Abstract
Fine structural observations have been made in the 11-day embryonic mouse of exocrine cells in pancreatic epithelium developing in tissue culture transfilter from salivary gland mesenchyme of the 13-day embryonic mouse. After 2 days in culture, the exocrine cells show increased cytoplasmic density, abundant ribosomes in aggregate or "rosette" form, and expanded profiles of rough-surfaced endoplasmic reticulum. After 3 and 4 days in culture, the cells exhibit continued expansion of the profiles of endoplasmic reticulum, increased amounts of Golgi membranes, and large areas of light density (prozymogen granules). After 5 days in culture, dense zymogen granules are present in the most highly differentiated cells. In addition, at the filter-epithelial surface, at 2 days, small fibers can be discerned which, after 4 days in culture, show obvious periodicity and are thought to be collagen. The significance of these changes, in relation to the mesenchymal effect, to the onset of specific synthesis and to the stabilization of differentiation is discussed.
Full Text
The Full Text of this article is available as a PDF (1.7 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- AUERBACH R. Morphogenetic interactions in the development of the mouse thymus gland. Dev Biol. 1960 Jun;2:271–284. doi: 10.1016/0012-1606(60)90009-9. [DOI] [PubMed] [Google Scholar]
- CONKLIN J. L. Cytogenesis of the human fetal pancreas. Am J Anat. 1962 Sep;111:181–193. doi: 10.1002/aja.1001110204. [DOI] [PubMed] [Google Scholar]
- FERREIRA D. L'ultrastructure des cellules du pancréas endocrine chez l'embryon et le rat nouveau-né. J Ultrastruct Res. 1957 Nov;1(1):14–25. doi: 10.1016/s0022-5320(57)80009-4. [DOI] [PubMed] [Google Scholar]
- GOLOSOW N., GROBSTEIN C. Epitheliomesenchymal interaction in pancreatic morphogenesis. Dev Biol. 1962 Apr;4:242–255. doi: 10.1016/0012-1606(62)90042-8. [DOI] [PubMed] [Google Scholar]
- GROBSTEIN C. Cell contact in relation to embryonic induction. Exp Cell Res. 1961;Suppl 8:234–245. doi: 10.1016/0014-4827(61)90352-4. [DOI] [PubMed] [Google Scholar]
- LUFT J. H. Improvements in epoxy resin embedding methods. J Biophys Biochem Cytol. 1961 Feb;9:409–414. doi: 10.1083/jcb.9.2.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MARKS P. A., RIFKIND R. A. DANON D: POLYRIBOSOMES AND PROTEIN SYNTHESIS DURING RETICULOCYTE MATURATION IN VITRO. Proc Natl Acad Sci U S A. 1963 Aug;50:336–342. doi: 10.1073/pnas.50.2.336. [DOI] [PMC free article] [PubMed] [Google Scholar]
- REYNOLDS E. S. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17:208–212. doi: 10.1083/jcb.17.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WARNER J. R., KNOPF P. M., RICH A. A multiple ribosomal structure in protein synthesis. Proc Natl Acad Sci U S A. 1963 Jan 15;49:122–129. doi: 10.1073/pnas.49.1.122. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WATSON M. L. Staining of tissue sections for electron microscopy with heavy metals. J Biophys Biochem Cytol. 1958 Jul 25;4(4):475–478. doi: 10.1083/jcb.4.4.475. [DOI] [PMC free article] [PubMed] [Google Scholar]