Showing papers in "Developmental Biology in 1972"

TL;DR: The morphological observations of this study are consistent with the previously proposed biphasic model of differentiation for the exocrine and endocrine B cells, and the development of specific organelles correlates with the pattern of accumulation of the specific exocrine proteins and insulin.

TL;DR: Some of the neurons dissociated from embryonic chick spinal cord and maintained in low density cell cultures establish functional contacts with muscle fibers that had formed in vitro from previously plated myoblasts.

TL;DR: It is tentatively concluded that, in the regulation of chicken skeletal muscle myogenesis, cell fusion potential and the potential for myosin synthesis are developed not simultaneously, but sequentially.

TL;DR: A hypothesis is further discussed in which hyaluronate production accompanies mesenchymal cell movements and its removal is necessary for differentiation of these cells.

TL;DR: Studies with autoradiography showed that the alterations in the cytoarchitectonics of both the heterozygous carrier and homozygous weaver cerebellums are associated with a reduced rate of granule cell migration.

TL;DR: The results suggest that increased collagen synthesis is a prerequisite for bone formation, but the significance of the developmental pattern of alkaline phosphatase in this process is unclear.

TL;DR: It is concluded that the level-specific morphogenetic capacity of the cervical and thoracic somitic mesoderm is determined before metamerization occurs, and despite this early determination, the unsegmented somites is endowed with regulative properties.

TL;DR: These experiments show that mtDNA is inherited cytoplasmically and maternally in Xenopus, and concludes that the nucleus does not contain a “master copy” of the mitochondrial sequences.

TL;DR: Hemocyanin labeled concanavalin A was used to study the distribution of sugar residues on the surface of various cell types.

TL;DR: Coaggregation of suspensions of mouse cerebrum cells with chick cells from various brain areas, or from nonnervous tissues resulted in bispecific aggregates which were generally intermediate in size between typical aggregates of each of the component cell populations.

TL;DR: Treatment with cytochalasin followed by recovery in the presence of colchicine demonstrates that recovery clefts can form in the absence of microtubules, suggesting normal salivary gland morphogenesis includes microfilament participation via contractile activity, in addition to mitosis and to extracellular stabilization processes.

TL;DR: A selection method especially designed for isolation of X-linked lethals in Drosophila having defective imaginal discs has generated 26 mutants with high larval viability, but which terminate development in late larval and prepupal stages.

TL;DR: It is concluded that the inductive signal emanating from the AER remains qualitatively constant from stage to stage and from level to level during limb-bud outgrowth; information for proper sequencing of level-specific patterns in the limb must therefore be programmed intrinsically within the mesoderm.

TL;DR: Coincident with the postnatal rise in fatty acid activation and palmitylcarnitine transferase activity in developing rats, the oxidation of palmityl-CoA plus carnitine and of Palmitylc Carnitine increased from barely measurable levels at birth to adult levels by 30 days of age.

TL;DR: The mitochondria synthesized during oogenesis and present in the egg are used during embryogenesis and are thus a storage product of eggs, indicating that these components are under separate metabolic control.

TL;DR: Measurements of local area changes of the embryonic myocardial surface indicate that the prospective right side expands during looping and it is proposed that regional changes in cell shape and alignment mediate heart looping.

TL;DR: A cell-free supernatant from short-term monolayer cultures of 14-day embryonic mouse cerebrum cells markedly and specifically enhanced the histotypic aggregation of suspensions of dissociated cerebrUM cells from mouse and from chick embryos.

TL;DR: The principal conclusion reached from these studies is that at least 99% of the protein present in the yolk platelet crystal is derived from a source outside the oocyte.

TL;DR: Cells in the cultured lens epithelium of the chick embryo undergo changes that are characteristic of epithelial cells differentiating into lens fibers, including a decrease in organelle density, a clustering of ribosomes and an alignment of longitudinally oriented microtubules along the cell membrane.

TL;DR: Findings agree well with previous reports that l -azetidine inhibits the secretion of normal collagen: the gross and microscopic changes observed reflect this collagen deficiency and emphasize the importance of collagen in normal organization of the matrix and the resultant shape of the cartilage.

TL;DR: Embryonic chick chondrocytes growing in suspension culture excrete into the medium chondromucoprotein which appears to be identical to chondomucop protein isolated from epiphyseal cartilage.

TL;DR: In this article, DNA from spermatids, 4-cell stages, and larvae of Ascaris lumbricoides was isolated, and the genome size before and after chromatin elimination was determined by isotope dilution.

TL;DR: The thick cellulose wall surrounding each macrocyst is produced by the cytophagic cell soon after it has engulfed all the cells in the mass and before the granular stage.

TL;DR: A mutant gene, c (for “cardiac lethal”), carried by an adult Ambystoma mexicanum imported from Mexico, causes failure of onset of heart action at the usual time in hearts of apparently normal morphology, and it is revealed that the hearts of mutants lack organized myofibrils.

TL;DR: It is concluded that UV destroys a cytoplasmic factor essential to neural induction in the amphibian gray crescent, and donor nuclei from different regions of irradiated blastulae and gastrulae were transplanted into enucleated eggs suggesting that gray c Crescent inductive ability was destroyed.

TL;DR: Electron and phase-contrast microscopic observations demonstrated that depigmentation of iris epithelial cells in vivo after lentectomy is preceded by alterations of cell shape and increases in microfilaments and microtubules in the periphery of the cell.

TL;DR: In this article, the mtDNA of Xenopus laevis and Xenopus mulleri were compared with respect to size, composition, and sequence, and it was suggested that the remaining, rapidly evolving sequences of mtDNA may be equivalent to the "spacer" sequences which have been found within certain nuclear DNAs.

TL;DR: It is suggested that β-ecdysone stimulates adenyl cyclase (and guanyl cyclase) but that the hormone also exerts effects on target cells independent of the cyclic AMP system.

TL;DR: In the case of dark-grown, nondividing Euglena gracilis var. bacillaris, the plastid structure remains unchanged during the first 6 hr, a period of slow chlorophyll accumulation, and no new membranes are formed as discussed by the authors.