54 CRYOPRESERVATION OF BOVINE IN VITRO-PRODUCED EMBRYOS: INTRINSIC FACTORS DETERMINING VITRIFICATION OUTCOMES

2015 ◽  
Vol 27 (1) ◽  
pp. 120
Author(s):  
M. N. Saucedo ◽  
M. Kurome ◽  
M. Reichenbach ◽  
E. Wolf ◽  
H.-D. Reichenbach

As a part of a study on bovine embryo genomic evaluation, effects of an intact (iZP) or opened zonae pellucidae (oZP) of in vitro-produced embryos on vitrification outcomes were assessed. In the first experiment, only iZP embryos were subjected to vitrification, using either the hollow fibre vitrification method (HFV; Matsunari et al. 2012 J. Reprod. Dev.) or the cryologic vitrification method (CVM; CryoLogic®, Blackburn, Victoria, Australia). Developmental stage (morula = M; early blastocyst = EaB; blastocyst = B) and quality (good = 1; fair = 2) before vitrification were evaluated. In a first set of experiments, quality 1 and 2 iZP embryos were vitrified either by the HFV or the CVM method. A significant difference between the 2 methods was found when comparing overall survival rates (24–48 h post-thaw; HFV 59.32% v. CVM 78.9%; P < 0.001; unpaired t-test, GraphPad Prism, GraphPad Software Inc., La Jolla, CA, USA). Concerning hatching rates, no significant difference was found (HFV 48.7% v. CVM 57.8%; P > 0.1). In order to evaluate influence of embryo stage and quality on HFV or CVM outcomes, iZP embryos vitrified by the HFV method were classified regarding quality (1: n = 207; 2: n = 66; total n = 273) and embryo stage (M: n = 78; EaB: n = 74; B: n = 121). Concerning survival rates, no significant difference was found between M 1 (57.4%) and M 2 (44.6%), or EaB 1 (80%) and EaB 2 (68%). However, a significant difference was found when comparing B 1 (77%) and B 2 (29%; P < 0.05). With regard to hatching rate, no significant difference was found between M 1 (39.9%) and M 2 (30%), or EaB 1 (66.6%) and EaB 2 (57%). However, significant difference was found between B 1 (60.9%) and B 2 (22%; P < 0.05). With regard to the CVM (1: n = 172; 2: n = 82; total n = 254), no significant difference was found when analysing survival rates of EaB 1 (82%) and EaB 2 (80%), or B 1 (87%) and B 2 (74%), whereas the survival rates were significantly different between M 1 (80%) and M 2 (53%; P < 0.05). Significant differences regarding hatching rates were not found between M 1 (51%) and M 2 (28%) or EaB 1 (55%) and EaB 2 (65%), whereas the hatching rate of B 1 (76%) was not significantly higher than that of B 2 (48.8%; P < 0.05). In a second set of experiments, oZP EaB (1: n = 14) and oZP B (1: n = 30) were vitrified by the CVM method. No significant difference regarding survival rates concerning stage (95 and 72%, EaB and B, respectively), or between treatments (EaB iZP v. oZP, and B iZP v. oZP; P > 0.1) was found. Effect of ZP, either intact or opened, does not seem to affect survival rates (judged by their re-expansion 24–48 h post-thaw) of good-quality embryos.The authors thank the Bavarian Research Foundation for the financial support (AZ-1031-1; DOK-153-12).

2020 ◽  
Author(s):  
Iris Martínez-Rodero ◽  
Tania García-Martínez ◽  
Erika Alina Ordóñez-León ◽  
Meritxell Vendrell-Flotats ◽  
Carlos Olegario-Hidalgo ◽  
...  

