The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform

Zoltan Machaty - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive biology and endocrinology : RB&E, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive Biology and Endocrinology, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer. Methods First, changes in the intracellular free calcium concentration [Ca2+]i in the oocytes induced by a number of artificial stimuli were characterized. The stimuli included electroporation, ethanol, ionomycin, thimerosal, strontium-chloride and sodium (Na+)-free medium. The potential of the most promising treatments (with or without subsequent incubation in the presence of cycloheximide and cytochalasin B) to stimulate oocyte activation and support development of the resultant parthenogenetic embryos was then evaluated. Finally, the most effective methods were selected to activate oocytes reconstructed during nuclear transfer with fibroblasts from mucopolysaccharidosis I- and alpha-mannosidosis-affected Cats. Results All treatments were able to elicit a [Ca2+]i elevation in the ooplasm with various characteristics. Pronuclear formation and development up to the blastocyst stage was most efficiently triggered by electroporation (60.5 +/- 2.9 and 11.5 +/- 1.7%) and the combined thimerosal/DTT treatment (67.7 +/- 1.8 and 10.6 +/- 1.9%); incubation of the stimulated oocytes with cycloheximide and cytochalasin B had a positive effect on embryo development. When these two methods were used to activate oocytes reconstructed during nuclear transfer, up to 84.9% of the reconstructed oocytes cleaved. When the 2 to 4-cell embryos (a total of 220) were transferred into 19 recipient females, 4 animals became pregnant. All of the fetuses developed from oocytes activated by electroporation followed by cycloheximide and cytochalasin B incubation; no fetal development was detected as a result of thimerosal/DTT activation. Although heartbeats were detected in two of the cloned fetuses, no term development occurred. Conclusion Electroporation proved to be the most effective method for the activation of Cat oocytes reconstructed by nuclear transfer. The combined thimerosal/DTT treatment followed by cycloheximide and cytochalasin B incubation triggered development effectively to the blastocyst stage; whether it is a viable option to stimulate term development of cloned Cat embryos needs further investigations.

Chunmin Wang - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive biology and endocrinology : RB&E, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive Biology and Endocrinology, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer. Methods First, changes in the intracellular free calcium concentration [Ca2+]i in the oocytes induced by a number of artificial stimuli were characterized. The stimuli included electroporation, ethanol, ionomycin, thimerosal, strontium-chloride and sodium (Na+)-free medium. The potential of the most promising treatments (with or without subsequent incubation in the presence of cycloheximide and cytochalasin B) to stimulate oocyte activation and support development of the resultant parthenogenetic embryos was then evaluated. Finally, the most effective methods were selected to activate oocytes reconstructed during nuclear transfer with fibroblasts from mucopolysaccharidosis I- and alpha-mannosidosis-affected Cats. Results All treatments were able to elicit a [Ca2+]i elevation in the ooplasm with various characteristics. Pronuclear formation and development up to the blastocyst stage was most efficiently triggered by electroporation (60.5 +/- 2.9 and 11.5 +/- 1.7%) and the combined thimerosal/DTT treatment (67.7 +/- 1.8 and 10.6 +/- 1.9%); incubation of the stimulated oocytes with cycloheximide and cytochalasin B had a positive effect on embryo development. When these two methods were used to activate oocytes reconstructed during nuclear transfer, up to 84.9% of the reconstructed oocytes cleaved. When the 2 to 4-cell embryos (a total of 220) were transferred into 19 recipient females, 4 animals became pregnant. All of the fetuses developed from oocytes activated by electroporation followed by cycloheximide and cytochalasin B incubation; no fetal development was detected as a result of thimerosal/DTT activation. Although heartbeats were detected in two of the cloned fetuses, no term development occurred. Conclusion Electroporation proved to be the most effective method for the activation of Cat oocytes reconstructed by nuclear transfer. The combined thimerosal/DTT treatment followed by cycloheximide and cytochalasin B incubation triggered development effectively to the blastocyst stage; whether it is a viable option to stimulate term development of cloned Cat embryos needs further investigations.

William F. Swanson - One of the best experts on this subject based on the ideXlab platform.

