Suppression of keratin 18 gene expression in bovine blastocysts by RNA interference

2010 ◽  
Vol 22 (2) ◽  
pp. 395 ◽  
Author(s):  
Karen Goossens ◽  
Dawit Tesfaye ◽  
Franca Rings ◽  
Karl Schellander ◽  
Michael Hölker ◽  
...  
Keyword(s):  
Rna Interference ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Preimplantation Embryos ◽  
Blastocyst Formation ◽  
Blastocyst Development ◽  
Binding Partner ◽  
Keratin 18 ◽  
Phosphate Buffered Saline ◽  
Bovine Blastocyst

The expression of the cytoskeleton protein Keratin 18 (KRT18) starts at the onset of bovine blastocyst formation. KRT18 is solely expressed in the trophectoderm and can therefore be used as a marker for trophectodermal differentiation. In the present study, the expression of KRT18 was suppressed by RNA interference to probe its functional importance in bovine blastocyst formation. Microinjection of KRT18 double-stranded RNA into the cytoplasm of zygotes resulted in reduced KRT18 mRNA (76% reduction) and protein expression at the blastocyst stage and a lower developmental competence (41% reduction in the percentage of blastocyst formation) compared with non-injected and phosphate-buffered saline (PBS)-injected controls. KRT18 downregulation was associated with reduced mRNA expression of KRT8, the binding partner of KRT18, but had no effect on the expression of KRT19, CDH1 and DSP, other genes involved in intermediate filament and cytoskeleton formation. The results of the present study demonstrated that KRT18 knockdown in preimplantation embryos results in reduced blastocyst formation, but no further morphological aberrations were observed with regard to the biological function of KRT18. These observations could be due to the function of KRT18 being replaced by that of another gene, the surviving blastocysts expressing the minimum level of KRT18 required for normal blastocyst development or the possibility that further aberrations may occur later in development.

237 THE EFFECTS OF BULLS AND X-SORTING OF SPERM ON THE ACCURACY OF NONINVASIVE CRITERIA TO PREDICT BLASTOCYST FORMATION OF IN VITRO-PRODUCED BOVINE EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 208
Author(s):  
S. Matoba ◽  
T. Somfai ◽  
T. Nagai ◽  
M. Geshi
Keyword(s):  
Formation Rate ◽  
Calf Serum ◽  
Time Lapse ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Bovine Embryos ◽  
Blastocyst Formation ◽  
Blastocyst Development ◽  
Chi Square

Previously, an early first cleavage and a second cleavage after IVF with a normal cleavage pattern defined by even blastomeres without fragments or protrusions was found to be a potent marker for the selection of embryos with high developmental competence (Sugimura et al. 2012 PLoS ONE 7, e36627). The aim of this study was to investigate the effects of bulls and X-sorting of sperm on the ability of these simple noninvasive markers to predict the potency of bovine IVF embryos to develop to the blastocyst stage in vitro. Immature oocytes were matured in TCM199 supplemented with 0.02 armour unit mL–1 FSH and 5% calf serum at 38.5°C in 5% CO2 and 95% air for 22 to 23 h. After maturation, oocytes were inseminated with either of non-sorted frozen-thawed sperm from 3 bulls (A–C) or X-sorted sperm of bull A. Putative zygotes were cultured (IVC) in CR1aa medium supplemented with 5% calf serum and 0.25 mg mL–1 linoleic acid albumin at 38.5°C in 5% CO2, 5% O2, and 90% N2 for 216 h. Embryo kinetics were observed individually by time-lapse cinematography (CCM-1.3Z; Astec, Fukuoka, Japan; Sugimura et al. 2010 Biol. Reprod. 83, 970–978). First and second cleavage kinetics and pattern were categorized according to Sugimura et al. (2012). For each bull, blastocyst development from embryos possessing the following 3 selection markers was compared: (marker 1) the first cleavage within 28 h after IVF, (marker 2) marker 1 combined with 2 even blastomeres without fragments or protrusions, and (marker 3) marker 2 combined with the second cleavage within 50 h after IVF with ≥6 even blastomeres without fragments or protrusions, respectively. Data were analysed by the Yates' corrected chi-square test. A total of 823 oocytes were used in at least 3 replications. When non-sorted sperm was used for IVF, there was not difference (P > 0.05) in total blastocyst formation rates on Day 8 (Day 0 = IVF) among bulls (ranging between 49.5 and 60.8%); however, blastocyst formation rate of embryos generated from X-sorted sperm of bull A (39.5%) was lower (P < 0.05) compared with other groups despite of similar cleavage rates. Embryos having marker 3 criteria developed to the blastocysts stage at significantly higher rates than those having marker 1 criteria in case of non-sorted sperm of bulls A, B, C, and X-sorted sperm of bull A (75.9, 87.0, 90.0, and 75.0% v. 59.5, 62.2, 63.6, and 46.3%, respectively). In groups produced from non-sorted sperm of bulls A, B, C, and X-sorted sperm of bull A, blastocyst development rates of embryos with marker 2 criteria (73.7, 75.0, 90.0, and 65.8%, respectively) were higher (P < 0.05) than those of embryos having marker 1 criteria but did not differ significantly from those with marker 3 criteria. Our results reveal that a first cleavage within 28 h after IVF to 2 even blastomeres without fragments or protrusions are potent predictive markers of the developmental competence of bovine embryos to the blastocyst stage regardless of bulls and sperm sorting.Research was partly supported by JSPS KAKENHI (26450388).

