scholarly journals Effect of the Nutrient Microenvironment of an Ovarian Follicle on Gap Junction Activity in Cumulus-Oocyte Complexes in  Post-Partum Cows

2021 ◽  
Author(s):  
◽  
Norma Lorraine Hudson

<p>For mammalian oocyte maturation it is important for the oocyte to communicate with the surrounding somatic cells in a bidirectional manner. In part, this is achieved through gap junction connections between cumulus cells and the oocyte. These gap junctions permit the transfer of essential metabolites, nucleotides, amino acids and ions from the cumulus cells to the oocyte in order for growth and development to occur. It is hypothesized that one reason for post-partum infertility in dairy cows is poor oocyte quality due to an inappropriate nutrient microenvironment in the developing antral follicle. In turn, this might compromise the nutrient and/or energy delivery by cumulus cells to the oocyte and thus affect oocyte quality. The objectives of this study were to: (1) -develop a reliable in vitro measure of gap junction activity for bovine cumulus–oocyte-complexes (COC) using a fluorescent (calcein) dye technique, and (2)- assess the effects of different amino acid compositions, cholesterol and fatty acid concentrations on gap junction activity in COC. The development and validation of the bovine COC gap junction assay was undertaken using a standard commercial medium (M199). Thereafter, media were prepared representing the amino acid concentrations in follicular fluid of both non-lactating and lactating dairy cows as measured in a NZ pastoral situation. These media formed the basis for subsequent measures of COC gap junction activity with differing concentrations of cholesterol and the essential fatty acids- oleic acid, stearic acid and palmitic acid. The major findings from this study were that the different amino acid concentrations typical of that in the follicular fluid of the non-lactating and lactating dairy cow and M199 do not significantly affect the gap junction activity in COC. Given that the amino acid compositions in lactating and non-lactating cows were approximately 50% of those in M199; this indicates that the amino acid concentrations within the ovarian follicle are not a critical factor affecting oocyte quality. However, high concentrations of cholesterol or of the essential fatty acids significantly compromised gap junction activity in bovine COC. High concentrations of the fatty acids were identified in a number of lactating dairy cows during the post-partum interval. In times of negative energy balance, which is common in pasture fed NZ dairy cows during the early post-partum interval and lactation, a significant mobilisation of fatty acids occurs. In turn, this is known to result in an increase in lipid concentrations within the ovarian follicle. The results from this study support the hypothesis that the nutrient environment of the ovarian follicle during early lactation is detrimental to the quality and developmental competence of the oocyte and thus may account for post-partum infertility in some animals.</p>

2021 ◽  
Author(s):  
◽  
Norma Lorraine Hudson

<p>For mammalian oocyte maturation it is important for the oocyte to communicate with the surrounding somatic cells in a bidirectional manner. In part, this is achieved through gap junction connections between cumulus cells and the oocyte. These gap junctions permit the transfer of essential metabolites, nucleotides, amino acids and ions from the cumulus cells to the oocyte in order for growth and development to occur. It is hypothesized that one reason for post-partum infertility in dairy cows is poor oocyte quality due to an inappropriate nutrient microenvironment in the developing antral follicle. In turn, this might compromise the nutrient and/or energy delivery by cumulus cells to the oocyte and thus affect oocyte quality. The objectives of this study were to: (1) -develop a reliable in vitro measure of gap junction activity for bovine cumulus–oocyte-complexes (COC) using a fluorescent (calcein) dye technique, and (2)- assess the effects of different amino acid compositions, cholesterol and fatty acid concentrations on gap junction activity in COC. The development and validation of the bovine COC gap junction assay was undertaken using a standard commercial medium (M199). Thereafter, media were prepared representing the amino acid concentrations in follicular fluid of both non-lactating and lactating dairy cows as measured in a NZ pastoral situation. These media formed the basis for subsequent measures of COC gap junction activity with differing concentrations of cholesterol and the essential fatty acids- oleic acid, stearic acid and palmitic acid. The major findings from this study were that the different amino acid concentrations typical of that in the follicular fluid of the non-lactating and lactating dairy cow and M199 do not significantly affect the gap junction activity in COC. Given that the amino acid compositions in lactating and non-lactating cows were approximately 50% of those in M199; this indicates that the amino acid concentrations within the ovarian follicle are not a critical factor affecting oocyte quality. However, high concentrations of cholesterol or of the essential fatty acids significantly compromised gap junction activity in bovine COC. High concentrations of the fatty acids were identified in a number of lactating dairy cows during the post-partum interval. In times of negative energy balance, which is common in pasture fed NZ dairy cows during the early post-partum interval and lactation, a significant mobilisation of fatty acids occurs. In turn, this is known to result in an increase in lipid concentrations within the ovarian follicle. The results from this study support the hypothesis that the nutrient environment of the ovarian follicle during early lactation is detrimental to the quality and developmental competence of the oocyte and thus may account for post-partum infertility in some animals.</p>


