(Changes in polyamines associated with zygotic embryogenesis in the Brazilian pine, Araucaria angustifolia (Bert.) O. Ktze.). Changes in the polyamine content were analyzed in different embryo developmental stages and tissues during seed development in the conifer Araucaria angustifolia (Bert.) O. Ktze. Free polyamine contents varied according to the tissue and stage of embryo development, the ...

The aim of this study was to gain insight into whether the first trimester embryo could control its own heart rate (HR) in response to hypoxia. The gestational day 13 rat embryo is a good model for the human embryo at 5-6 weeks gestation, as the heart is comparable in development and, like the human embryo, has no functional autonomic nerve supply at this stage. Utilizing a whole-embryo culture...

Advice is provided on five questions that were addressed by subjecting emu eggs, as a model for kiwi eggs, to transport-induced jarring during three stages of embryo development. The jarring associated with two kiwi egg recovery operations was also measured. Jarring during transportation had no demonstrable effect on embryo development, the need for hatching assistance, or the incidence of embr...

Despite the well-known benefits of omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation on human health, relatively little is known about the effect of n-3 PUFA intake on fertility. More specifically, the aim of this study was to determine how oocyte and preimplantation embryo development might be influenced by n-3 PUFA supply and to understand the possible mechanisms underlying thes...

BACKGROUND Sperm of poor quality can negatively affect embryo development to the blastocyst stage. The aim of this comparative prospective randomized study was to evaluate the role of an intracytoplasmic morphologically selected sperm injection (IMSI) in the same infertile couples included in the programme of intracytoplasmic sperm injection (ICSI) due to their indications of male infertility w...

The first events of the development of any embryo are under maternal control until the zygotic genome becomes activated. In the mouse embryo, the major wave of transcription activation occurs at the 2-cell stage, but transcription starts already at the zygote (1-cell) stage. Very little is known about the molecules involved in this process. We show that the transcription intermediary factor 1 a...

BACKGROUND Early mammalian blastomeres are thought to be flexible and totipotent allowing the embryo to overcome perturbations in its organization during preimplantation development. In the past, experiments using single blastomeres from 2-, 4- and 8-cell stage mammalian embryos have provided evidence that at least some of the isolated cells can develop into healthy fertile animals and therefor...

The offspring of brood parasitic birds benefit from hatching earlier than host young. A proposed but little-known strategy to achieve this is 'internal incubation', by retaining the egg in the oviduct for an additional 24 h. To test this, we quantified the stage of embryo development at laying in four brood parasitic birds (European cuckoo, Cuculus canorus; African cuckoo, Cuculus gularis; grea...

We have evaluated the safety of intracytoplasmic sperm injection(ICSI) procedures by using bovine zygotes. Bovine zygotes were injected with a small amount (2-3 pl) of either medium alone or medium containing polyvinylpyrrolidone (PVP) (sham-ICSI, without spermatozoon) using the same procedure as ICSI, and the subsequent in-vitro embryonic development and embryo quality (number of cells/blastoc...