scholarly journals Effects of heat stress on development, quality and survival of Bos indicus and Bos taurus embryos produced in vitro

2013 ◽  
Vol 79 (2) ◽  
pp. 351-357 ◽  
Author(s):  
C.F. Silva ◽  
E.S. Sartorelli ◽  
A.C.S. Castilho ◽  
R.A. Satrapa ◽  
R.Z. Puelker ◽  
...  
Keyword(s):  
2011 ◽  
Vol 23 (1) ◽  
pp. 203
Author(s):  
F. Paludo ◽  
M. M. Pereira ◽  
C. C. R. Quintao ◽  
L. T. Iguma ◽  
M. M. Gioso ◽  
...  

Heat stress has been a challenge for bovine reproduction in tropical and subtropical environments. Although the role of the oocyte in thermotolerance has been studied, little attention has been paid to the contributions of sperm to embryo resistance to heat shock. The current study aimed to evaluate the development of fertilized and nonfertilized (parthenogenetic) bovine embryos undergoing heat stress during the pre-implantation stage. Cumulus–oocyte complexes obtained from ovaries collected from Bos indicus × Bos taurus crossbred cows at slaughter were in vitro matured with TCM-199 supplemented with 20 μg mL–1 of FSH, under 5% CO2 at 38.5°C for 24 h. Afterward, oocytes were randomly allocated into 2 groups: 1) IVF and 2) PART (chemical activation for parthenogenesis induction). In vitro-fertilized oocytes were cultured with 2.0 × 106 Holstein sperm mL–1 in Fert-TALP medium supplemented with heparin, for 20 h. For chemical activation, oocytes were activated with calcium ionomycin for 4 min, followed by 6-DMAP for 4 h, both in CR2aa medium supplemented with 0.1% BSA. Presumptive IVF (n = 1 262) or PART (n = 1 206) zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% of FCS under 5% CO2, 5% O2, and 90% N2 at 38.5°C. At 44 h post-insemination or chemical activation, embryos were exposed to 38.5 or 41°C for 12 h in an atmosphere of 5% CO2, 5% O2, and 90% N2. After that, embryos were cultured at 38.5°C under 5% CO2, 5% O2, and 90% N2 until Day 8 post-insemination. Blastocyst rates were evaluated at Day 7 and Day 8 post-insemination and were calculated based on the total number of presumptive zygotes. Blastocysts at 192 h post-insemination or activation were fixed and permeabilized for TUNEL assay (DeadEndTM Florimetric TUNEL System, Promega, Madison, WI) according to the manufacturer’s instructions. The effect of heat stress was compared within groups (IVF or PART) and the data were analysed by ANOVA. As expected, heat stress reduced the blastocyst rate of IVF embryos at Day 7 (24.3 ± 2.0% and 17.4 ± 2.2% for nonstressed and stressed IVF embryos; P < 0.05) and at Day 8 (32.4 ± 1.9% and 23.0 ± 2.1% for nonstressed and stressed IVF embryos; P < 0.01). However, the effect of heat stress on blastocyst rate of PART embryos was observed only at Day 8 post-insemination (30.0 ± 1.7% and 22.6 ± 2.0% for nonstressed and stressed PART embryos; P < 0.05), with no difference in blastocyst rate at Day 7 (21.6 ± 1.5% and 18.2 ± 1.8% for nonstressed and stressed PART embryos; P > 0.05). There was no difference in total cell numbers between nonstressed and stressed IVF or PART embryos. Apoptosis cell numbers and the apoptotic cell index were higher (P < 0.05) for stressed IVF (18.45 ± 1.24 and 0.16 ± 0.00) and PART (16.40 ± 5.20 and 0.17 ± 0.00) embryos than for nonstressed IVF (13.70 ± 0.75 and 0.13 ± 0.00) and PART (14.15 ± 0.86 and 0.13 ± 0.00) embryos. In conclusion, heat stress can induce apoptosis in both IVF and PART embryos, but its effect on pre-implantation development may occur at earlier stages in IVF embryos when compared with PART embryos. Financial support from Fapemig and CNPq.


2012 ◽  
Vol 24 (1) ◽  
pp. 199
Author(s):  
C. F. Silva ◽  
A. C. S. Castilho ◽  
R. A. Satrapa ◽  
R. Z. Puelker ◽  
E. M. Razza ◽  
...  

