Rowett Research Institute

About: Rowett Research Institute is a based out in . It is known for research contribution in the topics: Rumen & Population. The organization has 2986 authors who have published 4459 publications receiving 239472 citations.

Hypothalamic gene expression in sheep for cocaine- and amphetamine-regulated transcript, pro-opiomelanocortin, neuropeptide Y, agouti-related peptide and leptin receptor and responses to negative energy balance.

Abstract: Hypothalamic pathways involved in the regulation of energy balance have not been widely studied in ruminants to date. Here, we used in situ hybridisation to study the gene expression of a number of leptin-sensitive receptors and neuropeptides in the ovine hypothalamus. Gene expression was first localised for cocaine- and amphetamine-regulated transcript (CART) and agouti-related peptide (AGRP). We then examined in adult male castrated sheep the effects of acute negative energy balance induced by a 4-day fast on the amounts of these mRNAs and those for leptin receptor (OB-Rb), neuropeptide Y (NPY) and pro-opiomelanocortin (POMC). CART mRNA was localised in the arcuate nucleus (ARC), paraventricular nucleus, median eminence and ventromedial hypothalamic nucleus, and extensive co-localisation with POMC mRNA was demonstrated in the ARC. AGRP mRNA was localised in the ARC. Fasting up-regulated gene expression for OB-Rb and for the orexigenic neuropeptides NPY and AGRP in the ARC. There was a trend towards down-regulation of gene expression for the anorexigenic neuropeptide CART and no effect on POMC in the ARC, although these results are inconclusive. The presence or absence of oestradiol-containing subcutaneous implants did not influence gene expression or the effects of fasting. The hypothalamic changes were consistent with responses to the observed reduction in circulation leptin and suggest that the peripheral feedback and central mechanisms for restoring the energy balance may be largely conserved across monogastric and ruminant species.

The interactions between selenium and iodine deficiencies in man and animals.

Abstract: Up to one billion people live in areas where they may be at risk from I deficiency. Many of the debilitating effects of the deficiency may be irreversible, consequently it is essential to understand the mechanisms whereby lack of I can cause disease through decreased thyroxine and 3, 3',5-triiodothyronine (T3) synthesis. Since Se has an essential role in thyroid hormone metabolism, it has the potential to play a major part in the outcome of I deficiency. These effects of Se derive from two aspects of its biological function. First, three Se-containing deiodinases regulate the synthesis and degradation of the biologically active thyroid hormone, T3. Second, selenoperoxidases and possibly thioredoxin reductase (EC 1.6.4.5) protect the thyroid gland from H2O2 produced during the synthesis of thyroid hormones. The mechanisms whereby Se deficiency exacerbates the hypothyroidism due to I deficiency have been elucidated in animals. In contrast to these adverse effects, concurrent Se deficiency may also cause changes in deiodinase activities which can protect the brain from low T3 concentrations in I deficiency. Animals with Se and I deficiency have changes in serum thyroid hormone concentrations that are similar to those observed in patients with I deficiency disease. However such animal models show no thyroid involution, a feature which is characteristic of myxoedematous cretinism in man. These observations imply that if Se deficiency is involved in the outcome of I deficiency in human populations it is likely that other interacting factors such as goitrogens are also implicated. Nevertheless the protection of the thyroid gland from H2O2 and the regulation of tissue T3 levels are the functions of Se that are most likely to underlie the interactions of Se and I.

Distribution of specific tetracycline and erythromycin resistance genes in environmental samples assessed by macroarray detection.

Abstract: A macroarray system was developed to screen environmental samples for the presence of specific tetracycline (Tc(R)) and erythromycin (erm(R)) resistance genes. The macroarray was loaded with polymerase chain reaction (PCR) amplicons of 23 Tc(R) genes and 10 erm(R) genes. Total bacterial genomic DNA was extracted from soil and animal faecal samples collected from different European countries. Macroarray hybridization was performed under stringent conditions and the results were analysed by fluorescence scanning. Pig herds in Norway, reared without antibiotic use, had a significantly lower incidence of antibiotic resistant bacteria than those reared in other European countries, and organic herds contained lower numbers of resistant bacteria than intensively farmed animals. The relative proportions of the different genes were constant across the different countries. Ribosome protection type Tc(R) genes were the most common resistance genes in animal faecal samples, with the tet(W) gene the most abundant, followed by tet(O) and tet(Q). Different resistance genes were present in soil samples, where erm(V) and erm(E) were the most prevalent followed by the efflux type Tc(R) genes. The macroarray proved a powerful tool to screen DNA extracted from environmental samples to identify the most abundant Tc(R) and erm(R) genes within those tested, avoiding the need for culturing and biased PCR amplification steps.