Ovatech LLC

Gainesville, FL, United States

Ovatech LLC

Gainesville, FL, United States
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Sakatani M.,Japan National Agriculture and Food Research Organization | Bonilla L.,University of Florida | Bonilla L.,Minitube International Center for Biotechnology | Dobbs K.B.,University of Florida | And 7 more authors.
Reproductive Biology and Endocrinology | Year: 2013

Background: While initially sensitive to heat shock, the bovine embryo gains thermal resistance as it progresses through development so that physiological heat shock has little effect on development to the blastocyst stage by Day 5 after insemination. Here, experiments using 3' tag digital gene expression (3'DGE) and real-time PCR were conducted to determine changes in the transcriptome of morula-stage bovine embryos in response to heat shock (40 degrees C for 8 h) that could be associated with thermotolerance.Results: Using 3'DGE, expression of 173 genes were modified by heat shock, with 94 genes upregulated by heat shock and 79 genes downregulated by heat shock. A total of 38 differentially-regulated genes were associated with the ubiquitin protein, UBC. Heat shock increased expression of one heat shock protein gene, HSPB11, and one heat shock protein binding protein, HSPBP1, tended to increase expression of HSPA1A and HSPB1, but did not affect expression of 64 other genes encoding heat shock proteins, heat shock transcription factors or proteins interacting with heat shock proteins. Moreover, heat shock increased expression of five genes associated with oxidative stress (AKR7A2, CBR1, GGH, GSTA4, and MAP2K5), decreased expression of HIF3A, but did not affect expression of 42 other genes related to free radical metabolism. Heat shock also had little effect on genes involved in embryonic development. Effects of heat shock for 2, 4 and 8 h on selected heat shock protein and antioxidant genes were also evaluated by real-time PCR. Heat shock increased steady-state amounts of mRNA for HSPA1A (P<0.05) and tended to increase expression of HSP90AA1 (P<0.07) but had no effect on expression of SOD1 or CAT.Conclusions: Changes in the transcriptome of the heat-shocked bovine morula indicate that the embryo is largely resistant to effects of heat shock. As a result, transcription of genes involved in thermal protection is muted and there is little disruption of gene networks involved in embryonic development. It is likely that the increased resistance of morula-stage embryos to heat shock as compared to embryos at earlier stages of development is due in part to developmental acquisition of mechanisms to prevent accumulation of denatured proteins and free radical damage. © 2013 Sakatani et al.; licensee BioMed Central Ltd.

Bonilla L.,University of Florida | Bonilla L.,Minitube Of America | Block J.,University of Florida | Block J.,Ovatech LLC | And 2 more authors.
Journal of Dairy Science | Year: 2014

No reports exist on consequences of in vitro production (IVP) of embryos for the postnatal development of the calf or on postparturient function of the dam of the calf. Three hypotheses were evaluated: calves born as a result of transfer of an IVP embryo have reduced neonatal survival and altered postnatal growth, fertility, and milk yield compared with artificial insemination (AI) calves; cows giving birth to IVP calves have lower milk yield and fertility and higher incidence of postparturient disease than cows giving birth to AI calves; and the medium used for IVP affects the incidence of developmental abnormalities. In the first experiment, calves were produced by AI using conventional semen or by embryo transfer (ET) using a fresh or vitrified embryo produced in vitro with X-sorted semen. Gestation length was longer for cows receiving a vitrified embryo than for cows receiving a fresh embryo or AI. The percentage of dams experiencing calving difficulty was higher for ET than AI. We observed a tendency for incidence of retained placenta to be higher for ET than AI but found no significant effect of treatment on incidence of prolapse or metritis, pregnancy rate at first service, services per conception, or any measured characteristic of milk production in the subsequent lactation. Among Holstein heifers produced by AI or ET, treatment had no effect on birth weight but the variance tended to be greater in the ET groups. More Holstein heifer calves tended to be born dead, died, or were euthanized within the first 20. d of life for the ET groups than for AI. Similarly, the proportion of Holstein heifer calves that either died or were culled for poor health after 20. d of age was greater for the ET groups than for AI. We observed no effect of ET compared with AI on age at first service or on the percentage of heifers pregnant at first service, calf growth, or milk yield or composition in the first 120. d in milk of the first lactation. In a second experiment, embryos were produced using 1 of 2 culture media: synthetic oviductal fluid-bovine embryo 1 (SOF-BE1) or Block-Bonilla-Hansen 7 (BBH7). We detected no difference between cows receiving an SOF-BE1 or BBH7 embryo in gestation length, the percentage of cows in which parturition was induced, or the percentage of cows that experienced calving difficulty, retained placenta, prolapse, or metritis. Among Holstein heifers, birth weight was higher for BBH7 calves than for SOF-BE1 calves. Treatment had no significant effect on calf death. Results indicate that calves born as a result of IVP-ET are more likely to experience alterations in birth weight and increased death in early life but that there were few consequences to the dam of carrying a fetus derived by IVP-ET. © 2014 American Dairy Science Association.

