The Arabidopsis GNOM protein, a guanine nucleotide exchange factor (GEF) that acts on ADP ribosylation factor (ARF)-type G proteins, is required for coordination of cell polarity along the apical-basal embryo axis. Interallelic complementation of gnom mutants suggested that dimerization is involved in GNOM function. Here, direct interaction between GNOM molecules is demonstrated in vitro and by...

Preimplantation genetic diagnosis (PGD) involves testing for specific genetic conditions prior to the implantation [5] of an embryo in the uterine wall. This form of genetic screening has been made possible by the growth of in-vitro fertilization [6] (IVF) technology, which allows for the early stages of development to occur in a laboratory dish rather than in vivo [7]. The purpose of PGD is to...

In 2005, the European Society for Human Reproduction and Embryology (ESHRE) Preimplantation Genetic Diagnosis (PGD) Consortium published a set of Guidelines for Best Practice to give information, support and guidance to potential, existing and fledgling PGD programmes (Thornhill AR, De Die-Smulders CE, Geraedts JP, Harper JC, Harton GL, Lavery SA, Moutou C, Robinson MD, Schmutzler AG, Scriven P...

As a strategy for the identification of T-DNA-tagged gametophytic mutants, we have used T-DNA insertional mutagenesis based on screening for distorted segregation ratios by antibiotic selection. Screening of approximately 1000 transgenic Arabidopsis families led to the isolation of eight lines showing reproducible segregation ratios of approximately 1:1, suggesting that these lines are putative...

embryo culture were used to produce inter specific walnut hybrid plants between juglans nigra l. and j. regia l. developed ovaries were collected from j. rejia female flowers which were pollinated with j. nigra pollen grain by high dusting on a mature tree. in order to isolate embryos, exocarps were aseptically removed. isolated embryos from ovules at different developmental stages were transfe...