Secretome derived from different cell lines in bovine embryo production in vitro

2018 ◽  
Vol 30 (4) ◽  
pp. 658 ◽  
Author(s):  
C. Perrini ◽  
P. Esposti ◽  
F. Cremonesi ◽  
A. Lange Consiglio
Keyword(s):  
Embryo Quality ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Control Group ◽  
Bovine Embryo ◽  
Blastocyst Development ◽  
Glutathione Peroxidase 1 ◽  
Amniotic Cell ◽  
Amniotic Cells

The present study investigated the effects of conditioned medium (CM), composed of microvesicles (MVs) and soluble factors present in the supernatant (SN), of bovine endometrial and amniotic cells on embryo quality and rate of blastocyst production. Presumptive zygotes were randomly assigned on Days 1, 3 and 5 after fertilisation to synthetic oviducal fluid with amino acids (SOFaa; control) or to SOFaa supplemented with either 20% endometrial or amniotic CM, 20% SN or 100 × 106 MVs mL−1. Embryos were evaluated on Day 7. For groups supplemented with MVs derived from either endometrial or amniotic cells on Day 1 of culture, blastocysts had developed, but at a lower rate than in the control group. Blastocysts had developed in all groups in which endometrial or amniotic cell-derived CM or MVs were added on Day 3 of culture, but the rate of blastocyst development was significantly lower in both CM groups than in the MVs groups. The addition of all secretome fractions (CM, MVs and SN) derived from either bovine endometrial or amniotic cells on Day 5 of culture resulted in blastocyst production, but only amniotic MVs resulted in a blastocyst production rate comparable to that in the control group. Supplementation of SOFaa on Day 5 resulted in a qualitatively higher number of inner cell mass cells compared with the control group only for the amniotic CM and MVs groups. At day 7, these data were confirmed by RT-qPCR evaluation of genes (Bcl-2-associated X protein (BAX) and glutathione peroxidase 1 (GPX1) involved in apoptosis and protection against reactive oxygen species. In conclusion, of the different secretome fractions tested, only amniotic MVs added to SOFaa resulted in better outcomes than in the control group.

58 ISOLATION OF BOVINE TROPHOBLAST AND ITS REPROGRAMMING BY NUCLEAR TRANSFER

2011 ◽  
Vol 23 (1) ◽  
pp. 134
Author(s):  
I. M. Saadeldin ◽  
B. H. Kim ◽  
B. Roibas da Torre ◽  
O. J. Koo ◽  
G. Jang ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Inner Cell Mass ◽  
Quantitative Polymerase Chain Reaction ◽  
Cell Mass ◽  
Donor Cell ◽  
Developmental Competence ◽  
Control Group ◽  
Embryonic Cells ◽  
Blastocyst Development

Nuclear transfer (NT) has been used to produce many cloned offspring using several types of cells, including embryonic cells. Even though inner cell mass cells have been used as donor karyoplast for producing cloned animals, there are few studies using trophoblast. In mice, clones were born by nuclear transfer of trophoblasts from the expanded blastocyst into enucleated oocytes as a trial to show the totipotency of both inner cell mass and trophectoderm cells isolated from blastocysts (Tsunoda and Kato 1998 J. Reprod. Fertil. 113, 181–184). However, bovine trophoblast cell (TC) lines have not been used in NT to date. The purpose of this study was to elucidate whether TC as donor cell can be reprogrammed in bovine enucleated oocyte and determine the relative abundance of interferon tau (IFNτ) expression in the resulting cloned preimplantational embryos. Hatched blastocysts produced by IVF were used to isolate TCs on mouse embryonic fibroblasts treated with mitomycin C as feeder cells. TCs and adult fibroblasts (AF, control group for NT) were microinjected to perivitelline space of in vitro mature enucleated oocytes and electrically fused. Reconstructed embryos were chemically activated and cultured in a 2-step chemically defined medium. Levels of IFNτ expression in IVF-, TC-, and AF-derived blastocysts were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). IVF produced embryos were used as reference to analyze the linear progressive expression of IFNτ through mid-, expanded, and hatching blastocysts. As a result, TCs expressing IFNτ were successfully isolated and cultured on feeder layers. It grew as cell sheets of cuboidal epithelium with high proliferation capacity as a single colony originated from a small clump of cells measured 0.5 cm within 7 days of culture. TCs were reprogrammed in the enucleated oocytes to blastocyst with similar efficiency to AF (14.5% and 15.6%, respectively; P ≤ 0.05). RT-qPCR studies showed that IFNτ expression was higher in TC-derived blastocysts than IVF- and AF-derived blastocysts. Both IVF- and TC-derived blastocysts, showed progressive increase of IFNτ expression through the advancement of blastocyst development when it was compared to AF-derived blastocysts. In conclusion, using TCs expressing IFNτ as donor cell for bovine NT could increase the developmental competence of cloned embryos as indicated by progressive linear increase in IFNτ expression. This study was supported by grants from IPET (#109023-05-1-CG000), NRF (#M10625030005-10N250300510), MKE (#2009-67-10033839, #2009-67-10033805), and BK21 program. Saadeldin I. M. is supported by Islamic Development Bank (IDB) merit scholarship, Jeddah, Saudi Arabia.

