scholarly journals Effect of follicular diameter, time of first cleavage and H3K4 methylation on embryo production rates of Bos indicus cattle

2016 ◽  
Vol 37 (5) ◽  
pp. 3189
Author(s):  
Paula Alvares Lunardelli ◽  
Luciana Simões Rafagnin Marinho ◽  
Camila Oliveira Rosa ◽  
Amauri Alcindo Alfieri ◽  
Marcelo Marcondes Seneda

This study aimed investigate the relationship between epigenetics, follicular diameter and cleavage speed, by evaluating the developmental potential and occurence of H3K4 monomethylation of early-, intermediate- and late-cleaving Bos indicus embryos from in vitro fertilized oocytes originating from follicles up to 2 mm in diameter or between 4 and 8 mm in diameter. Oocytes (n = 699) from small follicles (? 2 mm) and 639 oocytes from large follicles (4-8 mm) were punched from 1,982 Bos indicus’ slaughterhouse ovaries. After maturation and in vitro fertilization (IVF), the cultured embryos were separated into early (? 28 h post-IVF), intermediate (> 28 h and ? 34 h post-IVF) and late (> 34 h and ? 54 h post-IVF) cleavage groups. Blastocysts were subjected to an immunofluorescence assessment for H3K4me investigation. The blastocyst rate for large follicles (36.3%) was higher than that for small follicles (22.9%, P < 0.05). In addition, blastocyst rates for early and intermediate cleavage groups (45.3% and 33.8%, respectively) were higher than that for late cleavage group (13.5%, P < 0.05). The blastocysts from all groups displayed H3K4me staining by immunofluorescence, particularly intense in what seemed to be trophectoderm cells and weak or absent in cells seemingly from the inner cell mass. For the first time for indicus embryos, data from this study demonstrate that higher blastocyst embryo rates are obtained from embryos that cleave within 34 h after fertilization and from those produced from follicles of 4-8 mm in diameter, indicating a greater ability of these embryos to develop to the stage of embryonic preimplantation. This is the first article demonstrating the occurrence of H3K4me in cattle embryos; its presence in all the evaluated blastocysts suggests that this histone modification plays a key role in maintaining embryo viability at preimplantation stage.

2013 ◽  
Vol 25 (1) ◽  
pp. 200
Author(s):  
F. Oliveira ◽  
F. Perecin ◽  
F. Meireles ◽  
J. Sangalli ◽  
Y. Watanabe ◽  
...  

It is known that embryos produced in vitro may have structural alterations that often compromise the normal embryo development, generating a high rate of pregnancy loss. The study of these changes is of great importance because it may elucidate the cause of embryonic loss during the first trimester of pregnancy. Thus, the objective of this study was to characterize and compare ultrastructurally bovine blastocysts in the 7th day of development produced by IVF, cloning by somatic cell nuclear transfer (SCNT), and parthenogenesis. In vitro-produced embryos were derived from in vitro-matured oocytes. The somatic cell used to make cloning was fibroblasts of adult cows, and the protocol for parthenogenetic activation of the embryos was done with ionomycin-DMAP. The blastocysts derived from the different experimental groups were fixed in 2.5% glutaraldehyde and processed for transmission electron microscopy evaluation. The results showed that blastocysts derived by SNC and parthenogenesis exhibited a significantly reduced size; the inner cell mass and the blastocoel were not well defined compared with IVF embryos, indicating a less-advanced state of development. Furthermore, organelles of blastocysts derived from SCNT and parthenogenesis were fewer in number and had changes in form, when compared with IVF blastocysts. In parthenogenetic embryos there was the presence of phagosomes, suggesting a high degradation activity of cellular. Mitochondria showed the most significant changes. Although they occur in large quantities in all blastocysts, the morphology of them was impaired in SNC and parthenogenetic embryos (vacuolization, abnormal shape). Such modifications could suggest changes in mitochondria functionality, which may decrease cellular metabolic activity. Thus, we find that the D7 blastocysts derived from SCNT and parthenogenesis showed several ultrastructural differences compared with IVF embryos, with particular reference to a reduced number and morphology of embryo organelles.