Abstract Background VitTrans is a device that enables the vitrification and warming/dilution of in vitro produced bovine embryos followed by their direct transfer to recipient females in field conditions. This study sought to improve the VitTrans method by comparing two equilibration times: short (SE: 3 min) and long (LE: 12 min). Outcome measures recorded in vitrified D7 and D8 expanded blastocysts were survival and hatching rates, differential cell counts, apoptosis rate and gene expression. Results While survival rates at 3 h and 24 h post-warming were reduced (P < 0.05) after vitrification, hatching rates of D7 embryos vitrified after SE were similar to those obtained in fresh non-vitrified blastocysts. Hatching rates of vitrified D8 blastocysts were lower (P < 0.05) than of fresh controls, regardless of treatment. Total cell counts, and inner cell mass and trophectoderm cell numbers were similar in hatched blastocysts derived from D7 blastocysts vitrified after SE and fresh blastocysts, while vitrified D8 blastocysts yielded lower values, regardless of treatment. The rate of apoptotic cells was significantly higher in both treatment groups when compared to fresh controls, although apoptosis rates were lower using the SE than LE protocol. No differences emerged in expression of the genes BAX, AQP3, CX43 and IFNτ between blastocysts vitrified after SE or LE, whereas a significantly higher abundance of BCL2L1 and SOD1 transcripts was observed in blastocysts vitrified after SE compared to LE. Conclusions The VitTrans device combined with a shorter exposure to the equilibration medium improves vitrification/warming outcomes facilitating the direct transfer of vitrified embryos under field conditions.


2018 ◽  
Vol 30 (1) ◽  
pp. 205 ◽  
Author(s):  
R. Emmerstorfer ◽  
K. Radefeld ◽  
V. Havlicek ◽  
U. Besenfelder ◽  
H. Yu ◽  
...  

The aim of this work was to establish an in vitro culture approach using bovine oviducal fluid (OF) to improve embryo quality and to provide an in vitro system to study oviduct function. Bovine oviducts ipsilateral to ovulation were collected at the slaughterhouse, 1 to 4 days after ovulation. The OF was collected by flushing the oviducts with 1 mL of Charles Rosenkrans 1 medium (CR1). Samples from 21 oviducts were pooled and proteins were concentrated using centrifugal filter devices. Aliquots of 3 different protein concentrations, determined by Bradford assay, were prepared and stored at –20°C. Abattoir-retrieved cumulus–oocyte complexes were used for standard in vitro maturation (IVM) and IVF (Day 0). On Day 1, presumptive zygotes (n = 1498) were randomly allocated to 4 different culture groups and cultured up to Day 9. The presumptive zygotes of the control group (n = 364) were cultured in CR1 with 5% oestrous cow serum (OCS) supplemented with 1 mg mL−1 hyaluronan. In the experimental groups, OCS was replaced by OF, resulting in 3 groups with final protein concentrations of 0.1 mg mL−1 (n = 380), 0.5 mg mL−1 (n = 380) or 1 mg mL−1 (n = 374). Cleavage rate was recorded on Day 2 and blastocyst yield on Days 7, 8, and 9 after fertilization. On Day 7, blastocysts were removed and either stained (Hoechst 33342) for cell number or subjected to a slow freezing protocol using 1.5 M ethylene glycol. After thawing, the re-expansion and hatching rate of blastocysts were determined at 24, 48 and 72 h. Eight replicates were carried out and data were analysed by ANOVA. Cleavage rate increased with increasing protein concentration (0.1 mg mL−1: 80.9 ± 4.2%; P > 0.05; 0.5 mg mL−1: 83.4 ± 2.5%; P < 0.1) and was significantly higher in the 1 mg mL−1 group (84.5 ± 4.4%; P < 0.05) compared with the control group (79.7 ± 3.4%). The cumulative blastocyst rate on Day 9 was significantly lower (P < 0.05) in all experimental groups (0.1 mg mL−1: 15.8 ± 8.9%; 0.5 mg mL−1: 18.7 ± 12.0%; 1 mg mL−1: 17.0 ± 11.2%) compared with the control group (34.1 ± 5.4%). The total number of cells was not affected by OF (P > 0.05). There was no significant difference (P > 0.05) in the post-thaw re-expansion rate between the experimental groups (0.1 mg mL−1: n = 26 thawed blastocysts; 0.5 mg mL−1: n = 27; 1 mg mL−1: n = 23) and the control group (n = 58). The post-thaw hatching rate was significantly higher at 24 and 72 h, respectively, in the 0.5 mg mL−1 group (44.4% and 74.1%; P < 0.05) and the 1 mg mL−1 group (47.8%; P < 0.05; and 82.6%; P < 0.01) compared with the control group (18.9% and 44.8%). The replacement of serum with OF during in vitro culture of bovine embryos had a stage specific effect, resulting in higher cleavage rates but lower blastocyst rates. To address this issue, OF will be collected at different stages and applied in the matching in vitro culture phases in future studies. Interestingly, the post-thaw hatching rate was up to twice as high in the experimental groups, indicating better quality of those embryos developing to blastocyst stage.


