Somatic embryogenesis of Norway spruce (Picea abies L.) is a versatile model system to study molecular mechanisms regulating embryo development because it proceeds through defined developmental stages corresponding to specific culture treatments. Normal embryonic development involves early differentiation of proembryogenic masses (PEMs) into somatic embryos, followed by early and late embryogen...

The pluripotent epiblast cells in the early embryo are destined to form both the somatic cells and primordial germ cells. In the few cells that undergo specification to establish the germ cell lineage, there is repression of the somatic programme. Recent evidence shows that, Blimp1, a known transcriptional repressor with a SET/PR domain, is crucial for the specification of primordial germ cells...

Kalanchoë daigremontiana reproduces asexually by generating numerous plantlets on its leaf margins. The formation of plantlets requires the somatic initiation of organogenic and embryogenic developmental programs in the leaves. However, unlike normal embryogenesis in seeds, leaf somatic embryogenesis bypasses seed dormancy to form viable plantlets. In Arabidopsis (Arabidopsis thaliana), seed do...

Pluripotency is generated naturally during mammalian development through formation of the epiblast, founder tissue of the embryo proper. Pluripotency can be recreated by somatic cell reprogramming. Here we present evidence that the homeodomain protein Nanog mediates acquisition of both embryonic and induced pluripotency. Production of pluripotent hybrids by cell fusion is promoted by and depend...

It is thought that at least some of the initial specification of the five somatic founder cells of the C. elegans embryo occurs cell-autonomously through the segregation of factors during cell divisions. It has been suggested that in embryos from mothers homozygous for mutations in the maternal-effect gene mex-1, four blastomeres of the 8-cell embryo adopt the fate of the MS blastomere. It was ...

The timing and tissue localization of small heat shock proteins (sHSPs) during cork oak somatic embryo development was investigated under normal growing culture conditions and in response to stress. Western blot analyses using polyclonal antibodies raised against cork oak recombinant HSP17 showed a transient accumulation of class I sHSPs during somatic embryo maturation and germination. Moreove...

Somatic or asexual embryogenesis is the process whereby genetically identical trees are produced through the production of embryo-like structures from somatic cells and are the primary enabling technology for all plant biotechnology products. A well-established and commonly used method for the study of plant samples is light optical microscopy. High resolution and depth of field of scanning ele...

An embryo classification system has been developed based on observations of Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) and Pinus taeda L. (loblolly pine) zygotic embryos and on the literature concerning embryology within the pine family. This system is suitable for classification of both zygotic and somatic embryos of loblolly pine, Picea abies L. (Norway spruce), and Douglas-fir. This ...

The MADS domain protein AGL15 (AGAMOUS-Like 15) has been found to preferentially accumulate in angiosperm tissues derived from double fertilization (i.e. the embryo, suspensor, and endosperm) and in apomictic, somatic, and microspore embryos. Localization to the nuclei supports a role in gene regulation during this phase of the life cycle. To test whether AGL15 is involved in the promotion and ...

Abstract To determine the optimal embryogenic capacity (somatic embryo production) of selected elite nematode-resistant genotypes Pinus thunbergii , variables such as tissue (ET) morphology, maternal genotype, proliferation rate and age were analyzed. ET morphology histological evaluation stage showed a decrease in filamentous clump protuberant surfaces decline acetocarmine-staining area, which...