92 UTILISATION OF ENDOGENOUS FATTY ACID STORES FOR ENERGY PRODUCTION IN BOVINE PRE-IMPLANTATION EMBRYOS

2012 ◽  
Vol 24 (1) ◽  
pp. 158
Author(s):  
M. Sutton-McDowall ◽  
D. Feil ◽  
R. Robker ◽  
J. Thompson ◽  
K. Dunning

Current embryo culture media are based on the carbohydrate metabolism of embryos. However, little is known about the metabolism of endogenous lipids. This is surprising given the high intracellular lipid densities of embryos of some species and the potential for ATP production via β-oxidation. L-carnitine is a β-oxidation co-factor that is absent in most culture media. The aim of this study is to investigate the influence of carnitine supplementation ± carbohydrates on bovine embryo development. Abattoir-derived cattle cumulus–oocyte complexes were cultured and fertilised (Sutton-McDowall et al. 2006 Biol. Reprod. 74, 881–888). Post-fertilisation (24 h), presumptive zygotes were transferred into an amino acid-free cleavage media ± carbohydrates (glucose, lactate and pyruvate) ±5 mM carnitine and cultured for 4 days. The absence of carbohydrates during culture resulted in embryos arresting at the 2- and 4-cell stages. Remarkably, +carnitine significantly increased development to the morula stage compared with +carbohydrates alone (20.4 ± 3% vs 4.7 ± 2.5% morula development; P < 0.001). The combination of carbohydrates and carnitine supplementation further improved embryo development, with 14-fold more embryos reaching the morula stage after culture in the +carbohydrates +carnitine group compared with the +carbohydrates group (+carbohydrates = 3.1 ± 1.9 vs +carbohydrates +carnitine = 43.8 ± 9.1% morula development; P < 0.05). The beneficial effects of carnitine supplementation on embryo development were reversed when embryos were cultured in presence of etomoxir, a non-reversible inhibitor of the rate-limiting enzyme of β-oxidation (development to 8-cell stage; +carnitine = 33.9 ± 8% vs +carnitine +etomoxir = 19.2 ± 4.9%; P < 0.05). Intracellular lipid content of embryos +carnitine was determined by culturing presumptive zygotes in media -carbohydrates ± carnitine for 24 h. Lipid content of embryos was determined by measuring BODIPY 493/503 dye fluorescence. Carnitine supplementation reduced fluorescence intensity 1.8-fold (P < 0.001). Adenosine triphosphate and ATP:ADP levels were measured in embryos after 24 h of culture ± carbohydrates ± carnitine. While there was a trend for +carnitine to increase ATP levels (P = 0.09), ADP levels were higher and ATP:ADP ratio were 1.9-fold lower (main effect, P < 0.05) compared with embryos cultured in –carnitine. This indicates +carnitine embryos were more metabolically active, with higher rates of ATP-ADP conversion. We have shown carnitine supplementation supports pre-compaction embryo development and there is an additive effect of +carnitine +carbohydrate on early embryo development. This is most likely through increased β-oxidation levels within embryos. Current disparities between in vivo and in vitro embryo production, in particular increased lipid content (Romek et al. 2010 Theriogenology 74, 265–276) and decreased developmental potential of in vitro-produced embryos, may be an artefact resulting from limited lipid oxidation in vitro.

2016 ◽  
Vol 28 (8) ◽  
pp. 1172 ◽  
Author(s):  
Luis Baldoceda ◽  
Dominic Gagné ◽  
Christina Ramires Ferreira ◽  
Claude Robert

The decreased rate of pregnancy obtained in cattle using frozen in vitro embryos compared with in vivo embryos has been associated with over-accumulation of intracellular lipid, which causes cell damage during cryopreservation. It is believed that the higher lipid content of blastomeres of bovine embryos produced in vitro results in darker-coloured cytoplasm, which could be a consequence of impaired mitochondrial function. In this study, l-carnitine was used as a treatment to reduce embryonic lipid content by increasing metabolism in cultured bovine embryos. We have observed previously that in vivo embryos of different dairy breeds collected from cows housed and fed under the same conditions differed in lipid content and metabolism. As such, breed effects between Holstein and Jersey were also examined in terms of general appearance, lipid composition, mitochondrial activity and gene expression. Adding l-carnitine to the embryo culture medium reduced the lipid content in both breeds due to increased mitochondrial activity. The response to l-carnitine was weaker in Jersey than in Holstein embryos. Our results thus show that genetics influence the response of bovine embryos to stimulation of mitochondrial metabolism.


