Treatment of fetal fibroblasts with DNA methylation inhibitors and/or histone deacetylase inhibitors improves the development of porcine nuclear transfer-derived embryos.

This study investigated whether treating fetal fibroblast cells (donor cells) with epigenetic modification-inducing drugs could improve the development of porcine cloned embryos. Donor cells were treated with different DNA methylation inhibitors (5-aza-dC, zebularine or RG108; 5nM) or histone deacetylase inhibitors (TSA, NaBu or SCR; 50nM) for 1h, and then subjected to SCNT. All of the treated groups showed significantly higher blastocyst formation rates compared to the control group.

Halogenated nucleotide labeling of nascent RNAs reveals dynamic transcription in growing pig oocytes.

Background: Germ cells differentiate into oocytes in females and are arrested at the first meiotic prophase. However, during arrest, oocytes undergo a growth phase leading to a dramatic increase in size, which is under control of transcription events. In the current study, we examined the transcriptional activity of growing pig oocytes using an immunocytochemical approach.

Detection of early pregnancy-specific proteins in Holstein milk.

Bovine pregnancy is commonly diagnosed by rectal palpation or ultrasonography and changes in progesterone concentration. To determine a simpler and less expensive diagnostic method, we sought to identify early pregnancy-specific proteins in bovine milk by comparing samples collected from pregnant and non-pregnant Holstein cattle. Of the 600-700 protein spots visible on 2-DE gel images, 39 were differentially expressed in milk from pregnant and non-pregnant cattle.

Effect of endoplasmic reticulum stress on porcine oocyte maturation and parthenogenetic embryonic development in vitro.

X-box-binding protein 1 (XBP1) is an important regulator of a subset of genes active during endoplasmic reticulum (ER) stress. In the present study, we analyzed XBP1 level and location to explore the effect of ER stress on oocyte maturation and developmental competency of porcine embryos in an in vitro culture system. First, we examined the localization of XBP1 at different meiotic stages of porcine oocytes and at early stages of parthenogenetic embryo development.

Cardiovascular risk assessment of atypical antipsychotic drugs in a zebrafish model.

The zebrafish model has been developed and evaluated for its ability to predict the toxicity of chemicals. Zebrafish additionally serve as an excellent model for assessing drug-induced cardiotoxicity, although zebrafish and mammalian hearts differ in structure. Recently, regulatory authorities have expressed concerns about a possible relationship between antipsychotics and risk of QTc interval prolongation, serious arrhythmia and sudden cardiac death.

Epigenetic characterization of the PBEF and TIMP-2 genes in the developing placentae of normal mice.

Reprogramming errors, which appear frequently in cloned animals, are reflected by aberrant gene expression. We previously reported the aberrant expression of TIMP-2 and PBEF in cloned placenta and differential expression of PBEF genes during pregnancy. To examine the epigenetic modifications that regulate dynamic gene expression in developing placentae, we herein analyzed the mRNA and protein expression levels of PBEF and TIMP-2 in the placentae of normal mice during pregnancy and then examined potential correlations with epigenetic modifications.

Aberrant protein expression in the placenta of cloned mouse derived from embryonic stem cell.

Placentomegaly is a common phenotype in cloned mice. To assess differences in protein expression between placentae of cloned and uncloned mice, we used a proteomic approach involving 2-dimensional electrophoresis (DE) and MALDI-TOF MS. Proteins within isoelectric point range of 4-11 separately were analyzed in 2-DE with 3 replications of each sample.

A two-dimensional electrophoresis reference map for the bovine placenta during late pregnancy.

An understanding of bovine placental gene expression is essential for the study of animal reproductive physiology. Recent reports have found that placental abnormalities occur frequently in cloned bovines and mice. However, the molecular mechanisms underlying bovine placenta function remain unclear.