Lipid content, active mitochondria and brilliant cresyl blue staining in bovine oocytes.

Bovine oocytes that stain with brilliant cresyl blue (BCB) have a relatively higher developmental competence. The aim of the present study was to investigate the relationships among BCB staining, lipid content, and active mitochondria. Bovine oocytes (N = 133) with at least three layers of cumulus cells were segregated as BCB retained (BCB+) or metabolized (BCB-) and then stained for active mitochondria (Mitotracker Red) and lipid (Bodipy), with analysis by confocal microscopy.

The sound of arousal in music is context-dependent.

Humans, and many non-human animals, produce and respond to harsh, unpredictable, nonlinear sounds when alarmed, possibly because these are produced when acoustic production systems (vocal cords and syrinxes) are overblown in stressful, dangerous situations. Humans can simulate nonlinearities in music and soundtracks through the use of technological manipulations. Recent work found that film soundtracks from different genres differentially contain such sounds.

In vitro manipulation of mammalian preimplantation embryos can alter transcript abundance of histone variants and associated factors.

Manipulation of mammalian embryos and gametes in vitro reduces viability. Specific causes for these reductions are still largely undetermined. Accumulating evidence suggests that survival rates and developmental competency may be reduced following disruptions in the epigenetic regulation of gene expression.

Expression of genes coding for histone variants and histone-associated proteins in pluripotent stem cells and mouse preimplantation embryos.

The histone code is an epigenetic regulatory system thought to play a crucial role in cellular events such as development, differentiation and in the maintenance of pluripotency. In order to gain an insight into the role variant histones may play during mammalian development; we studied gene expression of histone variants and remodelling enzymes in mouse embryonic stem (ES) cells and during mouse preimplantation development. Using quantitative reverse-transcription PCR (qRT-PCR) we document the gene expression pattern of 12 histone variants and 2 of their associated remodelling enzymes in undifferentiated ES cells and during preimplantation embryo development.

Do film soundtracks contain nonlinear analogues to influence emotion?

A variety of vertebrates produce nonlinear vocalizations when they are under duress. By their very nature, vocalizations containing nonlinearities may sound harsh and are somewhat unpredictable; observations that are consistent with them being particularly evocative to those hearing them. We tested the hypothesis that humans capitalize on this seemingly widespread vertebrate response by creating nonlinear analogues in film soundtracks to evoke particular emotions.

Glucose deprivation, oxidative stress and peroxisome proliferator-activated receptor-alpha (PPARA) cause peroxisome proliferation in preimplantation mouse embryos.

Ex vivo two-cell mouse embryos deprived of glucose in vitro can develop to blastocysts by increasing their pyruvate consumption; however, zygotes when glucose-deprived cannot adapt this metabolic profile and degenerate as morulae. Prior to their death, these glucose-deprived morulae exhibit upregulation of the H+-monocarboxylate co-transporter SLC16A7 and catalase, which partly co-localize in peroxisomes. SLC16A7 has been linked to redox shuttling for peroxisomal beta-oxidation.

Characterization and regulation of monocarboxylate cotransporters Slc16a7 and Slc16a3 in preimplantation mouse embryos.

Concurrent with compaction, preimplantation mouse embryos switch from the high pyruvate consumption that prevailed during cleavage stages to glucose consumption against a constant background of pyruvate uptake. However, zygotes exposed to and subsequently deprived of glucose can form blastocysts by increasing pyruvate uptake. This metabolic switch requires cleavage-stage exposure to glucose and is one aspect of metabolic differentiation that normally occurs in vivo.

Nutrient sensing by the early mouse embryo: hexosamine biosynthesis and glucose signaling during preimplantation development.

Although mouse oocytes and cleavage-stage embryos are unable to utilize glucose as a metabolic fuel, they have a specific requirement for a short exposure to glucose prior to compaction. The reason for this requirement has been unclear. In this study we confirm that cleavage-stage exposure to glucose is required for blastocyst formation and show that the absence of glucose between 18-64 h after hCG causes an irreversible decrease in cellular proliferation and an increase in apoptosis.

IGF-I and insulin activate mitogen-activated protein kinase via the type 1 IGF receptor in mouse embryonic stem cells.

Although IGF-I and insulin are important modulators of preimplantation embryonic physiology, the signalling pathways activated during development remain to be elucidated. As a model of preimplantation embryos, pluripotent mouse embryonic stem cells were used to investigate which receptor mediated actions of physiological concentrations of IGF-I and insulin on growth measured by protein synthesis. Exposure of mouse embryonic stem (ES) cells to 1.

Glucose affects monocarboxylate cotransporter (MCT) 1 expression during mouse preimplantation development.

Cleavage-stage embryos have an absolute requirement for pyruvate and lactate, but as the morula compacts, it switches to glucose as the preferred energy source to fuel glycolysis. Substrates such as glucose, amino acids, and lactate are moved into and out of cells by facilitated diffusion. In the case of lactate and pyruvate, this occurs via H+-monocarboxylate cotransporter (MCT) proteins.

Insulin acts via mitogen-activated protein kinase phosphorylation in rabbit blastocysts.

The addition of insulin during in vitro culture has beneficial effects on rabbit preimplantation embryos leading to increased cell proliferation and reduced apoptosis. We have previously described the expression of the insulin receptor (IR) and the insulin-responsive glucose transporters (GLUT) 4 and 8 in rabbit preimplantation embryos. However, the effects of insulin on IR signaling and glucose metabolism have not been investigated in rabbit embryos.

Identification of the facilitative glucose transporter 12 gene Glut12 in mouse preimplantation embryos.

In this study we report the cloning and characterisation of the mouse Glut12 gene and examine for the first time its expression pattern in the earliest stages of development. Mouse Glut12 (mGlut12) was cloned from preimplantation embryos by 5'RACE RT-PCR using primers designed from an EST clone corresponding to a human GLUT12 antigenic sequence after positive immunoreactivity was observed in mouse two-cell embryos by western immunoblotting. The mGlut12 gene contains an open reading frame of 1869 base pairs, potentially encoding a polypeptide of 622 amino acids.