2014 ◽  
Vol 26 (1) ◽  
pp. 154
Author(s):  
G. Singina ◽  
T. Taradajnic ◽  
N. Taradajnic ◽  
N. Zinovieva

The culture of in vitro matured and fertilized oocytes is a critical step of in vitro production of bovine embryos. Generally, oocytes are co-incubated with sperm in TALP medium containing different additions and then zygotes are transferred to a medium with another composition. At the same time the effect of the medium alteration on the development of early embryos is unknown. Continual adjustment of fertilized oocytes to the changing culture environment may result in a reduction of their developmental potential. The aim of the present study was to compare effects of two different culture systems on the embryo development and subsequent pregnancy rate in cattle. Slaughterhouse-derived cumulus–oocyte complexes were matured for 24 h in TCM-199 supplemented with 10% FCS, 0.2 mM sodium pyruvate, 10 μg mL–1 porcine FSH, and 5 μg mL–1 ovine LH. Frozen/thawed sperm from different Russian Black Pied bulls were prepared in Sperm-TALP medium by swim-up procedure. In vitro matured oocytes were co-incubated for 18 h with prepared sperm in the modified Fert-TALP medium containing 10 μg mL–1 heparin, PHE (20 μM penicillamine, 10 μM hypotaurine, 1 μM epinephrine), and 0.1% MEM nonessential amino acids. The embryo culture was carried out using 2 systems. A total of 340 presumptive zygotes were incubated in CR1aa medium (Rosenkrans et al. 1994 J. Anim. Sci. 72, 434–437) up to Day 5 post-insemination (System 1) and a total of 442 presumptive zygotes were incubated for 24 h in a fresh Fert-TALP medium without PHE and heparin and then cleaved embryos were transferred to CR1aa medium and incubated until Day 5 post-insemination (System 2). Thereupon, the embryos were transferred to a fresh CR1aa medium supplemented with 5% FCS and cultured for 3 or 5 days. The embryo development was evaluated at Days 2, 8, and 10 for cleavage and blastocyst formation and hatching rates, respectively. A portion of blastocysts (of Grade 1 according to IETS classification) obtained at Day 8 were immediately transferred to recipients or were frozen in 1.5 M ethylene glycol and stored in liquid nitrogen until transplantation. The embryo development data (from 6–8 replicates) were analysed by ANOVA and the embryo transplantation data were analysed using the chi-squared test. The cleavage rates did not differ among Systems 1 and 2 and were 63.6–65.7%. On the other hand, the significant differences between culture Systems 1 and 2 were detected in rates of blastocysts (21.9 ± 1.4 v. 28.8 ± 2.8; P < 0.05) and hatched blastocysts (7.2 ± 1.2 v. 12.3 ± 1.6; P < 0.05). The pregnancy rate for frozen embryos was also higher (but not significantly) in System 2 than in System 1 [26.3% (9/34) v. 16.7% (2/12)], whereas for fresh embryos the similar values of the pregnancy rate were observed [on average 42.9% (6/14)]. Thus the additional 24-h culture of zygotes in Fert-TALP medium favourably affects bovine embryo development in vitro.