scholarly journals Lipid Stores and Lipid Metabolism Associated Gene Expression in Porcine and Bovine Parthenogenetic Embryos Revealed by Fluorescent Staining and RNA-seq

2020 ◽  
Vol 21 (18) ◽  
pp. 6488
Author(s):  
Arkadiusz Kajdasz ◽  
Ewelina Warzych ◽  
Natalia Derebecka ◽  
Zofia E. Madeja ◽  
Dorota Lechniak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Inner Cell Mass ◽  
Mammalian Species ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Rna Seq ◽  
Expression Of Genes ◽  
Bovine Blastocyst

Compared to other mammalian species, porcine oocytes and embryos are characterized by large amounts of lipids stored mainly in the form of droplets in the cytoplasm. The amount and the morphology of lipid droplets (LD) change throughout the preimplantation development, however, relatively little is known about expression of genes involved in lipid metabolism of early embryos. We compared porcine and bovine blastocyst stage embryos as well as dissected inner cell mass (ICM) and trophoblast (TE) cell populations with regard to lipid droplet storage and expression of genes functionally annotated to selected lipid gene ontology terms using RNA-seq. Comparing the number and the volume occupied by LD between bovine and porcine blastocysts, we have found significant differences both at the level of single embryo and a single blastomere. Aside from different lipid content, we found that embryos regulate the lipid metabolism differentially at the gene expression level. Out of 125 genes, we found 73 to be differentially expressed between entire porcine and bovine blastocyst, and 36 and 51 to be divergent between ICM and TE cell lines. We noticed significant involvement of cholesterol and ganglioside metabolism in preimplantation embryos, as well as a possible shift towards glucose, rather than pyruvate dependence in bovine embryos. A number of genes like DGAT1, CD36 or NR1H3 may serve as lipid associated markers indicating distinct regulatory mechanisms, while upregulated PLIN2, APOA1, SOAT1 indicate significant function during blastocyst formation and cell differentiation in both models.

246 IN VITRO PRODUCTION OF SPRINGBOK (ANTIDORCAS MARSUPIALIS) EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 239 ◽  
Author(s):  
R. Krisher ◽  
A. Auer ◽  
K. Clark ◽  
K. Emsweller ◽  
S. Rogers ◽  
...  
Keyword(s):  
South Africa ◽  
Oocyte Maturation ◽  
Assisted Reproductive Technologies ◽  
Reproductive Technologies ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Genetic Management ◽  
Blastocyst Development ◽  
Antidorcas Marsupialis