You J.,Kangwon National University | Lee E.,Kangwon National University | Bonilla L.,University of Florida | Francis J.,University of Florida | And 7 more authors.
PLoS ONE | Year: 2012

Maturation of the oocyte involves nuclear and cytoplasmic changes that include post-translational processing of proteins. The objective was to investigate whether inhibition of proteasomes during maturation would alter competence of the bovine oocyte for fertilization and subsequent development. Cumulus-oocyte complexes were cultured in the presence or absence of the proteasomal inhibitor MG132 from either 0-6 h or 16-22 h after initiation of maturation. Treatment with MG132 early in maturation prevented progression to meiosis II and reduced fertilization rate and the proportion of oocytes and cleaved embryos that became blastocysts. Conversely, treatment with MG132 late in maturation improved the percentage of oocytes and cleaved embryos that became blastocysts without affecting nuclear maturation or fertilization rate. Optimal results with MG132 were achieved at a concentration of 10 μM - effects were generally not observed at lower or higher concentrations. Using proteomic analysis, it was found that MG132 at the end of maturation increased relative expression of 6 proteins and decreased relative expression of 23. Among those increased by MG132 that are potentially important for oocyte competence are GAPDH, involved in glycolysis, TUBA1C, needed for organellar movement, and two proteins involved in protein folding (P4HB and HYOU1). MG132 decreased amounts of several proteins that exert anti-apoptotic actions including ASNS, HSP90B1, PDIA3 and VCP. Another protein decreased by MG132, CDK5, can lead to apoptosis if aberrantly activated and one protein increased by MG132, P4HB, is anti-apoptotic. Finally, the pregnancy rate of cows receiving embryos produced from oocytes treated with MG132 from 16-22 h of maturation was similar to that for control embryos, suggesting that use of MG132 for production of embryos in vitro does not cause a substantial decrease in embryo quality. © 2012 You et al.

Block J.,University of Florida | Block J.,Ovatech LLC | Bonilla L.,University of Florida | Hansen P.J.,University of Florida
Journal of Dairy Science | Year: 2010

Objectives were to determine whether pregnancy success could be improved in lactating cows with timed embryo transfer when embryos were produced in vitro using a medium designed to enhance embryo development and survival after cryopreservation. In experiment 1, embryos (n = 569 to 922) were cultured in either modified synthetic oviduct fluid or a serum-free medium, Block-Bonilla-Hansen-7 (BBH7). Development to the blastocyst stage was recorded at d 7, and selected blastocysts (n = 79 to 114) were vitrified using open pulled straws. Culture of embryos in BBH7 increased development to the blastocyst stage (41.9 ± 2.0 vs. 14.7 ± 2.0%) and advanced blastocyst stages (expanded, hatching, hatched; 31.1 ± 1.3 vs. 6.4 ± 1.3%) at d 7 and resulted in higher hatching rates at 24. h postwarming compared with embryos cultured in modified synthetic oviduct fluid (59.0 ± 0.5 vs. 26.7 ± 0.5%). In experiment 2, embryos were produced using X-sorted semen and cultured in BBH7. At d 7 after insemination, embryos were transferred fresh or following vitrification. Lactating Holstein cows were either subjected to timed artificial insemination (TAI) on the day of presumptive ovulation or used as embryo recipients 7 d later. Embryo recipients received an embryo if a corpus luteum was present. The percentage of cows pregnant at d 32, 46, and 76 of gestation was higher among cows that received fresh embryos compared with TAI cows or cows that received vitrified embryos. At d 76, for example, the proportion and percentage pregnant was 47/150 (31.3%) for cows subjected to TAI, 48/95 (50.5%) for cows receiving fresh embryos, and 39/141 (27.7%) for cows receiving a vitrified embryo. No difference was observed in the percentage of cows pregnant among TAI cows and those that received vitrified embryos. There was a service or transfer number × treatment interaction because differences in pregnancy rate between embryo transfer recipients and cows bred by TAI were greater for cows with more than 3 services or transfers. Pregnancy success in lactating cows can be improved by transferring fresh embryos produced in BBH7 compared with TAI. Moreover, no decline in fertility was observed when cryopreserved embryos were transferred compared with TAI. Embryo transfer is particularly efficacious for infertile cows that have previously experienced several failed breeding attempts. © 2010 American Dairy Science Association.