scholarly journals Zinc supplementation during in vitro embryo culture increases inner cell mass and total cell numbers in bovine blastocysts1

2019 ◽  
Vol 97 (12) ◽  
pp. 4946-4950 ◽  
Author(s):  
Lydia K Wooldridge ◽  
Madison E Nardi ◽  
Alan D Ealy
Keyword(s):  
Embryo Culture ◽  
Zinc Supplementation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Retention Rates ◽  
Bovine Embryo ◽  
Blastocyst Development ◽  
Cell Numbers

Abstract Deficiencies in current embryo culture media likely contribute to the poor blastocyst development rates and pregnancy retention rates for in vitro produced (IVP) bovine embryos. Of special concern is the lack of micronutrients in these media formulations. One micronutrient of interest is zinc, an essential trace element involved with various enzyme and transcription factor activities. The objective of this work was to describe whether zinc sulfate supplementation during in vitro embryo culture affects bovine embryo development and blastomere numbers. Either 0, 2, 20, or 40 µM zinc sulfate was supplemented to presumptive zygotes cultured in synthetic oviductal fluid containing AAs and bovine serum albumin for 8 d. None of the treatments affected cleavage rates. Percentage of blastocysts on days 7 and 8 postfertilization was not affected by supplementing 2 or 20 µM zinc but were reduced (P < 0.05) with 40 µM zinc. In blastocysts harvested on day 8, inner cell mass (ICM) and total cell number were increased (P < 0.05) with 2 µM zinc supplementation but not with the other zinc concentrations. Numbers of trophectoderm cells were not affected by zinc treatment. In conclusion, supplementing zinc during bovine embryo culture did not impact blastocyst development but improved ICM cell numbers. This improvement in ICM cell number may have implications for improved pregnancy retention rates after IVP embryo transfer as smaller ICM sizes are associated with poor pregnancy success in cattle.

Frozen–thawed ampullary cell monolayer improves bovine embryo in vitro development and quality

Zygote ◽  
2019 ◽  
Vol 27 (05) ◽  
pp. 337-346 ◽  
Author(s):  
Anise Asaadi ◽  
Mojtaba Kafi ◽  
Hadi Atashi ◽  
Mehdi Azari ◽  
Miel Hostens
Keyword(s):  
Epithelial Cell ◽  
Embryo Quality ◽  
Inner Cell Mass ◽  
Cell Monolayer ◽  
Cell Mass ◽  
Bovine Embryo ◽  
Yield And Quality ◽  
Trophectoderm Cells ◽  
Vitro Development

