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Zugl.: Berlin, Freie Universiẗat, Diss., 2007.

Thesis (M.S.)--Florida State University, 2006. / Advisor: Guosheng Liu, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed Sept. 15, 2006). Document formatted into pages; contains vii, 45 pages. Includes bibliographical references.

Thesis. 1977. Sc.D.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Vita. / Bibliography : leaves 249-256. / Sc.D.

<p> An investigation of the effects of cumulus clouds on solar radiation was carried out during the 1977 field season at McMaster University, Hamilton. The measurement of total incoming solar radiation, direct beam radiation and the diffuse flux calculated as a residual, were used to draw inferences regarding the transmission properties of cumulus clouds, both on a daily basis and for different cloud fields, The diffuse flux, showing the greatest variability, was sub-divided into three components and each were evaluated under unobscured and obscured sun conditions. Measured values were compared with those derived for a model atmosphere.</p> / Thesis / Bachelor of Arts (BA)

Nos travaux de recherche ont consisté à étudier chez trois mammifères (la vache, la truie et la souris), la distribution des membres de la famille des protéines liées au X-fragile (protéines liant l'ARNm). Selon notre hypothèse, ces protéines seraient impliquées dans la formation et la fonction de transport des extensions cytoplasmique des cellules du cumulus vers l'ovocyte appelées projections transzonales (TZPs). L'étude de la présence de ces protéines (FMRP, FXR1P et FXR2P) dans l'ovaire a révélé une distribution selon le stade folliculaire. Nous avons observé une forte expression de FMRP dans les follicules primordiaux et primaires suivi d'une diminution de celle-ci à partir des follicules secondaires. Une expression faible mais stable de la protéine FXR2P le long de la folliculogenèse et une forte expression de la protéine FXR1P à partir du stade secondaire avec une compartimentation périnucléolaire. Nous avons également caractérisé la présence des protéines CYFIP1 comme ayant la même distribution que FMRP tout au long de la folliculogenèse. Le passage du follicule au stade secondaire étant marqué par la présence du réseau de TZPs, nous avons pu déduire un rôle de FMRP dans la formation des TZPs. Nous avons également pu observer que l'absence de FMRP aune incidence sur le réseau de TZPs en ce qu'elle entraîne l'immaturité de celui-ci. De plus, cette absence semble être en partie compensée par une augmentation de la protéine FXR2P mettant ainsi en évidence un processus essentiel à l'établissement de la compétence au développement supporté par l'infertilité des souris femelles double KO pour les gènes FMR1 et FXR2. Des trois protéines de la famille du X-fragile, FXR1P a été déterminé comme étant le plus abondant à l'intérieur des TZPs. Cette observation nous a permis de supposer une plus grande contribution de ce dernier au transport actif des transcrits. Ces travaux s'inscrivent dans une optique d'approfondissement des connaissances du rôle de soutien des cellules du cumulus. / Using three mammalian animal models (cow, pig, mouse), the focus of my work was to study the role and distribution of members of the Fragile X protein family (mRNA binding proteins) which we hypothesize as being implicated in the establishment and function of transzonal projections network (TZPs) which is a network formed by cytoplasmic extension of cumulus cells (CC) towards the oolemma (OO). Our results show an overall fluctuation in protein abundance during folliculogenesis. We observed high FMRP levels in primordial and primary follicles and declining of those levels in secondary follicles. FXR2P was weakly but stably detected in all stages of folliculogenesis. FXR1P was highly abundant and characterized by a perinucleolar localization starting from the secondary follicle stage. Finally, CYFIP1 showed a similar distribution to FMRP during folliculogenesis. One of the main physical differences of reaching the secondary follicle stage is the noticeable presence of TZP's network. The distribution of FMRP and CYFIP1 in folliculogenesis suggests a role for FMRP and CYFIP1 in the establishment of TZPs. In the absence of FMRP, the TZPs network was noticeably immature in appearance. The absence of FMRP also led to the up regulation of FXR2P in primordial and primary follicles proving that this family has an important role in the ovaries. This was further supported by evidence in the literature of infertility in the absence of both FMRP and FXR2P. Of the three the fragile X protein family members, FXR1P was the most abundant in TZPs suggesting that it is the likely one involved in active transport of mRNA granules from the cumulus cells to the oocyte. This work is part of an effort to deepen our knowledge of the supporting role of cumulus cells.

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During folliculogenesis, oocytes and cumulus cells undergo many morphological and physiological changes. Transcriptome data were produced from single oocytes and corresponding cumulus cells (CC) to infer the differences in the transcript abundance from fully grown versus growing phase oocytes and surrounding CC. Using cow ovaries from an abattoir, COC were collected from follicles ranging from 3 to 8 mm in diameter. Cumulus-oocyte complexes were incubated in the supravital stain brilliant cresyl blue (BCB) as a means of separating oocytes based on the growth phase. Fully developed oocytes remained stained and were categorized as BCB+, whereas oocytes in the growing phase were colorless and were categorized as BCB-. Following the classification, COC were used for in vitro embryo production. Blastocyst yield from COC classified as BCB+, BCB- and unstained controls were 20%, 14% and 16.5%, respectively (P=0.18). Transcriptome data were also produced from oocytes and cumulus cells from BCB+ and BCB- COC. Transcripts from one long non-coding gene were differentially abundant in fully grown oocytes compared to oocytes in the growing phase. Eleven protein-coding genes were differentially expressed in cumulus cells collected from COC containing growing and fully grown oocytes. The results indicate no significant variation of transcript abundance of protein-coding genes in oocytes and limited regulation of transcript abundance in cumulus cells relative to the oocyte's growth phase in mid to large antral follicles. / Master of Science / The implementation of assisted techniques for achieving pregnancy is becoming increasingly adopted in the production of agriculturally important animals. However, most artificial reproductive methods have limited success, including in vitro embryo production. While many factors can contribute to reduced pregnancy rates relative to natural breeding, the developmental competence of the female egg is one of the many limiting factors. During its residence within the ovary, until it is fertilized by sperm, the egg is surrounded by layers of supporting cells. The egg and somatic cells interact by exchanging micro and macromolecules, but there is limited knowledge of the dynamics involving this interaction. It also remains unclear how these connections aid the egg in proceeding through development. Using a blue stain, the eggs were separated based on their stage of maturation. Then I investigated the interaction of the egg and the surrounding cells by measuring gene transcripts, which are a proxy of cellular function. Changes in the transcript abundance in the egg's surrounding cells were identified, which may be related to the egg's ability to be fertilized and proceed through embryonic development.