244 CHANGES IN THE TRANSCRIPTOME OF THE BOVINE PRE-IMPLANTATION EMBRYO INDUCED BY COLONY-STIMULATING FACTOR-2

2010 ◽  
Vol 22 (1) ◽  
pp. 279
Author(s):  
B. Loureiro ◽  
L. Oliveira ◽  
P. J. Hansen

Colony-stimulating factor-2 (CSF-2) is a cytokine expressed in bovine oviduct and endometrium that has been reported to improve the proportion of embryos that become blastocysts in vitro and survive after transfer to recipients. One effect of CSF-2 that might be related to increased embryonic survival is a preferential increase in the number of cells in the inner cell mass. The objective of the current study was to determine changes in the embryo transcriptome caused by CSF-2 that promote blastocyst formation and establishment and maintenance of pregnancy after transfer. Bovine embryos were produced in vitro and cultured in KSOM-BE2 +10 ng/mL recombinant BoCSF-2 added at Day 5 after insemination. On Day 6 (24 h after treatment), embryos at the morula and early blastocyst stage were harvested and stored in groups of 50 at -80°C. A total of 4 pools of GM-colony-stimulating factor treated blastocysts and 4 control blastocysts were subjected to transcriptional profiling using the Bos taurus 2-color Agilent chip (4 × 44 K format). Before labeling, total RNA starting sample was spiked with control genes (artificial clones) of known concentration provided by Agilent. Labeling was done simultaneously with complimentary RNA (cRNA) amplification. Two rounds of linear RNA amplification were employed. Images were extracted using the Agilent Feature Extraction Software (Agilent Technologies, Santa Clara, CA, USA) and normalized within arrays by the Lowess method. Statistical analysis was performed using the JMP Genomics program (SAS Inst., Cary, NC, USA). The normalized data were log2 transformed, and the quantile normalization method was used to normalize data between arrays. Differences in gene expression were determined using PROC ANOVA (fixed false discovery rate = 0.01). Only genes with a 1.5-fold difference and P < 0.05 were considered differentially expressed. A total of 216 genes were differentially expressed between CSF-2 and control embryos. Of these, 141 could be annotated (61 genes up-regulated and 80 genes down-regulated by CSF-2). These included 13 genes involved in Wnt pathways, including 5 inhibitors of Wnt signaling (FRP, MAB21L2, PCDH24, PDE7, PPPR23A) that were up-regulated by CSF-2 and 5 genes involved in transmission of Wnt signals (WNT16, ROR2, CSNK2B, CELSR2, DTX3) that were down-regulated by CSF-2. Several other genes associated with differentiation were down-regulated by CSF-2 including CXCL12, FEZF1, PLD2, and RGS12. Expression of 1 gene that inhibits apoptosis (PRKAR2B) was increased by CSF-2, whereas expression of 6 genes involved in apoptosis pathways (DAPK1, MADD, NOD2, PIK3IP1, RIPK3, RNF7) were down-regulated. Results indicate that CSF-2 promotes pluripotency and decreases apoptosis in bovine pre-implantation embryos. This research was supported by USDA-AFRI. B. Loureiro andL. Oliveira were supported by a CAPES (Brazil)/Fulbright Fellowship.

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1333-1339 ◽  
Author(s):  
P. Bhatnagar ◽  
V.E. Papaioannou ◽  
J.D. Biggers

The effects of macrophage colony stimulating factor on the development of the zygote to the blastocyst stage of an outbred strain of mouse have been studied in KSOM, an improved medium that supports a high rate of in vitro development. Macrophage colony stimulating factor accelerates the formation of the blastocyst cavity by day 4 (96 hours post-hCG). It also increases overall embryonic cell number through a differential increase in the number of trophoblast cells, with no significant effect on the number of inner cell mass cells. By day 5 of culture (120 hours post-hCG), colony stimulating factor-treated embryos have about 20 more trophoblast cells than control embryos, an increase of about 30 percent of the total number of cells in a control blastocyst. The maximum response of embryos was obtained at a concentration around 540 U ml-1 colony stimulating factor (identical to 918 Stanley units ml-1), and the cytokine can produce the same effects even if it is present in the medium for only part of the culture period. This in vitro stimulation of preimplantation development with macrophage colony stimulating factor is compatible with continued normal fetal development in vivo.


Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 5046-5054 ◽  
Author(s):  
Bárbara Loureiro ◽  
Luciano Bonilla ◽  
Jeremy Block ◽  
Justin M. Fear ◽  
Aline Q. S. Bonilla ◽  
...  