2010 ◽  
Vol 22 (1) ◽  
pp. 323 ◽  
Author(s):  
M. G. Catalá ◽  
D. Izquierdo ◽  
R. Romaguera ◽  
M. Roura ◽  
M. T. Paramio

The aim of this study was to assess the effect of an in vitro growth medium (De Wu et al. 2006 Biol. Rep. 75, 547-554) in prepubertal ewe oocytes selected by the brilliant cresyl blue (BCB) test. Prepubertal ewe oocytes were recovered by slicing ovaries of slaughtered animals and immediately exposed during 1 h to 13 μM BCB and classified according to their cytoplasm coloration (Rodriguez-Gonzalez E et al. 2002 Theri- ogenology 57(5), 1397-1409): BCB+ (blue cytoplasm, hypothetically grown oocytes) and BCB- (uncolored cytoplasm, hypothetically growing oocytes). Uncolored oocytes (BCB-) were matured using three culture media: growth medium (GM: TCM-199, 0.04 μg mL-1 FSH, 0.04 μg mL-1 LH, 0.004 μg mL-1 estradiol, 100 μg mL-1 ascorbic acid, and 5 μL mL-1 ITS: insulin transferrin selenium), conventional maturation medium (CM: TCM-199, 10 μg mL-1 FSH, 10 μg mL-1 LH and 1 μg mL-1 estradiol) and modified maturation medium (MM: CM with the addition of 100 μg mL-1 ascorbic acid and 5 μL mL-1 ITS). Oocytes were matured in GM for 12 h and then separated into 2 groups, CM (GM+CM) and MM (GM+MM) for another 12 h of maturation. Two extra groups of BCB- oocytes were directly cultured for 24 h in CM or MM media (BCB-/CM and BCB-/MM). Colored oocytes (BCB+) and a control group (oocytes not exposed to BCB) were matured for 24 h in CM. All groups were cultured at 38.5°C and 5% CO2 in humidified atmosphere. Fertilization took place in SOF medium supplemented with 10% of estrous sheep serum during 20 h with a sperm concentration of 1 × 106 spermatozoa/mL. Presumptive zygotes were cultured for 8 days in SOF with 10% FCS at 38.5°C, 5% CO2 and 5% O2. Results are shown in Table 1. The percentage of morula plus blastocyst obtained from BCB - oocytes was significantly increased in oocytes exposed to growth medium (containing ITS, ascorbic acid and low hormone concentrations; groups GM+CM and GM+MM) for the first 12 h. An increasing tendency has also been observed in blastocyst yield in these two groups. Regarding maturation rate, no differences were found in all groups (data not shown). In conclusion, as De Wu et al. (2006) showed in prepubertal gilts, we also achieved some improvements in embryo development of growing oocytes when the first 12 h of maturation took place in a growth medium. However, embryo developmental potential of BCB- oocytes is still lower compared with that of BCB+ oocytes. Table 1.Effect of GM on embryo development of BCB- oocytes Grant sponsor Spanish Ministry of Science and Innovation.Code: AGL2007-60227-CO2-01


2011 ◽  
Vol 59 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Santiago Varga ◽  
Carmen Diez ◽  
Lina Fernández ◽  
Jenny Álvarez ◽  
Adelino Katchicualula ◽  
...  

The optimum culture system for in vitro matured and fertilised oocytes still remains to be clarified. Culture media (CM) for mammalian embryos are routinely prepared fresh for use and preserved under refrigeration during one or two weeks. The purposes of this work were (1) to compare the efficiency of a synthetic oviduct fluid (SOF) with two different bovine serum albumin (BSA) concentrations (3 and 8 g/L) for the in vitro production of bovine blastocysts, (2) to test the effect of timing on adding fetal calf serum (FCS) to the SOF, and (3) to evaluate the effects on bovine embryo development of freezing and lyophilisation as procedures for preserving the SOF. Supplementation of SOF with 3 g/L BSA increased Day-7 blastocyst expansion rates (18.3 ± 1.6 vs. 14.4 ± 0.7; P < 0.05), although no differences in hatching rates were found. Addition of FCS to SOFaa (SOF with amino acids) medium supplemented with sodium citrate (SOFaaci) at 48 and at 72 h post-insemination (PI) allowed obtaining higher Day-6 embryo development rates than when FCS was added at 18 or 96 h PI (Day-6 morulae + blastocyst rate: 30.0 ± 1.1, 40.8 ± 1.1, 43.9 ± 2.3 and 39.3 ± 0.5 for FCS addition at 18, 48, 72 and 96 h, respectively). Hatching rates were significantly improved when serum was added at 72 h PI. Finally, both refrigeration and lyophilisation appeared as useful cryopreservation procedures for SOFaaci, although a significant loss of its ability to support embryo development, compared to the control fresh culture medium, was observed.


