scholarly journals Interplay between stress and reproduction: Novel epigenetic markers in response to shearing patterns in Australian Merino sheep (Ovis aries)

2021 ◽  
Author(s):  
Edward Narayan ◽  
Gregory Sawyer ◽  
Dylan Fox ◽  
Alan Tilbrook
Keyword(s):  
Early Pregnancy ◽  
Research Question ◽  
Quality Parameters ◽  
Ovis Aries ◽  
Late Gestation ◽  
Protein Coding ◽  
Epigenetic Markers ◽  
Gps Collars ◽  
Forkhead Box ◽  
Australian Merino

In this study, we determined the effect(s) of shearing on Australian Merino ewes (Ovis aries). To test this research question, we used a suite of field and laboratory methods including GPS collars, wool cortisol and novel epigenetic markers identified using Illumina NovaSeq RRBS. Single shorn ewes (n =24) kept on their full fleece throughout the entire gestation period while twice shorn ewes (n =24) had their wool shorn early in gestation. We have discovered one locus (Chr20:50404014) which was significantly associated with different shearing treatments (twice or single shorn ewes), (FDR = 0.005). This locus is upstream of a protein coding gene (ENSOARG00000002778.1), which shows similarities to the forkhead box C1 (FOXC1) mRNA using BLAST searches. We discovered that 36 gene loci were significantly modulated either between different shearing treatments or late vs early pregnancy ewes. Similarly, in lambs we identified 16 annotated gene loci that were significant between late vs early pregnancy. Early shorn ewes grazed 10% higher and maintained stronger body condition. Wool cortisol levels were significantly lower in the early shorn ewes during mid- and late gestation. Lambs bred from twice shorn ewes had on average better visual wool quality parameters in terms of micron, spin finesses and curvature. Collectively, this research provides a new dataset combining physiological, molecular epigenetics and digital tracking indices that advances our understanding of how Merino ewes respond to shearing frequency and this information could guide further research on sheep breeding and welfare.

scholarly journals PSI-40 Two mitochondrial lineages revealed in North American yak

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 477-477
Author(s):  
Leah K Treffer ◽  
Edward S Rice ◽  
Anna M Fuller ◽  
Samuel Cutler ◽  
Jessica L Petersen
Keyword(s):  
Sequence Data ◽  
Haplotype Network ◽  
Ovis Aries ◽  
Similar Species ◽  
Nucleotide Polymorphisms ◽  
Mt Dna ◽  
Protein Coding ◽  
Sister Clade ◽  
Mtdna Sequence ◽  
The Impact

Abstract Domestic yak (Bos grunniens) are bovids native to the Asian Qinghai-Tibetan Plateau. Studies of Asian yak have revealed that introgression with domestic cattle has contributed to the evolution of the species. When imported to North America (NA), some hybridization with B. taurus did occur. The objective of this study was to use mitochondrial (mt) DNA sequence data to better understand the mtDNA origin of NA yak and their relationship to Asian yak and related species. The complete mtDNA sequence of 14 individuals (12 NA yak, 1 Tibetan yak, 1 Tibetan B. indicus) was generated and compared with sequences of similar species from GeneBank (B. indicus, B. grunniens (Chinese), B. taurus, B. gaurus, B. primigenius, B. frontalis, Bison bison, and Ovis aries). Individuals were aligned to the B. grunniens reference genome (ARS_UNL_BGru_maternal_1.0), which was also included in the analyses. The mtDNA genes were annotated using the ARS-UCD1.2 cattle sequence as a reference. Ten unique NA yak haplotypes were identified, which a haplotype network separated into two clusters. Variation among the NA haplotypes included 93 nonsynonymous single nucleotide polymorphisms. A maximum likelihood tree including all taxa was made using IQtree after the data were partitioned into twenty-two subgroups using PartitionFinder2. Notably, six NA yak haplotypes formed a clade with B. indicus; the other four haplotypes grouped with B. grunniens and fell as a sister clade to bison, gaur and gayal. These data demonstrate two mitochondrial origins of NA yak with genetic variation in protein coding genes. Although these data suggest yak introgression with B. indicus, it appears to date prior to importation into NA. In addition to contributing to our understanding of the species history, these results suggest the two major mtDNA haplotypes in NA yak may functionally differ. Characterization of the impact of these differences on cellular function is currently underway.

