Glucogenic supply increases oocyte developmental competence in sheep

2012 ◽  
Vol 24 (8) ◽  
pp. 1055 ◽  
Author(s):  
F. Berlinguer ◽  
A. Gonzalez-Bulnes ◽  
I. Contreras-Solis ◽  
A. Spezzigu ◽  
L. Torres-Rovira ◽  
...  

The present study aimed to determine the influence of a glucogenic supply on oocyte developmental competence. Oestrous cycles were synchronised in 22 Sarda ewes by the insertion (Day 0) of one intravaginal progestagen-impregnated sponge that was removed after 6 days. After removal, the ewes were randomly allocated into two experimental groups (treated and control ewes) and, from Day 7 to Day 11, treated ewes received oral administration of a glucogenic mixture, whereas control animals received water. Follicular development was stimulated by FSH administration from Days 8 to 10. Glucose metabolism was assessed from Days 7 to 11, whilst follicle and corpus luteum growth dynamics and functionality were evaluated between Days 6 and 11. At Day 11 ovaries were collected and processed for in vitro embryo production. Glucogenic treatment increased both the plasma levels of glucose, progesterone, oestradiol and the number of 2–3-mm follicles (P < 0.05). Higher fertilisation and blastocyst rates (P < 0.05) were obtained after IVM of oocytes recovered from treated ewes compared with control ones. In conclusion, glucogenic treatment modifies follicle and corpus luteum functionality and improves oocyte quality, as evaluated by in vitro developmental kinetics and blastocyst output.

2010 ◽  
Vol 22 (1) ◽  
pp. 260
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen

Effective in vitro maturation (IVM) is essential for successful in vitro embryo production. The morphology of the cumulus investment before and after IVM may be a useful noninvasive indicator of oocyte quality. In pigs, oocyte developmental competence is reduced during the summer months. The aim of this study was to determine whether the morphology of cumulus-oocyte complexes (COC) before and after IVM are associated with oocyte quality, using COC collected from small and large follicles in summer and winter as models of poor and good oocyte quality. Ovaries were collected from sows slaughtered 4 days after weaning. The COC recovered from small (3-4 mm) and large (5-8 mm) antral follicles were morphologically graded and parthenogenetically activated following IVM during winter (n = 1419; 10 replicates) and summer (n = 2803; 10 replicates). Grade 1 and 2 COC had >2 layers of compact cumulus cells and a homogenous cytoplasm. Grade 3 COC were either partially or fully denuded, had a heterogeneous cytoplasm, or were vacuolated or dark in color. Grade 4 COC had expanded cumulus cells. Cumulus expansion was also assessed subsequent to IVM. The COC recorded as having a cumulus expansion index (CEI) of 1 had the poorest expansion with no detectable response to IVM, whereas those with a CEI of 4 had the greatest amount of expansion, including that of the corona radiata. Data were analyzed using a generalized linear mixed model in GenStat® (release 10, VSN International, Hemel Hempstead, UK). There was an effect of follicle size for Grade 1 COC, with COC from large follicles in both seasons yielding better quality COC (P < 0.05). The proportion of COC in Grade 2 was higher in small follicles during winter compared with large follicles, but there were no differences between follicle sizes during summer (P < 0.05). The proportion of COC with CEI 1 was highest in COC from small follicles during summer (P < 0.05). The proportion of COC from large follicles with CEI 2 was higher during summer compared with winter (P < 0.05). There were no seasonal or follicle size effects on COC with CEI 3 or 4 (P > 0.05). The proportion of oocytes that developed to blastocysts was greater in winter than in summer (39.06% ± 5.67 v. 22.27% ± 4.01; P < 0.05). Oocytes derived from large follicles had a greater ability to form blastocysts compared with those from small follicles (37.13% ± 5.65 v. 23.32% ± 4.56; P < 0.06). Morphological assessment of cumulus cells before and after IVM may be a useful tool to evaluate the effects of follicle size on oocyte developmental competence. However, the results of the present study indicate that cumulus cell morphology is not a good indicator of the effect of season on oocyte developmental competence.


2011 ◽  
Vol 23 (6) ◽  
pp. 788 ◽  
Author(s):  
D. R. Li ◽  
G. S. Qin ◽  
Y. M. Wei ◽  
F. H. Lu ◽  
Q. S. Huang ◽  
...  

