ABSTRACT
We studied the capacity of nuclei of rabbit fibroblasts taken from various developmental stages for reprogramming in the cytoplasm of mature aging enucleated oocytes and development of the cloned embryos to the preimplantation stages. A negative correlation was found between the age of an animal--donor of fibroblasts and efficiency of the development of cloned embryos (rmorula-blastocyst = -0.826, rblastocyst = -0.7139). A reliably decreased capacity for reprogramming of the nuclei of donor fibroblasts was shown upon transition from prenatal development to the postnatal one, as well as a trend to a decreased capacity of nuclei for reprogramming during aging. Aging of cells in the culture, at least until the 10th passage, did not affect the capacity of the nuclei of fetal fibroblasts for reprogramming and development of cloned embryos.
Subject(s)
Age Factors , Cloning, Organism , Embryonic and Fetal Development , Nuclear Transfer Techniques , Animals , Cells, Cultured , Cellular Senescence , Female , RabbitsABSTRACT
A review of the development of the method of nuclear transplantation and cloning of animals with the use of nuclei of embryonic and adult cells is presented. We also present the results of studies of nuclear remodeling and reprogramming in the reconstructed oocyte and of cytoplasmic factors that control these processes.
Subject(s)
Cell Nucleus , Cloning, Organism/methods , Oocytes/cytology , Oocytes/physiology , Animals , Cattle , Embryo, Mammalian/physiology , MiceABSTRACT
We investigated the mode of TNF-dependent death of L929 murine fibroblasts and the influence of overexpression of bcl-2 family genes on this process. Based on morphological and biochemical data it has been shown that L929 cells died after TNF treatment by apoptosis irrespective of TNF dose and protein synthesis inhibition. Analysis of bcl-2 family gene transfectants revealed a down-regulation of TNF-induced apoptosis by bcl-2 and bclX overexpression, and an up-regulation by bax gene.
Subject(s)
Apoptosis/drug effects , Fibroblasts/pathology , Tumor Necrosis Factor-alpha/pharmacology , Animals , Apoptosis/genetics , Cell Line , Fibroblasts/drug effects , Fibroblasts/physiology , Gene Expression Regulation , Genes, bcl-2 , MiceABSTRACT
Recent success in assisted fertilization mainly depended on the development of sperm microinjection methods: intracytoplasmic sperm injection and subzonal insemination. Some basic mechanisms that underlie fertilization were revealed by using intracytoplasmic sperm injection. In respect to this, problems of fertility, oocyte activation, formation of pronuclei and practical aspects of intracytoplasmic sperm injection are discussed.
Subject(s)
Fertilization/physiology , Sperm Injections, Intracytoplasmic/methods , Animals , Female , Humans , Male , Ovum/physiology , Risk Factors , Sperm-Ovum Interactions/physiology , Spermatozoa/physiologyABSTRACT
The action of nonthermal electromagnetic radiation (EMR) of the millimeter range on the early development of murine and sea urchin embryos was investigated. An MRTA-01E-03 generator with a frequency of 54-78 GHz and radiation intensity of 0.06 mWt/cm2 was used. The embryos were irradiated during 30 min at the stage of two blastomeres. The number of murine embryos that reached the blastocyst stage increased (up to 97.3% in comparison with 87.5% in control). The total time of cultivation up to the blastocyst stage was also shorter (72 h) than in control (96 h). The irradiation had effect on the development of sea urchin embryos only if embryos with a weakened viability were tested. The results indicate that millimeter electromagnetic radiation has a stimulating effect on the early development of embryos, increasing the resistance of embryos to unfavorable environmental conditions.
Subject(s)
Electromagnetic Fields , Embryonic and Fetal Development/radiation effects , Sea Urchins/embryology , Animals , Embryo, Nonmammalian/radiation effects , Mice , Mice, Inbred C57BL , Mice, Inbred CBAABSTRACT
Successful transplantation of mammalian nuclei from differentiated cells has become possible after the application of original methods directed at the synchronization of cell cycles of the donor cell and recipient cytoplasm. We obtained a line of rabbit fetal fibroblasts which was used to study factors affecting the success of reprogramming. The nuclei of fetal fibroblasts (up to the 10th passage inclusive) proved to be capable of reprogramming and ensuring development of the cloned embryos until the preimplantation stages. The influence of synchronization of the cell cycles of the nucleus donor and recipient on the efficiency of reprogramming was studied. The rate of development of the cloned rabbit embryos to the morula-blastocyst stage reached 67% when the nuclei used were from stationary culture cells (G0-phase).