Heat stress (HS) reduces the production of bovine embryos, especially taurine embryos, which are not adapted to heat. However, little is known about the competence of embryos produced under HS in breeds adapted or not adapted to heat. The aim of this study was to compare the gene expression of PLAC8, HSF1, COX2 and CDX2, related to competence and implantation, in bovine in vitro-produced embryos (Bos taurus vs Bos indicus), submitted or not submitted to HS. Oocytes from Nelore (zebu) and Jersey (taurine) cows were aspirated by ovum pickup, in vitro-matured in TCM-199 medium with bicarbonate containing 10% FCS, 2 μg mL–1 of pyruvate, 75 μg mL–1 of gentamicin, 20 μg mL–1 of FSH and 10 IU mL–1 of LH for 22 h at 38.5°C in 5% CO2 in air. Matured oocytes were fertilized with semen from Nelore (n = 6) and Jersey (n = 6) bulls, respectively, at 38.5°C in 5% CO2 in air. The fertilization medium was TALP-IVF supplemented with 6 mg mL–1 of fatty acid-free BSA, 2 μL mL–1 of pyruvate, 75 μg mL–1 of gentamicin, 11 μg mL–1 of heparin and 44 μL mL–1 of penicillamine, hypotaurine and epinephrine. The day of fertilization was considered Day 0. Twelve hours post-insemination, presumptive zygotes were denuded and randomly divided into 2 groups, nonstressed or stressed and both were in vitro cultured at 38.5°C in 90% N2, 5% CO2 and 5% O2 in SOFaaci medium supplemented with 5% FCS, 5% BSA and 0,2% sodium pyruvate. In the stressed group, 96-h post-insemination embryos were subjected to HS of 41°C for 6 consecutive hours and then returned to 38.5°C. On Day 7, pools with 5 blastocysts [Nelore (n = 9); Nelore HS (n = 7); Jersey (n = 5); Jersey HS (n = 5)] were subjected to RNA extraction (RNeasy, Qiagen Inc., Valencia, CA, USA). The expression of target genes was analysed by real-time reverse transcription PCR with oligo-dT in reverse transcription and bovine specific-primers in PCR. The expression of cyclophilin A was used as an internal control. The mean mRNA levels of target genes among groups were compared by parametric ANOVA, followed by orthogonal contrast. Heat stress reduced (P < 0.05) mRNA expression of CDX2 and PLAC8 in both breeds; additionally, the expression of these genes was higher in the zebu breed when compared with the taurine breed. Messenger RNA expression of COX2 did not differ between groups, under HS or not, in both the Jersey and Nelore breeds. Moreover, HS reduced the mRNA expression of HSF1 (P < 0.05) in Nelore groups, but not in Jersey groups. The highest levels of PLAC8 and CDX2 in nonstressed Nelore embryos indicate better competence and a higher capacity of implantation of these embryos when compared with Jersey and HS embryos in both breeds. Moreover, low HSF1 levels in stressed Nelore embryos indicate the thermotolerance ability of this breed. In conclusion, the data indicate that HS alters the pattern of gene expression in Nelore and Jersey in vitro-produced bovine embryos. This research was supported by FAPESP.


2021 ◽  
pp. 102998
Author(s):  
Bianca Vilela Pires ◽  
Nedenia Bonvino Stafuzza ◽  
Luara Afonso de Freitas ◽  
Maria Eugênia Zerlotti Mercadante ◽  
Ester Silveira Ramos ◽  
...  

2010 ◽  
Vol 22 (1) ◽  
pp. 285
Author(s):  
S. Wohlres-Viana ◽  
M. M. Pereira ◽  
A. P. Oliveira ◽  
J. H. M. Viana ◽  
M. A. Machado ◽  
...  