Author(s):  
Orhan Örnek ◽  
Yusuf Ziya Güzey

Progesterone plays a key role in the establishment and maintenance of pregnancy in mammalian. Increasing levels of circulating progesterone in the post-conception period are associated with conceptus elongation and high pregnancy rates in cattle. Contradictory results are available on the direct role of progesterone in early embryo development. The objective of this study was to evaluate direct effects of progesterone on in vitro development of cattle embryos. Immature oocytes collected from slaughtered animals and cultured in the presence of different concentrations of progesterone (25, 50, 100 ng/mL) following in vitro fertilization. Cleavage rates in 25 and 50 ng/mL concentrations of progesterone were significantly higher than those in controls and 100 ng/mL. Rate of embryos that reached to the morula stage was similar in all groups. Supplementation of 25 and 50 ng/mL progesterone to the culture media significantly increased blastocyst yield while 100 ng/mL progesterone resulted in a decrease. As a conclusion, we can suggest that progesterone supplementation in in vitro culture may support embryo development at low levels.


2010 ◽  
Vol 22 (1) ◽  
pp. 302
Author(s):  
E. A. Ordoñez-Leon ◽  
G. Cancino ◽  
J. Hernandez-Ceron ◽  
J. A. Medrano ◽  
Y. C. Ducolomb ◽  
...  

Bovine embryo development in vitro can be affected by many factors, including protein source, which can cause embryo development failure. The use of in vitro culture media supplemented with serum-free compounds could allow a better understanding of embryo requirements during the preimplantation stages by eliminating a highly variable and undefined compound such as serum. The objective of this study was to evaluate the effect of 3 different protein supplements used during IVM, IVF, and IVC on embryo production. Ovaries were collected from slaughtered cows and then aspirated to obtain oocytes for in vitro embryo production procedures. A total of 2056 oocytes were used, from which 685 were processed with maturation medium supplemented with 10% serum replacement (SR) (Gibco Knockout Serum Replacement, Invitrogen, Carlsbad, CA, USA), a defined serum-free formulation (TCM-199 + SR), fertilization medium with SR (TALP + SR), and culture medium with SR (SOF + SR). These were compared with 675 and 696 oocytes processed with the same IVM, IVF, and IVC media, but supplemented with 10% FCS or 10% heat-inactivated estrous cow serum (ECS), respectively. Data obtained from the variables studied were processed by analysis of variance and means were compared by Tukey’s test. The percentages of embryos produced with FCS (52.4%) and ECS (52.7%) were significantly higher compared with the percentage obtained with SR (41.5%) (P < 0.05). The percentages of morulae were similar in the groups supplemented with FCS (36.5%) and SR (36.7%), but significantly higher than the percentage in the ECS group (26.9%) (P < 0.05). For blastocysts, the percentages of embryos developed with FCS (35.2%) and ECS (35.6%) were significantly higher than that obtained with SR (29.2%) (P < 0.05). When evaluating expanded blastocysts, the percentage obtained in the FCS (45.9%) group was significantly higher than that in the ECS group (33.2%), and this was significantly higher than that obtained in SR (21%), with all these differences being significant (P < 0.05). It is concluded that it is possible to produce bovine embryos in vitro using FCS, ECS, or SR as supplements in IVM, IVF, and IVC media. Significant differences were found in different embryo stages, with the highest proportion of embryos developing with the addition of FCS, whereas supplementation with SR only improved the production of morulae. We thank Consejo Nacional de Ciencia y Tecnologia (CONACYT-Mexico) for the graduate student’s scholarship.