The objective of this experiment was to develop in vitro embryo production (IVP) technologies in springbok (Antidorcas marsupialis), a southern African antelope. Springbok, a fairly common species on game farms in parts of South Africa, may be used as a model species for gamete rescue and IVP techniques to be applied to the conservation of other threatened antelope species. Springbok belong to the family bovidae, subfamily antilopinae, tribe antilopini, which comprises about twenty species in genera Gazella, Antilope, Procapra, Antidorcas, Litocranius, and Ammodorcas. In this tribe alone, there are 4 species or subspecies that are critically endangered, 3 that are endangered, and 10 that are considered vulnerable, demonstrating the need for antelope conservation efforts. In addition, our studies contributed to the South African biological resource bank, so that banked springbok semen and embryos might be used in the future for managed genetic contribution to isolated captive or wild populations via assisted reproductive technologies. Oocytes were recovered (3 replicates) from ovaries obtained at supervised culls for management purposes in South Africa, and cultured in defined Gmat or undefined TCM-199 with FCS maturation medium for 28-30 h (Brad et al. 2004 Reprod. Fertil. Dev. 16, 223). Oocytes were fertilized with frozen-thawed springbok epididymal spermatozoa in modified SOF fertilization medium with caffeine (Herrick et al. 2004 Biol. Reprod. 71, 948–958). Eighteen hours after insemination, a randomly selected subset of the zygotes were fixed to determine fertilization success. The remaining zygotes were cultured in G1/G2 media. On Day 7 of culture, embryos were analyzed for development to the morula or blastocyst stage. A total of 259 selected oocytes were collected from 50 females (5.2 selected oocytes/female on average). There was no difference in the percentage of oocytes normally fertilized (2 pronuclei, PN) between oocytes matured in Gmat (n= 43; 12%) and those matured in TCM-199 (n= 42; 10%). There were significantly (P &lt; 0.05) more oocytes penetrated (e2 PN) when matured in TCM (50%) compared to Gmat (23%). There were no differences in embryonic cleavage or morula/blastocyst development (of total oocytes inseminated) between treatments (Gmat,n= 89, 54%, 9.0%; TCM-199, n= 85, 68%, 9.4%, respectively). In both treatments, the average blastocyst grade was 2.125 using the standard bovine grading system (Curtis, Cattle Embryo Transfer Procedure, 1991). In conclusion, in vitro oocyte maturation, fertilization, and embryo culture to the blastocyst stage is possible in springbok. Importantly, blastocysts can be produced in vitro under semi-defined conditions, demonstrating that oocyte maturation without serum does support developmental competence. This is important for the potential international movement of IVP embryos to be used for genetic management in the conservation of antelope species.

125 EXAMINING CRITERIA FOR EXTENDING BOVINE BLASTOCYST SURVIVAL IN VITRO

2008 ◽  
Vol 20 (1) ◽  
pp. 143
Author(s):  
F. N. T. Cooke ◽  
T. M. Rodina ◽  
P. J. Hansen ◽  
A. D. Ealy
Keyword(s):  
Conditioned Medium ◽  
Culture System ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Bovine Embryo ◽  
Blastocyst Development ◽  
Interferon Tau ◽  
Cell Numbers ◽  
Bovine Blastocyst

Most of the current culture procedures used for bovine in vitro embryo production terminates at the blastocyst stage. Developing procedures for extending embryo lifespan beyond this phase will provide a valuable tool for understanding events that occur during the second week of pregnancy in cattle. The overall objective of the present studies was to identify culture conditions required to support bovine blastocyst development beyond its initial formation. In the first study, individual day 8 blastocysts (day 0 = day of IVF) were cultured until day 11 in 30 µL microdrops of Potassium Simplex Optimized Medium-Bovine Embryo 2 containing 0.1 mm non-essential amino acids or Tissue Culture Medium 199 (M199). Both media were supplemented with 5% [v/v] fetal bovine serum (FBS) and incubations were in an atmosphere of either 5 or 21% (v/v) oxygen. A medium by oxygen interaction (P = 0.007) occurred when assessing cell number on day 11. Blastocysts cultured in M199 and in a 5% O2 environment had greater (P < 0.002) cell numbers (536 � 49) than blastocysts incubated in other conditions (339 � 28). Conditioned medium from blastocysts incubated in 21% O2 contained greater (P < 0.05) concentrations of bioactive interferon-tau (IFNT) than blastocysts incubated in 5% O2 regardless of medium type (70.5 � 28 v. 17.2 � 2.6 ng mL–1). In a follow-up study, blastocysts could remain morphologically viable through day 11 in M199 containing at least 2.5% FBS. To examine whether oxidative stress was responsible for the increase in IFNT production under 21% O2, blastocysts were incubated under a 5% O2 atmosphere in M199 containing 2.5% FBS and increasing concentrations of tert-butylhydroperoxide (tBH), a membrane-permeable oxidative agent. Addition of e3 nm tBH decreased cell numbers but did not increase IFNT concentrations in conditioned medium. To examine whether blastocysts could survive beyond day 11 in culture, day 11 blastocysts were transferred to 400 �L of M199 with 20% FBS under 5% oxygen and cultured from day 11 to 20–21 post-IVF. Half of the medium was replaced every 2–3 days. On day 13–14, 16.6 � 6.1% of blastocysts showed initial signs of degeneration. A portion of blastocysts (32.9 � 9.6%) began attaching to plates on days 13–15 and produced outgrowths that appeared viable on days 20–21. All of the non-attached blastocysts degenerated by day 17–18. No blastocyst elongation was detected. In conclusion, a culture system was developed that sustains blastocyst viability and IFNT production in vitro to day 11. Although this culture system allowed blastocyst survival until day 14, normal conceptus development (i.e. elongation/filamentation) was not achieved. Nonetheless, the culture system provides a useful tool for examining the initial stages of blastocyst development and IFNT production from individual bovine embryos.

