Effects of activin A and follistatin on developmental kinetics of bovine embryos: cinematographic analysis in a chemically defined medium

Reproduction ◽  
2000 ◽  
pp. 119-125 ◽  
Author(s):  
K Yoshioka ◽  
C Suzuki ◽  
S Iwamura

The effects of recombinant human activin A and follistatin on the developmental kinetics of bovine presumptive zygotes matured and fertilized in vitro using time-lapse cinematography were investigated. The presumptive zygotes were cultured for 9 days in a chemically defined medium (modified synthetic oviduct fluid, control) and modified synthetic oviduct fluid supplemented with activin A or follistatin. Development under cine-recording conditions was similar to that in an incubator. Addition of activin A to modified synthetic oviduct fluid increased, while addition of follistatin decreased, the percentage of zygotes that developed to morulae and blastocysts. Follistatin significantly prolonged the timing of development to the 9-16-cell stage compared with the control and activin A media. Activin A significantly shortened the duration of the third cell cycle compared with the control, but follistatin significantly prolonged the fourth cell cycle compared with the control and activin A. Developmental arrest ('lag-phase') during the 4-8-cell stage was observed in 95% of embryos developed to more than the 9-16-cell stage in all treatments. The greater the number of cells at the onset of the lag-phase, the earlier the onset of the phase and the shorter the duration of the phase, the further embryos were able to develop by day 9 in all treatments. The number of cells at the onset of the lag-phase in the medium containing activin A was significantly higher than it was in control or follistatin-containing media. Moreover, activin A significantly shortened the duration of the lag-phase compared with follistatin. The present results indicate that activin A may enhance in vitro development of bovine embryos by improving developmental kinetics, especially by increasing the number of cells at the onset of the lag-phase and shortening the duration of this phase.

Zygote ◽  
2001 ◽  
Vol 9 (2) ◽  
pp. 105-113 ◽  
Author(s):  
J. Peippo ◽  
M. Kurkilahti ◽  
P. Bredbacka

In this study, a simple time-lapse video recording system was used to compare developmental kinetics of female and male bovine embryos produced in vitro. Following embryo sex determination, the timing of each cleavage up to the 4-cell stage was compared between the sexes from the videotapes after culture in the presence and absence of glucose. In the second experiment, the consequences of exposure to a time-lapse video recording (TL) environment were studied by culturing embryos further until day 7 in an incubator, followed by collection and sex determination of morulae and blastocysts. In the absence of glucose, female embryos cleaved earlier than male ones. In the presence of glucose, however, male embryos cleaved earlier than female ones. There was no difference in the number of morulae/blastocysts in the absence of glucose, but in the presence of glucose more male than female embryos reached the morula and blastocyst stage. Exposure to the TL environment itself also had a sex-related effect, being more detrimental to male than female embryos. The difference in the number of functional X chromosomes between the sexes during early preimplantation development could explain these findings. In females, an increased capacity for oxygen radical detoxification through the pentose phosphate pathway could result in a reduced cleavage rate. Furthermore, glucose may influence the expression of enzymes located on the X chromosome. According to these results, a simple time-lapse video recording system is suitable for investigating embryo developmental kinetics and perhaps for the selection of embryos with the greatest developmental potential.


2020 ◽  
Vol 146 ◽  
pp. 39-47 ◽  
Author(s):  
Enrique Gómez ◽  
Susana Carrocera ◽  
David Martín ◽  
Juan José Pérez-Jánez ◽  
Javier Prendes ◽  
...  

2007 ◽  
Vol 19 (1) ◽  
pp. 259 ◽  
Author(s):  
M. Alomar ◽  
H. Tasiaux ◽  
S. Remacle ◽  
F. George ◽  
D. Paul ◽  
...  

