1985 — 1987 |
Bavister, Barry D |
P51Activity Code Description: To support centers which include a multidisciplinary and multi-categorical core research program using primate animals and to maintain a large and varied primate colony which is available to affiliated, collaborative, and visiting investigators for basic and applied biomedical research and training. R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Rhesus Monkey in Vitro Fertilization and Embryogenesis @ University of Wisconsin Madison
Proven procedures for fertilizing rhesus monkey oocytes in vitro and sustaining development through early cleavage stages will be used to examine fundamental aspects of primate fertilization and embryogenesis. The investigation will include: (1) physiological and pharmacological studies on acquisition of fertilizing ability by rhesus spermatozoa, in which the functional correlations between hyperactivated sperm motility, acrosome reactions and penetration of the zona pellucida will be examined; this work will extend previous studies on the stimulation of sperm fertilizing ability by cyclic nucleotide mediators and will also examine the possible role of cumulus oophorus. (2) Studies on the fertilizability of oocytes recovered from normal animals and animals stimulated by gonadotropins or clomiphene, in order to optimize yields of viable oocytes and to examine the steroid profiles of follicles that produce oocytes capable of undergoing fertilization and normal embryonic development; this project will provide information on folliculogenesis and will also facilitate other parts of the program. (3) Attempts to extend development of in vitro fertilized oocytes through all stage of preimplantation embryogenesis and to obtain early post-implantation embryonic growth in vitro in order to provide a primate model for more detailed analyses of these critical phases of development. (4) Transfer of in vitro fertilized rhesus embryos to recipients to obtain offspring and monitoring their post-natal development in order to ascertain if any defects are associated with in vitro fertilization procedures in primates. A project will also be undertaken to ascertain if primate embryos are able to withstand freeze-preservation; if successful, this project would facilitate experimental embryological studies by (e.g.) permitting embryos to be pooled in sufficient numbers to reduce experimental variability, allowing embryos to be transferred to oocyte-donor recipients (autotransfers) following re-establishment of normal menstrual cycles and provide a means for transporting rhesus embryos to other laboratories for breeding purposes or for experimental studies. Taken together, the proposed research will considerably extend knowledge, which is presently very sparse, about primate oocyte development, fertilization and embryogenesis, and may provide new insights into the etiology of embryonic losses and developmental defects in primates.
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1 |
1985 |
Bavister, Barry D |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Studies On Sperm Motility and Fertilizing Ability @ University of Wisconsin Madison
The functional significance will be investigated of physiological and biochemical changes taking place during acquisition of fertilizing ability by spermatozoa. These processes will be studied using new methodology made possible in part by discoveries in our laboratory. The functional relationship between the acrosome reaction and sperm penetration of the egg investments (granulosa cell layer and zona pellucida) will be investigated using a micro-incubation in vitro fertilization system that we have devised, featuring chemically defined factors that sustain sperm motility. This system will permit the fertilizing sperm to be identified and details of its acrosomal condition to be recorded as it traverses the egg investments. Information will also be provided on the location within the egg-cumulus complex of the putatuve acrosome-reaction inducing factor. This information could eventually assist elucidation of the mechanism of the acrosome reaction, which is presently unknown. Related studies will be performed to examine biochemical parameters of sperm capacitation/acrosome reactions (cyclic nucleotide and phospholipid changes, and pharmacological parameters) using a new technique that permits comparative data to be obtained on highly motile but non-capacitated sperm. This study will focus critically on biochemical properties of sperm and events that are directly concerned in the capacitation/acrosome reaction sequence. The overall study will provide new, precise data on processes taking place in sperm that lead to fertilization; at present these mechanisms are obscure. Such information is urgently needed in order to facilitate productive research on the alteration of human fertility characteristics.
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1 |
1986 — 1988 |
Bavister, Barry D |
U01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Normal Fertilization and Preimplantion Growth in Vitro @ University of Wisconsin Madison
This research will provide data on culture requirements for supporting normal growth of hamster preimplantation embryos in vitro. Embryos at all stages of preimplantation development will be cultured in a relatively simple medium, which will be progressively modified as important rate-limiting parameters for embryo growth are defined. Parameters to be examined include physicochemical conditions and nutrients. Embryo growth will be evaluated by several qualitative criteria, including transfer of cultured embryos to pseudopregnant recipients to assess their normality. The primary purpose of this study is to determine which features of the environment are critically important for normal embryo growth and differentiation. The information obtained in this study will also be applied to embryos from cattle and rhesus monkeys to test the general applicability of the data. Steroid metabolic pathways in cultured hamster embryos will also be examined since steroids seem to exercise important regulatory actions on embryo growth and differentiation. The final part of the research will make use of our ability to obtain normal preimplantation growth of hamster embryos in vitro to examine consequences of delayed fertilization on subsequent embryogenesis. Overall, the research will provide data on the regulation of normal preimplantation embryo development by environmental conditions; this information is likely to be helpful in understanding some of the regulatory events involved in normal human development and in anomalous embryogenesis, including pregnancy losses and developmental defects. The data are also likely to assist efforts aimed at improving the efficiency of in vitro fertilization and embryo culture/transfer as therapeutic procedures for human infertility.