This study was carried out to test the feasibility of enhancing embryo production in vivo and in vitro by immunoneutralisation against inhibin or follistatin. In Experiment 1, multi-parity buffaloes were assigned into three groups: High group (n = 8), which received one primary (2 mg) and two booster (1 mg) vaccinations (28-day intervals) with a recombinant inhibin α subunit in 1 mL of white oil adjuvant; Low group (n = 8), which received half that dose; and Control group (n = 7), which received only adjuvant. Immunisation against inhibin stimulated development of ovarian follicles. Following superovulation and artificial insemination, inhibin-immunised buffaloes had more developing follicles than the Control buffaloes. The average number of embryos and unfertilised ova (4.5 ± 0.6, n = 6) in the High group was higher (P < 0.05) than in the Control group (2.8 ± 0.6, n = 5) and was intermediate (4.1 ± 0.7, n = 7) in the Low group. The pooled number of transferable embryos of the High and Low groups (3.2 ± 0.5, n = 13) was also higher (P < 0.05) than that (1.6 ± 0.7, n = 5) of the controls. The immunised groups also had higher plasma concentrations of activin, oestradiol and progesterone. In Experiment 2, the addition of anti-inhibin or anti-follistatin antibodies into buffalo oocyte IVM maturation medium significantly improved oocyte maturation and cleavage rates following parthenogenic activation. Treatment with anti-follistatin antibody also doubled the blastocyst yield from activated embryos. These results demonstrated that immunisation against inhibin stimulated follicular development, enhanced oocyte quality and maturation competence, yielded more and better embryos both in vivo and in vitro.


2019 ◽  
Vol 31 (1) ◽  
pp. 196
Author(s):  
M. Saad ◽  
Z. Sarwar ◽  
M. Saleem ◽  
U. Arshad ◽  
M. Shahzad ◽  
...  

Assisted reproductive technologies have modernized the dairy industry for the rapid multiplication of superior genetic traits. However, the exploitation of genetics through in vitro embryo production in farm animals has been struggling during the last 3 decades. The presence or absence of a corpus luteum (CL) on ovaries from which cumulus-oocyte complexes were recovered has been shown to affect the quality of oocytes and in vitro embryo production outcome in Bos taurus cows. Similar information is lacking in Bos indicus cows. Therefore, the objectives of the present study were to determine the effect of presence or absence of a CL on recovery rate, quality, and in vitro developmental competence of oocytes in Bos indicus dairy cows. This study was conducted from December 2017 to April 2018. The ovaries were harvested from a local abattoir (Bos indicus; 5- to 8-year-old cows having mixed parity with clinically normal reproductive tracts). These ovaries (n=750) were divided into 2 groups [(1) CYCLIC (n=318) and (2) ACYCLIC (n=432)] based on the presence or absence of mature CL having follicles on either left or right ovaries of slaughtered cows. Blood samples from the jugular vein were collected at slaughter. Serum concentrations of progesterone of CYCLIC and ACYCLIC cows were measured using radioimmunoassay. Mean number of recovered oocytes per ovary and serum concentration of progesterone were compared using PROC TTEST model. However, quality, maturation, cleavage, 8-cell, 16-cell, and morula rates were analysed by PROC FREQ model of Chi-squared. All the data was analysed using SAS (SAS Institute Inc., Cary, NC, USA). Results revealed that the mean serum concentrations of progesterone (4.21±0.4v. 0.5±0.2ng mL−1; P&lt;0.05) were higher in CYCLIC as compared with ACYCLIC cows, respectively. The mean number of oocytes recovered per ovary (6.5±4.5v. 4.0±4.4; P&lt;0.05) was higher in CYCLIC than in ACYCLIC cows. The oocytes with grade I+II quality (55.3v. 47.6%; P&lt;0.05) were higher, whereas oocytes with grade III+IV quality (44.5v. 52.4%; P&lt;0.05) were lower, in CYCLIC as compared with ACYCLIC cows, respectively. Furthermore, cleavage rate (70.9v. 52.8%; P&lt;0.05) was higher in CYCLIC than in ACYCLIC cows, respectively. Similarly, the 8-cell (38.5v. 20.8%; P&lt;0.05) and 16-cell (20.0v. 10.9%; P&lt;0.05) stage embryos were greater in CYCLIC as compared with ACYCLIC cows, respectively. In conclusion, the presence of CL has a beneficial effect on recovery rate, quality, and in vitro embryo production outcomes in Bos indicus dairy cows. It is implied that for ovum pickup, cyclic cows should be preferred.