Reproduction ◽  
2005 ◽  
Vol 130 (4) ◽  
pp. 485-495 ◽  
Author(s):  
J L M R Leroy ◽  
T Vanholder ◽  
B Mateusen ◽  
A Christophe ◽  
G Opsomer ◽  
...  

In this study concentration and composition of non-esterified fatty acids (NEFA) in follicular fluid (FF) of high-yielding dairy cows were determined during the period of negative energy balance (NEB) early post partum. NEFA were then added during in vitro maturation at concentrations measured previously in FF to evaluate their effect on the oocyte’s developmental competence. At 16 and 44 days post partum, FF of the dominant follicle and blood were collected from nine high-yielding dairy cows. Samples were analysed for NEFA concentration and composition. NEFA concentrations in FF (0.2–0.6 mmol/l) during NEB remained ± 40% lower compared with serum (0.4–1.2 mmol/l). The NEFA composition differed significantly between serum and FF with oleic acid (OA), palmitic acid (PA) and stearic acid (SA) being the predominant fatty acids in FF. Based on these results, 5115 oocytes were matured for 24 h in serum-free media with or without (negative control) the addition of 0.200 mmol/l OA, 0.133 mmol/l PA or 0.067 mmol/l SA dissolved in ethanol or ethanol alone (positive control). Matured oocytes were fertilized and cultured for 7 days in SOF medium. Addition of PA or SA during oocyte maturation had negative effects on maturation, fertilization and cleavage rate and blastocyst yield. More (late) apoptotic cumulus cells were observed in cumulus–oocyte complexes matured in the presence of SA or PA. Ethanol or OA had no effect. These in vitro results suggest that NEB may hamper fertility of high-yielding dairy cows through increased NEFA concentrations in FF affecting oocyte quality.


2001 ◽  
Vol 2001 ◽  
pp. 199-199 ◽  
Author(s):  
C. Rymer ◽  
C. Dyer ◽  
D.I. Givens ◽  
R. Allison

The dietary essential fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are predominantly found in fish oil, but fish consumption in the UK is low. Increasing the yield of EPA and DHA in cows’ milk would increase human intakes of EPA and DHA, and this can be achieved by including fish oil in cows’ diets. However, because EPA and DHA are susceptible to rumen biohydrogenation, their transfer efficiency into milk is low.In vitroobservations by Gulatiet al. (1999) suggested that if the concentration of fish oil in the rumen exceeded 1 mg/ml, EPA and DHA were not hydrogenated. The objectives of this study were therefore to determine the relationships between fish oil intake by dairy cows, and the probable concentrations of fish oil in the cows’ rumen, with the yield of EPA and DHA in their milk.


2017 ◽  
Vol 16 (1) ◽  
pp. 156-164 ◽  
Author(s):  
Taiana Denardi-Souza ◽  
Kelly Cristina Massarolo ◽  
Sabina M Tralamazza ◽  
Eliana Badiale-Furlong

Reproduction ◽  
2009 ◽  
Vol 138 (5) ◽  
pp. 771-781 ◽  
Author(s):  
Ali A Fouladi-Nashta ◽  
Karen E Wonnacott ◽  
Carlos G Gutierrez ◽  
Jin G Gong ◽  
Kevin D Sinclair ◽  
...  

