In Nature, the embryogenesis process proceeds from a single fertilized cell through division, migration, specialization and apoptosis. Although a lot is known about development, we still have a long way to go from theories of pattern formation towards understanding the intelligence within an unsupervised manufacturing process which robustly assembles complex biological forms. Our approach has b...

Five P-tubulin isotypes are expressed differentially during chicken brain development. One of these isotypes is encoded by the gene cP4 and has been assigned to an isotypic family designated as Class I11 (PIII). In the nervous system of higher vertebrates, PI11 is synthesized exclusively by neurons. A PIII-specific monoclonal antibody was used to determine when during chick embryogenesis cP4 is...

The ability to produce morphologically and developmentally normal embryos and, indeed, whole plants from undifferentiated somatic cells in culture, through the process of somatic embryogenesis, resides uniquely within the plant kingdom. Since the initial description of somatic embryo production from carrot callus cells more than 35 years ago (Steward et al., 1958), this unique developmental pot...

(In vitro somatic embryogenesis and adventitious root initiation have a common origin in eggplant (Solanum melongena L.)). Somatic embryogenesis was induced from cotyledon explants of eggplant cultured on MS medium supplemented with 54 μM NAA. Anatomical analysis of somatic embryo initiation and development was performed during the first four weeks. Proembryo formation was observed after the se...

The optimum temperature for embryogenesis in Meloidogyne javanica lies between 25 and 30 C. Embryogenesis is slightly more rapid at 30 C (9-10 days), but more eggs complete development at 25 C (11-13 days). At temperatures of 25, 27.5, and 30 C, embryogenesis is about twice as rapid as at 20 C (23-25 days), and about four times as rapid as at 15 C (46-48 days). Time-lapse studies showed that th...

Abstract Programmed cell death occurs in browning explants of Fraxinus mandshurica during somatic embryogenesis, but the underlying mechanism is unclear. In this study, single cotyledons zygotic embryos F. were used as explants. Mitochondrial structure and function, caspase-3-like protease activity, hydrogen peroxide metabolism, nitric oxide accumulation induced by high concentrations sucrose p...

In the preceding paper [l] a model was proposed which offers an explanation to many aspects of embryogenesis in volvox. In particular, the model explains pattern formation during embryogenesis, i.e., it correctly predicts the very regular positioning of the reproductive cells (gonidia) within the Volvox spheroids. The assumption was made that membrane proteins mediating cell-cell contacts are i...

Uniparental transcripts during embryogenesis may arise due to gamete delivery during fertilization or genomic imprinting. Such transcripts have been found in a number of plant species and appear critical for the early development of embryo or endosperm in seeds. Although the regulatory expression mechanism and function of these genes in embryogenesis require further elucidation, recent studies ...