Establishment of totipotency after somatic cell nuclear transfer (NT) requires not only reprogramming of gene expression, but also conversion of the cell cycle from quiescence to the precisely timed sequence of embryonic cleavage. Inadequate adaptation of the somatic nucleus to the embryonic cell cycle regime may lay the foundation for NT embryo failure and their reported lower cell counts. We ...

The embryogenic capacity of seven cucumber (Cucumis sativus L.) cultivars was examined by tissue culture of cotyledon, young first-leaf, and internode explants. Somatic embryogenesis frequencies differed significantly among the tested cultivars, and ‘Fushinarimidori’ produced the highest number of embryos from either cotyledons or young first leaves. Cotyledonand first-leaf-derived calluses pro...

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...

Although somatic embryos of alfalfa (Medicago sativa L.) had acquired some tolerance to desiccation at the cotyledonary stage of development (22 d after plating), additional culturing in 20 microm abscisic acid (ABA) for 8 d induced greater desiccation tolerance, as determined by increased germination. Compared with fast drying, slow drying of the ABA-treated embryos improved desiccation tolera...

Embryogenesis in plants can commence from cells other than the fertilized egg cell. Embryogenesis initiated from somatic cells in vitro is an attractive system for studying early embryonic stages when they are accessible to experimental manipulation. Somatic embryogenesis in Arabidopsis offers the additional advantage that many zygotic embryo mutants can be studied under in vitro conditions. Tw...

An efficient method of somatic embryogenesis using exogenous polyamines through suspension culture protocol was developed from leaf derived callus of spine gourd (Momordica dioica Roxb. ex. Willd.). Embryogenic callus was originated from cut slices of leaf explants on MS solid medium supplemented with 4.4 μM 2,4-D with addition of polyamines (putrescine, spermidine and spermine). Putrescine at ...

Somatic cell nuclear transfer to an enucleated oocyte is used for reprogramming somatic cells with the aim of achieving totipotency, but most cloned embryos die in the uterus after transfer. While modifying epigenetic states of cloned embryos can improve their development, the production rate of cloned embryos can also be enhanced by changing other factors. It has already been shown that abnorm...

The GRAS protein family of putative transcription factors, which includes SHORT-ROOT (SHR), SCARECROW (SCR) and SCARECROW-LIKE (SCL) proteins, is involved in root development in Arabidopsisthaliana and other plant species [1]. In forest species, genes with homology to the A. thalianaSCR gene have been involved in the induction of somatic embryogenesis in Picea glauca (Moench) Voss [2] and Pinus...

Somatic embryos of Arabidopsis thaliana can be produced from explants of developing zygotic embryos. Cultivation of explants on maturation medium results in development of three main classes of regenerative structures: adventitious shoots, fused shoots, and complete somatic embryos. The ontogeny and anatomy of these structures was examined using serial plastic sections. Furthermore, two molecul...

The selection of good quality oocytes is crucial for in vitro fertilization and somatic cloning. Brilliant cresyl blue (BCB) staining has been used for selection of oocytes from several mammalian species. However, the effects of differential oocyte selection by BCB staining on nuclear reprogramming and in vivo development of SCNT embryos are not well understood. Immature compact cumulus-oocyte ...