In this study, we tested the role of colony-stimulating factor 2 (CSF2) as one of the regulatory molecules that mediate maternal effects on embryonic development during the preimplantation period. Our objective was to verify effects of CSF2 on blastocyst yield, determine posttransfer survival, and evaluate properties of the blastocyst formed after CSF2 treatment. In vitro, CSF2 increased the percentage of oocytes that became morulae and blastocysts. Blastocysts that were treated with CSF2 tended to have a greater number of inner cell mass cells and had a higher ratio of inner cell mass to trophectoderm cells. There was no effect of CSF2 on the incidence of apoptosis. Treatment with CSF2 from d 5 to 7 after insemination increased embryonic survival as indicated by improved pregnancy rate at d 30–35 of gestation. Moreover, treatment with CSF2 from either d 1–7 or 5–7 after insemination reduced pregnancy loss after d 30–35. Results indicate that treatment with CSF2 can affect embryonic development and enhance embryo competence for posttransfer survival. The fact that treatment with CSF2 during such a narrow window of development altered embryonic function much later in pregnancy suggests that CSF2 may exert epigenetic effects on the developing embryo that result in persistent changes in function during the embryonic and fetal periods of development.


Zygote ◽  
2002 ◽  
Vol 10 (2) ◽  
pp. 155-162 ◽  
Author(s):  
H.P.S. Kochhar ◽  
K.B.C. Appa Rao ◽  
A.M. Luciano ◽  
S.M. Totey ◽  
F. Gandolfi ◽  
...  

Interspecific hybrid embryos are useful models for the study of maternal-fetal interactions, transmission pattern of species-specific markers and parental contributions to growth and developmental potential of pre-attachment embryos. In an attempt to investigate the possibility of producing hybrid embryos of domestic cattle (Bos taurus) and water buffalo (Bubalus bubalis), cattle oocytes were exposed to buffalo sperm and buffalo oocytes were exposed to cattle sperm and the cleavage rate and the post-fertilisation features of hybrid embryos up to the blastocyst stage were compared with those of buffalo and cattle embryos. The cleavage rate in buffalo oocytes exposed to cattle sperm was low (40.8%), with only 8.8% of these hybrid embryos reaching the blastocyst stage. Cattle oocytes exposed to buffalo sperm showed 86.3% cleavage, while 25.9% of these attained the blastocyst stage. The speed of development of both types of hybrids was intermediate between that of cattle and buffalo embryos, with hatching occurring on day 7.5 in hybrid embryos, day 8-9 in cattle and day 7 in buffalo. The proportions of cells contributing to the trophectoderm and the inner cell mass were closer to those of the maternal species in both types of hybrid embryos. Our results indicate that cattle-water buffalo hybrid embryos produced using interspecies gametes are capable of developing to advanced blastocyst stages and that their in vitro fate, and developmental potential, are influenced by the origin of the oocyte.


2017 ◽  
Vol 29 (1) ◽  
pp. 173
Author(s):  
M. S. Ortega ◽  
P. J. Hansen

A single nucleotide polymorphism (SNP) in WBP1 has been previously associated with embryonic development to the blastocyst stage. WBP1 interacts with WW domain containing proteins including YAP1 from the hippo signalling pathway that is involved in trophectoderm (TE) formation. Here we tested whether reduction in mRNA abundance for WBP1 would reduce development to the blastocyst stage and formation of cells in the inner cell mass (ICM) and TE. Knockdown was performed using a GapmeR LNATM antisense oligonucleotide designed to target WBP1. A scrambled version of the same sequence was used as a control. Embryos were produced in vitro from slaughterhouse oocytes and bulls from Bos taurus and Bos indicus breeds. At 20 to 22 h after insemination (hpi), embryos were treated with 5 µM anti-WBP1 GapmeR (KD), 5 µM scrambled GapmeR (SC), or vehicle (CTL). At 72 to 75 hpi (the time of maximal WBP1 expression), groups of 18 to 20 embryos were collected from each treatment to evaluate WBP1 expression. Other cultured embryos (minimum of 50/treatment for each replicate) were cultured until Day 8 after insemination. Cleavage was assessed at Day 3 and blastocyst formation at Day 7 and 8. Embryos were collected at Day 8 to determine ICM and TE cell number by determining nuclear immunoreactive CDX2. All experiments were replicated 5 times. Fold change was calculated relative to the CTL group. Data were analysed by analysis of variance for gene expression and cell number, and through logistic regression for embryonic development. WBP1 expression was reduced (P = 0.04) in KD embryos compared to CTL (least squares means ± SEM: 1 ± 0.19 v. 0.64 ± 0.19 fold change) or SC (1.05 ± 0.19). There was no difference in expression between CTL and SC. Percent of embryos that cleaved was not affected by treatment (P > 0.05); however, percent of inseminated oocytes that became blastocysts tended to be lower in KD compared to CTL and SC at Day 7 (P = 0.09) [10.8 ± 2.8, 20 ± 3.0, and 16.3 ± 3.1% for KD, CTL, and SC, respectively] and 8 after insemination (P = 0.06) [13.7 ± 3.3, 24.2 ± 3.3, and 22.9 ± 3.6%]. Knockdown of WBP1 caused a reduction in number of total (P = 0.0004) and TE (P < 0.0001) cells with no effect on ICM cell number (P = 0.83). Total cell numbers for KD, SC, and CTL were 124.2 ± 6.4, 157.75 ± 7.4, and 124.28 ± 6.4 and numbers of TE cells were 59.7 ± 3.8, 90.0 ± 4.47, and 90.0 ± 4.4. Results show that reduction in mRNA for WBP1 decreases TE formation and tends to reduce competence of embryos to become blastocysts. This study was supported by USDA AFRI 2013–68004–20365.


Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 597-604 ◽  
Author(s):  
K. Hardy ◽  
A.H. Handyside ◽  
R.M. Winston

The development of 181 surplus human embryos, including both normally and abnormally fertilized, was observed from day 2 to day 5, 6 or 7 in vitro. 63/149 (42%) normally fertilized embryos reached the blastocyst stage on day 5 or 6. Total, trophectoderm (TE) and inner cell mass (ICM) cell numbers were analyzed by differential labelling of the nuclei with polynucleotide-specific fluorochromes. The TE nuclei were labelled with one fluorochrome during immunosurgical lysis, before fixing the embryo and labelling both sets of nuclei with a second fluorochrome (Handyside and Hunter, 1984, 1986). Newly expanded normally fertilized blastocysts on day 5 had a total of 58.3 +/− 8.1 cells, which increased to 84.4 +/− 5.7 and 125.5 +/− 19 on days 6 and 7, respectively. The numbers of TE cells were similar on days 5 and 6 (37.9 +/− 6.0 and 40.3 +/− 5.0, respectively) and then doubled on day 7 (80.6 +/− 15.2). In contrast, ICM cell numbers doubled between days 5 and 6 (20.4 +/− 4.0 and 41.9 +/− 5.0, respectively) and remained virtually unchanged on day 7 (45.6 +/− 10.2). There was widespread cell death in both the TE and ICM as evidenced by fragmenting nuclei, which increased substantially by day 7. These results are compared with the numbers of cells in morphologically abnormal blastocysts and blastocysts derived from abnormally fertilized embryos. The nuclei of arrested embryos were also examined. The number of TE and ICM cells allocated in normally fertilized blastocysts appears to be similar to the numbers allocated in the mouse. Unlike the mouse, however, the proportion of ICM cells remains higher, despite cell death in both lineages.


2012 ◽  
Vol 24 (1) ◽  
pp. 164 ◽  
Author(s):  
M. Zhang ◽  
H. H. Chen ◽  
J. W. Tang ◽  
X. W. Liang ◽  
M. T. Chen ◽  
...  

Embryo-splitting technology provides an effective procedure for increasing the number of transferable embryos per donor, producing genetically identical offspring and facilitating embryo sexing. The ability to identify the sex of embryos before transfer will offer a reliable, economical and practical procedure for buffalo breeding. In this study, we have assessed the feasibility of production of offspring with controlled sex in buffalo by first comparing the effect of blastocyst quality on the viability of demi-embryos and then identifying the sex of a demi-embryo by multiplex-nested PCR before transfer into the recipient. In vitro-matured buffalo oocytes were fertilized by IVF and cultured to the blastocyst stage for 6 to 7 days as described by Lu et al. (2007 Anim. Reprod. Sci. 100, 192–196). These blastocysts were classified in terms of their developmental pattern and morphology on a scale of 1 to 3 grades as described by McEvoy et al. (1990 Theriogenology 33, 1245–1253). Blastocysts were split into 2 equal parts by a micromanipulation system. Viability of the resulting demi-embryos was confirmed by formation of a blastocoel cavity and definite inner cell mass after culture for 24 h. One of the zone-free demi-embryos derived from a grade-1 blastocyst was cultured in TCM 199 supplemented with 10% fetal bovine serum for another 2 h, then was transplanted to a spontaneous oestrous recipient. The other demi-embryo was used for sexing by multiplex-nested PCR (Fu et al. 2007 Theriogenology 68, 1211–1218). The results showed that grade-1 blastocysts yielded more viable demi-embryos than grade-2 and grade-3 blastocysts [P < 0.01; 73/92 (79.67%) vs 32/76 (47.05%) vs 26/94 (26.53%), respectively]. Transplantation of the presumed-Y demi-embryo derived from grade-1 blastocyst into a recipient resulted in the birth of a male buffalo calf. To the best of our knowledge, this is the first buffalo calf produced following embryo splitting and PCR sexing of the embryo at the blastocyst stage. Successful birth of the desired-sex offspring in the present study indicates the feasibility of using embryo splitting in combination with multiplex-nested PCR sexing to produce offspring of controlled sex in swamp buffalo. However, the quality of embryos before splitting was an important factor governing the in vitro development of viable demi-embryos. This study was supported by the Guangxi Science and Technology R&D Program (0626001-3-1, 0815008-2-4).


