Identifying the composition of large vesicles in the cytoplasm of oocytes.

Context Oocyte vesicles, or vacuoles, have been described using transmission electron microscopy in most species. In sheep and cow oocytes, vesicles constitute up to 30% of the cytoplasm, their volume decreases during maturation and is lower in poorer quality oocytes, suggesting they are important for oocyte competence. However, the composition and function of these organelles is unknown.

The role of the oviduct environment in embryo survival.

Context: Declining fertility is an issue in multiple mammalian species. As the site of fertilisation and early embryo development, the oviduct plays a critical role in embryo survival, yet there is a paucity of information on how the oviduct regulates this process.

Aims: We hypothesised that differences in steroid hormone signalling and/or immune function would be observed in a model of poor embryo survival, the peripubertal ewe.

Activin B and Activin C Have Opposing Effects on Prostate Cancer Progression and Cell Growth.

Current prognostic and diagnostic tests for prostate cancer are not able to accurately distinguish between aggressive and latent cancer. Members of the transforming growth factor-β (TGFB) family are known to be important in regulating prostate cell growth and some have been shown to be dysregulated in prostate cancer. Therefore, the aims of this study were to examine expression of TGFB family members in primary prostate tumour tissue and the phenotypic effect of activins on prostate cell growth.

High pressure frozen oocytes have improved ultrastructure but reduced cleavage rates compared to conventionally fixed or vitrified oocytes.

Context: Live birth rates are lower for cryopreserved oocytes than for fresh IVF cycles, indicating a need for improved methodologies.

Aims: The aim of this study was to determine if high pressure freezing (HPF) could improve both ultrastructural preservation and cryopreserved oocyte quality when compared to conventional fixation and vitrification methods.

Methods: Sheep oocytes and embryos were prepared by HPF or vitrification, with or without cryoprotectants.

A schizophrenia risk factor induces marked anatomical deficits at GABAergic-dopaminergic synapses in the rat ventral tegmental area: Essential evidence for new targeted therapies.

To develop new therapies for schizophrenia, evidence accumulated over decades highlights the essential need to investigate the GABAergic synapses that presynaptically influence midbrain dopaminergic neurons. Since current technology restricts these studies to animals, and evidence accumulated in recent decades indicates a developmental origin of schizophrenia, we investigated synaptic changes in male rat offspring exposed to maternal immune activation (MIA), a schizophrenia risk factor. Using a novel combination of lentiviruses, peroxidase-immunogold double labeling, three-dimensional serial section transmission electron microscopy and stereology, we observed clear anatomical alterations in synaptic inputs on dopaminergic neurons in the midbrain posterior ventral tegmental area (pVTA).