background: successful embryo transfer (et) technique is a fateful step of all efforts to achieve live births from in vitro produced embryos in assisted reproductive techniques or in knockout, transgenic or cloned animal projects. small reproductive tract of mice and limitation of current techniques may not well satisfy the requirements for mass production of genetically modified mice. genetic ...

In early embryos of Ciona, an invertebrate chordate, the animal-vegetal axis is established by combinatorial actions maternal factors. One target these factors, Foxd, specifically expressed in vegetal hemisphere and stabilizes activating hemisphere-specific genes repressing animal genes. This dual functionality essential for embryogenesis ascidian embryos; however, mechanism which Foxd can act ...

introduction: it is now generally accepted that vero cells provide beneficial effects on improving embryo quality in many animal species. the aim of this research was to determine the effect of vero cell co-culture on the development of vitrified 8-cell mouse embryos. material and methods: eight- cell mouse embryos were provided from superovulated female nmri mice and divided into treatment cas...

The property of primordial germ cells (PGCs) in fragmented goldfish embryos was investigated. When 1- and 2- cell embryos were cut at several perpendicular levels at the animal-vegetal axis, cells expressing vas mRNA were observed in the resultant embryos derived from all kinds of animal fragments. Blastodisc fragments from the 1- to 2-cell stage developed to spherical embryos containing yolk b...

The HE gene is the earliest strictly zygotic gene activated during sea urchin embryogenesis. It is transiently expressed in a radially symmetrical domain covering the animal-most two-thirds of the blastula. The border of this domain, which is orthogonal to the primordial animal-vegetal axis, is shifted towards the animal pole in Li+-treated embryos. Exogenous micromeres implanted at the animal ...

Human-animal chimeric embryos are embryos obtained by introducing human cells into a non-human animal embryo. It is envisaged that the application of human-animal chimeric embryos may make possible many useful research projects including producing three-dimensional human organs in animals and verification of the pluripotency of human ES cells or iPS cells in vivo. The use of human-animal chimer...

The Human Fertilisation and Embryology Bill (HFE Bill) allows the creation of four different types of human-animal hybrid embryos. This page deals with the issues raised by cloned human-animal hybrid embryos (also known as cytoplasmic hybrids), which are the main focus of debate about hybrid embryos in the HFE Bill. In our view, although important, the issues raised by GM embryos, which are one...