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Study of differential potential of germ stem cells in vitro in higher vertebrates
Smolík, Ondřej ; Krylov, Vladimír (advisor) ; Krulová, Magdaléna (referee)
Spermatogonial stem cells are unipotent male germ cells which provide spermatogenesis during the whole life. In 2004, an important experiment was conducted. During in vitro cultivation mouse spermatogonial stem cells gained the characteristics of embryonic stem cells, pluripotency by all means. Those cells had the feature to spontaneously differentiate into all three germ layers, endoderm, ectoderm and mesoderm. They also could pass its genetic information to the next generation and they could give rise to teratomas. By this event, experiments started on other vertebrates including rodents, domestic animals and also human. Differentiation of these cells can be directed in vitro to generate specific cell types. On base of these facts, spermatogonial stem cells are alternative source of pluripotent cells which possess many applications in life sciences. The purpose of this thesis is to summarize actual knowledge about differentiation potential in vitro of spermatogonial stem cells in higher vertebrates and try to identify tendencies which they prefer during differentiation, if they exist. Powered by TCPDF (www.tcpdf.org)
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Study of differential potential of spermatogonial stem cells via transplantation in vertebrates
Kodedová, Barbora ; Krylov, Vladimír (advisor) ; Pšenička, Martin (referee)
Spermatogonia, or spermatogonial stem cells are necessary to maintain male fertility. In the complex process of ongoing spermatogenesis in the testes these pluripotent stem cells proliferate and differentiate into sperm cells. In 1994 the first spermatogonial transplantation technique was described in rodents to allow the study of male germ cells. The following series of studies of intra- and inter-species transmission of testicular tissue revealed the regenerative capacity of transplanted spermatogonial stem cells and their possible usage. Recently, spermatogonia transplantation systems are developed in many vertebrates making it possible to study the development of sperm as well as artificial production of male and female gametes derived from germ cell donors. The differentiation potential of spermatogonial stem cells enabled the creation of transgenic organisms by genetic manipulation of isolated spermatogonia and subsequent transplantation into a suitable recipient. Spermatogonial transplantation in the future may find their application in regenerative medicine, the treatment of disorders of spermatogenesis, or serve to preservation of genetic stock of endangered species.
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Meiosis and fertility of juvenile mouse males
Valtrová, Pavlína ; Trachtulec, Zdeněk (advisor) ; Reifová, Radka (referee)
This work is a summary of literature on pecularities of spermatogenesis in juvenile mouse males (Mus musculus) and their utilization. Spermatogenesis is a process that leads through meiosis to sperm production. The cell undergoes in waves the following cell types: spermatogonia, spermatocytes, spermatids, and spermatozoa. Juvenile mice (whose testes size and sperm count have not reached their maximum) are often used to study individual cell types. The transition between cell types takes shorter time in juveniles. Spermatozoa from the 1st wave of spermatogenesis (WS) are derived from prenatal gonocytes, allowing earlier sperm production. They have a lower frequency of crossing over (CO rate) due to a different processing of CO intermediates; the consequence can be aneuploidy (one chromosome less/more). Spermatozoa from the 2nd WS still display lower CO rate. In 3rd WS testes descend and their temperature decreases to 33řC; CO rate is more like in adults. In 4th WS is typical testicular supportive cells mature and CO rate is similar to adult levels. Juvenile males also suffer from more frequent and severe sperm malformations. Low CO rate should not have an impact on fertility; errors are eliminated during meiotic checkpoints. However, the children of young fathers have a higher risk of aneuploidy,...
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Study of differential potential of germ stem cells in vitro in higher vertebrates
Smolík, Ondřej ; Krylov, Vladimír (advisor) ; Krulová, Magdaléna (referee)
Spermatogonial stem cells are unipotent male germ cells which provide spermatogenesis during the whole life. In 2004, an important experiment was conducted. During in vitro cultivation mouse spermatogonial stem cells gained the characteristics of embryonic stem cells, pluripotency by all means. Those cells had the feature to spontaneously differentiate into all three germ layers, endoderm, ectoderm and mesoderm. They also could pass its genetic information to the next generation and they could give rise to teratomas. By this event, experiments started on other vertebrates including rodents, domestic animals and also human. Differentiation of these cells can be directed in vitro to generate specific cell types. On base of these facts, spermatogonial stem cells are alternative source of pluripotent cells which possess many applications in life sciences. The purpose of this thesis is to summarize actual knowledge about differentiation potential in vitro of spermatogonial stem cells in higher vertebrates and try to identify tendencies which they prefer during differentiation, if they exist. Powered by TCPDF (www.tcpdf.org)
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Study of differential potential of spermatogonial stem cells via transplantation in vertebrates
Kodedová, Barbora ; Krylov, Vladimír (advisor) ; Pšenička, Martin (referee)
Spermatogonia, or spermatogonial stem cells are necessary to maintain male fertility. In the complex process of ongoing spermatogenesis in the testes these pluripotent stem cells proliferate and differentiate into sperm cells. In 1994 the first spermatogonial transplantation technique was described in rodents to allow the study of male germ cells. The following series of studies of intra- and inter-species transmission of testicular tissue revealed the regenerative capacity of transplanted spermatogonial stem cells and their possible usage. Recently, spermatogonia transplantation systems are developed in many vertebrates making it possible to study the development of sperm as well as artificial production of male and female gametes derived from germ cell donors. The differentiation potential of spermatogonial stem cells enabled the creation of transgenic organisms by genetic manipulation of isolated spermatogonia and subsequent transplantation into a suitable recipient. Spermatogonial transplantation in the future may find their application in regenerative medicine, the treatment of disorders of spermatogenesis, or serve to preservation of genetic stock of endangered species.
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