We give an overview of the applications and methods of high-resolution anatomical magnetic resonance imaging (MRI) in the study of embryonic and fetal development in animal models. Challenges associated with performing in utero studies are described. Recent in utero images in mouse and in nonhuman primates are presented. Results using magnetic resonance microscopy in fixed mouse embryos and in ...

search and education, alternative methods for animal testing came to be discussed on account of criticisms made on animal welfare and humanitarian grounds as well as awareness among scientists. Thus, based on social acceptance, experimental studies using chick embryos have drawn attention. In order to develop alternative methods, we have studied the biological effects of drugs on the cardiovasc...

We have cultured explants of Xenopus blastular animal cap tissue from embryos that had received an earlier treatment with LiCl and from their untreated siblings, in various concentrations of XTC-cell-derived mesoderm-inducing factor (XTC-MIF, Smith, 1987; Smith et al. 1988). The pretreatment with lithium that we used transforms later morphogenesis in the whole embryo to give radialized body for...

The correlation between cell-to-cell communication through gap junctions at the 32-cell stage and the subsequent patterning of the embryonic axis has been examined in Xenopus laevis embryos. Disturbances of embryonic axis formation were generated by exposure to u.v. irradiation at the vegetal pole before 0-6 in the cell cycle, which generates embryos with dorsal axial deficiencies. Alternativel...

Xenopus eggs, artificially fertilized, were prevented from undergoing equilibrium rotation by incubation in medium containing ficoll. Three orientations were selected: normal, with animal pole uppermost; inverted, with vegetal pole away from gravity; and an off-axis orientation, with embryos tilted approximately 90 degrees from the animal-vegetal axis. At blastula stage 8, cells forming the bla...

Although rats are preferred over mice as an animal model, transgenic animals are generated predominantly using mouse embryos. There are limitations in the generation of transgenic rat by embryo manipulation. Unlike mouse embryos, most of the rat embryos do not survive after male pronuclear DNA injection which reduces the efficiency of generation of transgenic rat by this method. More importantl...

After artificial insemination and multiple ovulation and embryo transfer (MOET), in vitro production of embryos (IVP) represents the third generation of techniques aimed at a better control of animal reproduction. This technique involves four major steps (Figure 1): oocyte collection, oocyte in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro development of the resulting embryo...

Evaluation of quality and viability of bovine and rabbit preimplantation embryos following cryopreservation was the objective of this study. Bovine embryos of Holstein breed (n = 88) at the morula-early blastocyst stage (on the 7 day after the first insemination) and rabbit embryos (n = 135) from New Zealand breed at the morula stage (90–92 hpc) were cryopreserved by the two-step vitrification ...

British government plans to outlaw the creation of embryos which are part human, part animal are " unacceptable " and threaten to undermine the country's leading position in stem-cell science, a group of MPs reported last month. A report by the House of Commons science and technology committee called on ministers to scrap the proposed ban and accuses the government of basing its opposition to t...