Errata inserted. Bibliography: leaves 98-120. This study is concerned with the identification of genes related to the very early stages of meiosis when homologous pairing occurs. A cDNA library is prepared at the premeiotic interphase and prophase stages of meioses. Differential screening is used to identify and select clones showing preferential expression in anthers at early meiosis. Two selected clones are chosen for further analysis and to investigate a possible role in chromosome pairing.

No description available.

Errata inserted. / Bibliography: leaves 98-120. / x, 120, [4] leaves, [13] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study is concerned with the identification of genes related to the very early stages of meiosis when homologous pairing occurs. A cDNA library is prepared at the premeiotic interphase and prophase stages of meioses. Differential screening is used to identify and select clones showing preferential expression in anthers at early meiosis. Two selected clones are chosen for further analysis and to investigate a possible role in chromosome pairing. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Thesis (Ph. D.)--University of Chicago, Dept. of Molecular Genetics and Cell Biology, August 1999. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Chicago, Pritzker School of Medicine, Department of Molecular Genetics and Cell Biology, December 2000. / Includes bibliographical references (p. 81-88). Also available on the Internet.

Thesis (Ph. D.)--Miami University, Dept. of Chemistry and Biochemistry, 2005. / Title from second page of PDF document. Document formatted into pages; contains [3], vi, 124 p. : ill. Includes bibliographical references.

Thesis (Ph.D. in Biochemistry) -- University of Colorado at Denver and Health Sciences Center, 2005. / Typescript. Includes bibliographical references (leaves 93-103). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

Thesis (Ph. D.)--Case Western Reserve University, 2007. / [School of Medicine] Department of Genetics. Includes bibliographical references. Available online via OhioLINK's ETD Center.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 90-110). Also available on the World Wide Web.

Resumo: Este estudo visou avaliar e comparar a eficiência e reversibilidade da inibição meiótica promovida pela roscovitina e ciclohexemida nos COCs de ovinos cultivados in vitro, assim como analisar o efeitos desses inibidores da meiose sobre a ultraestrutura dos COCs e expansão das células do cumulus. Para isto, COCs grau 1 e 2 recuperados de ovários de ovelhas, obtidos em frigoríficos, foram cultivados, por 24 horas a 38,5ºC e atmosfera com 5% de CO2, em meio de maturação constituído por TCM 199 suplementado com 0,1UI/mL de FSH; 0,1UI/mL de LH; 0,3mM de piruvato; 75µg/mL de penicilina/estreptomicina; 10% SFB e 100µM/mL de cisteamina (Grupo Controle) acrescido de 100μM de roscovitina ou 1μg/mL de ciclohexemida (Grupos Tratamentos). Para retomada e progressão da maturação nuclear, os COCs foram cultivados por mais 22 horas em meio de maturação livre de inibidores da meiose, nas mesmas condições acima descritas. Após 24 e 46 horas de cultivo in vitro, os COCs foram avaliados quanto à expansão das células cumulus em estereomicroscópio, quanto à maturação nuclear em microscópio de fluorescência e quanto à maturação citoplasmática, em microscópio eletrônico de transmissão. Foi constatado adequado bloqueio meiótico em 53,07% e 89,67% dos COCs tratados com roscovitina e ciclohexemida, respectivamente. Em ambos os tratamentos, o bloqueio meiótico foi reversível, com aproximadamente 60% dos oócitos em MII ao final de 46 horas de cultivo in vitro. No entanto, o tratamento com roscovitina inibiu de maneira irreversível a expansão do cumulus em aproximadamente 90% dos COCs e também afetou a ultraestrutura oocitária. Em contrapartida, no tratamento com ciclohexemida, 84,23% dos COCs apresentaram expansão total do cumulus ao final de 46 horas de cultivo in vitro, e houve adequada progressão da maturação citoplasmática, o que denota que a ciclohexemida confirmou a hipótese proposta no presente estudo / Abstract: This study aimed to evaluate and compare the efficiency and reversibility of meiotic inhibition promoted bv roscovitine and cycloheximide in ovine COCs in vitro cultured, as well as, to assess the effects of these inhibitors on the ultrastructure of COCs and on the cumulus cells expansion. To this, grades I and II COCs recovered from ovines ovaries, obtained from slaughterhouse, were cultured, for 24 hours at 38.5ºC in a 5% CO2 humidified air atmosphere, in a specific maturation medium consisting of TCM 199 supplemented with 0,1UI/mL FSH, 0,1UI/mL LH, 1µg/mL estradiol, 0,3mM sodium pyruvate, 75µg/mL penicillin/ streptomycin, 10% FBS and 100µM/mL cysteamine (Control Group) plus 100 μM roscovitine or 1μg/ml cycloheximide (Treatment Groups). For the resumption and progression of nuclear maturation, COCs were cultured for another 22 hours in maturation medium free of meiosis inhibitors in the same conditions (as described before). After 24 and 46 hours of in vitro culture, COCs were evaluated according to cumulus cells expansion under stereomicroscope, to nuclear maturation under fluorescence microscope and to cytoplasmic maturation under electronic transmission microscope. There was adequate meiotic arrest in 53,07% and 89,67% of COCs treated with roscovitine and cycloheximide, respectively. In both treatments, the meiotic arrest was reversible, with approximately 60% MII oocytes at the end of 46 hours of in vitro culture. However, treatment with roscovitine irreversibly inhibited the cumulus expansion by approximately 90% of COCs and also affected the ultrastructure of COC. In contrast, in the treatment with cycloheximide, 84,23% of COCs showed total cumulus expansion at the end of 46 hours of in vitro culture, and there was adequate progression of cytoplasmic maturation, which indicates that the cycloheximide confirmed the hypothesis proposed in this study / Orientador: Sony Dimas Bicudo / Coorientador: Fernanda da Cruz Landim e Alvarenga / Banca: Maria Denise Lopes / Banca: Yeda Fumie Watanabe / Mestre