Relationship of neuropeptide FF receptors with pubertal maturation of gilts.

Mechanisms governing the timing of puberty in pigs are poorly understood. A genome-wide association study for age at first estrus in pigs identified candidate genes including neuropeptide FF receptor 2 (NPFFR2), which is a putative receptor for RFamide-related peptides (RFRP). RFRP has been shown to negatively regulate secretion of reproductive hormones from hypothalamic and pituitary tissue of pigs in culture.

Gene expression profiling in adipose tissue from growing broiler chickens.

In this study, total RNA was collected from abdominal adipose tissue samples obtained from ten broiler chickens at 3, 4, 5, and 6 weeks of age and prepared for gene microarray analysis with Affymetrix GeneChip Chicken Genome Arrays (Affymetrix) and quantitative real-time PCR analysis. Studies of global gene expression in chicken adipose tissue were initiated since such studies in many animal species show that adipose tissue expresses and secretes many factors that can influence growth and physiology. Microarray results indicated 333 differentially expressed adipose tissue genes between 3 and 6 wk, 265 differentially expressed genes between 4 and 6 wk and 42 differentially expressed genes between 3 and 4 wk.

Effects of nesfatin-1 on food intake and LH secretion in prepubertal gilts and genomic association of the porcine NUCB2 gene with growth traits.

Nesfatin-1, a product of the nucleobindin 2 (NUCB2) gene, purportedly plays important roles in whole-body energy homeostasis. Experiments were conducted to determine how NUCB2 expression in fat depots may be controlled in the pig and to test the hypothesis that nesfatin-1 regulates appetite and LH secretion in the gilt. Prepubertal gilts were used to study expression of NUCB2 in fat and the effects of intracerebroventricular (i.

Leptin and reproductive function.

Adipose tissue plays a dynamic role in whole-body energy homeostasis by acting as an endocrine organ. Collective evidence indicates a strong link between neural influences and adipocyte expression and secretion of leptin. Developmental changes in these relationships are considered important for pubertal transition in reproductive function.

Expression of genes for interleukins, neuropeptides, growth hormone receptor, and leptin receptor in adipose tissue from growing broiler chickens.

In this study, total RNA was collected from abdominal adipose tissue samples obtained from 10 broiler chickens at 3, 4, 5, and 6 wk of age and prepared for quantitative real-time PCR analysis. Quantitative real-time PCR analysis was used to examine the influence of age on the expression of the adipose tissue genes for IL-1β, -6, -10, -15, -18; brain-derived neurotropic factor; ciliary neurotropic factor; interferon γ, neuropeptide Y receptor Y1; neuropeptide Y; nucleobindin 2; growth hormone receptor; leptin receptor; and visfatin. Between 3 and 6 wk of age, leptin receptor expression decreased (P=0.

Gene expression profiling in developing pig adipose tissue: non-secreted regulatory proteins.

The expression of many genes encoding secreted and non-secreted factors have been studied in human and rodent adipose tissue with cDNA microarrays, but few such studies in adipose tissue from growing pigs have been reported. Total RNA was collected at slaughter from outer subcutaneous adipose tissue (OSQ) and middle subcutaneous adipose tissue (MSQ) samples from gilts at 90, 150 and 210 days (n = 5/age). Dye-labeled cDNA probes were hybridized to custom microarrays (70-mer oligonucleotides) representing about 600 pig genes involved in growth and reproduction.

Effects of organic selenium supplementation on growth performance, carcass measurements, tissue selenium concentrations, characteristics of reproductive organs, and testis gene expression profiles in boars.

The objective was to compare growth and physiological responses in boars fed diets supplemented with organic or inorganic sources of Se. At weaning, crossbred boars (n = 117; 8.3 kg of BW) were placed in nursery pens (3 boars/pen) and assigned within BW blocks to receive on an ad libitum basis 1 of 3 dietary treatments: I) basal diets with no supplemental Se (controls), II) basal diets supplemented with 0.

Luteinizing hormone secretion as influenced by age and estradiol in the prepubertal gilt.

The aim of this study was to determine if there is an age related reduction in the sensitivity of the negative feedback action of 17β-estradiol (estradiol) on luteinizing hormone (LH) secretion in the prepubertal gilt. Ovariectomized gilts at 90 (n=12), 150 (n=11) or 210 (n=12) days of age received estradiol benzoate (EB) osmotic pump implants 6/group and the remaining animals received vehicle control (C) implants except for 150-day C (n=5) on Day 0. On Day 10 blood samples were collected every 15 min for 8h and serum LH and estradiol concentrations were measured.