2013 ◽  
Vol 25 (1) ◽  
pp. 213
Author(s):  
V. Ghaffarilaleh ◽  
F. Ghafari ◽  
M. Teresa-Paramio ◽  
A. Fouladi-Nashta

Hyaluronan (HA), a component of extracellular matrix in mammalian tissues including that of the reproductive system, has been shown to support embryo development. HA is produced in various sizes with distinct physiological functions. Cleaved sheep embryos produced after in vitro maturation and in vitro fertilization were cultured in serum free synthetic oviduct fluid medium supplemented with increasing concentrations (0, 0.25, 0.5, and 1 mg mL–1) of large size HA (Healon; 6 × 106 Da). Development to blastocyst stage was recorded at Day 7 when a group of the embryos were fixed and stained by differential staining combined with TUNEL labelling to analyse embryo quality. The remainder of the blastocysts from each treatment/repeat were vitrified in open pulled straws and then cultured for an extra period of 48 h to analyse their survival rate and quality after cryopreservation. SPSS version 20 software (SPSS Inc., Chicago, IL, USA) was used for analyzing the data with generalized linear model. Healon did not change blastocyst (33 ± 5.7, 32 ± 6.0, 35 ± 5.5; P ≥ 0.05) or survival rates (63 ± 17.1, 83 ± 15.2, 58 ± 14.2; P ≥ 0.05) as compared to the respective controls (25 ± 5.2, 38 ± 17.1). It increased the total cell (TC) number (83.6 ± 4.6, 100.7 ± 3.8, 97.2 ± 3.7, 105.0 ± 3.9; P ≤ 0.05) and trophectoderm cells (TE) (58.4 ± 3.8, 74.2 ± 3.2, 75.6 ± 3.3, 80.1 ± 3.4; P ≤ 0.05) but had no effect on the number of inner cell mass (ICM) and apoptotic cells. The ICM : TE ratio was not affected (0.45 ± 0.04, 0.36 ± 0.03, 0.33 ± 0.03, 0.30 ± 0.03; P ≥ 0.05). Surviving embryos had higher TC (63.2 ± 3.7, 130.8 ± 3.6, 113.9 ± 5.2, 149.8 ± 5.4; P ≤ 0.05), TE (42.9 ± 3.0, 96.7 ± 3.1, 85.2 ± 4.5, 111.9 ± 4.7; P ≤ 0.05) and ICM (20.3 ± 2.2, 32.9 ± 1.8, 27.7 ± 2.6, 36.5 ± 2.7; P ≤ 0.05). The apoptotic cell numbers and ICM : TE ratio of the survived embryos after cryopreservation were not affected by HA supplementation. The results indicate that large size HA improves the embryo viability and quality, which may have implication for improving embryo transfer.


2001 ◽  
Vol 21 (10) ◽  
pp. 3598-3603 ◽  
Author(s):  
Cynthia J. Guidi ◽  
Arthur T. Sands ◽  
Brian P. Zambrowicz ◽  
Tod K. Turner ◽  
Delia A. Demers ◽  
...  

ABSTRACT SNF5/INI1 is a component of the ATP-dependent chromatin remodeling enzyme family SWI/SNF. Germ line mutations ofINI1 have been identified in children with brain and renal rhabdoid tumors, indicating that INI1 is a tumor suppressor. Here we report that disruption of Ini1 expression in mice results in early embryonic lethality. Ini1-null embryos die between 3.5 and 5.5 days postcoitum, and Ini1-null blastocysts fail to hatch, form the trophectoderm, or expand the inner cell mass when cultured in vitro. Furthermore, we report that approximately 15% ofIni1-heterozygous mice present with tumors, mostly undifferentiated or poorly differentiated sarcomas. Tumor formation is associated with a loss of heterozygocity at the Ini1 locus, characterizing Ini1 as a tumor suppressor in mice. Thus, Ini1 is essential for embryo viability and for repression of oncogenesis in the adult organism.