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1 |
1986 — 1993 |
Bavister, Barry D |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Studies On Sperm Fertilizing Ability @ University of Wisconsin Madison
The overall objective of the proposed research is to provide new information on the regulation of sperm:egg interaction in mammals by components of the normal oviductal milieu. This information is needed for a more complete understanding of the way that gamete interactions are facilitated and coordinated at the site of fertilization in vivo. Increased knowledge of these regulatory mechanisms could assist the development of improved methods for amelioration of infertility in humans and for fertility control. Specific aims are (i) to identify molecules modulating terminal events of sperm:zona interactions and acrosome reactions, and to differentiate their sites of production (follicle or oviduct); (ii) to isolate and identify a heat labile oviductal factor that facilitates sperm penetration into zonae pellucidae, and to determine its mechanism of action; and (iii) to isolate and identify a heat stable factor present in the ovulated cumulus oophorus that facilitates acrosome reactions in free-swimming (i.e., non-zona bound) sperm. The research will use well-defined in vitro fertilization techniques to examine details of the regulatory mechanisms with golden hamster gametes. Hamster epididymal spermatozoa will be capacitated in vitro, then incubated for 60 or 90 min with living or salt-stored follicular or ovulated eggs. These eggs and/or sperm will be treated with impure or (later) purified heat labile and/or heat stable factors and the effects on sperm penetration of the zonae pellucidae will be evaluated; differential responses with these preparations will provide detailed information about the functions and mechanisms of action of the factors. Sperm acrosome reactions will be monitored using fluorescent monoclonal antibodies. The sites of production and of functional activities of these factors will be localized using polyclonal and monoclonal antibodies. Factors will be isolated by standard biochemical procedures, including SDS-polyacrylamide gel electrophoresis followed by western blotting, and identified using immunoenzymatic assay. Tests will show if the factors' actions are enzyme-like or ligand-like. The hypotheses will be tested that the factor(s) act as co-acrosome reaction inducing factors, i.e., in synergism with zonae pellucidae, and that the factors alter the physical characteristics of zonae pellucidae. Possible homology between some of the oviductal factors and the oviductal protein 'oviductin' will be examined. It will be determined whether the acrosome reaction inducing activity of the heat-stable factor can be ascribed to a macromolecule or to a ligand, such as progesterone, bound to a macromolecule. The results of these experiments will provide deeper insights into the functional roles of these naturally-occurring factors, and into their mechanisms of action in regulating events immediately preceding egg penetration.
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1 |
1989 — 1995 |
Bavister, Barry D |
U01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Normal Fertilization and Preimplantation Growth in Vitro @ University of Wisconsin Madison |
1 |
1995 — 1997 |
Bavister, Barry D |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Maternal Age-Related Oocyte/Embryo Defects @ University of Wisconsin Madison |
1 |
1996 — 1999 |
Bavister, Barry D |
U01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Epigenetic Control of Normal Embryo Development in Vitro @ University of Wisconsin Madison
DESCRIPTION: The long-term goal of this proposal is to devise new culture media that support normal preimplantation embryo development. The developmental competence and viability of cultured embryos are compromised, showing that improvements in culture media are still needed. Improved media are urgently needed by human IVF clinics to increase the mean embryo viabili-ty, allowing fewer embryos, perhaps only one, to be transferred and support a successful pregnancy; this could eliminate the need for gonadotropin stimulation of patients. Other applications could benefit from improved embryo culture media, e.g., production of transgenic hamsters and rats for biomedical and toxicological research. Improvements are also needed to better support development of embryos stressed by cryopreservation or by micromanipulation (e.g., for preimplantation genetic diagnosis). Instead of using empirical methods for cultured medium design, the proposed research takes a mechanistic approach to find how hamster and rhesus monkey embryo development are regulated by key epigenetic factors, so these can be optimized and incorporated into new media formulations. The connecting theme of the re-search is "cytoplasmic homeostasis," targeting three critically important aspects if preimplantation embryo development the ionicregulation of intracellular protons (pHi) and calcium (pCai), oxidative metabolism and cytoplasmic organization, which are all perturbed in culture. The experimental strategy is to determine how culture conditions perturb these components, then modify the culture environment to compensate for these perturbations, and finally incorporate this new knowledge into improved culture media for preimplantation embryos. The proposed research is hypothesis-driven to provide answers to specific questions. Specific aims are to examine mechanisms of pHi homeostasis and relationships among pHi, calcium/magnesium and phosphate, and embryo development: to determine relationships among mitochondrial metabolism, glycolysis and development; to find how cytoplasmic components, including mitochondria and the cytoskeleton, are perturbed by culture conditions; and to test new media formulations on development. Techniques include fluorescent probe measurement of pHi and pCai; measuring substrate utilization by single embryos; static confocal and dynamic two-photon microscopic analysis of cell structural changes; objective analysis of embryo development by four-dimensional videomicroscopy; and embryo transfers.