scholarly journals 205.The effect of FSH concentration during IVM and gamete co-incubation length during IVF on the development of unstimulated prepubertal ewe oocytes

2004 ◽  
Vol 16 (9) ◽  
pp. 205 ◽  
Author(s):  
K. M. Morton ◽  
W. M. C. Maxwell ◽  
G. Evans
Keyword(s):  
Blastocyst Stage ◽  
Developmental Competence ◽  
Blastocyst Formation ◽  
In Vitro Development ◽  
Oocyte Collection ◽  
Chi Squared ◽  
Development In Vitro ◽  
Stage 1 ◽  
Vitro Development

The developmental competence of prepubertal oocytes can be increased by the administration of gonadotrophins prior to oocyte collection (1); but this is not possible with abattoir-sourced oocytes, and modifications to the IVP system may increase in vitro development. Experiments were conducted to determine the effects of FSH concentration (10, 20 or 60 μg mL-1) during IVM (5 replicates) and gamete co-incubation length (short: 2-3 h, long: 18-20 h) during IVF (6 replicates) on subsequent embryonic development. For both experiments ovaries were collected from prepubertal lambs (16-24 weeks) slaughtered at an abattoir and embryos produced in vitro (1). Data were analysed by chi-squared test. Oocyte cleavage at 48 hours post-insemination (hpi) was higher for oocytes matured in medium containing 20 (60/77; 77.9%) and 60 (56/73; 76.7%) than 10 μg mL-1 (40/67; 59.7%) FSH. Blastocyst formation (% cultured oocytes) on Day 7 (Day 0 = IVF) was higher for oocytes matured with 20 (31/77; 40.3%) than 10 (16/67; 23.9%) or 60 μg mL-1 (20/73; 27.4%). Oocyte cleavage at 48 hpi was reduced for short (36/57; 63.2%) compared with long (49/55; 89.1%) co-incubation, although blastocyst formation (% cultured oocytes; Day 7) did not differ between groups (22/57; 38.6% and 23/55; 41.8%, respectively). These results demonstrate that increasing the FSH concentration above normal levels during IVM of prepubertal lamb oocytes improves development in vitro. Gamete co-incubation length did not influence the proportion of oocytes progressing to the blastocyst stage. (1) Morton et al. (2003) Proc. Soc. Reprod. Fert. P18.

scholarly journals 152EFFECT OF REPLACEMENT OF PYRUVATE/LACTATE IN CULTURE MEDIUM WITH GLUCOSE ON PREIMPLANTATION DEVELOPMENT OF PORCINE EMBRYOS IN VITRO

2004 ◽  
Vol 16 (2) ◽  
pp. 198
Author(s):  
N.W.K. Karja ◽  
S. Medvedev ◽  
D. Fuchimoto ◽  
A. Onishi ◽  
M. Iwamoto ◽  
...  
Keyword(s):  
Energy Source ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Culture Period ◽  
Blastocyst Formation ◽  
Cell Stage ◽  
Energy Substrates ◽  
Anova Test