2013 ◽  
Vol 25 (1) ◽  
pp. 226 ◽  
Author(s):  
E. P. López-Damián ◽  
T. Fiordelisio ◽  
M. A. Lammoglia ◽  
M. Alarcón ◽  
M. Asprón ◽  
...  

Accurate evaluation of bovine embryos for assessing developmental stage and quality is critical to the success of any embryo transfer program. However, this evaluation process has been reported to be highly subjective in Bos indicus (BI) and can vary as much as 23% compared with that of Bos taurus (BT). These differences in assessment may be related to the quantity of lipid droplets (LD) within the embryo, which has been shown to have a negative effect in cryopreserving embryos. The aim of the present study was to characterize the number and size of LD in different developmental stages of fresh embryos from BI and BT and to compare LD across the three different embryo quality grades (1 = excellent or good, 2 = fair, and 3 = poor). Nonsurgical embryo collection was performed 7 days post-insemination in 10 BI and 10 BT females. Forty-eight embryos were evaluated for stage and grade using stereoscopic microscopy, processed for transmission electron microscopy, and stained with Nile red. Digitalized images were analyzed with ImageJ (National Institutes of Health, Bethesda, MD, USA), contour of lipid droplets were designed, and values of perimeter, area, and fluorescence intensity were assessed. Nonparametric statistical analysis (Mann–Whitney) was utilized. There was no difference in LD number for BT or BI for morulae and blastocyst; however, BI morulae presented larger LD compared with blastocyst stage embryos (286 µm2 v. 223 µm2; P < 0.05). Likewise, BI TF cells had more LD compared with inner cell mass (ICM) cells (48 v. 36; P < 0.05). BT TF cells exhibited larger LD compared with ICM cells (149 µm2 v. 128 µm2; P < 0.05), while BI embryos exhibited a larger area of LD in the ICM compared with the TF (591 µm2 v. 472 µm2; P < 0.05). In all embryos, BI contained more lipid droplets than BT (78 v. 49; P < 0.05). Across all quality grades (good, fair, and poor) there was no difference in the number of LD in BT embryos; however, BI grade-3 embryos presented more LD than grade-1 (36 v. 25). BT embryos LD were larger than BI LD (907 µm2 v. 625 µm2; P < 0.05). Fluorescence images showed higher arbitrary units of fluorescence (auf) for LD in BI. Compared with BT embryos (386 auf v. 280 auf; P < 0.05). These results suggest that BI embryos contain more and smaller LD than BT embryos and the LD described for BI embryo quality grade 1 are larger than those of quality grades 2 and 3, and even though the number of LD in morulae and blastocyst stage embryos are not different LD size is reduced as development occurs. Research funding provided by UNAM-DGAPA-PAPIIT IN200810.


1995 ◽  
Vol 29 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Th. Rülicke ◽  
P. Autenried

Approximately 18% of cryopreserved 2-cell mouse embryos of 26 different batches showed various degrees of morphological damage after the freeze-thaw process. Normal and damaged morphology were assessed by light microscopy and the ability of an embryo to develop in vitro to a blastocyst, or to develop to term, after transfer to foster mothers. Using vital stains such as Fluorescein-diacetate (FDA) and 4',6-Diamidino-2-Phenylindole (DAPI) it was found that in approximately 82% of the cases, both of the 2 blastomeres of the cryopreserved embryos survived the freeze-thaw process; in 10% only one cell survived the process; and in 8% none survived. Normally, only intact 2-cell embryos are considered for transfer. Here it was shown that over 60% of the partially damaged embryos developed in vitro to the blastocyst stage and, of those, 26% developed to term after transfer to suitable foster mothers. Although the inner cell mass (ICM) appeared to remain smaller during culture after the transfer of partially damaged 2-cell stage embryos, no difference during gestation period was found compared with intact embryos.


2004 ◽  
Vol 16 (2) ◽  
pp. 144
Author(s):  
P. Kasinathan ◽  
M.F. Nichols ◽  
J.E. Griffin ◽  
J.M. Robl

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.


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