Reproduction ◽  
2012 ◽  
Vol 143 (6) ◽  
pp. 735-747 ◽  
Author(s):  
Isabelle Gilbert ◽  
Claude Robert ◽  
Christian Vigneault ◽  
Patrick Blondin ◽  
Marc-André Sirard

In the case of in vitro embryonic production, it is known that not all oocytes detain the developmental capacity to form an embryo. This capacity appears to be acquired through completion of folliculogenesis, during which the oocyte and follicular cells influence their respective destinies. The differentiation status of granulosa cells (GCs) could therefore offer an indicator of oocyte quality. The aim of this study was to compare mRNA transcript abundance in GCs associated with oocytes that subsequently reach or not the blastocyst stage. GCs were collected from cattle following an ovarian stimulation protocol that did or did not include the administration of LH. GCs were classified according to the developmental stage achieved by the associated oocytes. Transcript abundance was measured by microarray. Follicles (n=189) obtained from cows before and after the LH surge were essentially similar and the rates of oocytes reaching the blastocyst stage were not significantly different (52 vs 41%), but blastocyst quality was significantly better in the post-LH-surge group. In GCs from the pre-LH-surge group and associated with developmentally competent oocytes, 18 overexpressed and 22 underexpressed transcripts were found, including novel uncharacterized transcripts, whereas no differentially expressed transcripts were associated with developmentally different oocytes in the post-LH-surge group. The novel transcriptomic response associated with LH appeared to mask the difference. Based on oocyte developmental competence, the period prior to the LH surge appears best suited for studying competence-associated mRNA transcripts in bovine follicle cells.


2019 ◽  
Vol 102 (2) ◽  
pp. 388-398 ◽  
Author(s):  
N G J Costermans ◽  
K J Teerds ◽  
A Middelkoop ◽  
B A J Roelen ◽  
E J Schoevers ◽  
...  

Abstract Metabolic demands of modern hybrid sows have increased over the years, which increases the chance that sows enter a substantial negative energy balance (NEB) during lactation. This NEB can influence the development of follicles and oocytes that will give rise to the next litter. To study effects of a lactational NEB on follicular development, we used 36 primiparous sows of which 18 were subjected to feed restriction (3.25 kg/day) and 18 were full-fed (6.5 kg/day) during the last 2 weeks of a 24.1 ± 0.3 day lactation. Feed restriction resulted in a 70% larger lactational body weight loss and 76% higher longissimus dorsi depth loss, but similar amounts of backfat loss compared to the full fed sows. These changes were accompanied by lower plasma insulin-like growth factor 1 (IGF1) and higher plasma creatinine levels in the restricted sows from the last week of lactation onward. Ovaries were collected 48 h after weaning. Restricted sows had a lower average size of the 15 largest follicles (−26%) and cumulus–oocyte complexes showed less expansion after 22 h in vitro maturation (−26%). Less zygotes of restricted sows reached the metaphase stage 24 h after in vitro fertilization and showed a higher incidence of polyspermy (+89%). This shows that feed restriction had severe consequences on oocyte developmental competence. Follicular fluid of restricted sows had lower IGF1 (−56%) and steroid levels (e.g., β-estradiol, progestins, and androgens), which indicated that follicles of restricted sows were less competent to produce steroids and growth factors needed for oocytes to obtain full developmental competence.


2009 ◽  
Vol 57 (2) ◽  
pp. 331-335 ◽  
Author(s):  
Theodora Tsiligianni ◽  
Irene Valasi ◽  
Sándor Cseh ◽  
Emmanuel Vainas ◽  
Vera Faigl ◽  
...  

Follicular development and oocyte quality were assessed by laparoscopic observation and in vitro fertilisation, respectively, in melatonin-treated (Group M) and control (Group C) anoestrous Chios ewes (n = 10 in each group). Fourteen days after melatonin insertion, all ewes had laparoscopic evaluation of the follicular population followed by oocyte pick-up (OPU); on day 22 intravaginal progestagen sponges were inserted for 14 days. Two days after sponge removal the follicular population was re-evaluated and a second follicular aspiration was performed. Collected oocytes from the second OPU underwent in vitro maturation, fertilisation and culture. The number of large follicles was higher in Group M than in the control ewes during the first OPU and tended to be so (P = 0.06) at the second. Morphologically, oocytes collected from controls were of better quality than those from Group M; however, more oocytes collected from melatonintreated animals fertilised and developed in vitro . These results indicate that melatonin is a potent regulator of follicular development and oocyte competence during the anoestrous period of the ewe.