Different fatty acid (FA) sources are known to influence reproductive hormones in cattle, yet there is little information on how dietary FAs affect oocyte quality. Effects of three dietary sources of FAs (supplying predominantly palmitic and oleic, linoleic (n-6) or linolenic (n-3) acids) on developmental potential of oocytes were studied in lactating dairy cows. A total of 12 Holstein cows received three diets containing rumen inert fat (RIF), soyabean or linseed as the main FA source for three periods of 25 days in a Latin-square design. Within each period, oocytes were collected in four ovum pick-up sessions at 3–4 day intervals. FA profiles in plasma and milk reflected profiles of dietary FA sources, but major FAs in granulosa cells were not affected. Dietary FA source did not affect plasma concentrations of leptin, insulin, IGF1, GH, or amino acids. RIF led to a higher proportion of cleaved embryos than soya or linseed, but blastocyst yield and embryo quality were not affected. It is concluded that the ovary buffers oocytes against the effects of fluctuations in plasma n-3 and n-6 FAs, resulting in only modest effects on their developmental potential.


2019 ◽  
Vol 31 (1) ◽  
pp. 188
Author(s):  
G. Santos ◽  
M. P. Bottino ◽  
A. P. C. Santos ◽  
R. E. Orlandi ◽  
L. M. S. Simões ◽  
...  

The objective of this study was to evaluate the effect of mastitis diagnosed by somatic cell count (SCC) on follicular growth, ovulation, oocytes and cumulus cells quality and the concentration and size of exosomes in follicular fluid of dairy cows. In the study, crossbred cows (Bos taurus-Holstein×Bos indicus-Gir) were classified for analysis as control (SCC &lt;200.000 cells mL−1) and mastitis (SCC &gt;400.000 cells mL−1) groups. In Experiment 1 (follicular dynamics), cows (n=57: control=31; mastitis=26) received a progesterone intravaginal device (Sincrogest®, Ourofino Saude Animal, Cravinhos, Brazil) and 2mg of oestradiol benzoate (Sincrodiol®, Ourofino Saude Animal) injected IM. Eight days later (D8), the progesterone device was removed and cows received IM 500mg of cloprostenol (Sincrocio®, Ourofino Saude Animal), 1mg of oestradiol cypionate (SincroCP®, Ourofino Saude Animal) and 300IU of eCG (SicroeCG®, Ourofino Saude Animal). Ultrasound exams (Mindray 4900, probe linear de 5MHz, Shenzhen, China) were performed every 24h from removal of the progesterone-releasing intravaginal device (D8) until 48h later. Thereafter, evaluations were performed every 12h, until ovulation or up to 96h after removal of the progesterone-releasing intravaginal device. In Experiment 2 (oocyte, cumulus complexes, and follicular fluid evaluation), cows (n=26: control=13; mastitis=13) were submitted to follicular aspiration (ovum pickup) for oocyte quality and cumulus cells transcript evaluation. Transcript abundance of apoptosis markers (BCL2, BAX, PI3K, PTEN, FOXO3) was determined by real-time RT-PCR. Moreover, 7 days after the ovum pickup session, the dominant follicle was aspirated and follicular fluid samples were obtained. Exosomes were isolated from the follicular fluid by serial centrifugations, which were also performed for evaluation of particle size and concentration. Statistical analyses were performed using the SAS (SAS Institute Inc., Cary, NC, USA), and the GLIMMIX procedure was used to determine significant differences between groups. Gene expression and exosome data were submitted to the Student’s t-test. Ovulation rate [control 77.4% (24/31) and mastitis 57.7% (15/26); P=0.09] and viable oocytes rate [control 59.1% (130/220) and mastitis 41.9% (125/298); P=0.01] were higher in control animals. Additionally, there was a greater number of degenerate oocytes (control 6.7±1.2 and mastitis 13.3±5.5; P=0.001) in subclinical mastitis cows. There was greater abundance (P=0.003) of BAX cumulus cell transcripts and exosome mean (P=0.03) was smaller in subclinical mastitis cows. However, BCL2, PI3K, PTEN, nd FOXO3 cumulus cell transcripts was similar between treatments. In conclusion, ovulation rate, oocyte quality, and exosome diameter were smaller in cows with SCC &gt;400.000 cells mL−1, demonstrating that subclinical mastitis can influence the fertility of dairy cows.


Sign in / Sign up

Export Citation Format

Share Document