A5050826731- Hypothalamic control of reproductive hormones
- Effects and risks of endocrine disrupting chemicals
- Reproductive Physiology in Livestock
- Toxic Organic Pollutants Impact
- Birth, Development, and Health
- Growth Hormone and Insulin-like Growth Factors
- Ovarian function and disorders
- Animal Behavior and Reproduction
- Estrogen and related hormone effects
- Avian ecology and behavior
- Sperm and Testicular Function
- Plant Pathogens and Resistance
- Animal Behavior and Welfare Studies
- Reproductive Biology and Fertility
- Plant Pathogens and Fungal Diseases
- Neuropeptides and Animal Physiology
- Neuroendocrine regulation and behavior
- Plant Disease Resistance and Genetics
- Carcinogens and Genotoxicity Assessment
- Fungal Plant Pathogen Control
- Effects of Environmental Stressors on Livestock
- Genetic and phenotypic traits in livestock
- Agriculture, Plant Science, Crop Management
- Plant and animal studies
- Wheat and Barley Genetics and Pathology
University of Glasgow
2015-2025
Institute of Biological, Environmental and Rural Sciences
2022
Institute for Biodiversity
2022
Département Santé Animale
2012-2022
University of the Punjab
2021
University of Aberdeen
2015-2019
Natural Environment Research Council
2015
NOAA National Marine Fisheries Service Alaska Fisheries Science Center
2014
U.S. Geological Survey, Alaska Science Center
2014
North Dakota State University
2014
Acute stress triggers peripheral vasoconstriction, causing a rapid, short-term drop in skin temperature homeotherms. We tested, for the first time, whether this response has potential to quantify stress, by exhibiting proportionality with stressor intensity. used established behavioural and hormonal markers: activity level corticosterone level, validate mild more severe form of an acute restraint hens (Gallus gallus domesticus). then infrared thermography (IRT) non-invasively collect...
There is growing international interest in how environmental conditions experienced during development can shape adult phenotypes and the extent to which such induced changes are adaptive. One physiological system that links an individual circumstances hypothalamic-pituitary-adrenal axis. Mammalian studies have linked early postnatal stress later axis; however, link [lactational corticosterone (CORT) transfer] between mother offspring constrains ability determine direct effects of stressors...
Ubiquitous environmental chemicals, including endocrine-disrupting chemicals (EDCs), are associated with declining human reproductive health, as well an increasing incidence of cancers the system. Verifying such links requires animal models exposed to "real-life," environmentally relevant concentrations/mixtures EDC, particularly in utero, when sensitivity EDC exposure is maximal.We evaluated effects maternal a pollutant cocktail (sewage sludge) on ovine fetal neuroendocrine axes, kisspeptin...
Anthropogenic noise is a major pollutant in terrestrial and aquatic ecosystems. Since the industrial revolution, human activities have become increasingly noisy, leading to both acute chronic disturbance of wide variety animals. Chronic exposure can affect animals over their lifespan, changes species interactions likely altering communities. However, community-level impacts are not well-understood, which impairs our ability for effective mitigation. In this review, we address effects on...
Progesterone (P) powerfully inhibits gonadotropin-releasing hormone (GnRH) secretion in ewes, as other species, but the neural mechanisms underlying this effect remain poorly understood. Using an estrogen (E)-free ovine model, we investigated immediate GnRH and luteinizing (LH) response to acute manipulations of circulating P concentrations whether was mediated by nuclear receptor. Simultaneous hypophyseal portal jugular blood samples were collected over 36 hr: 0–12 hr, presence exogenous (P...
It has been proposed that the maternal androgens in avian egg yolk enhance offspring fitness by accelerating growth and improving competitive ability. Because quality is strongly influenced condition, we predicted females good condition would produce high-quality eggs with relatively high androgen content. We experimentally enhanced supplementary feeding lesser black-backed gulls (Larus fuscus) during formation compared concentrations of androstenedione (A4), 5alpha-dihydrotestosterone (DHT)...
An experiment was conducted to investigate the central regulatory effects of estradiol on GnRH secretion leading up preovulatory LH surge in ewe. Midluteal phase ewes were ovariectomized, treated with steroid implants maintain luteal concentrations progesterone and estradiol, fitted an apparatus for collection hypophyseal portal blood. After simulated luteolysis (removal implants), allocated one three groups: withdrawn, maintained at a level, or raised from level peak follicular two...
Increased occurrence of reproductive disorders has raised concerns regarding the impact endocrine-disrupting chemicals on health, especially when such exposure occurs during fetal life. Prenatal testosterone (T) treatment leads to growth retardation, postnatal hypergonadotropism, compromised estradiol-positive feedback, polycystic ovaries, and infertility in adult. dihydrotestosterone failed affect ovarian morphology or suggesting that effects prenatal T may be facilitated via conversion...