The Zebu breeds (Bos indicus) are different from European breeds (Bos taurus) in some aspects of their reproductive physiology, including follicle recruitment, number of follicular waves, and oocyte ultrastructure. On the other hand, embryos produced in vivo and in vitro show morphological and developmental differences, which can be related to culture environment. The aim of this study was to evaluate the effect of breed (Gyr v. Holstein) within embryo production system (in vivo and in vitro), as well as effect of production systems within breeds on relative abundance of transcripts related to formation, survival, and subsequent development of blastocysts, such as those involved in water and small solutes transport (Aquaporins 3 and 11), blastocoel formation (Na+/K+-ATPase a1 and |52), and cellular stress response (Peroxiredoxin 1). For in vivo embryo production, donors were superstimulated with FSH and inseminated, and embryos were recovered 7 days after AI. For in vitro embryo production, oocytes recovered by ovum pickup were in vitro matured and fertilized and then cultured for 7 days in culture medium under 5% CO2 at 38.5°C. For each group, blastocysts (n = 15) distributed in 3 pools were used for RNA extraction (RNeasy MicroKit, Qiagen, Valencia, CA, USA), followed by RNA amplification (Messageamp II amplification kit, Ambion-Applied Biosystems, Foster City, CA, USA) and reverse transcription (SuperScript III First-Stand Synthesis Supermix, Invitrogen, Carlsbad, CA, USA). The cDNA were submitted to real-time PCR, using the H2a gene as endogenous control, and analyzed by REST© software. To evaluate breed effect within the production systems, 2 comparisons were performed: (1) in vivo: Gyr v. Holstein and (2) in vitro: Gyr v. Holstein, considering Holstein data as 1.00. To evaluate production system effect within breeds, 2 comparisons were performed: (1) Gyr: in vivo v. in vitro and (2) Holstein: in vivo v. in vitro, considering in vivo produced embryo data as 1.00. The results are shown as mean ± SEM. For in vivo comparison between breeds, Aquaporin 3 (1.66 ± 0.77), Na+/K+-ATPase a1 (1.61 ± 0.56), and Peroxiredoxin 1 (1.61 ± 0.66) were up-regulated (P < 0.05) in Gyr embryos when compared with Holstein embryos, whereas for in vitro comparison, no differences (P > 0.05) were found. For comparisons between production systems within breeds, only Peroxiredoxin 1 (0.31 ± 0.39) was down-regulated (P < 0.01) in in vitro produced Gyr embryos when compared with in vivo counterparts. No differences (P > 0.05) were found between production systems for the Holstein breed. In conclusion, these data suggest that there is a difference on gene expression between Bos taurus and Bos indicus blastocysts, but such difference between breeds can be attenuated by the in vitro production system, indicating an embryo adaptation to the in vitro culture conditions. The data also suggest that the in vitro production system can influence the amount of transcripts in Gyr embryos. Other genes should be evaluated for a better understanding of these differences. Financial support was provided by CNPq and FAPEMIG.


2009 ◽  
Vol 21 (1) ◽  
pp. 160
Author(s):  
L. Nasser ◽  
P. Stranieri ◽  
A. Gutiérrez-Adán ◽  
M. Clemente ◽  
L. Jorge de Souza ◽  
...  

Brazil is a leading country in the world of commercial use of in vitro-produced bovine embryos with 200 000 transfers per year. The majority of in vitro-produced embryos are pure breed Nelore and are transferred fresh with 40% pregnancy rate. However, pregnancies are drastically reduced with frozen in vitro embryos. This experiment is part of our effort to learn more about molecular composition and morphology of in vitro-derived embryos that may be responsible for such discrepancy. We examined molecular expression of mRNA transcripts of 6 selected genes; apoptosis Bax,TP53(p53), SHC1SHC(p66), insulin growth factor receptor (IGF2R), stabilization of the plasma membrane PLAC8 and glucose conversion H6PD in in-vivo (control) and in-vitro Nelore and Bos taurus embryos. In vivo embryos were collected from superovulated cows at Day 7. In vitro embryo was produced from oocytes aspirated from live cows. A total of 284 oocytes (4 replicates) were matured and fertilized by standard IVF procedures. Presumptive zygotes were cultured in CR2 medium with 5% BSA in 50 μL drops (25 zygotes per drop) at 39°C under paraffin oil and 5% CO2 in humidified air. Embryos that developed on Days 7 to blastocyst were transferred to recipients, and 10 blastocysts from each replicate were frozen for evaluation of gene expression patterns. Poly(A) mRNA was prepared from 3 groups of pools of 10 in vitro embryos and 10 of control in vivo-derived embryos. The quantification of all gene transcripts was carried out by real-time quantitative RT-PCR using the comparative CT method. Data on mRNA expression were normalized to the endogenous H2a.z and was analyzed by one-way repeated-measures ANOVA. The cleavage rates at Day 2 and number of blastocysts developed at Day 7 were 80.3 ± 3.2 and 42.2 ± 6.4, respectively. The level of expression of IGF2R was significantly (P < 0.05) higher in in vivo-derived embryos than in both groups of in vitro embryos. The expression of all 3 apoptosis genes were lower (P < 0.05) in in vivo than in vitro embryos with exception of p53 gene that was not different between Nelore in vitro and in vivo embryos but was significantly higher (P < 0.05) in Bos taurus in vitro embryos. There was no difference in expression of PLAC8 gene among any tested group of embryos and in expression of H6PD gene between Nelore in vitro and in vivo embryos. We concluded that significant differences in molecular makeup between in vitro and in vivo-derived Nelore embryos exist. Of particular importance seems to be pattern of expression of IGF2R receptor gene known as a good indicator of embryo quality, which promotes proliferation and differentiation. Similarly, higher expression of 2 BAX and p66 genes of apoptosis in in vitro embryos seems to be a further indication of inferior quality of Nelore in vitro-derived embryos that showed to be more profound in Bos taurus in vitro-derived embryos.