2014 ◽  
Vol 26 (1) ◽  
pp. 138 ◽  
Author(s):  
A. Ruiz ◽  
P. J. Hansen ◽  
J. Block

The overall objective was to determine the effects of addition of lipid metabolic regulators during embryo culture on blastocyst development and survival following cryopreservation. For Experiment 1, embryos produced in vitro were cultured in 5% (vol/vol) oxygen in SOF-bovine embryo 1 (SOF-BE1) medium supplemented with or without 100 μM trans-10,cis-12 conjugated linoleic acid (CLA) and 0.3 μM phenazine ethosulfate (PES). Treatment with CLA began at the initiation of culture, whereas treatment with PES began at Day 3 after insemination. At Day 7 after insemination, the proportion of oocytes that developed to the blastocyst and advanced blastocyst (expanded, hatching, or hatched) stages was recorded. Blastocysts and expanded blastocyst-stage embryos were harvested and slow frozen in 1.5 M ethylene glycol. Embryos were thawed and then cultured for 72 h in SOF-BE1 medium containing 10% (vol/vol) fetal bovine serum and 50 μM dithiothreitol. Re-expansion and hatching rates were recorded at 24, 48, and 72 h. Addition of CLA had no effect on embryo development, whereas PES reduced (P < 0.01) development to the blastocyst (26.0 ± 0.8 v. 22.1 ± 0.8%) and advanced blastocyst (19.2 ± 0.9 v. 14.4 ± 0.9%) stages. Blastocysts cultured in the presence of CLA had higher (P < 0.05) re-expansion rates at 24, 48, and 72 h (50.8 ± 3.7 v. 65.7 ± 3.7%, 57.2 ± 4.0 v. 72.0 ± 4.05%, and 57.2 ± 4.0 v. 72.0 ± 4.0%, respectively). Addition of CLA tended (P < 0.07) to increase the hatching rate at 24 h and did increase (P < 0.05) the hatching rate at 48 h (12.4 ± 1.3 v. 16.2 ± 1.3% and 39.0 ± 3.2 v. 50.0 ± 3.2%, respectively). Treatment with PES had no effect on re-expansion rates but reduced (P < 0.05) hatching rates at 24 and 48 h (18.2 ± 1.3 v. 10.3 ± 1.3 and 50.2 ± 3.2 v. 38.8 ± 3.2%, respectively). There was no interaction between CLA and PES affecting embryo development or cryosurvival. For Experiment 2, embryos were produced in vitro as in Experiment 1 and cultured in SOF-BE1 medium with or without 3.03 mM L-carnitine (LC) and 10 μM forskolin (FK). Treatment with LC began at the initiation of culture and treatment with FK began at Day 6. All other methods were as described for Experiment 1. Addition of LC did not affect development to the blastocyst stage but reduced (P < 0.05) development to the advanced blastocyst stage (21.0 ± 1.2 v. 17.1 ± 1.2%). Treatment with FK had no effect on embryo development to the blastocyst or advanced blastocyst stages. Blastocysts cultured in the presence of LC had increased (P < 0.05) re-expansion rates at 24, 48, and 72 h (60.2 ± 2.0 v. 78.0 ± 2.0%, 62.9 ± 1.2 v. 83.3 ± 1.2%, and 63.0 ± 2.4 v. 82.8 ± 2.4%, respectively) and hatching rates at 48 and 72 h (48.6 ± 4.3 v. 64.1 ± 4.3% and 59.6 ± 3.0 v. 78.5 ± 3.0%, respectively). There was no effect of FK on cryosurvival and no interaction between LC and FK affecting embryo development or cryosurvival. In conclusion, blastocyst yield was not improved by any of the lipid metabolic regulators tested. Cryosurvival was enhanced by addition of CLA and LC but FK reduced survival following freezing. There were no additive effects of either CLA and PES or LC and FK for blastocyst yield or cryosurvival.Support was provided by USDA AFRI Grant 2010-85122-20623.


Zygote ◽  
2009 ◽  
Vol 17 (1) ◽  
pp. 57-61 ◽  
Author(s):  
M. Popelková ◽  
Z. Turanová ◽  
L. Koprdová ◽  
A. Ostró ◽  
S. Toporcerová ◽  
...  