Kikuchi et al. (2002 Biol. Reprod. 66, 1033–1041) reported that replacement of pyruvate and lactate with glucose, as energy substrates, at 48h of culture in IVC medium enhanced the quality of IVP porcine blastocysts. However, the exact time during early cleavage stages when the utilization of glucose as an energy source is optimal has not yet been determined. The purpose of this study was to examine the effects of glucose supplementation at different times of culture on the developmental competence of IVP porcine embryos. Porcine cumulus-oocytes complexes were matured in modified NCSU-37 solution and fertilized in vitro according to Kikuchi et al. All cultures were performed at 38.5°C, 5% O2, 5% CO2, and 90% N2. In experiment 1, after being fertilized (Day 0), putative zygotes (1158 in 6 trials) were cultured in NCSU-37 supplemented with 0.4% BSA, 0.17mM sodium pyruvate, and 2.73mM sodium lactate (IVC-pyr/lac). Embryos (30–50 in each group) were then transferred into NCSU-37 supplemented with 0.4% BSA and 5.55mM D-glucose (IVC-glu) at 24, 48, 72, 96, or 118h of culture. As control groups, putative zygotes (391) were cultured in IVC-pyr/lac or IVC-glu for the whole culture period. In experiment 2, after being fertilized, putative zygotes (543 in 4 trials, 30–50 in each group) were cultured in IVC-pyr/lac, and then were transferred into IVC-glu at 48h, 53h, 58h, or 63h of culture, because glycolytic activity of in vitro-derived porcine embryos was reported to increase around the 8-cell stage, and some embryos develop to that stage before 72h of culture in experiment 1. All embryos were cultured for 6 days, and then development to the blastocyst stage and number of cells per blastocyst were assessed. When IVF embryos were cultured in IVC pyr/lac for 24h or 48h and subsequently in IVC-glu until day 6 in experiment 1, the rates of blastocyst formation were significantly higher (P&lt;0.05, ANOVA test) than those of embryos cultured in IVC-pyr/lac for the whole culture period (24.4% and 23.0% v. 14.5%, respectively). However, when IVC pyr/lac was replaced with IVC-glu, there were no significant differences between the energy source replacement groups and the glucose-only group in terms of the proportions of cleavage, development to the blastocyst stage and mean cell number per blastocyst (P&gt;0.05, ANOVA test) (15.2%–24.4%, and 16.8%, respectively). Replacement of pyruvate and lactate with glucose at 58h of culture in experiment 2 significantly enhanced the rate of blastocyst formation (P&lt;0.05, ANOVA test) but not the mean cell number compared with zygotes in which the replacement was done at 48, 53, and 63h of culture (31.3% v. 20.6%, 20.8%, and 21.1%, respectively) (P&lt;0.05, ANOVA test). In conclusion, replacement of pyruvate and lactate with glucose as energy substrates was optimal at 58h of culture for the in vitro development of pig embryos to the blastocyst stage.

210 CLEAVAGE ASSESSMENT AT DAY 2 TO PREDICT BLASTOCYST DEVELOPMENTAL POTENTIAL IN PORCINE IN VITRO-FERTILIZED EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 203
Author(s):  
Y. J. Kim ◽  
Y. P. Jeon ◽  
S. H. Hyun
Keyword(s):  
Cumulus Cells ◽  
Preimplantation Development ◽  
Developmental Competence ◽  
Preimplantation Embryos ◽  
Embryo Morphology ◽  
Blastocyst Formation ◽  
Developmental Potential ◽  
Vitro Fertilization ◽  
The Relationship

Porcine embryos could be a valuable tool to study preimplantation development, implantation, and pregnancy, but to do this it is necessary to establish an efficient in vitro embryo production system. Because the cause of high mortality in embryos during preimplantation development is not clear, a noninvasive method of determining the developmental potential of cleavage-stage embryos is needed. The objective was to evaluate the developmental potential of Day 2 embryos in a porcine in vitro fertilization (IVF) system. Specifically, this study was conducted to examine the relationship between embryo morphology 48 h after IVF on rates of blastocyst formation 5 days later. To prepare in vitro maturation (IVM) of porcine oocytes, cumulus–oocyte complexes were obtained from slaughterhouse-derived ovaries and matured in M-199 medium supplemented with 10% pig follicular fluid and 0.57 mm cysteine for 44 h and then freed from cumulus cells. After IVM, cumulus-free oocytes were coincubated with frozen–thawed sperm (2 × 106 cells mL–1) and 2 mm caffeine for 6 h. Inseminated embryos were cultured in NCSU-23 medium that was supplemented with 0.5 mm pyruvate and 0.5 mm lactate. Data were analyzed by ANOVA and Duncan’s test (P < 0.05). Morphology data on a total of 919 embryos were analyzed retrospectively. Forty-eight hours after insemination, embryos were classified into the following 5 groups based on the cleavage state: 1 cell, 2 cells, 4 cells, 5 to 8 cells, and fragmentation. These groups were cultured another 120 h and then evaluated for blastocyst formation. Blastocyst formation rates were significantly higher in the 4-cell (38.07%) and 5- to 8-cell (40.65%) cleaving groups than in the other groups (P < 0.05). In contrast, the 2-cell and fragmentation groups produced 7.5 and 2.9% blastocysts, respectively. Data suggest that embryos reaching 4 cells and 5 to 8 cells by 48 h after insemination have high developmental competence, and this parameter may be useful to predict the development of preimplantation embryos and their ability to establish pregnancy. This work was supported by a grant (No. 20070301034040) from the BioGreen 21 program, Rural Development Administration, Republic of Korea.

