
(a, b, e, and h) and electron (c, d, f,
and g) microscopy showing cytokeratin
filaments in oocytes (a-e)
and early embryos (f-h) of X. laevis.
(a) Frozen section of ovary
stained with antibodies to bovine
cytokeratin. Note staining of follicle
cells (F) and offibrillar arrays
inthreeadjacentstage6oocytes(O°,
02, and 03). (Bar = 100 ,um.) (b)
Higher magnification of cytokeratin
fibril arrays (same preparation
as in a). (Bar = 50 ,um.) (c) Thin
sections through cytoskeleton from
oocyte cortex (stage 6) showing a
bundle of loosely fasciated cytokeratin
IFs terminating at a dense
aggregate (arrow). (Bar = 0.5 ,um.)
(d) Same preparation showing the
more frequent irregular meshwork
arrays of cytokeratin IFs. (Bar
= 0.2 um.) Insert shows electrontranslucent
cores (arrows) typical
of cross-sectioned IFs (Bar = 40
nm.) (e) Same ovary as in a but
stained with antibodies to vimentin.
Note that only interfollicular
mesenchymal cells are stained,
whereas oocytes (01, 02, and 03) are
negative. (Bar = 50 ,um.) (f) Thin
section through outer cells (S, surface)
of stage 7 embryo (early blastula)
showing an IF bundle (arrows)
in subapical position. Bracket
denotes the actin-rich cortex. (Bar
= 0.5 Pm.) (g) Same stage showing
association of cytokeratin IFs (arrows)
to typical desmosome (D).
(Bar = 0.2 /Lm.) (h) Immunofluorescence
microscopy of outer cells
of blastula (5, surface) showing
positive cortical staining with antibodies
to bovine cytokeratin. (Bar
=25 um.)
FIG. 2. Two-dimensional gel electrophoresis of cytoskeletal proteins
from stage 6Xenopus oocytes (a), intestinal mucosa of adult frogs
(b), cultured epithelial cells of Ar line (c), epidermis (d), leg skeletal
muscle (e), and stomach wall (f) of adult frogs. First-dimension electrophoresis
was by isoelectric focusing (IEF) ornonequilibrium pH gradient
electrophoresis (NEPHGE). Reference proteins in coelectrophoresis
are bovine serum albumin (BSA), phosphoglycerokinase (PGK),
and 0- and a-actin (A; only a-actin is denoted in c-f). Major cytoskeletal
polypeptides are designated 1, 2, and 3 (a-c andf). Arrowhead in
a denotes residual P-tubulin; bracket in c, a cytoskeletal polypeptide
notfurthercharacterized; bracketsin d, epidermal keratins; and brackets
in e and f, cytoskeletal polypeptides of muscle and stomach (one of
these, D, has been identified as desmin).
FIG. 3. Polypeptide identification by NaDodSO4/polyacrylamide
gel electrophoresis (a) and binding of cytokeratin antibodies (b) as well
as by two-dimensional coelectrophoresis of unlabeled cytoskeletal proteins
ofA6 cells (Coomassie blue stain) (c) with [35S]methionine-labeled
cytoskeletal proteins from stage 6 oocytes (d). (a) Coomassie blue staining
of reference proteins (lane R from top to bottom: f3galactosidase,
phosphorylase a, bovine serum albumin, actin, and chymotrypsinogen),
cytoskeletal proteins from frog epidermis (lane 1), laid eggs (lane 2),
and stage 6 oocytes (lane 3). Dots, IF polypeptides; bars, an unidentified
minor cytoskeletal polypeptide of Mr 66,000 that often exhibits immunological
crossreaction with IF proteins (cf. ref. 1); asterisks, major
yolk components. (b) Fluoroautoradiography of a gel parallel to a after
blotting on nitrocellulose paper and reaction with antibodies to bovine
epidermal cytokeratins, followed by washes and reaction with l25I-labeled
protein A. Note antibody reaction with all keratins of frog epidermis
(lane 1') but with only one cytokeratin (component 1) of oocytes
(lane 3') and eggs (lane 2'). Coomassie blue staining (c) and fluoroautoradiography
(d) of the same gel showing comigration of cytokeratins
1-3 in both cells. X in c, cytoskeletal polypeptide not further characterized.
Designations are as in Fig. 2.
FIG. 4. Autoradiographs showing tryptic peptide maps of cytoskeletal
polypeptides excised after separation on two-dimensional gel electrophoresis
followed by radioiodination. (a) Component 1 fromXerwpus
oocytes. (b) Component 1 from Xenopus intestinal cells. (c) Mixture of
peptides shown in a and b. (d) Cytokeratin A from rat intestinal cells
(cf. ref. 37). (e) Component 2 from Xenopus oocytes. (f) Component 3
from Xenopus oocytes. Brackets and arrows in a and c denote identical
peptide spots; in d they indicate some characteristic peptide spots of
rat cytokeratin A similar to peptides obtained from Xenopus cytokeratin
1. Note that components 2 (e) and 3 are different from component
1 (a-c).
FIG. 5. Two-dimensional electrophoresis of- [3S]methionine-labeled
cytoskeletal polypeptides of Xenopus oocytes [Coomassie blue
staining (a) and fluoroautoradiograph (b)] in comparison with flubroautoradiographs
of cytoskeletal polypeptides from laid eggs (c) and
from embryos of'stages9 (d) (component 3 was identified only after long
exposure) and 17 (e). Designations are as in Fig. 2..
Anderton,
Intermediate filaments: a family of homologous structures.
1981, Pubmed
Anderton,
Intermediate filaments: a family of homologous structures.
1981,
Pubmed
Ballantine,
Changes in protein synthesis during the development of Xenopus laevis.