SummaryThe aim of the study was to determine the efficiency of two vitrification techniques followed by two assisted hatching (AH) techniques based on post-thaw developmental capacity of precompacted rabbit embryos and their ability to leave the zona pellucida (hatching) during in vitro culture. The total cell number and embryo diameter as additional markers of embryo quality after warming were evaluated. In vivo fertilized, in vitro cultured 8–12-cell rabbit embryos obtained from superovulated rabbit does were cryopreserved by two-step vitrification method using ethylene glycol (EG) as cryoprotectant or by one-step vitrification method with EG and Ficoll (EG+Ficoll). Thawed embryos were subjected to enzymatic or mechanical AH. Vitrified EG group showed significantly lower (P < 0.05) blastocyst rate (22.5%) and hatching rate (15%) than those vitrified with EG + Ficoll (63 and 63% resp.) and that of control (97 and 97% respectively). Significantly lower values of total cell number (P < 0.05) as well as embryo diameter (P < 0.01) in EG group compared with EG + Ficoll and control group were recorded. No significant difference was found in developmental potential of warmed embryos treated by either mechanical or enzymatic AH. The present study demonstrates that the EG + Ficoll vitrification protocol provides superior embryo survival rates over the EG vitrification protocol for 8–12-cell stage precompacted rabbit embryos. No positive effect of either mechanical or enzymatic AH on the post-thaw viability and quality of rabbit embryos in vitro was observed.


2005 ◽  
Vol 17 (2) ◽  
pp. 217 ◽  
Author(s):  
C. Daniaux ◽  
B. Verhaeghe ◽  
I. Donnay

Serum in embryo culture medium may be a potential cause of abnormal accumulation of lipid droplets, which is correlated to a higher sensitivity to cryopreservation. Moreover, serum may introduce pathogens. With the aim of developing a serum-free culture medium, we first (Experiment 1) investigated the effect of adding ITS (5 μg/mL insulin, 5 μg/mL transferrin, 5 ng/mL selenium) as a serum substitute in SOF medium on embryos cultured in large groups (20 embryos per culture drop of 20 μL) and we then (Experiment 2) analyzed the effect of adding BSA. In this second experiment, our serum-free culture media were also tested on embryos cultured in small numbers (5 embryos per drop of 20 μL) in order to mimic ovum pickup (OPU) conditions. Embryos were obtained from slaughterhouse oocytes, matured in vitro for 24 h in a serum-free enriched 199 medium (Donnay et al. 2004 Reprod. Fertil. Dev. 16, 274) containing ITS, and fertilized for 18 h. In experiment 1, embryos were cultured in SOF (Holm et al. 1999 Theriogenology 52, 683–700) supplemented with 0.1 mg/mL polyvinylpyrrolidane (PVP) without (SOF) or with ITS (SOF-ITS), or with 5% FCS (SOF-FCS). Cavitation occurred earlier in presence of serum (Table). Adding ITS to SOF increased blastocyst rates at Day 7 and Day 8 post-insemination (p.i.) and also the hatching rate. In experiment 2, embryos were cultured in SOF-FCS, SOF-ITS, or SOF-ITS supplemented with 4 mg/mL fatty acid free BSA (SOF-ITS-BSA). Within each condition, no differences were observed for blastocyst and hatching rates between embryos cultured in large or in small groups. Adding BSA to SOF-ITS increased blastocyst rate at Day 6 p.i. and also the hatching rate. At Days 7 and 8 p.i., blastocyst rates were higher in SOF-FCS than in SOF-ITS and tended to be higher than in SOF-ITS-BSA, especially for embryos cultured in small groups. Cell numbers of the resulting embryos were unaffected. These results indicate that: (1) ITS as supplement to SOF medium promotes embryo development in vitro. (2) BSA as protein supplement to SOF-ITS medium accelerates blastulation and improves hatching rate. (3) SOF-ITS and SOF-ITS-BSA are two serum-free culture media that can sustain development of embryos, also when cultured in small number, even though SOF-FCS tended to afford better rates of development. Further studies will include evaluation of other quality parameters including resistance to cryopreservation. This work was supported by the Ministery of Agriculture of the Region wallonne de Belgique.


