XB-ART-26051Differentiation March 1, 1990; 43 (1): 1-9.
XK endo B is preferentially expressed in several induced embryonic tissues during the development of Xenopus laevis.
XK endo B is a type I keratin that was originally identified by its preferential expression in the embryonic notochord of the amphibian Xenopus laevis. A peptide identical to a short region of its predicted amino acid sequence was used to generate antibodies against the XK endo B protein. This paper reports an immunocytochemical study of the spatial expression pattern of XK endo B during development. The protein was observed in the notochord and endoderm as predicted from previous RNA analysis. In addition, XK endo B was detected in the cement gland, in the pituitary, olfactory and pharyngeal pouch rudiments, and in a nonuniform distribution in the neural tube as well as the inner sensorial layer of the ectoderm. XK endo B expression is not limited to any germ layer or any particular cell type, but is nevertheless highly restricted in its distribution in the embryo. Its expression in several different embryonic tissues requiring inductive interactions for differentiation makes XK endo B a valuable tool with which to study the regulation of induced gene expression during embryogenesis.
PubMed ID: 1694800
Article link: Differentiation
Species referenced: Xenopus laevis
Genes referenced: krt12.4 krt18.1
Antibodies: Krt18 Ab1
Article Images: [+] show captions
|Fig. 1. Detection of XK endo B by Western-blot analysis. Equal embryo equivalents were loaded per lane from either total Trixon X 100-soluble protein preparations (lanes 1 and 2) or cytoskeletal protein preparations (lanes 3 and4). Filters were stained with either untreated antibody (lanes 1 and 3) or antobidy preabsorbed with HPLC-purified peptide. The positions of the polypeptide markers are indicated an the lefr by their sizes in kDa|
|Fig. 2A-D. Expression of XK endo B in the endoderm and notochord. A The planes o j section are indicated for B-D. B Crosssection of a stage-28 (tailbud) embryo. C, D Longitudinal sections through a stage-28 embryo and stage-41 tadpole, respectively. The endoderm (E), neural tube (NT), notochord (N) and the somites (9 are indicated. All staining was visualized by indirect immunofluorescence|
|Fig. 3A-F. Expression of XK endo B protein in the head at tailbud. of a stage-30 embryo. The brain cavity (BC), olfactory placodes A-D Cross-sections through the head of a stage-28 embryo. B (OP), stomodeal-hypophyseal rudiment (S-HR), eye vesicles (EV), Neighboring section to that shown in A stained with antibody inner ectoderm (I@, cement gland (CC) and pharyngeal cavity preabsorbed with high-performance liquid chromatography ( P o are indicated. F The planes of section are indicated for (HPLC)-purified peptide. E Longitudinal section through the head Fig. 3A-E and Fig. 4A-C|
|Fig. 4A-D. Expression of XK endo B in the inner ectoderm including the pharyngeal pouch rudiments. A Cross-section through the posterior region of the head of a stage-28 embryo. B Neighboring section stained with antibody preabsorbed with HPLC-purified peptide. C Cross-section through the anterior portion of the trunk. D The boxed area in C enlarged. The notochord (N), neural tube (NT), eye vesicles (EV), pharyngeal cavity (Pc), pharyngeal pouch rudiments (PPR), and inner ectoderm (ZE) are indicnted|
|Fig. SA, B. XK endo B expression in a wholemount of a stage30 embryo. A The notochord (N), neural tube (NT), and cement gland (CG ) are indicated. B The ventral half of the embryo shown in A. The plane of focus differs to highlight the staining in the pharyngeal pouches (PP)|