2014 ◽  
Vol 26 (8) ◽  
pp. 1094 ◽  
Author(s):  
Laura Torres-Rovira ◽  
Antonio Gonzalez-Bulnes ◽  
Sara Succu ◽  
Antonio Spezzigu ◽  
Maria E. Manca ◽  
...  

Circulating anti-Müllerian hormone (AMH) and antral follicle count (AFC) are addressed as suitable markers of oocyte quantity and quality during adulthood. To investigate whether AFC and circulating AMH could predict follicle development and oocyte quality during the prepubertal period we used 40-day-old ewe lambs with high, intermediate and low AFC (≥30, 16–29 and ≤15 follicles respectively). The analysis of the response to the exogenous FSH ovarian reserve test showed a positive correlation between AFC, AMH plasma levels, total follicle number and the number of large follicles (≥3 mm) grown after exogenous FSH administration. The incorporation of abattoir-derived oocytes collected from ovaries with different AFC in an in vitro embryo production system showed that a high AFC can predict oocyte quality in prepubertal ovaries, reflecting an ovarian status suitable for follicular development. The histological quantification of the ovarian reserve evidenced that AFC was not predictive of differences in either the number of healthy follicles or the size of the primordial follicle pool in prepubertal ovaries. Further studies are needed to investigate the implication on the reproductive performance of the significant inter-individual differences found in the present study in AFC and circulating AMH in the early prepubertal period.


2019 ◽  
Vol 31 (1) ◽  
pp. 162
Author(s):  
J. E. Seccafien ◽  
J. M. Kelly ◽  
H. McGrice ◽  
D. O. Kleemann ◽  
K. L. Kind ◽  
...  

Currently, the commercial viability of assisted reproductive embryo technologies within the Australian livestock industry is restricted by individual variability in response to treatment protocols as well as oocyte developmental competence. The majority of losses come from embryo wastage, resulting from poor developmental competence during in vitro embryo production. Follicular fluid is readily available when oocytes are collected for in vitro embryo production from juvenile or mature ewes, making it an appropriate target for analysis of phenotypic markers of oocyte developmental competence. Plasma anti-Müllerian hormone (AMH) is correlated with pregnancy losses, oocyte recovery, and blastocyst development in sheep and cattle and is an indicator for donors that respond best to gonadotrophin stimulation protocols in sheep, cattle, and goats. The aim of the current work was to determine the relationship between follicular fluid AMH and in vitro embryo production outcomes in sheep. Briefly, pairs of ovaries from 38 abattoir-derived lambs were collected individually and transferred to the laboratory. Ovaries were aspirated for in vitro embryo production following previously described methods (Walker et al. 1996 Biol. Reprod. 55, 703-708) and follicles counted. Aspirated oocytes from each of the 38 individual lamb’s pair of ovaries were pooled [n=4.11±0.53 cumulus-oocyte complexes (COC) matured/lamb; total COC matured=156], and remained as such during maturation, fertilisation, and culture. The remaining follicular fluid was centrifuged for 10min at 3000 rpm to remove excess cells and frozen at −20°C. The AMH was measured in follicular fluid by a human AMH Gen II ELISA kit validated for ovine samples (A79766, Beckman Coulter, Brea, CA, USA). Correlations between follicular fluid AMH levels and oocyte maturation and blastocyst development were determined using simple linear regression. Animals were divided into groups based on AMH levels [low (0.5-10.8ng mL−1), medium (10.81-17.89ng mL−1), or high (17.9-19.25ng mL−1)], with an unbalanced ANOVA used to determine group effects on oocyte maturation and blastocyst development (GenStat 18th edition, VSN International, Hemel Hempstead, UK). Follicular fluid AMH was positively correlated (P&lt;0.05) with the number of follicles greater than 2mm (r2=0.120) and the proportion of COC cleaved from recovered oocytes (r2=0.134). The number of COC matured per lamb was greater for those with high and medium versus low AMH (5.6±0.97 and 4.4±0.72 versus 2.1±0.97 COC/lamb). Animals with high AMH produced more blastocysts than those with medium or low AMH, when expressed as a proportion of COC recovered (P&lt;0.002) or cleaved (P&lt;0.009) oocytes. High AMH was also correlated with a greater number of expanded blastocysts produced from cleaved oocytes (P&lt;0.042). The current data support previous evidence that AMH levels positively correlate to higher antral follicle counts. The correlation between AMH and components of oocyte developmental competence suggests intrafollicular AMH may indicate the best oocytes to use for an in vitro embryo production system.


2004 ◽  
Vol 16 (2) ◽  
pp. 262
Author(s):  
D. Rizos ◽  
W. Griffin ◽  
P. Duffy ◽  
M. Wade ◽  
K. Quinn ◽  
...  