The between-bulls variation in in vitro fertility and the shift of sex ratio toward male embryos are two problems affecting the in vitro production (IVP) of bovine embryos. Our objective was to evaluate the possible correlation between the kinetics of fertilization, embryo development, and the sex ratio of the resulting embryos. In a first experiment, and using frozen-thawed semen of 4 different AI bulls, the kinetics of pronucleus (PN) formation was evaluated at 8, 12, and 18 h post-in vitro insemination (hpi) after fixation and staining with Hoechst 33342. Fertilized oocytes were classified in 3 PN stages: PN1: showing the first signs of sperm head decondensation; PN2: with two pronuclei of different sizes, the two being far from each other; and PN3: showing two symmetric pronuclei of equal size, close to each other. Differences between bulls were observed at each time point, but were greater at 12 hpi than at 8 or 18 hpi. At 8 hpi and 12 hpi, bull C showed a significantly faster PN formation by comparison with the 3 other bulls (chi-square test: P < 0.05), whereas at 18 hpi, the proportion at each of the PN stages was similar to that of bulls A and D, with bull B showing delayed PN development. In a second experiment, a standard IVP procedure was conducted with the 4 bulls to determine cleavage and blastocyst rates. The timing of first cleavage was measured using time-lapse cinematography. Compared with those of bull B, the embryos generated with bull C led to significantly higher Day 7 blastocyst yields (31.3 � 9.5% vs. 21.9 � 6.7%; ANOVA: P < 0.05). Moreover, the embryos from bull C reaching the blastocyst stage cleaved faster (first cleavage at 23.1 � 2.1 hpi vs. 25.4 � 2.7 hpi for bull B; ANOVA: P < 0.05). In a third experiment, 65 to 76 Day 8 blastocysts were sexed per bull. Embryo sexing was performed by PCR using the co-amplification of a Y-specific bovine SRY sequence and an autosomal btRep-137 sequence. Only blastocysts obtained with bull C showed a shift in sex ratio toward male embryos (76.0% male embryos vs. 53.8% for bull B; chi-square test: P < 0.05), whatever the size of the blastocyst. The shift in sex ratio was already present at the 2-cell stage (64.2% male embryos; n = 53; chi-square test: P < 0.05). In conclusion, for 2 out of 4 bulls, a correlation was observed between the kinetics of PN formation, the timing of first cleavage, and the sex ratio of the resulting embryos.


Development ◽  
1974 ◽  
Vol 31 (1) ◽  
pp. 235-245
Author(s):  
Yu-Chih Hsu ◽  
John Baskar ◽  
Leroy C. Stevens ◽  
John E. Rash

About 1–3% of mouse blastocysts, which had initially been cultured from the two-cell stage in chemically defined medium or about 3–5% of blastocysts which were explanted from the uterus, developed to the early somite stage when cultured in vitro on collagen. Two-cell eggs were initially cultivated in chemically defined medium to the blastocyst stage. Blastocysts were then transferred to Eagle's minimal essential medium (MEM) plus 10% heat-inactivated calf serum. Two barriers to further development were overcome. First, the formation of endoderm and ectoderm from the inner cell mass immediately after attachment to collagen. Second, formation of the embryo proper from the embryonic region. Both barriers were overcome by using heat-inactivated human cord serum after the blastocysts hatched from the zona pellucida and attached to collagen. After attachment, embryos were cultured in MEM plus 20% heat-inactivated human cord serum which was changed daily until early somite stages. Apparently normal healthy development in vitro occurred, as judged by light and electron microscopic examination.


Reproduction ◽  
2001 ◽  
pp. 601-610 ◽  
Author(s):  
MA Yaseen ◽  
C Wrenzycki ◽  
D Herrmann ◽  
JW Carnwath ◽  
H Niemann