138 THE RELATIONSHIP BETWEEN THE NORMALITY OF FIRST CLEAVAGE, THE GENE EXPRESSION IN BLASTOMERES, AND THE ABILITY TO DEVELOP TO THE BLASTOCYST STAGE IN IVF-DERIVED BOVINE 2-CELL STAGE EMBRYOS

2017 ◽  
Vol 29 (1) ◽  
pp. 177
Author(s):  
S. Matoba ◽  
M. Kaneda ◽  
T. Somfai ◽  
K. Imai ◽  
M. Geshi
Keyword(s):  
Target Genes ◽  
Calf Serum ◽  
Transcript Abundance ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Bovine Embryos ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Embryonic Cleavage ◽  
The Relationship

Early first and second cleaved embryos after IVF associated with even blastomeres without fragments or protrusions were found to be a potent criterion for the selection of embryos with high developmental competence (Sugimura et al. 2012 PLOS ONE 7, e36627). The aim of this study was to examine the relationship between an early normal first cleavage pattern, the transcript abundance, and their development to the blastocyst stage in each blastomere in 2-cell stage bovine embryos. The IVF-derived bovine embryos were cultured individually in well-of-the-well culture dishes in CR1aa medium supplemented with 5% calf serum and 0.25 mg mL−1 linoleic acid albumin at 38.5°C in 5% CO2, 5% O2, and 90% N2. The first embryonic cleavage was categorized as being either normal (occurring within 28 h after IVF with 2 even blastomeres without fragment or protrusion) or abnormal (2 uneven blastomeres, with/without fragment/protrusion and/or later than 28 h after IVF). Then, cleaved embryos were placed in 0.5% actinase-E in Ca- and Mg-free PBS and blastomeres were separated by pipetting (n = 85; 4 replicates). In each embryo, one blastomere was subjected to quantitative RT-PCR to analyse the expression of developmentally important genes. The remaining blastomere was subsequently cultured in an individually identifiable manner to verify their ability to develop to the blastocyst stage. Primers were designed for 12 target genes related to pluripotency, cell cycle, metabolism, pregnancy reorganization, placentation, and fetal growth (OCT4, ATP1A1, CCNB1, CDH1, COX1, CTNNB1, GLUT8, MNSOD-3, SOX2, DYNLL1, IGFBP3, and PMSB1) and a reference gene (PPIA). Transcript abundance of target genes in individual blastomeres was compared between embryos showing normal and abnormal cleavage. Values were normalized to the average values of the reference genes and all the means were compared by the Student t-test. Blastomeres resulted from normal cleavage developed to the blastocyst stage on Day 7 to 8 (Day 0 = IVF) at significantly higher rates than those resulted from abnormal cleavage (65.7% v. 37.5%, respectively, P < 0.05). Transcript abundance of OCT4 was significantly higher in blastomeres associated with all abnormal cleavage than in those associated with normal cleavage (P < 0.05). The expression of CCNB1, COX1, ATP1A1, GLUT8, and PMSB1 in blastomeres associated with normal cleavage and blastocyst development was higher than that in those of abnormal cleavage (P < 0.05). However, the level of OCT4, CCNB1, COX1, ATP1A1, and PMSB1 was lower in blastomeres associated with normal cleavage but failure of blastocyst development than those in blastomeres showing abnormal cleavage (P < 0.05). Our results reveal that significantly higher expression of CCNB1, COX1, ATP1A1, and PMSB1 in blastomeres at the 2-cell stage in bovine embryos with superior developmental competence compared with those showing abnormal cleavage and low competence. Research was supported by JSPS KAKENHI (26450388).