scholarly journals The Heterochromatin Landscape in Migrating Cells and the Importance of H3K27me3 for Associated Transcriptome Alterations

Cells ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 205 ◽  
Author(s):  
Tamar Segal ◽  
Mali Salmon-Divon ◽  
Gabi Gerlitz
Keyword(s):  
Transcriptome Analysis ◽  
Transcriptional Repression ◽  
Chromatin Condensation ◽  
Opposite Pattern ◽  
Protein Coding ◽  
Epigenetic Markers ◽  
Protein Coding Genes ◽  
Global Increase ◽  
General Signature ◽  
Migrating Cells

H3K9me3, H3K27me3, and H4K20me1 are epigenetic markers associated with chromatin condensation and transcriptional repression. Previously, we found that migration of melanoma cells is associated with and dependent on global chromatin condensation that includes a global increase in these markers. Taken together with more recent reports by others suggests it is a general signature of migrating cells. Here, to learn about the function of these markers in migrating cells, we mapped them by ChIP-seq analysis. This analysis revealed that induction of migration leads to expansion of these markers along the genome and to an increased overlapping between them. Significantly, induction of migration led to a higher increase in H3K9me3 and H4K20me1 signals at repetitive elements than at protein-coding genes, while an opposite pattern was found for H3K27me3. Transcriptome analysis revealed 182 altered genes following induction of migration, of which 33% are dependent on H3K27me3 for these changes. H3K27me3 was also required to prevent changes in the expression of 501 other genes upon induction of migration. Taken together, our results suggest that heterochromatinization in migrating cells is global and not restricted to specific genomic loci and that H3K27me3 is a key component in executing a migration-specific transcriptional plan.

scholarly journals Endocannabinoid System in Pregnancy Maintenance and Labor: A Mini-Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Melissa L. Kozakiewicz ◽  
Chad A. Grotegut ◽  
Allyn C. Howlett
Keyword(s):  
Early Pregnancy ◽  
Endocannabinoid System ◽  
Current Theory ◽  
Multiple Organ ◽  
Late Gestation ◽  
Signaling System ◽  
Organ Systems ◽  
A Cell ◽  
Term Labor ◽  
In Pregnancy

The endocannabinoid system (ECS) is a cell-signaling system present in multiple organ systems and is an integral part of sustaining the microenvironment necessary for early pregnancy success and maintenance. It plays a significant role in embryo development, transport and implantation as well as placentation. The current theory behind the initiation of term labor is that it is a complex, multifactorial process involving sex steroid hormones, prostaglandin production and interplay at the maternal-fetal interface resulting in increased expression of receptors and gap junctions that promote uterine activation. There is increasing evidence that, in addition to early pregnancy events, the ECS plays a regulatory role in pregnancy maintenance and the timing of labor. This review presents an overview of the ECS in pregnancy that focuses on late gestation and parturition.

scholarly journals Accelerated Fetal Growth in Early Pregnancy and Risk of Preterm Birth: A Prospective Cohort Study

2020 ◽  
Author(s):  
Evangelia Elenis ◽  
Anna-Karin Wikström ◽  
Marija Simic
Keyword(s):  
Cohort Study ◽  
Preterm Birth ◽  
Prospective Cohort Study ◽  
Fetal Growth ◽  
Early Pregnancy ◽  
Prospective Cohort ◽  
Late Gestation ◽  
Second Trimester ◽  
Spontaneous Preterm Birth ◽  
Increased Risk