  • 55 PROPAGATION OF MULTIPLE Cat HEREDITARY Disease MODELS FOLLOWING ASSISTED REPRODUCTION WITH FROZEN SEMEN AND EMBRYOS
    Reproduction Fertility and Development, 2012
    Co-Authors: William F. Swanson, Jason R. Herrick, H. L. Bateman, J. Newsom, Valéria A. Conforti, C. A. Lambo, M. E. Haskins, Leslie A. Lyons, Mark D Kittleson, S. P. Harris
    Abstract:

    Domestic Cats are invaluable research models for the study of hereditary Diseases that affect both Cats and humans. By necessity, most Cat models are maintained as living populations; however, semen and embryo cryopreservation could provide a cost-effective alternative for model conservation if viable offspring can be readily produced with assisted reproductive techniques such as IVF, embryo transfer (ET) and AI. In our earlier research, semen and IVF-derived embryos representing 24 Cat models at 7 veterinary/medical schools were frozen for liquid nitrogen storage. Our objectives in this study were to (1) assess the appliCation of assisted reproduction using frozen semen or embryos for producing pregnancies and viable kittens in several Cat models and (2) provide our university collaborators with rederived model offspring. Five Cat models (i.e. spinal muscular atrophy, SMA; porphyria, POR; Chediak-Higashi syndrome, CHS; progressive retinal atrophy, PRA; and hypertrophic cardiomyopathy, HCM) were selected for propagation based on investigator research needs. For 3 models (SMA, POR and CHS), semen from affected males, frozen as pellets in Test Egg Yolk medium (with 4% glycerol), was thawed and used to inseminate (5 × 105 motile sperm mL–1) oocytes from eCG/hCG-treated queens. Resulting embryos (2- to 8-cell stage) were transferred laparoscopically (3–5 embryos/recipient) into the oviducts of anestrual queens synchronized with eCG/pLH. For PRA, IVF embryos from affected Cats were frozen in 1.5 M ethylene glycol and later thawed for transfer into eCG/pLH-synchronized queens and for HCM, frozen semen from a carrier male was used for laparoscopic oviducal insemination (1 × 106 to 4 × 106 motile sperm/AI) of eCG/pLH-treated females. Ultrasonography was conducted approximately 21 days post-ET or -AI for pregnancy diagnosis. Following IVF with frozen-thawed semen, embryos were produced in all 3 models but overall fertilization success was low (21%, 34/164). All (5/5) recipients became pregnant after ET, giving birth to a total of 11 offspring (6 viable, 5 stillborn). Following frozen ET (PRA), most (3/5) recipients became pregnant with 6 kittens carried to term (3 viable, 3 stillborn), whereas with frozen semen AI (HCM), most (4/7) females conceived with the subsequent birth of 22 kittens (all viable). All surviving offspring (n = 25) for the 5 Disease models were distributed to collaborating veterinary schools to reestablish breeding colonies or for ongoing studies. These results indiCate that assisted reproduction using frozen semen or embryos may be applied effectively with specific Cat models to propagate desired lineages or reestablish research colonies, although some other models have proven more difficult to reproduce. These findings validate our contention that cryopreservation and assisted reproduction may be used to manage and conserve these irreplaceable Cat Disease models. Funded by NIH grants RR015338, RR02512, HL093603 and HD39888.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive biology and endocrinology : RB&E, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive Biology and Endocrinology, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer. Methods First, changes in the intracellular free calcium concentration [Ca2+]i in the oocytes induced by a number of artificial stimuli were characterized. The stimuli included electroporation, ethanol, ionomycin, thimerosal, strontium-chloride and sodium (Na+)-free medium. The potential of the most promising treatments (with or without subsequent incubation in the presence of cycloheximide and cytochalasin B) to stimulate oocyte activation and support development of the resultant parthenogenetic embryos was then evaluated. Finally, the most effective methods were selected to activate oocytes reconstructed during nuclear transfer with fibroblasts from mucopolysaccharidosis I- and alpha-mannosidosis-affected Cats. Results All treatments were able to elicit a [Ca2+]i elevation in the ooplasm with various characteristics. Pronuclear formation and development up to the blastocyst stage was most efficiently triggered by electroporation (60.5 +/- 2.9 and 11.5 +/- 1.7%) and the combined thimerosal/DTT treatment (67.7 +/- 1.8 and 10.6 +/- 1.9%); incubation of the stimulated oocytes with cycloheximide and cytochalasin B had a positive effect on embryo development. When these two methods were used to activate oocytes reconstructed during nuclear transfer, up to 84.9% of the reconstructed oocytes cleaved. When the 2 to 4-cell embryos (a total of 220) were transferred into 19 recipient females, 4 animals became pregnant. All of the fetuses developed from oocytes activated by electroporation followed by cycloheximide and cytochalasin B incubation; no fetal development was detected as a result of thimerosal/DTT activation. Although heartbeats were detected in two of the cloned fetuses, no term development occurred. Conclusion Electroporation proved to be the most effective method for the activation of Cat oocytes reconstructed by nuclear transfer. The combined thimerosal/DTT treatment followed by cycloheximide and cytochalasin B incubation triggered development effectively to the blastocyst stage; whether it is a viable option to stimulate term development of cloned Cat embryos needs further investigations.