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1 |
1997 |
Bavister, Barry D |
P41Activity Code Description: Undocumented code - click on the grant title for more information. |
Bovine Oocytes Mitochondria &Developmental Competence in Vitro @ University of Wisconsin Madison
reproductive system; microscopy; carbohydrates; biomedical resource;
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1 |
1997 — 1998 |
Bavister, Barry D |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Gamete and Embryo Biology @ University of Wisconsin Madison |
1 |
1997 — 1999 |
Bavister, Barry D |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
In Vitro Control of Rhesus Monkey Oocyte Maturation @ University of Wisconsin Madison
The long-term objectives of this project are to increase the yield of developmentally-competent oocytes from rhesus monkey. The information acquired in the proposed studies should be useful with respect to in vitro maturation of human oocytes and oocytes from endangered animals, as well as to the basic scientific understanding of the process involved in normal oocyte development. The two specific aims of the project are (1) to determine optimal culture conditions (energy, substrates, nutrients and vitamins) for supporting acquisition of developmental competence during oocyte maturation in vitro, and (2) to determine if maintaining meiotic arrest for several days during culture of germinal vesicle stage oocytes enhances their subsequent developmental competence.
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1 |
1998 |
Bavister, Barry D |
P41Activity Code Description: Undocumented code - click on the grant title for more information. |
Distribution of Mitochondria in Bovine Oocytes &Dvmtl Competence in Vitro @ University of Wisconsin Madison
The current study was developed in conjunction with previous work done in the D4R by Jayne Squirrell involving the distribution of mitochondria, in early stage hamster embryos. The hypothesis of this study is that mitochondrial distribution in bovine oocytes after in vitro maturation in suboptimal conditions is altered consistent with reduced developmental competence. The process of maturation is extremely critical, and can ultimately affect the ability of the resulting embryo to develop into a healthy blastocyst and fetus, and give rise to offspring. We would like to first investigate the distribution of mitochondria, in immature oocytes collected from the ovaries of slaughtered cattle. We will then subject oocytes to good and poor maturation medium developed in our laboratory, then stain the matured oocytes to look for mitochondrial distribution and also for tubulin and actin. We hypothesize that the distribution after maturation will reflect the developmental capability of the oocyte after in vitro fertilization and culture. This will assist us in further developing maturation medium for bovine oocytes to produce embryos with maximal developmental competence in vitro. After this first major project, we would like to investigate these same parameters with oocytes derived from transvaginal ultrasound guided oocyte retrieval. These oocytes are aspirated directly from the ovaries of living cattle, and will provide us with further information as to the optimal mitochondrial distribution. We would also like to divide the maturation period of 24 hours into 6 hour intervals and closely study the movements of mitochondria during the maturation process. We would then like to continue to investigate the effects of poor and good maturation medium on the resulting embryos, at the pronuclear, or one cell stage, at the 2 cell stage, and at the 8 cell stage. We hypothesize that the alterations in mitochondrial distribution that may occur during maturation persist in the resulting embryo and that this may be the mechanism whereby development is compromised. Lastly, we would like to examine these changes over time in a single living oocyte and embryo, using 2 photon microscopy. We believe these experiments will help us learn more about what happens to an oocyte during the critical process of maturation, and how perturbations which occur during maturation effect the development of the resulting embryo.
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1 |
2002 — 2006 |
Bavister, Barry Douglas |
R24Activity Code Description: Undocumented code - click on the grant title for more information. |
Embryo Technologies For Propagation of Rhesus Monkeys @ Louisiana State Univ-Univ of New Orleans
[unreadable] DESCRIPTION (provided by applicant): The overall goal of this application is to evaluate protocols important for the exploitation of ART that can enhance the propagation of NHP models of human disease. The use of ART to produce embryos from genetically valuable animals can contribute to a wide range of studies related to human health, from infertility to degenerative diseases. However, the current state of basic ART procedures in NHPs, such as embryo transfer and production of identical twins, is poor. Few studies have been devoted to improving these procedures. The proposed research will routinely produce embryos from rhesus monkeys using standard in vitro fertilization and embryo culture protocols in order to evaluate several different technical approaches to improve the production of animals for health related research. The aims of this resource development application are to evaluate: 1) strategies (number and stage of embryos) for transferring embryos to recipient females, in order to improve the success rate in producing offspring; 2) cross-species embryo transfer in macaques, in order to facilitate intra-uterine transfers; 3) the effectiveness of simple methods of blastomere separation or embryo splitting to produce identical twins; 4) a procedure for producing multiple embryos in vivo by superovulation and uterine flushing, thus avoiding possible artifacts from culturing in vitro produced embryos; and 5) preimplantation genetic diagnosis as a tool for selecting macaque embryos with specific genetic characteristics prior to embryo transfer, as a means to increase the efficiency of ART for propagating genetically valuable animals. By combining several of these technologies, the investigators will enhance the efficacy and utility of NHPs for health-related research, increase the fecundity of genetically-valuable animals, and improve the ability to select for specific genetic characteristics when breeding NHPs.
