Quercetin supplemented diet improves follicular development, oocyte quality, and reduces ovarian apoptosis in rabbits during summer heat stress

2017 ◽  
Vol 96 ◽  
pp. 136-141 ◽  
Author(s):  
Zahid Naseer ◽  
Ejaz Ahmad ◽  
Erkmen Tuğrul Epikmen ◽  
Uğur Uçan ◽  
Murat Boyacioğlu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Follicular Development ◽  
Oocyte Quality ◽  
Summer Heat

scholarly journals Improvement of quality of oocytes collected in the autumn by enhanced removal of impaired follicles from previously heat-stressed cows

Reproduction ◽  
2001 ◽  
pp. 737-744 ◽  
Author(s):  
Z Roth ◽  
A Arav ◽  
A Bor ◽  
Y Zeron ◽  
R Braw-Tal ◽  
...  
Keyword(s):  
Heat Stress ◽  
Embryo Development ◽  
Treated Group ◽  
Oocyte Quality ◽  
Control Group ◽  
Delayed Effect ◽  
Cleavage Rate ◽  
Lactating Cows ◽  
Summer Heat

The fertility of dairy cows decreases during the summer and remains low during the cooler autumn although the animals are no longer under heat stress. The aim of this study was to characterize a delayed effect of summer heat stress on oocyte quality in the autumn and to improve oocyte quality by enhanced removal of follicles damaged during the previous summer. Lactating cows (n = 16) were subjected to heat stress during the summer. In autumn, ovarian follicles (3-7 mm in diameter) were aspirated by an ultrasound-guided procedure during four consecutive oestrous cycles. Follicles were aspirated from control cows on day 4 and from treated cows on days 4, 7, 11 and 15 of each oestrous cycle. All cows received PGF(2alpha) and GnRH injections on days 19 and 21, respectively, and maintained cyclicity, as indicated by plasma progesterone concentrations. On day 4 of each cycle, the oocytes recovered were examined morphologically, matured and activated in vitro, and cultured for 8 days. In cycle 1 (early October) both groups showed low percentages of grade 1 oocytes, cleavage, four- and eight-cell embryos, morulae and parthenogenetic blastocysts. Subsequently, the number of grade 1 oocytes increased earlier (cycle 2) in treated than in control cows (cycle 3; P < 0.05). The cleavage rate in the control group remained relatively low throughout (32-58%), whereas in the treated group it increased from 40% (cycle 1) to 75% (cycles 3 and 4; P < 0.05). The number at each stage of embryo development increased slightly but remained low throughout in the control group, whereas in the treated group significant (P < 0.05) increases of all stages were observed in cycles 3 and 4. The results show a delayed effect of summer heat stress on oocyte quality and embryo development in the autumn. Enhanced removal of the impaired cohort of follicles led to earlier emergence of healthy follicles and high quality oocytes in the autumn.

Evaluation of Follicular Development and Oocyte Quality in Pre-pubertal Cats

2010 ◽  
Vol 45 (6) ◽  
pp. e405-e411 ◽  
Author(s):  
K Uchikura ◽  
M Nagano ◽  
M Hishinuma
Keyword(s):  
Follicular Development ◽  
Oocyte Quality

scholarly journals Large-Scale Metadata Analysis of Ovary Based Multi-Omics Datasets for Understanding the Genes Regulating Litter Size

2020 ◽  
Author(s):  
Ayyappa Kumar Sista Kameshwar ◽  
Julang Li
Keyword(s):  
Gene Expression ◽  
Differentially Expressed Genes ◽  
Litter Size ◽  
Large Scale ◽  
Expression Patterns ◽  
Genetic Selection ◽  
Follicular Development ◽  
Oocyte Quality ◽  
Differentially Expressed ◽  
Metadata Analysis