Epidemiological studies of the impact environmental chemicals on reproductive health demonstrate consequences exposure but establishing causative links requires animal models using 'real life' in utero exposures. We aimed to determine whether prolonged, low-dose, pregnant sheep a mixture affects fetal ovarian development. Exposure treated ewes (n = 7) pollutants was maximized by surface application processed sewage sludge pasture. Control 10) were reared pasture with inorganic fertilizer....
Stressful conditions early in life can give rise to exaggerated stress responses, which, while beneficial the short term, chronically increase lifetime exposure hormones and elevate disease risk later life. Using zebra finches Taeniopygia guttata , we show here that individuals whose glucocorticoid were experimentally increased for only a brief period post-natal life, inducing sensitivity, had reduced adult lifespans. Remarkably, breeding partners of such exposed also died at younger age....
This study was designed to test the hypothesis that endogenous opioid peptides (EOP) mediate negative feedback action of estradiol on GnRH pulse size in breeding season ewes. If this is correct, one would predict an EOP antagonist should increase estradiol-treated ovariectomized (OVX+E), but not OVX, We, therefore, examined effects naloxone profiles hypophyseal portal blood OVX and OVX+E ewes (n = 6/group). Samples were collected every 10 min for 6 h before, during, 4 after infusion....
Previous studies indicate an elevation of circulating progesterone blocks the positive feedback effect a rise in estradiol. This explains absence gonadotropin surges luteal phase menstrual or estrous cycle despite occasional rises estradiol to concentration sufficient for surge induction. Recent demonstrate initiates LH sheep by inducing large GnRH secretion, measurable hypophyseal portal vasculature. We tested hypothesis that estradiol-induced and FSH preventing this surge. Adult Suffolk...
Abstract Two experiments were performed to examine the temporal requirements of estradiol signal for GnRH and LH surges in ewe. Hypophyseal portal jugular blood (to measure LH, respectively) sampled from ewes set up an artificial follicular phase model. After progesterone withdrawal simulate luteolysis, circulating was raised a preovulatory level by inserting implants, which then removed at different times vary duration. The objective first experiment assess effect withdrawing surge onset on...
Effects of pretreatment Brassica napus leaves with ascospores Leptosphaeria biglobosa or chemical defence activators [acibenzolar‐ S ‐methyl (ASM) menadione sodium bisulphite (MSB)] on infection by maculans (phoma stem canker) and development disease were studied in controlled‐environment leaf spot) field spot experiments. In experiments, oilseed rape (cv. Madrigal) L. , ASM MSB delayed the appearance phoma lesions. These pretreatments also decreased lesion area both pretreated (local...
The present studies tested the hypothesis that either short or ultrashort loop negative feedback regulation of gonadotropin-releasing hormone (GnRH) secretion occurs in ewe. As part ongoing investigating follicle-stimulating-hormone secretion, we obtained unexpected result a GnRH antagonist (Nal-Glu) may stimulate secretion. In experiment, hypophyseal portal blood was collected from five short-term ovariectomized ewes at 5-min intervals for 6 h before and after intravenous injection Nal-Glu...
Quantitative resistance to Leptosphaeria maculans in Brassica napus was investigated field and controlled environments using cultivars Darmor (with quantitative resistance) Eurol (without resistance). In experiments, numbers of phoma leaf spot lesions autumn/winter severity stem canker the following summer were assessed three growing seasons. There no differences between number autumn/winter. However, cankers less severe on than at harvest summer. controlled‐environment development different...
The role of developmental conditions in shaping adult phenotypes has been the focus a great deal recent work. However, effects early life stress on reproductive performance have little studied, particularly avian species. In addition, although there is large body evidence to suggest that prevailing environmental are linked changes breeding behavior, very work investigated interaction between past and current exposure determining success. this study, we examined elevated hormone levels...
Summary Exposure to ubiquitous, environmental chemicals (ECs) has been hypothesized as a cause for declining male reproductive health. Understanding the long‐term effects of EC exposure on health in humans requires animal models and ‘real life’, environmentally relevant, mixtures during development, life stage particular sensitivity ECs. The aim this study was evaluate utero post‐natal relevant levels ECs, via sewage sludge application pasture, adult sheep testis. Hormones, liver...
Anthropogenic pollutants comprise a wide range of synthetic organic compounds and heavy metals, which are dispersed throughout the environment, usually at low concentrations. Exposure ruminants, as for all other animals, is unavoidable while levels exposure to most chemicals too induce any physiological effects, combinations can act additively or synergistically perturb multiple systems ages but particularly in developing foetus. In sheep, organs affected by pollutant include ovary, testis,...