The effect of maternal body condition on in vivo production of zygotes and behavior of delivered offspring in mice.

This study investigated the effects of maternal body condition on oocyte quality and zygote production. Additionally, we examined the possible consequences on somatic parameters and behavior of naturally delivered offspring. We used an experimental model based on overfeeding of outbred mice during intrauterine and early postnatal development to produce the following four types of females: physiological (7%-8%), slightly increased (8%-11%), highly increased (>11%), and low (<7%) body fat content (Echo Magnetic Resonance Imaging).

Amount of maternal body fat significantly affected the quality of isolated mouse preimplantation embryos and slowed down their development.

The aim of our study was to investigate the effect of maternal obesity on the quality and developmental capabilities of in vivo-derived preimplantation embryos. A two-generation dietary model, based on mice overfeeding during intrauterine and early postnatal development, was used to produce four types of female animals: with physiological (7%-8%), slightly elevated (8%-11%), highly elevated (>11%), and low (<7%) amounts of body fat. Spontaneously ovulating females (5-6 weeks old) were mated with male animals and subjected to embryo isolation at Day 4.

Maternal restraint stress negatively influences growth capacity of preimplantation mouse embryos.

In our study we investigated the effect of maternal restraint stress on preimplantation embryo development using a mouse model. We exposed hormonally stimulated (superovulated) and unstimulated (i.e.

Expression of adrenergic receptors in mouse preimplantation embryos and ovulated oocytes.

Epinephrine and norepinephrine can play an important role in basic developmental processes such as embryogenesis and morphogenesis, regulating cell proliferation, differentiation and migration. We showed that beta-adrenergic receptors can mediate the effects of catecholamines on preimplantation embryos in our previous work. In the present study, we designed specific oligonucleotide primers which can distinguish among all members of the alpha-adrenergic receptor family, and showed (using RT-PCR) that the alpha2C-adrenergic receptor is transcribed in ovulated oocytes, 8- to 16-cell morulae and expanded blastocysts.

Expression of beta adrenergic receptors in mouse oocytes and preimplantation embryos.

Accumulating evidence indicates the role of endogenous catecholamines in mammalian embryogenesis. We searched public databases containing nucleotide sequences derived from mouse preimplantation cDNA libraries and found a partial sequence homology between a cDNA clone from mouse blastocysts and the mouse beta 2-adrenergic receptor sequence. No significant sequence homology was found for other mouse adrenergic and dopamine receptors.

Serotonin localization and its functional significance during mouse preimplantation embryo development.

Serotonin is a neurotransmitter functioning also as a hormone and growth factor. To further investigate the biological role of serotonin during embryo development, we analysed serotonin localization as well as the expression of specific serotonin 5-HT1D receptor mRNA in mouse oocytes and preimplantation embryos. The functional significance of serotonin during the preimplantation period was examined by studying the effects of serotonin on mouse embryo development.

Inhibitory effect of IGF-I on induced apoptosis in mouse preimplantation embryos cultured in vitro.

Insulin-like growth factor I (IGF-I) has been shown to promote mammalian early embryo development. Increased cell division or decreased cell death have been proposed as two main possible mechanisms in its effect. Here we examine the nature of this promoting effect in a model situation.

Induced cell death of preimplantation mouse embryos cultured in vitro evaluated by comet assay.

The occurrence of apoptosis in mouse preimplantation embryos was analyzed using DNA staining (Hoechst 33342, PI) for the visualization of nuclear changes and by the comet assay, a single-cell gel electrophoresis assay, modified for the analysis of blastocysts. Mouse preimplantation embryos isolated 56 h after superovulation were cultured in vitro for 64 h. Apoptosis was induced by treatment with camptothecin and actinomycin D during the first 15 h of culture.