Loureiro B.,University of Florida | Block J.,University of Florida | Block J.,Ovatech LLC | Favoreto M.G.,University of Florida | And 4 more authors.
Reproduction | Year: 2011

Exposure of bovine conceptuses to colony-stimulating factor 2 (CSF2) from days 5 to 7 of development can increase the percentage of transferred conceptuses that develop to term. The purpose of this experiment was to understand the mechanism by which CSF2 increases embryonic and fetal survival. Conceptuses were produced in vitro in the presence or absence of 10 ng/ml CSF2 from days 5 to 7 after insemination, transferred into cows, and flushed from the uterus at day 15 of pregnancy. There was a tendency (P=0.07) for the proportion of cows with a recovered conceptus to be greater for those receiving a CSF2-treated conceptus (35% for control versus 66% for CSF2). Antiviral activity in uterine flushings, a measure of the amount of interferon-τ (IFNT2) secreted by the conceptus, tended to be greater for cows receiving CSF2-treated conceptuses than for cows receiving control conceptuses. This difference approached significance when only cows with detectable antiviral activity were considered (P=0.07). In addition, CSF2 increased mRNA for IFNT2 (P=0.08) and keratin 18 (P<0.05) in extraembryonic membranes. Among a subset of filamentous conceptuses that were analyzed by microarray hybridization, there was no effect of CSF2 on gene expression in the embryonic disc or extraembryonic membranes. Results suggest that the increase in calving rate caused by CSF2 treatment involves, in part, more extensive development of extraembryonic membranes and capacity of the conceptus to secrete IFNT2 at day 15 of pregnancy. © 2011 Society for Reproduction and Fertility.

Rasmussen S.,Colorado State University | Block J.,Ovatech L.L.C. | Block J.,University of Florida | Seidel G.E.,Colorado State University | And 6 more authors.
Theriogenology | Year: 2013

The main objective was to determine the efficacy of using X-sorted sperm to produce embryos in vitro for transfer into lactating dairy cows. Cows were bred by timed artificial insemination (TAI) using nonsorted semen or X-sorted sperm, or they received a fresh embryo produced in vitro by fertilization with X-sorted or nonsorted sperm using timed embryo transfer (TET). Pregnancy rates at approximately Day 32 averaged over all dairies were 39.3 ± 3.2% (least-squares mean ± SEM) for TAI nonsorted, 27.3 ± 3.4% for TET nonsorted fresh embryos, and 30.2 ± 3.3% for TET X-sorted fresh embryos (TAI vs. both TET groups, P < 0.05; 206 to 233 cows per group). Pregnancy losses between approximately Day 32 and term ranged from 16% to 37%, the latter from TET with X-sorted sperm. Pregnancy losses to term were higher for cows receiving embryos produced in vitro than for cows bred by TAI. Calves produced via TET were not substantively different from AI controls in physical measurements or standard blood chemistry profiles. © 2013 Elsevier Inc.

Hansen P.J.,University of Florida | Block J.,University of Florida | Block J.,Ovatech LLC | Loureiro B.,University of Florida | And 2 more authors.
Reproduction, Fertility and Development | Year: 2010

One limitation to the use of in vitro-produced embryos in cattle production systems is the fact that pregnancy rates after transfer to recipients are typically lower than when embryos produced in vivo are transferred. Conceptually, the oocyte and spermatozoon from which the embryo is derived could affect competence for post-transfer survival. There are sire differences in embryonic survival after transfer, but there is little evidence that an embryo's ability to establish pregnancy is determined by sex sorting of spermatozoa by flow cytometry. The role of the source of the oocyte as a determinant of embryonic survival after transfer has not been examined carefully. Conditions for embryo culture after fertilisation can have an impact on the ability of the embryo to establish pregnancy following transfer. Among the specific molecules produced in the reproductive tract of the cow that have been shown to improve competence of in vitro-produced embryos for post-transfer survival are colony-stimulating factor 2, insulin-like growth factor-1 (for recipients exposed to heat stress) and hyaluronan (for less-advanced embryos). There is also a report that embryo competence for post-transfer survival can be improved by inclusion of a carbon-activated air filtration system in the incubator used to culture embryos. Progress in developing culture systems to improve embryonic competence for survival after transfer would be hastened by the development of in vitro assays that accurately predict the potential of an embryo to establish pregnancy after transfer. A group of 52 genes has been identified that are differentially expressed in embryos that developed to term v. embryos that did not establish pregnancy. Perhaps a gene microarray consisting of these genes, alone or in combination with other genes, could be used to screen embryos for competence to establish pregnancy. © 2010 IETS.