Abstract Background : Litter size is a very important production index in the livestock industry, which is controlled by various complex physiological processes. To understand and reveal the common gene expression patterns involved in controlling prolificacy, we have performed a large-scale metadata analysis of five genome-wide transcriptome datasets of pig and sheep ovary samples obtained from high and low litter groups, respectively. We analyzed separately each transcriptome dataset using GeneSpring v14.8 software by implementing standard, generic analysis pipelines and further compared the list of most significant and differentially expressed genes obtained from each dataset to identify genes that are found to be common and significant across all the studies. Results : We have observed a total of 62 differentially expressed genes common among more than two gene expression datasets. The KEGG pathway analysis of most significant genes has shown that they are involved in metabolism, the biosynthesis of lipids, cholesterol and steroid hormones, immune system, cell growth and death, cancer-related pathways and signal transduction pathways. Of these 62 genes, we further narrowed the list to the 25 most significant genes by focusing on the ones with fold change >1.5 and p<0.05. These genes are CYP11A1, HSD17B2, STAR, SCARB1, IGSF8, MSMB, SERPINA1 , FAM46C, HEXA, PTTG1, TIMP1, FAM167B, CCNG1, FAXDC2, HMGCS1, L2HGDH, Lipin1, MME, MSMO1, PARM1, PTGFR, SLC22A4, SLC35F5, CCNA2, CENPU, CEP55, RASSF2, and SLC16A3 . Conclusions : Interestingly, comparing the list of genes with the list of genes obtained from our literature search analysis, we found only three genes in common. These genes are HEXA, PTTG1, and TIMP1. Our finding points to the potential of a few genes that may be important for ovarian follicular development and oocyte quality. Future studies revealing the function of these genes will further our understanding of how litter size is controlled in the ovary while also providing insight on genetic selection of high litter gilts.

scholarly journals Role of Melatonin as a Survival Factor for In vitro Development of Sheep Preantral Follicles

2021 ◽  
Author(s):  
C. Chetan Kumar ◽  
B. Rambabu Naik ◽  
A.V.N. Siva Kumar ◽  
A. Ravi ◽  
L.S.S. Varaprasad Reddy ◽  
...  
Keyword(s):  
Growth Factors ◽  
Ovarian Function ◽  
Follicular Development ◽  
Oocyte Quality ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Optimum Level ◽  
Preantral Follicles ◽  
Positive Effects

Background: Melatonin, a powerful free radical scavenger and broad-spectrum antioxidant may directly affect ovarian function by regulating folliculogenesis, maintenance of follicular integrity, oocyte quality and maturation capacity. Therefore, we aimed to study effects of melatonin and its interaction with growth factors in sheep preantral follicles. Methods: The influence of different concentrations of Melatonin (5-500 pM) on in vitro culture of preantral follicles (PFs’) isolated from sheep ovaries was studied. Experiments I and II were conducted to standardize the optimum concentration of Melatonin that supports better development of preantral follicles. Experiment III was conducted with the optimum level of Melatonin derived in the Experiments I and II to evaluate the effect of melatonin at 100pM in combination with various growth factors. Result: Overall follicular development was found to be the best in the PFs’ cultured in medium supplemented with 100pM of Melatonin. Melatonin supplementation showed positive effects on the preantral follicular development in combination with different growth factors.

scholarly journals Heat stress diminishes gonadotropin receptor expression and enhances susceptibility to apoptosis of rat granulosa cells

Reproduction ◽  
2005 ◽  
Vol 129 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Takashi Shimizu ◽  
Izumi Ohshima ◽  
Manabu Ozawa ◽  
Satoko Takahashi ◽  
Atsushi Tajima ◽  
...  
Keyword(s):  
Heat Stress ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Receptor Expression ◽  
Female Rats ◽  
Aromatase Activity ◽  
Mrna Levels ◽  
Gonadotropin Receptor ◽  
Estradiol Levels

Heat stress inhibits ovarian follicular development in mammalian species. We hypothesized that heat stress inhibits the function of follicular granulosa cells and suppresses follicular development. To test this, immature female rats were injected with pregnant mare serum gonadotropin (PMSG) at 48 h after the start of temperature treatment (control: 25 °C, 50% RH; heat stress: 35 °C, 70% Relative Humidity). The ovaries and granulosa cells of follicles at different developmental stages were analyzed for gonadotropin receptor levels and aromatase activity; estradiol levels were measured in follicular fluid. Before injection, heat stress diminished only the amount of FSH receptor on granulosa cells of antral follicles. During PMSG-stimulated follicular development, heat stress strongly inhibited gonadotropin receptor levels and aromatase activity in granulosa cells, and estradiol levels in the follicular fluid of early antral, antral and preovulatory follicles. To examine apoptosis and mRNA levels of bcl-2 and bax in granulosa cells, follicles harvested 48 h after PMSG injection were cultured in serum-free conditions. Heat-stressed granulosa cells showed a time-dependent increase in apoptosis. The bcl-2 mRNA levels were similar in control and heat-stressed granulosa cells; bax mRNA levels were increased in heat-stressed granulosa cells. According to these results, heat stress inhibits expression of gonadotropin receptors in granulosa cells and attenuates estrogenic activity of growing follicles, granulosa cells of heat-stressed follicles are susceptible to apoptosis, and the bcl2/bax system is not associated with heat-stress-induced apoptosis of granulosa cells. Our study suggests that decreased numbers and function of granulosa cells may cause ovarian dysfunction in domestic animals in summer.