1993 ◽  
Vol 13 (12) ◽  
pp. 7971-7976
Author(s):  
L M Whyatt ◽  
A Düwel ◽  
A G Smith ◽  
P D Rathjen

Embryonic stem (ES) cells, derived from the inner cell mass of the preimplantation mouse embryo, are used increasingly as an experimental tool for the investigation of early mammalian development. The differentiation of these cells in vitro can be used as an assay for factors that regulate early developmental decisions in the embryo, while the effects of altered gene expression during early embryogenesis can be analyzed in chimeric mice generated from modified ES cells. The experimental versatility of ES cells would be significantly increased by the development of systems which allow precise control of heterologous gene expression. In this paper, we report that ES cells are responsive to alpha and beta interferons (IFNs). This property has been exploited for the development of inducible ES cell expression vectors, using the promoter of the human IFN-inducible gene, 6-16. The properties of these vectors have been analyzed in both transiently and stably transfected ES cells. Expression was minimal or absent in unstimulated ES cells, could be stimulated up to 100-fold by treatment of the cells with IFN, and increased in linear fashion with increasing levels of IFN. High levels of induced expression were maintained for extended periods of time in the continuous presence of the inducing signal or following a 12-h pulse with IFN. Treatment of ES cells with IFN did not affect their growth or differentiation in vitro or compromise their developmental potential. This combination of features makes the 6-16-based expression vectors suitable for the functional analysis of developmental control control genes in ES cells.


2018 ◽  
Vol 110 (4) ◽  
pp. e378
Author(s):  
E. Ruggeri ◽  
E. Grow ◽  
X. Liu ◽  
A. Donjacour ◽  
P. Rinaudo

1996 ◽  
Vol 8 (8) ◽  
pp. 1193 ◽  
Author(s):  
B Mognetti ◽  
D Sakkas

Diploid parthenogenetic mouse embryos (which possess two maternally-derived genomes) can develop only as far as the 25-somite stage when transferred in utero and exhibit a substantial reduction in trophoblast tissue. The loss of cultured parthenogenetic embryos during postimplantation indicates that a defect in cell lineage may be evident as early as the blastocyst stage. The possibility that a defect may already be reflected at the preimplantation stage was investigated by examining the allocation of cells to the trophectoderm (trophoblast progenitor cells) and the inner cell mass of haploid and diploid parthenogenetic mouse blastocysts. Utilizing a differential labelling technique for counting cells, diploid parthenogenetic blastocysts were found to have fewer inner cell mass cells and trophectoderm cells than their haploid counterparts and normal blastocysts. In addition, both haploid and diploid parthenogenetic blastocysts had a lower inner cell mass: trophectoderm ratio than normal blastocysts. Thus, the relatively poor development of the trophectoderm lineage at the postimplantation stage is not reflected by a reduction in its allotment of cells at its first appearance. Nevertheless, the findings indicate that parthenogenetic development is already compromised at the blastocyst stage, and provide evidence that the expression of imprinted genes has significance for the development of the embryo at the preimplantation stage.


2017 ◽  
Vol 29 (7) ◽  
pp. 1392 ◽  
Author(s):  
Dandan Liu ◽  
Guolong Mo ◽  
Yong Tao ◽  
Hongmei Wang ◽  
X. Johné Liu

Mouse ovaries exhibit a peri-ovulatory rise of ornithine decarboxylase and its product putrescine concurrent with oocyte maturation. Older mice exhibit a deficiency of both the enzyme and putrescine. Peri-ovulatory putrescine supplementation in drinking water increases ovarian putrescine levels, reduces embryo resorption and increases live pups in older mice. However, it is unknown if putrescine acts in the ovaries to improve oocyte maturation. This study examined the impact of putrescine supplementation during oocyte in vitro maturation (IVM) on the developmental potential of aged oocytes. Cumulus–oocyte complexes from 9–12-month-old C57BL/6 mice were subjected to IVM with or without 0.5 mM putrescine, followed by in vitro fertilisation and culture to the blastocyst stage. Putrescine supplementation during IVM did not influence the proportion of oocyte maturation, fertilisation or blastocyst formation, but significantly increased blastocyst cell numbers (44.5 ± 1.9, compared with 36.5 ± 1.9 for control; P = 0.003). The putrescine group also had a significantly higher proportion of blastocysts with top-grade morphology (42.9%, compared with 26.1% for control; P = 0.041) and a greater proportion with octamer-binding transcription factor 4 (OCT4)-positive inner cell mass (38.3%, compared with 19.8% for control; P = 0.005). Therefore, putrescine supplementation during IVM improves egg quality of aged mice, providing proof of principle for possible application in human IVM procedures for older infertile women.