SummaryThe aim of this study was to evaluate the effects of different timing for frozen–thawed bovine ampullary epithelial cell (BAEC) and bovine oviductal epithelial cell (BOEC) co-culture on the development and quality of bovine embryos produced in vitro. Embryo development was assessed by day 8 blastocyst yield, whereas embryo quality was determined using blastocyst differential cell count, cryotolerance and the expression of selected genes related to embryo quality. The results showed that the presence of BAECs during the last 6 h of in vitro maturation (IVM) increased blastocyst yield and survival of the vitrified-warmed blastocysts. In addition, embryos produced in the presence of BAECs during the last 6 h of IVM or in the presence of BOECs during the first 4 days of in vitro culture (IVC) showed a greater number of trophectoderm cells and a greater inner cell mass. In terms of gene expression, IFN-T was downregulated and PLAC8, AQP3 and ATP1A1 were upregulated in the presence of the BAECs during the last 6 h of the IVM and/or in the presence of BOECs during the first 4 days of IVC. In conclusion, co-culturing bovine oocytes with a frozen–thawed ampullary cell monolayer during the last 6 h of maturation increased blastocyst yield and quality.

scholarly journals A shorter equilibration period in the VitTrans in-straw bovine embryo vitrification method improves post-warming outcomes

2020 ◽  
Author(s):  
Iris Martínez-Rodero ◽  
Tania García-Martínez ◽  
Erika Alina Ordóñez-León ◽  
Meritxell Vendrell-Flotats ◽  
Carlos Olegario-Hidalgo ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Survival Rates ◽  
Field Conditions ◽  
Bovine Embryo ◽  
Direct Transfer ◽  
Treatment Groups ◽  
Cell Counts ◽  
Hatching Rates

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.

scholarly journals Cell lineage allocation in equine blastocysts produced in vitro under varying glucose concentrations

Reproduction ◽  
2015 ◽  
Vol 150 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Young-Ho Choi ◽  
Pablo Ross ◽  
Isabel C Velez ◽  
B Macías-García ◽  
Fernando L Riera ◽  
...  
Keyword(s):  
High Glucose ◽  
Culture Medium ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
Primitive Endoderm ◽  
Blastocyst Development ◽  
Embryo Culture Medium ◽  
Effect Of Glucose

Equine embryos developin vitroin the presence of high glucose concentrations, but little is known about their requirements for development. We evaluated the effect of glucose concentrations in medium on blastocyst development after ICSI. In experiment 1, there were no significant differences in rates of blastocyst formation among embryos cultured in our standard medium (DMEM/F-12), which contained >16 mM glucose, and those cultured in a minimal-glucose embryo culture medium (<1 mM; Global medium, GB), with either 0 added glucose for the first 5 days, then 20 mM (0-20) or 20 mM for the entire culture period (20-20). In experiment 2, there were no significant differences in the rates of blastocyst development (31–46%) for embryos cultured in four glucose treatments in GB (0-10, 0-20, 5-10, or 5-20). Blastocysts were evaluated by immunofluorescence for lineage-specific markers. All cells stained positively forPOU5F1. An inner cluster of cells was identified that included presumptive primitive endoderm cells (GATA6-positive) and presumptive epiblast (EPI) cells. The 5-20 treatment resulted in a significantly lower number of presumptive EPI-lineage cells than the 0-20 treatment did.GATA6-positive cells appeared to be allocated to the primitive endoderm independent of the formation of an inner cell mass, as was previously hypothesized for equine embryos. These data demonstrate that equine blastocyst development is not dependent on high glucose concentrations during early culture; rather, environmental glucose may affect cell allocation. They also present the first analysis of cell lineage allocation inin vitro-fertilized equine blastocysts. These findings expand our understanding of the factors that affect embryo development in the horse.

scholarly journals PTPN11 (SHP2) Is Indispensable for Growth Factors and Cytokine Signal Transduction During Bovine Oocyte Maturation and Blastocyst Development

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1272 ◽  
Author(s):  
Muhammad Idrees ◽  
Lianguang Xu ◽  
Seok-Hwan Song ◽  
Myeong-Don Joo ◽  
Kyeong-Lim Lee ◽  
...  
Keyword(s):  
Growth Factors ◽  
Embryo Development ◽  
Oocyte Maturation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Specific Inhibitor ◽  
Mrna Translation ◽  
Bovine Oocyte ◽  
Blastocyst Development