Abstract Background: Preterm birth (occurring before 37 completed weeks of gestation) affects 15 million infants annually, 7.5% of which die due to related complications. The detection and early diagnosis are therefore paramount in order to prevent the development of prematurity and its consequences. So far, focus has been laid on the association between reduced intrauterine fetal growth during late gestation and prematurity. The aim of the current study was to investigate the association between accelerated fetal growth in early pregnancy and the risk of preterm birth. Methods: This prospective cohort study included 69 617 singleton pregnancies without congenital malformations and with available biometric measurements during the first and second trimester. Estimation of fetal growth was based on measurements of biparietal diameter (BPD) at first and second trimester scan. We investigated the association between accelerated fetal growth and preterm birth prior to 37 weeks of gestation. The outcome was further stratified into very preterm birth (before 32 weeks of gestation) or moderate preterm birth (between 32 and 37 weeks of gestation) and medically induced or spontaneous preterm birth and was further explored. Results: The odds of prematurity were increased among fetuses with accelerated BPD growth (> 90th centile) estimated between first and second ultrasound scan, even after adjustment for possible confounders (aOR 1.36; 95% CI 1.20-1.54). The findings remained significant what regards moderate preterm births but not earlier births. Regarding medically induced preterm birth, the odds were found to be elevated in the group of fetuses with accelerated growth in early pregnancy (aOR 1.34; 95% CI 1.11-1.63). On the contrary, fetuses with delayed fetal growth exhibited lower risk for both overall and spontaneous preterm birth.Conclusions: Fetuses with accelerated BPD growth in early pregnancy, detected by ultrasound examination during the second trimester, exhibited increased risk of being born preterm. The findings of the current study suggest that fetal growth in early pregnancy should be taken into account when assessing the likelihood for preterm birth.

scholarly journals Validation of the STRIVE model for coupling ecological processes and surface water flow

2010 ◽  
Vol 13 (4) ◽  
pp. 741-759
Author(s):  
L. De Doncker ◽  
P. Troch ◽  
R. Verhoeven ◽  
K. Buis ◽  
P. Meire
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Water Flow ◽  
Research Question ◽  
Quality Parameters ◽  
Water Levels ◽  
Ecological Processes ◽  
Vegetation Growth ◽  
Surface Water Flow ◽  
Quality Aspects

The 1D model package STRIVE is verified for simulating the interaction between ecological processes and surface water flow. The model is general and can be adapted and further developed according to the research question. The hydraulic module, based on the Saint-Venant equations, is the core part. The presence of macrophytes influences the water quality and the discharge due to the flow resistance of the river, expressed by Manning's coefficient, and allows an ecological description of the river processes. Based on the advection–dispersion equation, water quality parameters are incorporated and modelled. Calculation of the water quantity parameters, coupled with water quality and inherent validation and sensitivity analysis, is the main goal of this research. An important study area is the River Aa near Poederlee (Belgium), a lowland river with a wealth of vegetation growth, where discharge and vegetation measurements are carried out on a regular basis. The developed STRIVE model shows good and accurate calculation results. The work highlights the possibility of STRIVE to model flow processes, water quality aspects and ecological interaction combined and separately. Coupling of discharges, water levels, amount of biomass and tracer values provides a powerful prediction modelling tool for the ecological behaviour of lowland rivers.

scholarly journals Microscopic sperm head damage and abnormalities as heat stress indicators in Australian Merino rams (Ovis aries) in Northern Patagonia, Argentina

2018 ◽  
Vol 55 (1) ◽  
pp. 1
Author(s):  
María Fernanda López Armengol ◽  
Natalia Rubio ◽  
Guillermo Ariel Sabino ◽  
Nadia Soledad Bérgamo ◽  
Valeria Pelufo
Keyword(s):  
Heat Stress ◽  
Sperm Head ◽  
Ovis Aries ◽  
Stress Indicators ◽  
Northern Patagonia ◽  
Australian Merino