2015 ◽  
Vol 27 (1) ◽  
pp. 119
Author(s):  
A. Ruiz ◽  
P. J. Hansen ◽  
J. Block

The objective was to determine the effects of addition of l-carnitine (LC) and trans-10, cis-12 conjugated linoleic acid (CLA) during bovine embryo culture on cryosurvival, lipid content, and gene expression. For all experiments, embryos were produced in vitro using abattoir-derived oocytes. Following insemination, presumptive zygotes were randomly assigned in a 2 × 2 factorial to be cultured in SOF-BE1 supplemented with or without 3.03 mM LC and 100 μM CLA until Day 7. For Exp. 1, blastocyst- and expanded-blastocyst-stage embryos (n = 777) were slow-frozen in 1.5 M ethylene glycol. Embryos were thawed and then cultured for 72 h. Re-expansion and hatching rates were recorded at 24, 48, and 72 h. There was no effect of LC on post-thaw re-expansion rates, but CLA reduced (P < 0.05) and tended (P < 0.08) to reduce re-expansion rate at 24 and 48 h, respectively (76.5 ± 2.5 v. 70.4 ± 2.5 and 79.5 ± 2.2 v. 76.0 ± 2.2, respectively). Whereas hatching rate at 72 h tended (P < 0.08) to be higher for embryos cultured with LC (67.8 ± 2.5 v. 74.4 ± 2.5), treatment with CLA reduced (P < 0.05) hatching rate at 48 h (62.3 ± 2.6 v. 54.9 ± 2.6). In Exp. 2, to determine lipid content, expanded blastocyst-stage embryos (n = 263) were harvested and stained using Nile Red. Embryos were examined for fluorescence using an epifluorescence microscope, and intensity of fluorescence per unit area was quantified using ImageJ software (NIH, Bethesda, MD, USA). There was a significant interaction (P < 0.01) between LC and CLA affecting embryo lipid content. Whereas addition of CLA during culture increased lipid, treatment with LC and the combination of LC and CLA reduced lipid (22.8 ± 1.1 v. 19.1 ± 1.1 v. 28.4 ± 1.1 v. 19.2 ± 1.2 for no additive, +LC, +CLA, and +LC and CLA, respectively). For Exp. 3, the effect of LC and CLA on the relative abundance of genes involved in lipid metabolism (ELOVL6, SCD1, SQLE, HMGCS1, CYP51A1, FDPS, FDFT1, LDLR, and SC4MOL) was determined. Pools of 5 expanded blastocyst-stage embryos from each treatment were collected across 5 replicates. The RNA was purified and synthesised into cDNA for RT-qPCR analysis. The SDHA, GAPDH, and YWAZ were used as housekeeping genes. Addition of LC during culture reduced (P < 0.05) the abundance of 4 of the 9 genes analysed (SQLE, HMGCS1, CYP51A1, and FDPS) and tended (P < 0.08) to reduce a fifth (FDFT1). In addition, there was a tendency (P < 0.08) for LC to increase the abundance of SCD1. Addition of CLA during culture had minimal effects on transcript abundance. In particular, CLA treatment reduced (P < 0.01) ELOVL6 and tended (P < 0.08) to increase SCD1. In contrast to previous studies, post-thaw cryosurvival was not significantly improved by treatment with LC or CLA. Results indicate that reduced embryo lipid content caused by LC treatment is due, in part, to an alteration in the abundance of genes involved in lipid metabolism. Further research is still necessary to determine whether in vivo survival following transfer of cryopreserved embryos can be enhanced by treatment with LC or CLA.Support was provided by USDA AFRI Grant 2010–85122–20623.


2010 ◽  
Vol 22 (1) ◽  
pp. 231
Author(s):  
J. Block ◽  
L. Bonilla ◽  
P. J. Hansen

