In the developing embryo the foregut is surrounded by a group of vascular structures of bilateral distribution connected with the branchial arches. Portions of these arches are obliterated to form the normally described aorta and great vessels. The ultimate persistence of only one main vascular arch, the left, as the aorta, permits the trachea and oesophagus to lie freely to its right side. Whe...

Normal embryo development is required for correct seedling formation. The Arabidopsis gurke and pasticcino3 mutants were isolated from different developmental screens and the corresponding embryos exhibit severe defects in their apical region, affecting bilateral symmetry. We have recently identified lethal acc1 mutants affected in acetyl-CoA carboxylase 1 (ACCase 1) that display a similar embr...

The Drosophila embryonic salivary gland is a migrating tissue that undergoes a stereotypic pattern of migration into the embryo. We demonstrate that the migratory path of the salivary gland requires the PDGF/VEGF pathway. The PDGF/VEGF receptor, Pvr, is strongly expressed in the salivary glands, and Pvr mutations cause abnormal ventral curving of the glands, suggesting that Pvr is involved in g...

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...

Magnetic resonance (MR) microscopy was used to noninvasively investigate the development of live rat embryos in utero. The difficulty in making sequential observations of a developing mammalian embryo has frustrated developmental biologists for many years. Most current technologies analyze normal and abnormal development by observing end point phenotypes (in fixed specimens) rather than investi...

INTRODUCTION We aimed to develop and implement a short tandem repeat (STR) polymerase chain reaction alternative to fluorescence in situ hybridisation (FISH) for the preimplantation genetic diagnosis (PGD) of chromosomal translocations. METHODS Selected informative STRs located on translocated arms of relevant chromosomes were used to discriminate between normal and unbalanced chromosome stat...

In the developing embryo the foregut is surrounded by a group of vascular structures of bilateral distribution connected with the branchial arches. Portions of these arches are obliterated to form the normally described aorta and great vessels. The ultimate persistence of only one main vascular arch, the left, as the aorta, permits the trachea and oesophagus to lie freely to its right side. Whe...

Plant regeneration was achieved using somatic embryos obtained from the Vitis vinifera cvs Sugraone, Crimson Seedless and Don Mariano. White somatic embryos, 1.5-3 mm in length, were cultured on embryo germination medium with or without IAA (10 μM) + GA3 (1 μM). Germinated embryos showed 5 different morphologies, (1) one cotyledon, (2) two cotyledons, (3) three cotyledons, (4) trumpet-like and ...

Talipes equinovarus (clubfoot) is a skeletal anomaly of the embryo's legs, with a frequency of 1-3:1000 living born babies. It may occur as an independent anomaly, or as part of a syndrome with concomitant chromosomal abnormalities.XYY syndrome is a quite rare sex chromosomal abnormality with 47, XYY karyotype. Prenatal diagnosis is usually accidental because the syndrome is not associated with...

The possible relationship among malignancy, differentiation, and chro mosomal constitution of primary embryo-derived tumors was studied. Tumors were induced by transplanting 7-day-oId mouse embryos under the kidney capsule of syngeneic BALB/c recipients. Transplantation of 101 embryos resulted in 81 tumor-bearing mice: 36 teratocarcinomas; 18 teratomas; and 27 yolk sac tumors. Some of the yolk ...