BACKGROUND The ability of human embryos to undergo normal development has been shown previously to be subject to strong paternal (sperm-derived) effects. This study was undertaken to determine whether paternal influences on human embryo quality are detectable as early as the first cell cycle after fertilization. METHODS The quality of zygotes and cleaving embryos resulting from sibling donor ...

Sources of variation in Finnish Landrace and Targhee birth weights from pregnancies following natural matings and intra-breed, inter-breed and 2-breed embryo transfers were studied. Birth weights were recorded on 94 lambs from naturally mated ewes and 117 transfer lambs. Two analyses were done, one on observed weights, and one on deviations of observed weights from weights predicted from litter...

Chick embryo fibroblasts infected with Rous sarcoma virus in vitro are rendered malignant for such cells produce typical Rous sarcomas when injected into susceptible chicks since the tumors produced predominantly retain the sex chromatin patterns of the donor cells when such cells are injected into a recipient of the opposite sex. However, examination of the sex chromatin of cells at the periph...

Embryonic stem cells (ESCs) have the potential to be used as unlimited resources for tissue replacement therapy, thereby compensating for organ donor shortage. To reach this goal, the molecular principles governing early differentiation events in the developing embryo need to be addressed, understood and properly implemented in vitro. Studies carried out in several vertebrate models have establ...

The relationship between embryo and corpus luteum was studied in an experiment on Barbari goats which were made unilaterally pregnant by embryo transfer 5 days after oestrus. Two embryos were transferred to each recipient whose luteal stage was coinciding with that of the donor. The site of transfer was either ipsilateral uterine horn (group I) or contralateral uterine horn (group II). The "ips...

Evidence indicates low potential for transmission of pathogens with in vivo-derived embryos of cattle when appropriate precautions are taken. In apparent contrast, results of research with in vivo-derived embryos of small ruminants and swine and with in vitro-derived embryos of cattle suggest a greater tendency for their association with pathogens after artificial exposure. However, regardless ...

Domestic animals can be cloned using techniques such as embryo splitting and nuclear transfer to produce genetically identical individuals. Although embryo splitting is limited to the production of only a few identical individuals, nuclear transfer of donor nuclei into recipient oocytes, whose own nuclear DNA has been removed, can result in large numbers of identical individuals. Moreover, clon...

Double-nasal and double-temporal compound eyes were constructed in Xenopus embryos at stages 32 and 37/38. A particular half was removed from the host eye anlage and replaced with the opposite half-eye from the contralateral side of a donor embryo. Control operations consisted of removing a half-eye and replacing it with a similar half from the ipsilateral side of the donor embryo. Whereas in c...

Investigations in the rat model of pregnancy indicate an important role for the corpus luteal (CL) hormone relaxin in the maternal circulatory and osmoregulatory changes in pregnancy, which are epitomized by profound vasodilation and modest hypoosmolality, respectively. In a pilot study of infertile women who became pregnant through donor eggs, in vitro fertilization and embryo transfer, the ge...

Aggressive chemotherapy generally results in the loss of both endocrine and reproductive functions. If the patient has not undergone previous oocyte, embryo or ovarian tissue cryopreservation, orthotopic allotransplantation of fresh ovarian tissue from a genetically non-identical sister may be considered. Here, we describe a case report. The patient, aged 15 years and presenting with homozygous...