Tolerance of lamb and mouse oocytes to cryoprotectants during vitrification

Zygote ◽  
2018 ◽  
Vol 27 (1) ◽  
pp. 36-45
Author(s):  
Jaqueline Sudiman ◽  
Alice Lee ◽  
Kheng Ling Ong ◽  
Wu Zi Yuan ◽  
Sarah Jansen ◽  
...  
Keyword(s):  
Cell Number ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Cortical Granule ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
Parthenogenetic Activation ◽  
Mouse Oocytes ◽  
Different Response

SummaryMouse and lamb oocytes were vitrified with, or exposed to, different cryoprotectants and evaluated for their effects on their survival and developmental competence after in vitro fertilization (IVF) and activation treatments. Control oocytes remained untreated, whilst the remainder were exposed to three different combinations of vitrification solutions [dimethyl sulfoxide (DMSO) + ethylene glycol (EG), EG only, or propanediol (PROH) + EG] and either vitrified or left unfrozen (exposed groups). Oocytes in the control and vitrified groups underwent IVF and developmental competence was assessed to the blastocyst stage. In lambs, survival rate in vitrified oocytes was significantly lower than for oocytes in the exposed groups (P <0.05). Blastocyst development was low in vitrified oocytes compared with controls (<6% vs 38.9%, P <0.01). Parthenogenetic activation was more prevalent in vitrified lamb oocytes compared with controls (P <0.05). No evidence of zona pellucida hardening or cortical granule exocytosis could account for reduced fertilization rates in vitrified lamb oocytes. Mouse oocytes demonstrated a completely different response to lamb oocytes, with survival and parthenogenetic activation rates unaffected by the vitrification process. Treatment of mouse oocytes with DMSO + EG yielded significantly higher survival and cleavage rates than treatment with PROH + EG (87.8% and 51.7% vs 32.7% and 16.7% respectively, P <0.01), however cleavage rate for vitrified oocytes remained lower than for the controls (51.7% vs 91.7%, P <0.01) as did mean blastocyst cell number (33 ± 3.1 vs 42 ± 1.5, P <0.05). From this study, it is clear that lamb and mouse show different tolerances to cryoprotectants commonly used in vitrification procedures, and careful selection and testing of species-compatible cryoprotectants is required when vitrifying oocytes to optimize survival and embryo development.

Effects of lamb age, hormone stimulation and response to hormone stimulation on the yield and in vitro developmental competence of prepubertal lamb oocytes

2005 ◽  
Vol 17 (6) ◽  
pp. 593 ◽  
Author(s):  
Katherine M. Morton ◽  
Sally L. Catt ◽  
W. M. Chis Maxwell ◽  
Gareth Evans
Keyword(s):  
Recovery Rate ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Oocyte Development ◽  
Blastocyst Formation ◽  
In Vitro Production ◽  
Hormone Stimulation ◽  
Vitro Production ◽  
High Responders

Experiments were conducted to determine the effects of lamb age, hormone stimulation (Experiment 1) and response to stimulation (Experiment 2) on the in vitro production of embryos from prepubertal lambs aged 3–4 and 6–7 weeks of age. For 3–4-week-old lambs, hormone stimulation increased the number of follicles (29.9 ± 15.3 v. 70.6 ± 8.2), oocytes per ovary (18.3 ± 6.3 v. 39.3 ± 5.8) and oocyte development to the blastocyst stage (0/192 (0.0%) v. 115/661 (17.4%); P < 0.05). Lamb age (3–4 v. 6–7 weeks old) increased oocyte development to the blastocyst stage (115/661 (17.4%) v. 120/562 (21.4%) respectively). In Experiment 2, hormone-stimulated lambs (3–4 and 6–7 weeks old) were divided into low, medium or high responders based on the number of ovarian follicles (<20, 20–50 and >100 follicles per ovary respectively). The response to hormone stimulation did not affect oocyte recovery rate, but the number of oocytes suitable for culture was increased for high-responding 3–4-week-old lambs only (P < 0.05). Oocyte development to the blastocyst stage was not affected by response to stimulation for 3–4-week-old lambs (15.2–25.6%; P > 0.05), but was reduced for high (6.7%) compared with low (19.5%) and medium (30.9%) responding 6–7-week-old lambs (P < 0.05). These results demonstrate that the production of embryos from prepubertal lambs is increased by hormone stimulation and lamb age and the response to stimulation does not affect embryo production from 3–4-week-old lambs, although by 6–7 weeks of age a high response to stimulation reduces blastocyst formation.

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