Quantitative analysis of protein synthesis in mouse embryos. II: Differentiation of endoderm, mesoderm, and ectoderm
Autor: | Rosa S. P. Beddington, James I. Garrels, Keith E. Latham, Davor Solter |
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Rok vydání: | 1993 |
Předmět: |
Fetal Proteins
animal structures Ectoderm Germ layer Histogenesis Biology Mesoderm Embryonic and Fetal Development Mice Pregnancy Image Processing Computer-Assisted Genetics medicine Embryonic disc Animals Electrophoresis Gel Two-Dimensional Crosses Genetic Endoderm Embryogenesis Diploblasty Cell Differentiation Cell Biology Cell biology Mice Inbred C57BL medicine.anatomical_structure Mice Inbred DBA Epiblast embryonic structures Female Developmental Biology |
Zdroj: | Molecular Reproduction and Development. 35:140-150 |
ISSN: | 1098-2795 1040-452X |
DOI: | 10.1002/mrd.1080350207 |
Popis: | The changes in protein synthesis that occur during differentiation of the primitive germ layers were examined by high-resolution, two-dimensional gel electrophoresis of proteins synthesized in 6.5 and 7.5 days postcoitum (d.p.c.) mouse embryos. For 6.5 d.p.c. embryos, protein synthesis patterns were compared between whole extraembryonic and embryonic regions and between embryonic visceral endoderm and embryonic ectoderm. For 7.5 d.p.c. embryos, comparisons were made between extraembryonic and embryonic regions and between isolated embryonic endoderm, mesoderm, and ectoderm. Each of the isolated 7.5 d.p.c. germ layers was divided into anterior and posterior fragments in order to evaluate possible regional differences in gene expression along the anterior-posterior axis. Comparisons of protein synthesis patterns revealed the greatest difference between isolated endoderm and ectoderm, indicating that by as early as 6.5 d.p.c. patterns of gene expression differ significantly between these tissues. The greatest similarities were found between ectoderm and whole embryonic regions and between endoderm and whole extraembryonic regions, which most likely reflects the overall cellular compositions of the embryonic and extraembryonic regions. Based on their patterns of synthesis, four groups of proteins were identified that were preferentially synthesized in either endoderm or ectoderm. These provide useful markers for studying differentiation in these tissues. One other protein, migrating at the position expected for vimentin, was synthesized at an elevated rate in isolated mesoderm. We also observed differences in rates of synthesis of alpha-tubulin and tropomyosin-5 indicative of potential differences in cytoskeletal composition among the germ layers beyond those previously described. The difference in overall protein synthesis patterns between anterior and posterior regions was greatest in the embryonic endoderm, indicating that differentiation along the anterior-posterior axis may be initiated sooner or may proceed more rapidly in the endoderm than in the other germ layers. These data provide the first quantitative evaluation of the degree to which differentiation of the three primitive germ layers affects protein synthesis patterns and reveal potentially useful markers of endoderm and ectoderm differentiation. |
Databáze: | OpenAIRE |
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