The objective of the present study was to determine whether culture of bovine embryos in a proprietary serum-free culture medium, Block-Bonilla-Hansen-7 (BBH-7), could improve development to the blastocyst stage and enhance survival following vitrification. For Exp. 1, embryos were produced in vitro and cultured in BBH-7 or modified synthetic oviductal fluid (mSOF; as in zygote 10:341 except with 10 μL mL-1 of nonessential amino acids, 20 μL mL-1 of essential amino acids, and 1 mg mL-1 of polyvinyl alcohol instead of albumin) in 5% (v/v) oxygen. Grade 1 expanded blastocysts were harvested at Day 7 post-insemination and vitrified using the open-pulled straw method (Vagta et al. 1998 Mol. Reprod. Dev. 51, 53-58). Vitrified embryos were thawed and cultured in vitro in either mSOF or BBH-7 supplemented with 10% fetal bovine serum and 50 μM dithiolthreitol. Re-expansion and hatching rates were recorded at 24, 48, and 72 h post-thaw. There was no effect of culture medium on cleavage rate. The proportion of oocytes that developed to the blastocyst and advanced blastocyst stages (expanded, hatching, and hatched) at Day 7 was higher (P < 0.001) for embryos cultured in BBH-7 than for embryos cultured in mSOF (41.9 ± 2.0 v. 14.7 ± 2.0% and 31.1 ± 1.3 v. 6.4 ± 1.3%, respectively). There was no effect of culture medium on re-expansion rates at 24, 48, and 72 h post-thaw or on hatching rates at 48 or 72 h. However, the proportion of embryos that were hatching or had hatched by 24 h post-thaw was higher (P < 0.001) for BBH-7 than for mSOF (59.0 ± 0.5 v. 26.7 ± 0.5%). For Exp. 2, late lactation and/or repeat breeder, lactating Holstein cows were synchronized for timed embryo transfer using the OvSynch-56 protocol. Embryos were produced in vitro and cultured in BBH-7 in 5% (v/v) oxygen. Vitrified embryos were produced as for Exp. 1. Fresh embryos were grade 1 expanded blastocysts harvested at Day 7 after insemination. A single embryo was transferred at Day 7 after putative ovulation to all cows with a corpus luteum confirmed by ultrasonography. Pregnancy was diagnosed at Day 28-30 of gestation by ultrasonography. There was no difference in the proportion of recipients that became pregnant after receiving either a fresh (7/18 = 39%) or vitrified (10/27 = 37%) embryo cultured in BBH-7. The results of the present study indicate that BBH-7 can be used to increase the proportion of oocytes that develop to the blastocyst stage. Moreover, the results demonstrate that vitrified embryos produced after culture in BBH-7 can achieve pregnancy rates similar to those obtained using fresh embryos. Support: USDA 2006-55203-17390 and Southeast Milk Checkoff Program.


2008 ◽  
Vol 20 (1) ◽  
pp. 200
Author(s):  
T. H. C. De Bem ◽  
R. Rochetti ◽  
P. R. L. Pires ◽  
F. F. Bressan ◽  
P. R. Adona ◽  
...  

Prematuration provides an additional time for oocyte capacitation and maturation in an attempt to improve in vitro embryo production (IVP) rates and allows media supplementation during this period for IVP. The aim of this study was to use brain-derived neurotropic factor (BDNF) in prematuration to improve maturation of bovine oocytes subjected to parthenogenetic activation and cultured with different media. Oocytes were subjected to prematuration in TCM-199 medium supplemented with 10 µm butyrolactone I, 2.0 mm pyruvate, and 10 µg mL–1 gentamicin for 24 h in the absence of BDNF (control) or in the presence of 10 ng mL–1 BDNF (BD). Oocytes were then in vitro-matured (IVM) in TCM-199 medium supplemented with 10% FCS, 0.5 µg mL–1 FSH, 5.0 µg mL–1 LH, 2.0 mm pyruvate, and 10 µg mL–1 gentamicin at 38.5�C under 5% CO2 in air. After 19 h oocytes were denuded using hyaluronidase and vortexing for 3 min for the 1st polar body (1PB) selection. Those which extruded the 1PB were maintained in IVM until 26 h, when parthenogenetic activation was performed (5 min in 5 µm ionomycin, followed by 3 h in 2 mm 6-DMAP). Activated oocytes were then transferred to in vitro culture (IVC) for embryo development evaluation. Embryos from both groups were cultured in SOF medium with 2.5% FCS, 0.05 g mL–1 BSA, 0.2 mm pyruvate, and 10 mg mL–1 gentamicin. Cleavage rates on the second day of in vitro culture (D2), embryo production at Days 7 and 8 (D7 and D8), and hatching rate at Day 8 were evaluated. Data regarding 1PB extrusion, cleavage, blastocyst development on D7 and D8, and blastocyst D8 hatching rates of three replicates were analyzed by chi-square test at 5% significance using the BIOESTATS 4.0 software. Control and BD, respectively, did not show differences (P > 0.05) regarding 1PB extrusion (n = 164, 63.81%, and n = 175, 66.79%) or cleavage (n = 117, 71.34%, and n = 138, 78.86%). However, for control and BD, respectively, blastocyst development on D7 (n = 63, 38.41%, and n = 89, 50.86%), D8 (n = 63, 38.41%, and n = 91, 52.00%), and hatching on D8 (n = 22, 34.92%, and n = 39, 43.82%) were all significantly higher for BD when compared with control (P < 0.05). In conclusion, BDNF during prematuration improved in vitro embryo development by increasing blastocyst and hatching rates of parthenogenetic embryos.