High yielding dairy cows are typically in negative energy balance postpartum (pp). It has been shown that initiation of the first pp ovulation and, therefore, the resumption of normal oestrous cycles is delayed in high genetic merit dairy cows and is associated with lower circulating insulin concentration (Gutierrez et al., 1999 J. Reprod. Fertil. 24, 32 abst). Evidence shows that propylene glycol (PG) rapidly elevates systemic concentrations of insulin (Bremmer et al., 2000 J. Dairy Sci. 83, 2239–2251). The aim of this study was to determine the effects of PG feeding to dairy cows in the early pp period, on serum insulin and ovarian function, and on oocyte developmental competence after in vitro maturation, fertilization, and culture. Thirteen Holstein-Friesian cows were assigned to PG (n=6) or control (n=7) groups. Each treated cow received 500mL of PG and each control was given 500mL of water daily from Day 5pp until day of AI. Blood samples for insulin were collected at 0, 30, 60 and 90min post-drenching on Days 5, 15 and 25 pp. All cows were fed 3kg concentrates at milking (twice daily) and had ad libitum access to a 50:50 maize silage : grass silage forage from the time of last blood collection. Oocytes were collected by ovum pick-up (OPU) in four sessions (following treatment with pFSH) beginning on Day 25–35 pp. The recovered oocytes were graded (Grade 1 to 4) in terms of their surrounding cumulus cells and the appearance of the cytoplasm. Grade 1–2 oocytes were matured in vitro, then fertilized using frozen-thawed bull semen, and subsequently cultured up to Day 8 in synthetic oviduct fluid. All data were analyzed using SAS version 6.12 and split-plot designs, following square root or arc sine transformation, if appropriate. PG significantly increased (P&lt;0.001) serum insulin concentration (0min: 1.55±0.19; 30min: 4.48±0.82; 60min: 4.74±0.72; 90min: 4.10±0.56) compared to the control group (0min: 1.91±0.28; 30min 1.96±0.27; 60min: 2.37±0.44; 90min: 2.04±0.26). The follicle size distribution was similar between treated and control cows for categories 2–4mm (4.0±0.47; 4.3±0.70), 8–10mm (3.2±0.47; 2.5±0.39), and &gt;10mm (0.42±0.12; 0.67±0.17). However, there were significantly more follicles in the 5–7mm category (6.2±0.82 v. 3.3±0.43; P&lt;0.05) for treated cows. The number of follicles punctured (13.8±1.02; 10.7±1.04), the number of oocytes recovered (4.5±0.53; 3.5±0.61), and the number of Grade 1–2 oocytes (2.8±0.35; 1.8±0.35) were not different between treated and control cows. Although cleavage rate (68.3 v. 58.9%) and blastocyst yield (25.3 v. 14.4%) were higher for treated cows, the differences were not significant. In conclusion, these results indicate that feeding cows with PG during the early pp period increased the circulating insulin concentration. However, the developmental competence of the recovered oocytes did not differ between the groups.


2021 ◽  
Vol 10 (13) ◽  
pp. 2757
Author(s):  
Xia Hao ◽  
Amandine Anastácio ◽  
Kenny A. Rodriguez-Wallberg

Fertility preservation through ovarian stimulation, aiming at cryopreserving mature oocytes or embryos, is sometimes unsuccessful. This clinical situation deserves novel approaches to overcome infertility following cancer treatment in patients facing highly gonadotoxic treatment. In this controlled experimental study, we investigated the feasibility of in-vitro culturing secondary follicles isolated from superovulated ovaries of mice recently treated with gonadotropins. The follicle yields of superovulated ovaries were 45.9% less than in unstimulated controls. Follicles from superovulated ovaries showed faster growth pace during the initial 7 days of culture and secreted more 17β-estradiol by the end of culture vs controls. Parameters reflecting the outcome of follicular development and oocyte maturation competence in vitro were similar between superovulated and control groups, with a similar follicle size at the end of culture and around 70% survival. Nearly half of cultured follicles met the criteria for in-vitro maturation in both groups and approximately 60% of those achieved a mature MII oocyte, similarly in both groups. Over 60% of obtained MII oocytes displayed normal-looking spindle and chromosome configurations, without significant differences between the groups. Using a validated follicle culture system, we demonstrated the feasibility of secondary follicle isolation, in-vitro culture and oocyte maturation with normal spindle and chromosome configurations obtained from superovulated mice ovaries.


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