1979,
Pubmed
,
Xenbase
Bluemink,
Cytokinesis and cytochalasin-induced furrow regression in the first-cleavage zygote of Xenopus laevis.
1971,
Pubmed
,
Xenbase
Brûlet,
Monoclonal antibodies against trophectoderm-specific markers during mouse blastocyst formation.
1980,
Pubmed
Capco,
Transient localizations of messenger RNA in Xenopus laevis oocytes.
1982,
Pubmed
,
Xenbase
Carpenter,
A gradient of poly(A)+ RNA sequences in Xenopus laevis eggs and embryos.
1982,
Pubmed
,
Xenbase
De Robertis,
Somatic nuclei in amphibian oocytes: evidence for selective gene expression.
1977,
Pubmed
,
Xenbase
Dixon,
Regulation of protein synthesis and accumulation during oogenesis in Xenopus laevis.
1982,
Pubmed
,
Xenbase
Ducibella,
The preimplantation mammalian embryo: characterization of intercellular junctions and their appearance during development.
1975,
Pubmed
Elder,
Radioiodination of proteins in single polyacrylamide gel slices. Tryptic peptide analysis of all the major members of complex multicomponent systems using microgram quantities of total protein.
1977,
Pubmed
Franke,
Distribution and mode of arrangement of microfilamentous structures and actin in the cortex of the amphibian oocyte.
1976,
Pubmed
Franke,
Antibody to prekeratin. Decoration of tonofilament like arrays in various cells of epithelial character.
1978,
Pubmed
Franke,
Different intermediate-sized filaments distinguished by immunofluorescence microscopy.
1978,
Pubmed
Franke,
Widespread occurrence of intermediate-sized filaments of the vimentin-type in cultured cells from diverse vertebrates.
1979,
Pubmed
,
Xenbase
Franke,
Identification and characterization of epithelial cells in mammalian tissues by immunofluorescence microscopy using antibodies to prekeratin.
1979,
Pubmed
Franke,
Intermediate-sized filaments of the prekeratin type in myoepithelial cells.
1980,
Pubmed
Franke,
Isolation and characterization of desmosome-associated tonofilaments from rat intestinal brush border.
1981,
Pubmed
Franke,
Differences of expression of cytoskeletal proteins in cultured rat hepatocytes and hepatoma cells.
1981,
Pubmed
Franke,
Diversity of cytokeratins. Differentiation specific expression of cytokeratin polypeptides in epithelial cells and tissues.
1981,
Pubmed
Franke,
Differentiation-related patterns of expression of proteins of intermediate-size filaments in tissues and cultured cells.
1982,
Pubmed
Freudenstein,
Reaction of tonofilament-like intermediate-sized filaments with antibodies raised against isolated defined polypeptides of bovine hoof prekeratin.
1978,
Pubmed
,
Xenbase
Gigi,
Detection of a cytokeratin determinant common to diverse epithelial cells by a broadly cross-reacting monoclonal antibody.
1982,
Pubmed
Holtzer,
Intermediate-size filaments: changes in synthesis and distribution in cells of the myogenic and neurogenic lineages.
1982,
Pubmed
Jackson,
Formation of cytoskeletal elements during mouse embryogenesis. Intermediate filaments of the cytokeratin type and desmosomes in preimplantation embryos.
1980,
Pubmed
Jackson,
Formation of cytoskeletal elements during mouse embryogenesis. II. Epithelial differentiation and intermediate-sized filaments in early postimplantation embryos.
1981,
Pubmed
Kemler,
Reactivity of monoclonal antibodies against intermediate filament proteins during embryonic development.
1981,
Pubmed
Krohne,
Cell type-specific differences in protein composition of nuclear pore complex-lamina structures in oocytes and erythrocytes of Xenopus laevis.
1981,
Pubmed
,
Xenbase
Lazarides,
Intermediate filaments: a chemically heterogeneous, developmentally regulated class of proteins.
1982,
Pubmed
Moll,
The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells.
1982,
Pubmed
Nelson,
Intermediate (10 nm) filament proteins and the Ca2+-activated proteinase specific for vimentin and desmin in the cells from fish to man: an example of evolutionary conservation.
1982,
Pubmed
O'Farrell,
High resolution two-dimensional electrophoresis of proteins.
1975,
Pubmed
O'Farrell,
High resolution two-dimensional electrophoresis of basic as well as acidic proteins.
1977,
Pubmed
Osborn,
Intermediate filaments.
1982,
Pubmed
Paulin,
Antibodies as probes of cellular differentiation and cytoskeletal organization in the mouse blastocyst.
1980,
Pubmed
Renner,
Reconstitution of intermediate-sized filaments from denatured monomeric vimentin.
1981,
Pubmed
Schiller,
A subfamily of relatively large and basic cytokeratin polypeptides as defined by peptide mapping is represented by one or several polypeptides in epithelial cells.
1982,
Pubmed
Schmid,
Distribution of vimentin and desmin filaments in smooth muscle tissue of mammalian and avian aorta.
1982,
Pubmed
Steinert,
Isolation and characterization of intermediate filaments.
1982,
Pubmed
Sturgess,
Actin synthesis during the early development of Xenopus laevis.
1980,
Pubmed
,
Xenbase
Vandekerckhove,
Diversity of expression of non-muscle actin in amphibia.
1981,
Pubmed
,
Xenbase
Wallace,
Protein incorporation by isolated amphibian oocytes. 3. Optimum incubation conditions.
1973,
Pubmed
,
Xenbase
Wolf,
A molecular approach to fertilization. II. Viability and artificial fertilization of Xenopus laevis gemetes.
1971,
Pubmed
,
Xenbase
Woodland,
The synthesis and storage of histones during the oogenesis of Xenopus laevis.
1977,
Pubmed
,
Xenbase