2004 ◽  
Vol 16 (2) ◽  
pp. 186
Author(s):  
J.O. Gjørret ◽  
P. Maddox-Hyttel

Regulation of apoptosis may be affected by factors during preimplantation development, and this is possibly related to embryo developmental potential. Here we investigate differences in the incidence of apoptotic nuclei in Day 7 bovine blastocysts produced by two different in vivo and three different in vitro methods. In vivo embryos were produced either by a regular superovulation procedure (reg group; n=29; Laurincik et al., 2003, Mol. Reprod. Dev. 65, 73–85), or by postponement of the LH surge (pp group; n=35; van de Leemput et al., 2001, Therio. 55, 573–592). In vitro embryos were derived from systems using either co-culture (cc group; n=30, Avery and Greve 2000, Mol. Reprod. Dev. 55, 438–445), or culture in synthetic oviduct fluid (SOF) with (S+group; n=35) or without serum (S− group; n=38; Holm et al., 1999, Theriogenology, 52, 683–700). Embryos were collected at approx. 168h post ovulation/insemination and subjected to chromatin staining and detection of DNA degradation by TUNEL reaction. The total number of nuclei, number of nuclei displaying apoptotic morphology (+M), number of nuclei displaying TUNEL reaction (+T), and number of nuclei displaying both markers simultaneously (M&amp;T) were scored according to J.O. Gjørret et al. (2003 Biol. Reprod. 69. in press). Only M&amp;T nuclei were regarded as apoptotic, and +M, +T, and apoptotic (M&amp;T) indices (%) were calculated for the trophoblast (tb), inner cell mass (i) and the total blastocysts (t) in each group. Significant differences were observed for all parameters when all groups were compared (ANOVA, P ranging from 0.024 to&lt;0.0001). Highest number of total nuclei were observed in the S+ group, whereas the lowest indices were observed in the pp group, which had significant lower indices in the i and t than in the reg., S+ and S− groups P&lt;0.05; Tukey’s post test for ANOVA). Highest indices were generally observed in the S− group. The results demonstrate that not only embryo cell numbers but also incidences of apoptotic markers are affected by the mode of production. However, in Day 7 bovine blastocysts high cell number is not consistent with a low incidence of apoptosis. Even though cell numbers appeared comparable in the two in vivo groups, their incidences of apoptosis were different, and the reg group displayed indices comparable to the in vitro groups, highlighting the importance of ovulation protocols when in vivo embryos are used as reference material in general. Table 1


2009 ◽  
Vol 21 (9) ◽  
pp. 63
Author(s):  
L. Ganeshan ◽  
C. O'Neill

The developmental viability of the early embryo requires the formation of the inner cell mass (ICM) at the blastocyst stage. The ICM contributes to all cell lineages within the developing embryo in vivo and the embryonic stem cell (ESC) lineage in vitro. Commitment of cells to the ICM lineage and its pluripotency requires the expression of core transcription factors, including Nanog and Pou5f1 (Oct4). Embryos subjected to culture in vitro commonly display a reduced developmental potential. Much of this loss of viability is due to the up-regulation of TRP53 in affected embryos. This study investigated whether increased TRP53 disrupts the expression of the pluripotency proteins and the normal formation of the ICM lineage. Mouse C57BL6 morulae and blastocysts cultured from zygotes (modHTF media) possessed fewer (p < 0.001) NANOG-positive cells than equivalent stage embryos collected fresh from the uterus. Blocking TRP53 actions by either genetic deletion (Trp53–/–) or pharmacological inhibition (Pifithrin-α) reversed this loss of NANOG expression during culture. Zygote culture also resulted in a TRP53-dependent loss of POU5F1-positive cells from resulting blastocysts. Drug-induced expression of TRP53 (by Nutlin-3) also caused a reduction in formation of pluripotent ICM. The loss of NANOG- and POU5F1-positive cells caused a marked reduction in the capacity of blastocysts to form proliferating ICM after outgrowth, and a consequent reduced ability to form ESC lines. These poor outcomes were ameliorated by the absence of TRP53, resulting in transmission distortion in favour of Trp53–/– zygotes (p < 0.001). This study shows that stresses induced by culture caused TRP53-dependent loss of pluripotent cells from the early embryo. This is a cause of the relative loss of viability and developmental potential of cultured embryos. The preferential survival of Trp53–/– embryos after culture due to their improved formation of pluripotent cells creates a genetic danger associated with these technologies.


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