Adipose tissue and the reproductive axis: biological aspects.

The discovery of leptin has clearly demonstrated a relationship between body fat and the neuroendocrine axis since leptin influences appetite and the reproductive axis. Since adipose tissue is a primary source of leptin, adipose tissue is no longer considered as simply a depot to store fat. Recent findings demonstrate that numerous other genes, i.

Gene expression in hypothalamus, liver, and adipose tissues and food intake response to melanocortin-4 receptor agonist in pigs expressing melanocortin-4 receptor mutations.

Transcriptional profiling was used to identify genes and pathways that responded to intracerebroventricular injection of melanocortin-4 receptor (MC4R) agonist [Nle(4), d-Phe(7)]-α-melanocyte stimulating hormone (NDP-MSH) in pigs homozygous for the missense mutation in the MC4R, D298 allele (n = 12), N298 allele (n = 12), or heterozygous (n = 12). Food intake (FI) was measured at 12 and 24 h after treatment. All pigs were killed at 24 h after treatment, and hypothalamus, liver, and back-fat tissue was collected.

Effect of naloxone treatment on luteinizing hormone and testosterone concentrations in boars with high and low libido.

The objective was to determine the effects of the opioid peptide receptor antagonist, naloxone on circulating concentrations of luteinizing hormone (LH) and testosterone in boars characterized as having high (n=8) or low libido (n=8) based on the willingness to mount an artificial sow and allow semen collection. On the day of the experiment, blood was sampled every 15 min for 4 h before and 4 h after i.v.

Gene expression profiling of the short-term adaptive response to acute caloric restriction in liver and adipose tissues of pigs differing in feed efficiency.

Residual feed intake (RFI) is a measure of feed efficiency, in which low RFI denotes improved feed efficiency. Caloric restriction (CR) is associated with feed efficiency in livestock species and to human health benefits, such as longevity and cancer prevention. We have developed pig lines that differ in RFI, and we are interested in identifying the genes and pathways that underlie feed efficiency.

Insulin-like growth factor-I feedback regulation of growth hormone and luteinizing hormone secretion in the pig: evidence for a pituitary site of action.

Three experiments (EXP) were conducted to determine the role of insulin-like growth factor-I (IGF-I) in the control of growth hormone (GH) and LH secretion. In EXP I, prepuberal gilts, 65 ± 6 kg body weight and 140 days of age received intracerebroventricular (ICV) injections of saline (n = 4), 25 μg (n = 4) or 75 μg (n = 4) IGF-I and jugular blood samples were collected. In EXP II, anterior pituitary cells in culture collected from 150-day-old prepuberal gilts (n = 6) were challenged with 0.

Microarray gene expression profiles of fasting induced changes in liver and adipose tissues of pigs expressing the melanocortin-4 receptor D298N variant.

Transcriptional profiling coupled with blood metabolite analyses were used to identify porcine genes and pathways that respond to a fasting treatment or to a D298N missense mutation in the melanocortin-4 receptor (MC4R) gene. Gilts (12 homozygous for D298 and 12 homozygous for N298) were either fed ad libitum or fasted for 3 days. Fasting decreased body weight, backfat, and serum urea concentration and increased serum nonesterified fatty acid.

Energy metabolism and leptin: effects on neuroendocrine regulation of reproduction in the gilt and sow.

It is well established that reproductive function is metabolically gated. However, the mechanisms whereby energy stores and metabolic cues influence appetite, energy homeostasis and fertility are yet to be completely understood. Adipose tissue is no longer considered as only a depot to store excess energy.

Central and peripheral administration of kisspeptin activates gonadotropin but not somatotropin secretion in prepubertal gilts.

It is well established that kisspeptin signaling is necessary for the onset of puberty in laboratory animals. However, the role that kisspeptin may have in regulating puberty in large domestic animals is unknown. We tested the hypothesis that either central or peripheral infusion of kisspeptin would stimulate gonadotropin and GH secretion in prepubertal gilts.

Patterns of gene expression in pig adipose tissue: insulin-like growth factor system proteins, neuropeptide Y (NPY), NPY receptors, neurotrophic factors and other secreted factors.