This study was aimed to investigate the role of SHP2 (Src-homology-2-containing phosphotyrosine phosphatase) in intricate signaling networks invoked by bovine oocyte to achieve maturation and blastocyst development. PTPN11 (Protein Tyrosine Phosphatase, non-receptor type 11) encoding protein SHP2, a positive transducer of RTKs (Receptor Tyrosine Kinases) and cytokine receptors, can play a significant role in bovine oocyte maturation and embryo development, but this phenomenon has not yet been explored. Here, we used different growth factors, cytokines, selective activator, and a specific inhibitor of SHP2 to ascertain its role in bovine oocyte developmental stages in vitro. We found that SHP2 became activated by growth factors and cytokines treatment and was highly involved in the activation of oocyte maturation and embryo development pathways. Activation of SHP2 triggered MAPK (mitogen-activated protein kinases) and PI3K/AKT (Phosphoinositide 3-kinase/Protein kinase B) signaling cascades, which is not only important for GVBD (germinal vesical breakdown) induction but also for maternal mRNA translation. Inhibition of phosphatase activity of SHP2 with PHPS1 (Phenylhydrazonopyrazolone sulfonate 1) reduced oocytes maturation as well as bovine blastocyst ICM (inner cell mass) volume. Supplementation of LIF (Leukemia Inhibitory Factor) to embryos showed an unconventional direct relation between p-SHP2 and p-STAT3 (Signal transducer and activator of transcription 3) for blastocyst ICM development. Other than growth factors and cytokines, cisplatin was used to activate SHP2. Cisplatin activated SHP2 modulate growth factors effect and combine treatment significantly enhanced quality and rate of developed blastocysts.

77 Development and quality of in vitro bovine hemi embryos produced by blastomere separation and embryo bisection

2019 ◽  
Vol 31 (1) ◽  
pp. 164
Author(s):  
A. E. Ynsaurralde Rivolta ◽  
M. Suvá ◽  
V. Alberio ◽  
C. Vazquez Echegaray ◽  
A. Guberman ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Monozygotic Twin ◽  
Cell Number ◽  
Control Group ◽  
Cell Stage ◽  
Exact Test ◽  
Development Rates

Bovine monozygotic production of twins became popular in the 1980s as a technique to multiply high value genetics. Moreover, it also became a powerful model for research. Different techniques have been used on bovine embryos obtained by superovulation. In this work, we compared the development rates and quality of monozygotic twin embryos produced by blastomere separation (BS) and embryo bisection (EB) of IVF embryos. To this aim, cumulus-oocytes complexes collected from slaughterhouse ovaries were in vitro matured in TCM 199 containing 10% fetal bovine serum, 10µg mL−1 FSH, 0.3mM sodium pyruvate, 100mM cysteamine, and 2% antibiotic-antimycotic for 24h, at 6.5% CO2 in humidified air and 38.5°C. The IVF was performed with 16×106 spermatozoa per mL for 5h. Afterward, presumptive zygotes were cultured in SOF medium for 7 days at 38.5°C and 5% O2. After 24h of culture, blastomeres of 2-cell stage embryos (N=114) were separated and each one was cultured individually in a microwell for 7 days. Embryo bisection (N=179) was performed manually on Day-7 blastocysts previously depleted of their zonae pellucidae, under stereoscopic microscope. Hemi embryos were cultured for 24h and then twins and single blastocyst rates were calculated. For quality assessment, diameter, total and inner cell mass (ICM) cell number of hemi embryos (BS: 6 couples; ES: 10 couples) and the control group (C: 11) were evaluated. The ICM cell number was measured by immunofluorescence staining using SOX2 antibody and the percentage of ICM and trophectoderm (TE) cells was calculated. The results were analysed using Fisher’s exact test and ANOVA with mean comparison using Tukey’s test (P=0.05). No statistical differences were found in blastocyst rates of twins and single hemi embryos produced by BS (28 and 25%) or EB (23 and 32%). Blastocyst diameter was similar between groups and control. Hemi embryos exhibited lower total and ICM cell number than control (BS: 43±18, EB: 57±14v. C: 93±35 and BS: 16±7, EB: 12±8v. C: 34±19). However, BS hemi embryos had higher ICM and lower TE percentage (40/60%) compared with the EB group (20/80%). The control group did not differ with hemi embryo treatments for ICM and TE (30/70%). Our preliminary results have indicated that although the development rates of hemi embryos produced in vitro were similar between both techniques, blastomere separation generates better quality embryos than blastocyst bisection.