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0.943 |
2004 |
Bavister, Barry Douglas |
R13Activity Code Description: To support recipient sponsored and directed international, national or regional meetings, conferences and workshops. |
Supporting Human Art Through Basic Science @ Federated Animal Science Societies
[unreadable] DESCRIPTION (provided by applicant): This application seeks support for a 1-day symposium to be held in conjunction with the January 2004 Annual Meeting of the International Embryo Transfer Society in Portland, OR. The purpose of this symposium is twofold: (1) educate human Assisted Reproductive Technology (ART) practitioners (clinical embryologists and medical directors) in the latest basic and applied science relevant to their IVF programs, and (2) foster communication, exchange of information and awareness of how animal embryo research can address key problems in human IVF practice. These problems include: measurement of oocyte quality, selection of the most viable embryos for transfer and the etiology of defects in in vitro produced (IVP) embryos. At the same time, basic scientists will become aware of the practical problems inherent in human IVF clinics, by personal interactions with clinical personnel. These interactions will be strengthened by providing support for the speakers to attend the lnternational Embryo Transfer Society (IETS) meeting immediately following the symposium. Rationale: many aspects of human ART parallel those used in animal IVP. The first human in vitro fertilization successes were directly derived from studies with animals. However, with only a few notable exceptions, during the past two decades there has been little knowledge or technology transfer between these two applications. As a result, IVP in laboratory and domesticated animals has in some respects advanced far beyond that of human IVP, e.g., the high success rates of bovine offspring production from in vitro matured oocytes, development of specialized embryo culture media, and basic understanding of regulatory mechanisms and anomalies in animal IVP embryos. Better integration of these two communities will enhance the missions of both. The lETS is uniquely positioned to serve as the forum for ongoing exchange of information, ideas and technology between the animal and human ART efforts. Members of lETS work with a wide variety of species, including laboratory, domesticated and endangered animals and non-human primates, and employ a range of approaches including genetic, molecular, cellular and whole animal techniques to examine diverse basic and applied aspects of embryo production and quality. This Symposium will attract members of the human ART community and scientists working in animal ART, and will provide a basis for continued and expanded interactions between these two groups. [unreadable] [unreadable]
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0.91 |
2005 — 2007 |
Bavister, Barry Douglas |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Defects in Mitochondria Impacting Primate Oocyte Quality @ Louisiana State Univ-Univ of New Orleans
DESCRIPTION (provided by applicant): The overall goal of this study is to examine the functional significance of different mitochondrial characteristics in oocytes as markers or predictors of oocyte health, using the rhesus monkey as the most appropriate experimental model for humans. 3 approaches will be used: (i) assessment of mitochondrial localization profiles in oocytes before, during and after fertilization in vitro using multiphoton microscopy as a non-invasive analytical tool that provides 4-dimensional (4D) information; (ii) determining the functional activity of mitochondria in oocytes and embryos by measuring ATP levels at different stages of development; and (iii) evaluation of mitochondrial mutations in oocytes from humans and oocytes and embryos from young and old monkeys, as well as the evaluation of somatic mtDNA mutations in tissues and cells as a baseline marker for reproductive senescence. The study will determine the extent to which all 3 of these measures of mitochondrial characteristics are related to 1 another, and to embryo development subsequent to fertilization in vitro, in rhesus monkeys. If good correlations are found, this will indicate that the localization profiles and activity of mitochondria typical of developmentally incompetent oocytes represent a pathological condition. Thus, the "normal" localization profiles could be used as a non-invasive marker or predictor of oocyte competence so that only the most viable embryos are selected for embryo transfer. This information could then be evaluated in other clinical studies for application to human oocytes and embryos. This study will also determine if mtDNA defects are manifested as disturbed mitochondrial localization profiles, altered mitochondrial activity, and/or compromised oocyte developmental competence in rhesus monkeys. Information gained in this study will also improve our understanding of the role of mitochondria in primate oocyte and embryo biology, and in the progressive loss of female reproductive capacity with age.
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0.918 |