Although cDNA microarray studies have examined gene expression in human and rodent adipose tissue, only one microarray study of adipose tissue from growing pigs has been reported. Total RNA was collected at slaughter from outer subcutaneous adipose tissue (OSQ) and middle subcutaneous adipose tissue (MSQ) from gilts at 90, 150, and 210 d (n=5 age(-1)). Dye labeled cDNA probes were hybridized to custom porcine microarrays (70-mer oligonucleotides).

Hypothalamic neurons innervating fat tissue in the pig express leptin receptor immunoreactivity.

While leptin receptors have been found in both the autonomic ganglion neurons and the hypothalamic nuclei, studies dealing with the projections from the central nervous system to the adipose tissue have been conducted mainly in laboratory animals. Therefore, the purpose of our study was to establish whether hypothalamic neurons are transsynaptically connected to adipose tissue depots in the pig, and if these neurons express leptin receptor immunoreactivity. Pseudorabies virus (PRV; Bartha's K strain) was introduced in perirenal or subcutaneous adipose tissue depots in domestic pigs.

Patterns of gene expression in pig adipose tissue: transforming growth factors, interferons, interleukins, and apolipoproteins.

Although cDNA microarray studies have indicated the expression of unique and unexpected genes and their products in human and rodent adipose tissue, cDNA microarray studies of adipose tissue from growing pigs have not been reported. Total RNA was collected at slaughter from outer s.c.

Gene expression in the brain-pituitary adipose tissue axis and luteinising hormone secretion during pubertal development in the gilt.

The occurrence of puberty in the female is due to the interplay of central and peripheral mechanisms in which the hypothalamic-pituitary-ovarian axis regulates growth and gonadal function, as well as adipocyte hormone secretion. Hypothalamic GnRH mRNA expression increased at 3.5 months of age and declined by 6 months of age.

Secreted proteins and genes in fetal and neonatal pig adipose tissue and stromal-vascular cells.

Although microarray and proteomic studies have indicated the expression of unique and unexpected genes and their products in human and rodent adipose tissue, similar studies of meat animal adipose tissue have not been reported. Thus, total RNA was isolated from stromal-vascular (S-V) cell cultures (n = 4; 2 arrays; 2 cultures/array) from 90-d (79% of gestation) fetuses and adipose tissue from 105-d (92% of gestation) fetuses (n = 2) and neonatal (5-d-old) pigs (n = 2). Duplicate adipose tissue microarrays (n = 4) represented RNA samples from a pig and a fetus.

The role of neuropeptide Y and interaction with leptin in regulating feed intake and luteinizing hormone and growth hormone secretion in the pig.

Two experiments (EXP) were conducted in ovariectomized prepubertal gilts to test the hypothesis that neuropeptide Y (NPY) stimulates appetite and modulates LH and GH secretion, and that leptin modifies such acute effects of NPY on feeding behavior and LH and GH secretion. In EXP I, gilts received intracerebroventricular (ICV) injections of 0.9% saline (saline; n = 6), or 10 microg (n = 7), 50 microg (n = 5) or 100 microg (n = 7) NPY in saline and blood samples were collected.

Neuropeptide Y modulates growth hormone but not luteinizing hormone secretion from prepuberal gilt anterior pituitary cells in culture.

Pituitary cells, from seven 160- to 170-day-old pigs, were studied in primary culture to determine the affects NPY on LH and GH secretion at the level of the pituitary. On day 4 of culture, medium was discarded, plates were rinsed twice with serum-free medium and cells were cultured in 1 ml fresh medium without serum and challenged individually with 10(-10), 10(-8) or 10(-6) M [Ala(15)]-h growth hormone-releasing factor-(1-29)NH(2) (GRF); 10(-9), 10(-8) or 10(-7) M GnRH or 10(-9), 10(-8), 10(-7) or 10(-6) M NPY individually or in combinations with 10(-9) or 10(-8) M GnRH or 10(-8) or 10(-6)M GRF. Cells were exposed to treatment for 4 h at which time medium was harvested and quantified for LH and GH.

Leptin: a metabolic signal affecting central regulation of reproduction in the pig.

The discovery of the obesity gene and its product, leptin, it is now possible to examine the relationship between body fat and the neuroendocrine axis. A minimum percentage of body fat may be linked to onset of puberty and weaning-to-estrus interval in the pig. Adipose tissue is no longer considered as only a depot to store excess energy in the form of fat.

The control of adenohypophysial hormone secretion by amino acids and peptides in swine.

Several different amino acids and peptides control secretion of adenohypophysial hormones and this control may be indirect, via the modulation of hypothalamic hormone secretion. Indeed, classical hypothalamic hormones (e.g.