2010 ◽  
Vol 22 (1) ◽  
pp. 248 ◽  
Author(s):  
J. H. F. Pontes ◽  
K. C. F. Silva ◽  
A. C. Basso ◽  
C. R. Ferreira ◽  
G. M. G. Santos ◽  
...  

In recent years, Brazil has become the leading country in the world for the number of embryos produced in vitro (Thibier M 2009 IETS Embryo Transfer Newsletter 22, 12-19). This is partly due to the large numbers of Bos indicus animals in Brazil, making up about 80% of the total cattle. The mean oocyte production per ultrasound-guided follicular aspiration from Bos indicus is higher than those for European breeds (Pontes JHF et al. 2009 Theriogenology 71, 690-697). In the present study, we analyzed 5407 ovum pick ups (OPU) and compared the average production of total (n = 90,086) and viable (n = 64,826) oocytes and the number of embryos produced in vitro from Gir (Bos taurus indicus), Holstein (Bos taurus taurus), 1/4 Holstein × 3/4 Gir, and 1/2 Holstein-Gir crossbreed cows. To obtain oocytes, OPU was repeated from 4 to 7 times (mean = 5.7 ± 2.4) in each donor cow aged from 3 to 7 years (mean = 5.0 ± 2.3) during a 12-mo period. COCs (n = 90,086) obtained were classified according to the presence of cumulus cells and the oocyte cytoplasm aspect (homogeneous or heterogeneous/fragmented). The viable oocytes (n = 64,826) were in vitro matured for 24 h at 38.8°C in an atmosphere of 5% CO2 in air. Since this was a commercial programm, frozen sexed semen (2 × 106 mL-1) from Gir (n = 8) or Holstein (n = 7) sires previously tested for high efficiency was used for IVF. Fertilization was carried out (18-20 h) and the presumed embryos were cultured for 7 days in the same conditions as were used for IVM. Data were analyzed by ANOVA. On average, 16.7 ± 6.2 oocytes were obtained per OPU/IVF procedure and 71.96% were considered viable. The mean numbers of total oocytes per OPU/IVF procedure were 17.1 ± 4.4 for Gir cows (n = 617), 11.4 ± 3.9 for Holstein cows (n = 180), 20.4 ± 5.8 for 1/4 Holstein × 3/4 Gir (n = 44), and 31.4 ± 5.6 for 1/2 Holstein-Gir crossbreed females (n = 37, P < 0.01). The mean numbers of viable oocytes per OPU/IVF procedure were 12.1 ± 3.8 for Gir cows, 8.0 ± 2.6 for Holstein cows, 16.8, ± 5.0 for 1/4 Holstein × 3/4 Gir, and 24.3 ± 4.7 for 1/2 Holstein-Gir crossbreed females (P < 0.01). The average number of embryos produced by OPU/IVF were 3.2 (n = 12,243/3378) for Gir cows, 2.2 (n = 2426/1138) for Holstein cows, 3.9 (n = 1033/267) for 1/4 Holstein × 3/4 Gir, and 5.5 (n = 1222/224) for 1/2 Holstein-Gir. The average number of embryos produced per IVF session from 1/2 taurus × indicus donor cows was greater (P < 0.01) than from Bos indicus cows. The number of recoverable and viable oocytes and the number of embryos produced in vitro from Bos indicus donors were higher than from Bos taurus females. Therefore, the highest oocyte yield and the greatest embryo production were obtained from 1/2 taurus × indicus females. This work was supported by In Vitro Brasil.


