Immature chick oviducts differentiate in vivo in response to daily injections of DES. This is indicated by increases in general oviduct protein nitrogen: DNA ratios and the production of immunologically precipitable ovalbumin. Three types of ovalbumin are produced in response to estrogen. These results indicate that ovalbumin free of phosphorus appears first in the oviduct tissue in response to DES. The appearance of phosphorus containing ovalbumin follows. Attempts were made to induce the in vitro differentiation of oviduct tissue under a variety of culture conditions. A standard culture media was supplemented with DES and serum (fetal calf, cockerel, laying hen, or chick serum) as well as serum from DES injected chicks. No changes were observed in the tissue histology nor in the production of the specific protein, ovalbumin, under the above conditions. Closely associated tissues such as kidneys, ovaries, mesentary or ureter tissue cultured with the oviduct tissue failed to elicite any detectible morphological and chemical changes in the latter. The addition of insulin or homogenized pituitaries from DES injected or non-injected chicks was ineffective as an inducer of differentiation in this system. Substituting 17 6-estradiol for DES as an inducer did not alter the results. Thus, with the exception of estrogen any factor(s) necessary for the in vivo differentiation of immature oviduct tissue remains unknown at this time. / Land and Food Systems, Faculty of / Graduate

Chicken pectoralis muscle was inoculated with Pseudomonas fragi and incubated at room temperature. Alterations in the nonprotein nitrogen, water-soluble protein nitrogen, and salt-soluble protein nitrogen fractions were studied and attempts were made to relate these changes to structural changes observed by scanning and transmission electron microscopy. A significant decrease in myofibrillar protein solubility was found in the inoculated muscle during the protein extract-ability study. Results of the gel filtration study indicated that proteolysis of the sarcoplasmic proteins occurred and that the nonprotein nitrogen fraction increased due to growth of P. fragi. Alterations were observed in the disc gel electrophoretic patterns of the sarcoplasmic and myofibrillar protein fractions. Arginine, threonine, serine, proline and tyrosine were selectively utilized by P. fragi. Scanning electron micrographs indicated that proteolysis of the endomysium occurred after 2 days of incubation at 25°C. Proteolysis of the endomysium became more extensive as incubation time increased. After 4 days of incubation the myofibrils showed evidence of disruption as a result of bacterial growth. Disruption of the muscle fiber was limited to a depth of 2 to 4 micrometers after 9 days of incubation. Bacteria were observed growing between the muscle fibers. Proteolysis was not as extensive in samples incubated at 5°C. Electron micrographs prepared from thin sections of myofibrils inoculated with P. fragi showed marked disruption of the myofibrils due to bacterial growth. A clear zone, devoid of structural detail, surrounded the bacterial cell. A region of disrupted tissue exists between the clear zone and intact myofibrils. Cellular protrusions were observed on the surface of the bacteria. / Land and Food Systems, Faculty of / Graduate

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Call number: LD2668 .T4 1961 M38

Call number: LD2668 .T4 1966 R264 / Master of Science

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