Na Patagônia Norte, os ovinos têm sua estação de acasalamento iniciada em 15 de março, portanto, ficam sujeitos às temperaturas do verão. A exposição de carneiros a estresse térmico aumenta a prevalência de danos microscópicos e anomalias morfológicas nos espermatozoides, que implica uma redução na fertilidade. Este trabalho avaliou a capacidade adaptativa de carneiros Merino Australiano com lã (N = 6) e tosquiados (N = 6): metade ficou ao ar livre e outra metade foi mantida em uma câmara climática por oito horas, durante cinco dias, chegando gradualmente a uma temperatura máxima de 40 °C. Foram analisados danos microscópicos, anormalidades e alterações ultramicroscópicas da membrana plasmática e do acrossoma da cabeça dos espermatozoides. Os resultados microscópicos confirmaram a existência de diferença significativa na porcentagem de espermatozoides sem cauda e com gota citoplasmática proximal, entre os ejaculados pós-tratamento. A temperatura afetou os carneiros tosquiados, principalmente a cabeça de seus espermatozoides, durante a espermatogênese. Alterações submicroscópicas foram observados na membrana plasmática quando ela estava presente no segmento anterior: quando não intacta, ficava ondulada ou dilatada. Quando a membrana plasmática estava ausente, o acrossoma podia se apresentar ondulado ou dilatado. Além disso, sob efeito do calor, a membrana acrossomal externa pode perder completamente seu conteúdo ou apresentar núcleo desnudo. A membrana plasmática assume uma forma ondulada pelo efeito da temperatura no epidídimo. Depois de dez semanas, a cabeça dos espermatozoides recuperou sua forma normal. Como demonstrado neste estudo, a cabeça sem cauda, as gotas citoplasmáticas proximais e as categorias ultramicroscópicas estudadas são indicadores do efeito do estresse térmico no sêmen, e os carneiros com maior cobertura de lã se adaptam melhor ao estresse por calor. Alterações de microscopia e de microscopia eletrônica de transmissão têm se mostrado excelentes indicadores de estresse por calor em carneiros Merino Australiano e podem ser ferramentas úteis para ajudar criadores de ovelhas a escolher quando começar a época de acasalamento, o que irá variar de acordo com as condições ambientais do verão.

Effects of glucocorticoid treatment given in early or late gestation on growth and development in sheep

2013 ◽  
Vol 4 (2) ◽  
pp. 146-156 ◽  
Author(s):  
S. Li ◽  
D. M. Sloboda ◽  
T. J. M. Moss ◽  
I. Nitsos ◽  
G. R. Polglase ◽  
...  
Keyword(s):  
Growth Factor ◽  
Early Pregnancy ◽  
Plasma Insulin ◽  
Fetal Brain ◽  
Late Gestation ◽  
Fetal Weight ◽  
Postnatal Life ◽  
Insulin Like Growth Factor ◽  
Organ Weights ◽  
Fetal Organ

Antenatal corticosteroids are used to augment fetal lung maturity in human pregnancy. Dexamethasone (DEX) is also used to treat congenital adrenal hyperplasia of the fetus in early pregnancy. We previously reported effects of synthetic corticosteroids given to sheep in early or late gestation on pregnancy length and fetal cortisol levels and glucocorticoids alter plasma insulin-like growth factor (IGF) and insulin-like growth factor binding protein (IGFBP) concentrations in late pregnancy and reduce fetal weight. The effects of administering DEX in early pregnancy on fetal organ weights and betamethasone (BET) given in late gestation on weights of fetal brain regions or organ development have not been reported. We hypothesized that BET or DEX administration at either stage of pregnancy would have deleterious effects on fetal development and associated hormones. In early pregnancy, DEX was administered as four injections at 12-hourly intervals over 48 h commencing at 40–42 days of gestation (dG). There was no consistent effect on fetal weight, or individual fetal organ weights, except in females at 7 months postnatal age. When BET was administered at 104, 111 and 118 dG, the previously reported reduction in total fetal weight was associated with significant reductions in weights of fetal brain, cerebellum, heart, kidney and liver. Fetal plasma insulin, leptin and triiodothyronine were also reduced at different times in fetal and postnatal life. We conclude that at the amounts given, the sheep fetus is sensitive to maternal administration of synthetic glucocorticoid in late gestation, with effects on growth and metabolic hormones that may persist into postnatal life.

scholarly journals Genomics of estradiol-3-sulfate action in the ovine fetal hypothalamus