The aim of this study was to determine the relative abundance of mRNAs for the insulin-like growth factor I (IGF-I) and IGF-II ligands, and for the IGF receptors (IGF-IR and IGF-IIR) in in vitro preimplantation bovine embryos from the oocyte to the hatched blastocyst stage using two different culture systems: TCM-199 supplemented with oestrous cow serum, or synthetic oviduct fluid supplemented with polyvinyl alcohol. Development to the two- to four-cell stage and blastocyst stage was significantly higher (P < or = 0.05) in embryos cultured in TCM supplemented with oestrous cow serum than in those cultured in synthetic oviduct fluid supplemented with polyvinyl alcohol (61 and 25% versus 55 and 17%, respectively). A semi-quantitative RT-PCR assay did not detect IGF-I transcripts at any stage of preimplantation bovine development, including the hatched blastocyst stage. In both culture systems, IGF-IR, IGF-II and IGF-IIR were expressed throughout preimplantation development up to the hatched blastocyst stage in a varying pattern. The expression patterns of IGF-IR, IGF-II and IGF-IIR in embryos generated in the two culture systems were not significantly different, except at the expanded blastocyst stage, at which significantly higher amounts of IGF-IIR were observed in the TCM system than in the synthetic oviduct fluid system. These results indicate that transcripts of IGF-IR and IGF-IIR follow the standard pattern in which maternal stores of mRNA in the oocyte are slowly depleted up to the 16-cell stage and then re-established at the onset of embryonic expression of these genes. The lack of detectable IGF-I transcripts in the bovine embryo indicates a predominantly paracrine mode of action. The bovine embryo is capable of producing IGF-II, IGF-IIR and IGF-IR in large amounts, particularly after hatching, which may be important for the formation of the filamentous conceptus. Results indicate an autocrine mechanism for IGF-II and modulation of IGF family expression by culture conditions.


2011 ◽  
Vol 23 (1) ◽  
pp. 150
Author(s):  
J. Sanchez-Osorio ◽  
C. Cuello ◽  
J. Gomis ◽  
C. Maside ◽  
M. A. Gil ◽  
...  

The aim of this study was to design a chemically defined medium for the vitrification of in vitro produced porcine blastocysts avoiding the use of serum or serum components. Cumulus–oocyte complexes were matured in vitro in NCSU-23 for 44 h and were inseminated with frozen–thawed spermatozoa. Presumptive zygotes were cultured for 16 h to assess in vitro fertilization (IVF) parameters (N = 200) or for 6 days (N = 600) in order to obtain blastocysts. For chemically delipidation, 10 μM forskolin was added to the culture medium on Day 5 of in vitro culture. On Day 2, embryos were evaluated for cleavage rate. On Day 6, embryos were assessed for blastocyst formation; only those blastocysts showing excellent morphological appearance were selected for vitrification. Blastocysts were vitrified using as basic medium TCM-199 HEPES supplemented with 20% of newborn calf serum (NBCS; n = 65), with 0.1% of polyvinyl alcohol (PVA; n = 64) or without additives (WA; n = 65). The OPS-vitrification and warming were performed as described by (Sanchez-Osorio et al. 2010 Theriogenology 73, 300–308) using 16% of Etylenglycol and 16% of dimetyl sulfoxide as final concentrations of cryoprotectants. Vitrified blastocysts were warmed and cultured in vitro for 24 h to assess their viability. Blastocysts that totally reformed their blastocoel cavity showing a normal or excellent morphology were considered viable. In addition, after in vitro culture vitrified-warmed viable embryos were fixed in 4% paraformaldehyde in PBS medium and stained with Hoechst 33342 in order to assess the total number of cells. Data were analysed by using the MIXED procedure of SPSS. The threshold for significance was set at P < 0.05. Results are expressed as least squares means ± SEM. The maturation, penetration, and monospermy rates were 98.5 ± 1.2%, 85.3 ± 3.6%, and 48.8 ± 5%, respectively. The efficiency of IVF (defined as the ratio of monospermic oocytes to the total number of inseminated oocytes) was 41.0 ± 4.9%. The values of cleavage rate at Day 2 and blastocysts formation rate were 67.8 ± 1.4% and 37.3 ± 1.6%, respectively. After vitrification and warming, similar survival rates were observed for NBCS (33.8 ± 5.9) PVA (40.6 ± 6.0), and WA (30.8 ± 5.9) groups. No significant differences were found for the total number of cells (ranged from 35.4 ± 6.8 to 50.8 ± 8.3) among vitrification groups. In conclusion, in vitro derived porcine blastocysts can be vitrified in the absence of serum and serum components. Furthermore, PVA is a suitable substitute for serum in vitrification solutions with no detrimental effect on the viability of in vitro produced pig blastocysts. This study was supported by the Seneca foundation of Murcia (GERM 04543/07).


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