1966 ◽  
Vol 21 (6) ◽  
pp. 1784-1790 ◽  
Author(s):  
J. D. Skinner ◽  
G. N. Louw
Keyword(s):  

2015 ◽  
Vol 98 (5) ◽  
pp. 3086-3099 ◽  
Author(s):  
J.N.S. Sales ◽  
L.T. Iguma ◽  
R.I.T.P. Batista ◽  
C.C.R. Quintão ◽  
M.A.S. Gama ◽  
...  

2009 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Fernando Cerquera M. ◽  
Rodrigo Martínez S. ◽  
Rubén Toro O. ◽  
Jaime Tobón C. ◽  
Jaime Gallego G. ◽  
...  

<p>La resistencia natural a la brucelosis en bovinos ha sido asociada a factores genéticos, principalmente a algunos polimorfismos de nucleótido simple ubicados dentro del gen Nramp1. La presente investigación evalúa el efecto de variantes tipo polimorfismos de nucleótido simple presentes en regiones codificantes y en la región 3’UTR del gen Nramp1, en la clasificación de los animales como resistentes o susceptibles; además se determinan los genotipos predominantes en animales naturalmente infectados y comprobados como positivos por la presencia de anticuerpos anti <em>Brucella abortus</em>. Se establecieron las frecuencias genotípicas y alélicas para cinco polimorfismos de nucleótido simple identificados dentro del gen Nramp1 en animales de las razas blanco orejinegro (<em>Bos taurus taurus</em>) y cebú (<em>Bos taurus indicus</em>) y en muestras serológicamente positivas provenientes de animales cruzados (<em>Bos taurus </em>x <em>Bos indicus</em>). La determinación de genotipos se realizó mediante la metodología polimorfismo conformacional de cadena sencilla. Se realizó un ensayo de desafío infeccioso in vitro, para estimar la capacidad de los macrófagos bovinos para controlar la sobrevivencia bacterial, lo que permitió definir los individuos como resistentes o susceptibles. Los resultados sugieren una asociación significativa del SNP4 (<em>p </em>= 0,0506) con la variación para el fenotipo de susceptibilidad, pues se encontró el genotipo homocigoto (BB) en alta frecuencia en animales catalogados como resistentes y el genotipo heterocigoto (AB) en alta frecuencia en animales catalogados como susceptibles y en animales con títulos de anticuerpos anti <em>Brucella abortus</em>.  </p><p> </p><p><strong>Allelic frequencies for SNP variants in the gene Nramp1 in bovine infected with </strong><strong><em>Brucella abortus </em></strong><strong>or classified by resistance to the pathogen</strong>  </p><p>The natural resistance to brucellosis in cattle has been associated to genetic factors mainly to some single nucleotide polymorphism (SNP), located within Nramp1 gen. The current research has studied the effect of nucleotide variants to be found in coding regions and other one located in 3 non translated region of Nramp1 gene, on the animal classification as resistant or susceptible, moreover was identified the main genotypes to be found on the infected animals, confirmed as positives by antibody antibrucella titles. Was established the genotypic and allelic frequencies for five single nucleotide polymorphism in animals from blanco orejinegro (<em>Bos taurus taurus</em>) and zebu breeds (<em>Bos taurus indicus</em>) and serum samples belonging to positive crossbred animals (<em>Bos taurus x Bos indicus</em>). The genotype was defined by the methodology known as “single strand conformational polymorphism”. To estimate the macrophage capacity to control the bacterial survival, an in vitro assay was performed, which allowed define the phenotype as resistant or susceptible. The results suggest a significant association for SNP4 (p = 0.0506) with the phenotypic variation for resistant or susceptibility, because was found the genotype (BB) at higher frequency in susceptible animals and naturally infected animals, than those resistant animals. </p>


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