scholarly journals 45PRODUCTION OF CHIMERIC TRANSCHROMOSOMIC CALVES

2004 ◽  
Vol 16 (2) ◽  
pp. 144
Author(s):  
P. Kasinathan ◽  
M.F. Nichols ◽  
J.E. Griffin ◽  
J.M. Robl
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Peripheral Blood Lymphocytes ◽  
Blastocyst Stage ◽  
Human Artificial Chromosome ◽  
Fish Analysis ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Fetal Fibroblasts

Chimeras have been used for investigating fundamental aspects of early embryonic development, and differentiation, and for introducing foreign genes into mammals (Robertson et al., 1986 Nature 323, 445–448; Cibelli et al., 1998 Science 280, 1256–1258). The main objective of this study was to determine if the transfer of blastomeres from in vitro-produced (IVP) embryos into cloned, transchromosomic embryos improved the efficiency of producing transchromosomic calves. Cloned embryos were produced using in vitro-matured bovine oocytes and bovine fetal fibroblasts containing a human artificial chromosome (HAC) (Kuroiwa et al., 2002 Nat Biotechnol 20, 889–894). IVP embryos were produced using standard procedures and blastomeres were harvested at the 8–16 cell stage by removing the zona pellucida with protease. Cloned embryos were randomly divided on Day 4 into two groups. One group received 3–4 IVP blastomeres while a second group served as a control (nonmanipulated cloned embryos). After transferring the blastomeres, the chimeric and cloned embryos were placed in culture (Kasinathan et al., 2001 Biol. Reprod. 64, 1487–1493) and on Day 7 development to the blastocyst stage was evaluated. Grades 1 and 2 embryos were transferred; two each per synchronized recipient. Pregnancy maintenance, calving, and calf survival were evaluated in both groups. Presence of a HAC in live calves was evaluated in both fibroblasts and peripheral blood lymphocytes (PBLs) using FISH analysis. Embryo development to the blastocyst stage, maintenance of pregnancy and number of calves born were analyzed using Chi-square. There were no differences in the rate of blastocyst development at day 7 or establishment of pregnancy at 40d (P&gt;0.05). However, pregnancy rate at 120d, and number of calves that developed to term and were alive at birth (chimera 14/54 and clone 4/90), and at 1 month of age (chimera 13/54 and clone 1/90) were lower (P&lt;0.01) for cloned embryos. The proportion of cells containing an HAC in PBLs, was higher in cloned calves (100%) compared to chimeric calves (26%). The HAC retension rates in PBLs in HAC-positive chimeric and cloned calves were 84% and 95%, respectively. These data indicate that, although the proportion of calves retaining an HAC was lower in chimeras compared to clones, more HAC-positive calves were produced in the chimeric treatment from fewer cloned embryos. We speculate that higher rates of development in the chimeras may be related to the normality of the placenta. Future studies will be required to determine the contribution of the IVP blastomeres to both the inner cell mass and trophectoderm. Therefore, a chimeric approach may be useful for improving the efficiency of producing cloned transchromosomic calves.