2019 ◽  
Vol 31 (1) ◽  
pp. 156 ◽  
Author(s):  
B. Melo-Baez ◽  
E. Mellisho ◽  
L. Rodriguez-Alvarez

Extracellular vesicles (EV) are currently considered a mechanism of cell communication. These are secreted from different cell types, including embryos, to serve as mediators of short and long distance signals. EV can be identified in vivo in different biological fluids, as well as in vitro embryo culture medium. Usually, media used for embryo in vitro culture are supplemented with serum or other protein sources that favour cell proliferation and development. Serum and protein sources contain EV, including microvesicles and exosomes that in principle can be internalized by embryonic cells. The aim of this study was to evaluate if serum-derived EV are internalized by the embryo at different stages of the early development, and if EV from the serum are required for in vitro bovine embryo development. For that, it was first evaluated if EV depleted culture media affect embryo development up to the blastocyst stage; oocytes were in vitro matured for 22 to 23h and in vitro fertilized for 18h. Posteriorly, presumptive zygotes were in vitro cultured in groups (25 embryos/well in 4-well plates) in SOF or SOF depleted of EV for 8 days. To evaluate EV internalization, culture media was supplemented with labelled EV and confocal imaging was performed. The EV were obtained by ultrafiltration (centrifugal filter devices 100 kDa, Amicon; Millipore, Billerica, MA, USA) for 15min at 3000 rpm. Then, EV were stained with PKH67 dye and washed 3 times with PBS by ultrafiltration to remove excess dye. The EV labelled with PKH67 were resuspended in SOFaa depleted of EV (3×109 particles per 500µL) and supplemented for 24h at the 1-cell stage (Day 1 post IVF), 16 cells (Day 4 post IVF), and early blastocyst (Day 6 post IVF) in 5% CO2, 5% O2, and 90% N2. PBS with PKH67 dye was used as a control treatment. Hoechst 33343 was used to label the nuclei before washing with PBS and fixation with 0.4% paraformaldehyde. Images were acquired on a Zeiss (Zeiss, Jena, Germany) LSM 780 confocal microscope. There were no statistical differences on blastocyst rate at Day 8 between embryos cultured in SOF depleted of EV (19.5%) and control group (SOF; 22.7%; P&gt;0.05). We observed punctuated green fluorescence near the embryo nuclei in the 3 stages studied in embryos supplemented with EV but not in the control treatment, which indicates that EV from serum are uptaken by embryonic cells in early development. Therefore, we demonstrated uptake of EV from fetal calf serum added to culture media, although its absence does not affect embryo development. Research was supported by FONDECYT, Chile (1170310).


Author(s):  
Yulia N Cajas ◽  
Karina Cañón-Beltrán ◽  
Carolina Núñez-Puente ◽  
Alfonso Gutierrez-Adán ◽  
Encina M González ◽  
...  

Abstract During preimplantational embryo development, PI3K/AKT regulates cell proliferation and differentiation and nobiletin modulates this pathway to promote cell survival. Therefore, we aimed to establish whether, when the AKT cascade is inhibited using inhibitors III and IV, nobiletin supplementation to in vitro culture media during the minor (2 to 8-cell stage, MNEGA) or major (8 to 16-cell stage, MJEGA) phases of EGA is able to modulate the development and quality of bovine embryos. In vitro zygotes were cultured during MNEGA or MJEGA phase in SOF + 5% FCS or supplemented with: 15 μM AKT-InhIII; 10 μM AKT-InhIV; 10 μM nobiletin; nobiletin+AKT-InhIII; nobiletin+AKT-InhIV; 0.03% DMSO. Embryo development was lower in treatments with AKT inhibitors, while combination of nobiletin with AKT inhibitors was able to recover their adverse developmental effect and also increase blastocyst cell number. The mRNA abundance of GPX1, NFE2L2, and POU5F1 was partially increased in 8- and 16-cell embryos from nobiletin with AKT inhibitors. Besides, nobiletin increased the p-rpS6 level whether or not AKT inhibitors were present. In conclusion, nobiletin promotes bovine embryo development and quality and partially recovers the adverse developmental effect of AKT inhibitors which infers that nobiletin probably uses another signalling cascade that PI3K/AKT during early embryo development in bovine.


Sign in / Sign up

Export Citation Format

Share Document