2017 ◽  
Vol 29 (1) ◽  
pp. 188
Author(s):  
N. C. Negota ◽  
L. P. Nethenzheni ◽  
M. L. Mphaphathi ◽  
D. M. Barry ◽  
T. L. Nedambale

The in vitro culture media and assisted hatching techniques remain challenging obstacles to be utilised widely. Mechanical, chemical, enzymatic thinning, and laser-assisted techniques have been used previously but information is still lacking on its application in livestock. The aim of this study was to compare the effect of 2 in vitro culture media (Hamster F10 and TMC-199) and 4 (mechanical, chemical, enzymatic, and laser) assisted hatching techniques on blastocyst formation and hatching rate using murine embryos as a model. The C57/b and Balb/c breeds were raised until they reached maturity and bred naturally to produce F1 generation. The light in the breeding house was controlled at 14 h light and 10 h dark. Feed and water were provided ad libitum for the mice. Superovulation of females were stimulated using equine chorionic gonadotropin and human chorionic gonadotropin. The F1 generation was used for the collection of the 400 blastocysts and randomly allocated into 4 assisted hatching techniques. Blastocysts were paired into a group of 10 and replicated 4 times for each assisted hatching technique. The general linear model of SAS version 9.4 (SAS Institute Inc., Cary, NC, USA) was used to analyse the data. Assisted hatching techniques of laser, mechanical, enzymatic, and chemical yielded 46.9 ± 37.1, 51.1 ± 40.2, 39.1 ± 35.8, and 33.3 ± 4.5%, respectively, under in vitro culture of Hamster F10. The TCM-199, laser, mechanical, enzymatic, and chemical assisted hatching techniques yielded 56.3 ± 43.3, 52.6 ± 35.5, 49.2 ± 37.5, and 33.9 ± 35.5%, respectively, with a significant difference. There was no significant difference observed in assisted hatching techniques and Hamster F10 culture medium. However, the hatching rate of embryos for all techniques was higher when in vitro cultured in TCM than cultured in Hamster F10. Hatching rate of blastocysts increased from chemical, enzymatic, mechanical, and laser with response to Hamster F10 and TCM; thus, laser is a suitable assisted hatching technique with TCM-199.


2014 ◽  
Vol 74 (3) ◽  
pp. 642-648 ◽  
Author(s):  
LPM Brandão ◽  
DGF Pujoni ◽  
PM Maia-Barbosa

The effect of dormancy in zooplankton populations is still unknown, largely because of the lack of methods to estimate hatching and production of the dormant stages. This study aimed to compare the production and hatching rates of ephippia of Daphnia laevis between thermal stratification and mixing periods in Jacaré Lake (Middle Rio Doce, Minas Gerais, Brazil). For this, we collected ephippia on the sediment with core sampler and we created a device called the “Ephippial Collector”. There was a significant difference in ephippia hatching in situ between stratification and mixing periods (Pearson's Chi-squared test p <0.001), being higher in the second one. Significant differences in the hatching rates between periods was observed in the laboratory only for ephippia collected with Ephippial Collectors (Pearson's Chi-squared test p <0.001), being higher during the mixing period (∼8%). The core sample allows the collection of a certain fraction of the sediment that may contain a mixture of ephippia produced in different periods, i.e., may contain old and not viable ephippia, which masks the hatching rate. Thus, seasonality in hatching rates of ephippia was reported only by Ephippial Collectors. The higher hatching rate observed during the mixing period in the lake suggests that individuals hatched from ephippia may contribute to the increase in the population of D. laevis in the water column at this time.


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