157 EFFECT OF MELATONIN ON EMBRYO QUALITY OF BOVINE OOCYTES SUBJECTED TO HEAT SHOCK

2016 ◽  
Vol 28 (2) ◽  
pp. 208
Author(s):  
N. G. Alves ◽  
I. J. Ascari ◽  
L. S. A. Camargo ◽  
J. Jasmin ◽  
C. C. R. Quintão ◽  
...  
Keyword(s):  
Heat Shock ◽  
Embryo Quality ◽  
Linear Models ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Quality Data ◽  
Trophoblast Cells ◽  
Melatonin Concentration

The aim of this study was to evaluate the effect of different concentrations of melatonin added to in vitro maturation (IVM) medium of oocytes subjected to heat shock on embryo quality. Immature oocytes aspirated from ovaries obtained from a slaughterhouse were selected and randomly allocated in factorial experiment design (3 × 2). Three concentrations of melatonin (0, 10–6, and 10–4 M; M5250, Sigma, St. Louis, MO, USA) were added to the IVM medium and 2 incubation conditions (conventional: 24 h at 38.5°C and 5% CO2; heat shock: 12 h at 41°C followed by 12 h at 38.5°C and 5% CO2) were tested, resulting in treatments: M1 (0 M; 38.5°C; n = 15), M2 (10–6 M; 38.5°C; n = 15), M3 (10–4 M; 38.5°C; n = 15), M4 (0 M; 41°C; n = 15), M5 (10–6 M; 41°C; n = 15), and M6 (10–4 M; 41°C; n = 15). The IVM was performed in a Nunc plate (144444 – Thermo, Fisher Scientific Inc., Pittsburgh, PA, USA) containing 400 µL of TCM-199 (Invitrogen, Carlsbad, CA, USA) supplemented with 20 µg mL–1 of FSH (Pluset®, Calier Laboratories, Barcelona, Spain) and 10% oestrus cow serum. Oocytes were IVF in FERT-TALP medium for 20–22 h and incubated at 38.5°C and 5% CO2. After IVF, the presumptive zygotes were denuded and cultured in CR2aa medium supplemented with 2.5% FCS (Nutricell, Campinas, Brazil) in an incubator at 38.5°C under 5% CO2, 5% O2, and 90% N2, and saturated humidity for 8 days. Blastocysts with 8 days post-fertilization from different treatments were fixed in 4% paraformaldehyde in PBS for 1 h and analysed by TUNEL assay (Deadend™ Fluorometric TUNEL System, Promega, Madison, WI, USA) to evaluate embryonic quality. Data were analysed by generalised linear models considering the Poisson distribution and using the Proc Genmod of SAS software (version 9.1; SAS Institute Inc., Cary, NC, USA) considering effects of melatonin concentration, incubation conditions, and interaction between the factors. Values shown are the mean ± s.e.m. The interaction between melatonin concentration and incubation conditions was no significant (P > 0.05). The total number of cells was not affected (P > 0.05) by melatonin, but it was decreased (P < 0.05) by heat shock (M1 = 117 ± 6.7a; M2 = 118 ± 4.2a; M3 = 120 ± 6.3a; M4 = 102 ± 6.2b; M5 = 106 ± 5.7b; M6 = 108 ± 8.9b). Melatonin and heat shock did not affect (P > 0.05) the index of embryo apoptotic cells (M1 = 15.3% ± 2.0; M2 = 15.5% ± 1.3; M3 = 13.6% ± 2.0; M4 = 14.9% ± 1.5; M5 = 13.3% ± 1.3; M6 = 13.5% ± 1.2) and the index of trophoblast cells (M1 = 74.6% ± 2.3; M2 = 75.0% ± 1.7; M3 = 75.2% ± 1.9; M4 = 78.4% ± 2.3; M5 = 76.4% ± 3.0; M6 = 75.2% ± 2.6). The melatonin and heat shock affected the index of the inner cell mass (ICM; P < 0.05), and the heat shock reduced the index of the ICM of oocytes not treated with melatonin (M1 = 25.4% ± 2.3a; M2 = 25.0% ± 1.7a; M3 = 24.8% ± 1.8a; M4 = 21.6% ± 2.3b; M5 = 23.6% ± 3.0a; M6 = 24.8% ± 2.6a). In conclusion, melatonin supplementation to the medium IVM of oocytes subjected to heat shock had no effect on blastocyst total cell number, general apoptotic index, or index of the trophoblast cells, but increased index of the ICM. Research was supported by Fapemig, CNPq, Embrapa, and CAPES.