Climate Change and Livestock Fertility

2022 ◽  
pp. 1256-1277
Author(s):  
Vishakha Shrimali ◽  
Nibedita Naha ◽  
Sukanta Mondal
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Greenhouse Gases ◽  
Follicular Development ◽  
Mitigation Strategies ◽  
Adaptation To Climate Change ◽  
Oocyte Competence ◽  
Livestock Sector ◽  
Negative Effect ◽  
Global Threat

Climate change is a global threat to livestock sector to so many species and ecosystem in different parts of the world. Climate change, heat stress, and nutritional stress are the major intriguing factors responsible for reduced fertility in farm animals in tropical countries. Heat and nutritional stresses affect the reproductive performance by decreasing the expression of estrous behavior, altering ovarian follicular development and hormonal profiles, compromising oocyte competence, and inhibiting embryonic development in livestock. Climate is changed by greenhouse gases that released into atmosphere through man-made activities. Livestock contribute 18% of the production of greenhouse gases itself and causes climate change including heat stress, which has direct and indirect impact on fertility of the animals as well as reduce milk production. Adaptation to climate change and lowering its negative effect by alteration of animal micro-environment using different essential technologies are the main mitigation strategies to recover heat stress damage in this respect.

A Field Evaluation of Construction Workers’ Activity, Hydration Status, and Heat Strain in the Extreme Summer Heat of Saudi Arabia

2020 ◽  
Vol 64 (5) ◽  
pp. 522-535 ◽  
Author(s):  
Mohammed Al-Bouwarthan ◽  
Margaret M Quinn ◽  
David Kriebel ◽  
David H Wegman
Keyword(s):  
Heart Rate ◽  
Saudi Arabia ◽  
Heat Stress ◽  
Heat Exposure ◽  
Heat Strain ◽  
Construction Workers ◽  
Hydration Status ◽  
Summer Heat ◽  
Cardiovascular Strain ◽  
Indoor And Outdoor

Abstract Objectives Assess the impact of summer heat exposure (June–September) on residential construction workers in Al-Ahsa, Saudi Arabia by evaluating (i) heart rate (HR) responses, hydration status, and physical workload among workers in indoor and outdoor construction settings, (ii) factors related to physiological responses to work in hot conditions, and (iii) how well wet-bulb globe temperature-based occupational exposure limits (WBGTOELs) predict measures of heat strain. Methods Twenty-three construction workers (plasterers, tilers, and laborers) contributed 260 person-days of monitoring. Workload energy expenditure, HR, fluid intake, and pre- and postshift urine specific gravity (USG) were measured. Indoor and outdoor heat exposures (WBGT) were measured continuously and a WBGTOEL was calculated. The effects of heat exposure and workload on heart rate reserve (HRR), a measure of cardiovascular strain, were examined with linear mixed models. A metric called ‘heat stress exceedance’ (HSE) was constructed to summarize whether the environmental heat exposure (WBGT) exceeded the heat stress exposure limit (WBGTOEL). The sensitivity and specificity of the HSE as a predictor of cardiovascular strain (HRR ≥30%) were determined. Results The WBGTOEL was exceeded frequently, on 63 person-days indoors (44%) and 91(78%) outdoors. High-risk HRR occurred on 26 and 36 person-days indoors and outdoors, respectively. The HSE metric showed higher sensitivity for HRR ≥30% outdoors (89%) than indoors (58%) and greater specificity indoors (59%) than outdoors (27%). Workload intensity was generally moderate, with light intensity work more common outdoors. The ability to self-pace work was associated with a lower frequency of HRR ≥30%. USG concentrations indicated that workers began and ended their shifts dehydrated (USG ≥1.020). Conclusions Construction work where WBGTOEL is commonly exceeded poses health risks. The ability of workers to self-pace may help reduce risks.

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