2012 ◽  
Vol 44 (13) ◽  
pp. 669-677 ◽  
Author(s):  
Maria Belen Rabaglino ◽  
Elaine Richards ◽  
Nancy Denslow ◽  
Maureen Keller-Wood ◽  
Charles E. Wood
Keyword(s):  
Feeding Behavior ◽  
Transforming Growth Factor ◽  
Fetal Brain ◽  
Ovis Aries ◽  
Late Gestation ◽  
Postnatal Life ◽  
Growth Factor Signaling ◽  
Fetal Sheep ◽  
Ovine Fetal ◽  
Agouti Related Protein

In fetal sheep during late gestation sulfoconjugated estrogens in plasma reach a concentration 40–100 times greater than unconjugated estrogens. The objective of the present study was to determine the genomics of estradiol-3-sulfate (E2S) action in the ovine fetal brain. The hypothesis was that E2S stimulates genes involved in the neuroendocrine pathways that direct or facilitate fetal development at the end of gestation. Four sets of chronically catheterized ovine twin fetuses were studied (gestational age: 120–127 days gestation) with one infused with E2S intracerebroventricularly (1 mg/day) and the other remaining untreated (control). After euthanasia, mRNA samples were extracted from fetal brains. Only hypothalamic samples were employed for this study given the important function of this brain region in the control of the hypothalamus-pituitary-adrenal axis. Microarray analysis was performed following the Agilent protocol for one-color 8 × 15 microarrays, designed for Ovis aries. A total of 363 known genes were significantly upregulated by the E2S treatment ( P < 0.05). Network and enrichment analyses were performed using the Cytoscape/Bingo software, and the results validated by quantitative real-time PCR. The main overrepresented biological processes resulting from this analysis were feeding behavior, hypoxia response, and transforming growth factor signaling. Notably, the genes involved in the feeding behavior (neuropeptide Y and agouti-related protein) were the most strongly induced by the E2S treatment. In conclusion, E2S may be an important component of the mechanism for activating orexigenic, hypoxia responsiveness and neuroprotective pathways in the lamb as it approaches postnatal life.

Changes in baroreceptor sensitivity for heart rate during normotensive pregnancy and the puerperium

2000 ◽  
Vol 98 (3) ◽  
pp. 259-268 ◽  
Author(s):  
Melanie J. BLAKE ◽  
Allison MARTIN ◽  
Brad N. MANKTELOW ◽  
Charles ARMSTRONG ◽  
Aidan W. HALLIGAN ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pregnant Women ◽  
Early Pregnancy ◽  
High Frequency ◽  
Post Partum ◽  
Late Pregnancy ◽  
Late Gestation ◽  
Control Group ◽  
Pulse Interval ◽  
Normotensive Pregnancy

Normal pregnancy is associated with marked changes in cardiovascular haemodynamics, which in part may be due to changes in autonomic control mechanisms. Baroreflex sensitivity for heart rate (BRS) was calculated in the supine and standing positions using power spectral analysis of pulse interval (PI) and systolic blood pressure (SBP) in 16 normotensive pregnant women and 10 normotensive non-pregnant controls. The pregnant women were studied on three occasions during their pregnancy (early, mid- and late gestation) and once during the puerperium. Supine total SBP variability increased between early and late pregnancy by 79% [95% confidence intervals (CI) 30%, 145%; P < 0.001], and supine high-frequency PI variability decreased by 75% (CI 51%, 88%; P < 0.001). Supine BRS fell by 50% (P < 0.001), with values returning to early-pregnancy levels in the puerperium, which were similar to those recorded in the control group. Standing SBP variability and BRS values were unchanged during pregnancy and post partum. The low/high frequency ratio of PI variability, taken as a surrogate measure of sympathovagal balance, increased by 137% (CI 42%, 296%; P < 0.01) in the supine but not the standing position from early to late pregnancy. This was due to a decrease in high-frequency variability rather than to an increase in low-frequency variability, suggesting that these changes may have been due to vagal withdrawal rather than increased sympathetic activity. Normotensive pregnancy is associated with a marked decrease in supine BRS, although the exact mechanisms for these changes remain unclear. Further studies are required to define whether changes in BRS and sympathovagal tone in early pregnancy can be used to predict the onset of pregnancy-induced hypertension.

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