Jason R. Herrick - One of the best experts on this subject based on the ideXlab platform.

  • 55 PROPAGATION OF MULTIPLE Cat HEREDITARY Disease MODELS FOLLOWING ASSISTED REPRODUCTION WITH FROZEN SEMEN AND EMBRYOS
    Reproduction Fertility and Development, 2012
    Co-Authors: William F. Swanson, Jason R. Herrick, H. L. Bateman, J. Newsom, Valéria A. Conforti, C. A. Lambo, M. E. Haskins, Leslie A. Lyons, Mark D Kittleson, S. P. Harris
    Abstract:

    Domestic Cats are invaluable research models for the study of hereditary Diseases that affect both Cats and humans. By necessity, most Cat models are maintained as living populations; however, semen and embryo cryopreservation could provide a cost-effective alternative for model conservation if viable offspring can be readily produced with assisted reproductive techniques such as IVF, embryo transfer (ET) and AI. In our earlier research, semen and IVF-derived embryos representing 24 Cat models at 7 veterinary/medical schools were frozen for liquid nitrogen storage. Our objectives in this study were to (1) assess the appliCation of assisted reproduction using frozen semen or embryos for producing pregnancies and viable kittens in several Cat models and (2) provide our university collaborators with rederived model offspring. Five Cat models (i.e. spinal muscular atrophy, SMA; porphyria, POR; Chediak-Higashi syndrome, CHS; progressive retinal atrophy, PRA; and hypertrophic cardiomyopathy, HCM) were selected for propagation based on investigator research needs. For 3 models (SMA, POR and CHS), semen from affected males, frozen as pellets in Test Egg Yolk medium (with 4% glycerol), was thawed and used to inseminate (5 × 105 motile sperm mL–1) oocytes from eCG/hCG-treated queens. Resulting embryos (2- to 8-cell stage) were transferred laparoscopically (3–5 embryos/recipient) into the oviducts of anestrual queens synchronized with eCG/pLH. For PRA, IVF embryos from affected Cats were frozen in 1.5 M ethylene glycol and later thawed for transfer into eCG/pLH-synchronized queens and for HCM, frozen semen from a carrier male was used for laparoscopic oviducal insemination (1 × 106 to 4 × 106 motile sperm/AI) of eCG/pLH-treated females. Ultrasonography was conducted approximately 21 days post-ET or -AI for pregnancy diagnosis. Following IVF with frozen-thawed semen, embryos were produced in all 3 models but overall fertilization success was low (21%, 34/164). All (5/5) recipients became pregnant after ET, giving birth to a total of 11 offspring (6 viable, 5 stillborn). Following frozen ET (PRA), most (3/5) recipients became pregnant with 6 kittens carried to term (3 viable, 3 stillborn), whereas with frozen semen AI (HCM), most (4/7) females conceived with the subsequent birth of 22 kittens (all viable). All surviving offspring (n = 25) for the 5 Disease models were distributed to collaborating veterinary schools to reestablish breeding colonies or for ongoing studies. These results indiCate that assisted reproduction using frozen semen or embryos may be applied effectively with specific Cat models to propagate desired lineages or reestablish research colonies, although some other models have proven more difficult to reproduce. These findings validate our contention that cryopreservation and assisted reproduction may be used to manage and conserve these irreplaceable Cat Disease models. Funded by NIH grants RR015338, RR02512, HL093603 and HD39888.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive biology and endocrinology : RB&E, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive Biology and Endocrinology, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer. Methods First, changes in the intracellular free calcium concentration [Ca2+]i in the oocytes induced by a number of artificial stimuli were characterized. The stimuli included electroporation, ethanol, ionomycin, thimerosal, strontium-chloride and sodium (Na+)-free medium. The potential of the most promising treatments (with or without subsequent incubation in the presence of cycloheximide and cytochalasin B) to stimulate oocyte activation and support development of the resultant parthenogenetic embryos was then evaluated. Finally, the most effective methods were selected to activate oocytes reconstructed during nuclear transfer with fibroblasts from mucopolysaccharidosis I- and alpha-mannosidosis-affected Cats. Results All treatments were able to elicit a [Ca2+]i elevation in the ooplasm with various characteristics. Pronuclear formation and development up to the blastocyst stage was most efficiently triggered by electroporation (60.5 +/- 2.9 and 11.5 +/- 1.7%) and the combined thimerosal/DTT treatment (67.7 +/- 1.8 and 10.6 +/- 1.9%); incubation of the stimulated oocytes with cycloheximide and cytochalasin B had a positive effect on embryo development. When these two methods were used to activate oocytes reconstructed during nuclear transfer, up to 84.9% of the reconstructed oocytes cleaved. When the 2 to 4-cell embryos (a total of 220) were transferred into 19 recipient females, 4 animals became pregnant. All of the fetuses developed from oocytes activated by electroporation followed by cycloheximide and cytochalasin B incubation; no fetal development was detected as a result of thimerosal/DTT activation. Although heartbeats were detected in two of the cloned fetuses, no term development occurred. Conclusion Electroporation proved to be the most effective method for the activation of Cat oocytes reconstructed by nuclear transfer. The combined thimerosal/DTT treatment followed by cycloheximide and cytochalasin B incubation triggered development effectively to the blastocyst stage; whether it is a viable option to stimulate term development of cloned Cat embryos needs further investigations.