53 TARGETED SCREEN FOR AMINO ACIDS THAT REGULATE BOVINE INNER CELL MASS DEVELOPMENT

2016 ◽  
Vol 28 (2) ◽  
pp. 156
Author(s):  
V. Najafzadeh ◽  
R. Martinus ◽  
B. Oback
Keyword(s):  
Inner Cell Mass ◽  
Statistical Significance ◽  
Cell Mass ◽  
Positive Control ◽  
Drop Out ◽  
Blastocyst Development ◽  
Acetyl Coa ◽  
Cell Numbers ◽  
Fetal Fibroblasts

Pluripotency relies on species-specific amino acid (AA) metabolism. In the mouse, inner cell mass (ICM) and ICM-derived pluripotent stem cells (PSCs) need threonine, which is catabolized by threonine dehydrogenase (TDH) into acetyl–CoA and glycine. Depleting (Δ) the culture medium of threonine (ΔT) or blocking TDH activity induces PSC death. By contrast, human PSCs do not survive without lysine (ΔK), leucine (ΔL), or methionine (ΔM). Since isolated bovine PSCs cannot be propagated in vitro, we screened for AAs that selectively support pluripotent ICM cells in intact bovine embryos. Five days (D5) post-IVF, embryos were transferred into glutamine-free synthetic oviduct fluid (gSOF) with Eagle’s nonessential (NE) and essential (E) AAs (gSOF_AA) plus BSA. Embryos were individually cultured until D8 under different conditions. Statistical significance was determined using Fisher’s exact test for blastocyst development (morphological grading to IETS standard) and t-tests for cell numbers (differential stain) and gene expression (quantitative or qPCR). Removal of BSA reduced grade 1–3 blastocyst (B1–3) development (37% v. 25%, n = 3; P < 0.001). Depleting NEAAs from gSOF_AA did not significantly decrease B1–3, but depleting all 12 EAAs did (25% v. 8%, n = 6; P < 0.001). Because ΔEAA was most effective, we focused on this. Experiments were conducted in gSOF+NEAA and compared with gSOF_AA as a positive control (n = 2–6 replicates). One (ΔT, ΔM), two (ΔMT, ΔCM, ΔCT; ΔIL, ΔIK, ΔKL), three (ΔCMT, ΔIKL), or six (ΔHPRVWY) EAA drop-out did not affect blastocyst formation, even when NEAAs were also removed for ΔT and ΔM groups (n = 3). However, depleting another six (ΔCIKLMT), nine (+CMT, +IKL), or eleven EAAs (+T, +M) increasingly compromised B1–3 (P < 0.05). Because no clear EAA candidates emerged from the screen, we focused on TDH. TDH mRNA was present at similar levels in microsurgically isolated (by microblade) trophectoderm (TE) and chemically isolated (by Triton X-100) ICM, but undetectable in five adult tissues. Despite ΔT medium showing no effect, exposure to the TDH inhibitor QC1 (50 µM) reduced B1–3 and B1–2 compared with a dimethylsulfoxide (DMSO) solvent control (25% v. 37% and 8% v. 19%, n = 8; P < 0.005). ICM and TE cell numbers were equally reduced in QC1 v. DMSO-treated blastocysts (10 v. 19 and 37 v. 67 with N = 21 and N = 29 embryos, respectively, n = 3; P < 0.005). Yet TDH, hypoblast (PDGRFα), epiblast (NANOG, FGF4, SOX2), and trophoblast (CDX2, KRT8) markers were not consistently affected by QC1. We next applied 3-hydroxynorvaline (3-HNV), which TDH hydrolyses into glycine and propionyl-CoA instead of acetyl-CoA. Compared with solvent controls, 3-HNV (300 µM) killed all embryos and bovine fetal fibroblasts within 3 days in ΔT medium. This toxic effect was fully rescued by >10-fold T-supplementation. Thus, 3-HNV protein incorporation, rather than acetyl-CoA reduction, may nonspecifically impair cellular function. In summary, we found that bovine ICM formation did not specifically depend on metabolizing threonine or any other single EAA. Research was supported by AgResearch Core Funding.

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