Dobbs K.B.,University of Florida | Gagne D.,Laval University | Fournier E.,Laval University | Dufort I.,Laval University | And 9 more authors.
Biology of Reproduction | Year: 2014

Physiology of the adult can be modified by alterations in prenatal development driven by the maternal environment. Developmental programming, which can be established before the embryo implants in the uterus, can affect females differently than males. The mechanism by which sex-specific developmental programming is established is not known. Here we present evidence that maternal regulatory signals change female embryos differently than male embryos. In particular, actions of the maternally derived cytokine CSF2 from Day 5 to Day 7 of development affected characteristics of the embryo at Day 15 differently for females than males. CSF2 decreased length and IFNT secretion of female embryos but increased length and IFNT secretion of male embryos. Analysis of a limited number of samples indicated that changes in the transcriptome and methylome caused by CSF2 also differed between female and males. Thus, sex-specific programming by the maternal environment could occur when changes in secretion of maternally derived regulatory molecules alter development of female embryos differently than male embryos. © 2014 by the Society for the Study of Reproduction, Inc.

Block J.,University of Florida | Block J.,OvaTech LLC | Hansen P.J.,University of Florida | Loureiro B.,University of Florida | Bonilla L.,University of Florida
Theriogenology | Year: 2011

Technologies for in vitro embryo production have the potential to enhance the efficiency of cattle production systems. However, utilization of in vitro-produced embryos for transfer remains limited throughout much of the world. Despite improvements over the past two decades, problems associated with the production of bovine embryos in vitro still exist which limit the widespread commercial application of this technology. In particular, bovine embryos produced in vitro have a reduced capacity to establish and maintain pregnancy as compared with their in vivo-derived counterparts. Embryo competence for survival following transfer is improved by in vivo culture in the sheep oviduct, thus indicating that standard embryo culture conditions are sub-optimal. Therefore, one strategy to improve post-transfer survival is to modify embryo culture media to more closely mimic the in vivo microenvironment. The maternal environment in which the bovine embryo develops in vivo contains various growth factors, cytokines, hormones, and other regulatory molecules. In addition to affecting bovine embryo development in vitro, recent research indicates that embryo competence for survival following transfer can also be improved when such molecules are added to embryo culture medium. Among the specific molecules that can increase post-transfer embryo survival are insulin-like growth factor-1 (IGF-1), colony stimulating factor-2 (CSF-2) and hyaluronan. This paper will review the effects IGF-1, CSF-2 and hyaluronan on post-culture embryo viability and discuss the potential mechanisms through which each of these molecules improves post-transfer survival. © 2011 Elsevier Inc.

Denicol A.C.,Genetics Institute | Block J.,Genetics Institute | Block J.,Ovatech LLC | Kelley D.E.,Genetics Institute | And 5 more authors.
FASEB Journal | Year: 2014

Successful embryonic development is dependent on factors secreted by the reproductive tract. Dickkopf-1 (DKK1), an antagonist of the winglessrelated mouse mammary tumor virus (WNT) signaling pathway, is one endometrial secretory protein potentially involved in maternal-embryo communication. The purpose of this study was to investigate the roles of DKK1 in embryo cell fate decisions and competence to establish pregnancy. Using in vitro-produced bovine embryos, we demonstrate that exposure of embryos to DKK1 during the period of morula to blastocyst transition (between d 5 and 8 of development) promotes the first 2 cell fate decisions leading to increased differentiation of cells toward the trophectoderm and hypoblast lineages compared with that for control embryos treated with vehicle. Moreover, treatment of embryos with DKK1 or colony-stimulating factor 2 (CSF2; an endometrial cytokine known to improve embryo development and pregnancy establishment) between d 5 and 7 of development improves embryo survival after transfer to recipients. Pregnancy success at d 32 of gestation was 27% for cows receiving control embryos treated with vehicle, 41% for cows receiving embryos treated with DKK1, and 39% for cows receiving embryos treated with CSF2. These novel findings represent the first evidence of a role for maternally derived WNT regulators during this period and could lead to improvements in assisted reproductive technologies. - Denicol, A. C., Block, J., Kelley, D. E., Pohler, K. G., Dobbs, K. B., Mortensen, C. J., Ortega, M. S., Hansen, P. J. The WNT signaling antagonist Dickkopf-1 directs lineage commitment and promotes survival of the preimplantation embryo. © FASEB.

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