Kiho Lee - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive biology and endocrinology : RB&E, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer.

  • Analysis of Cat oocyte activation methods for the generation of feline Disease models by nuclear transfer
    Reproductive Biology and Endocrinology, 2009
    Co-Authors: Chunmin Wang, William F. Swanson, Jason R. Herrick, Kiho Lee, Zoltan Machaty
    Abstract:

    Background Somatic cell nuclear transfer in Cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of Cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of Cat Disease models by somatic cell nuclear transfer. Methods First, changes in the intracellular free calcium concentration [Ca2+]i in the oocytes induced by a number of artificial stimuli were characterized. The stimuli included electroporation, ethanol, ionomycin, thimerosal, strontium-chloride and sodium (Na+)-free medium. The potential of the most promising treatments (with or without subsequent incubation in the presence of cycloheximide and cytochalasin B) to stimulate oocyte activation and support development of the resultant parthenogenetic embryos was then evaluated. Finally, the most effective methods were selected to activate oocytes reconstructed during nuclear transfer with fibroblasts from mucopolysaccharidosis I- and alpha-mannosidosis-affected Cats. Results All treatments were able to elicit a [Ca2+]i elevation in the ooplasm with various characteristics. Pronuclear formation and development up to the blastocyst stage was most efficiently triggered by electroporation (60.5 +/- 2.9 and 11.5 +/- 1.7%) and the combined thimerosal/DTT treatment (67.7 +/- 1.8 and 10.6 +/- 1.9%); incubation of the stimulated oocytes with cycloheximide and cytochalasin B had a positive effect on embryo development. When these two methods were used to activate oocytes reconstructed during nuclear transfer, up to 84.9% of the reconstructed oocytes cleaved. When the 2 to 4-cell embryos (a total of 220) were transferred into 19 recipient females, 4 animals became pregnant. All of the fetuses developed from oocytes activated by electroporation followed by cycloheximide and cytochalasin B incubation; no fetal development was detected as a result of thimerosal/DTT activation. Although heartbeats were detected in two of the cloned fetuses, no term development occurred. Conclusion Electroporation proved to be the most effective method for the activation of Cat oocytes reconstructed by nuclear transfer. The combined thimerosal/DTT treatment followed by cycloheximide and cytochalasin B incubation triggered development effectively to the blastocyst stage; whether it is a viable option to stimulate term development of cloned Cat embryos needs further investigations.