Digitized by Kansas Correctional Industries

Orientador: Flávia Lombardi Lopes / Resumo: Os microRNAs (miRNAs) são pequenos RNAs não-codificadores (20-22 nucleotídeos) que exercem uma função de controle pós-transcricional em RNA mensageiro (RNAm), regulando a produção de proteínas. Variações genéticas, como os polimorfismos de nucleotídeo único (SNPs), quando estão presentes em sequências de miRNA, podem alterar o controle pós-transcricional, baseado em similaridade aos seus respectivos alvos. Na produção de suínos, a identificação de fenótipos, como crescimento e características da carne, é vital. Nosso objetivo foi identificar SNPs em sequências genômicas que dão origem a miRNAs, bem como investigar, in silico, possíveis alterações na regulação de alvos que poderiam estar relacionados a fenótipos de produção em suínos. A montagem do assembly Sscrofa10.2 foi utilizada como genoma de referência para a localização dos SNPs e dos miRNAs descritos em suínos. Utilizando um script desenvolvido em Python, foi possível localizar 86 SNPs em sequencias miRNAs maduros. Para a predição dos genes alvos, foram utilizados sequência do 3´UTR de suínos com a adaptação do pacote Mirmap. Descobrimos que 55 das sequências de miRNA geraram mais de 28.570 genes alvos, indicando a criação de novos miRNAs Interagindo com RNAm alvos. Nossos resultados indicam que SNPs afetam a predição de alvos para miRNAs em suínos. / Abstract: The microRNAs (miRNAs) are small non-coding RNAs (20-22 nucleotides) that exert a post-transcriptional control function in messenger RNA (mRNA), regulating the production of proteins. Genetic variations, such as single nucleotide polymorphisms (SNPs), when present in miRNA sequences, may change post-transcriptional control, based on similarity to their target genes. Pig production, identification of phenotypes, growth and meat characteristics is vital. Other in which SNPs in genetic sequences that give from miNNAs, as well as investigate, in silicon, changes in the data of alves, which are behaviert on a phenotypes of production in swines. The assembly of the Sscrofa10.2 assembly was used as a reference reference for the location of SNPs and panel miRNAs in swine. Using a script deployed in Python, it was possible to locate 86 SNPs in mature miRNAs sequences. For a prediction of the target genes, the 3'UTR of pigs were completed with an adaptation of the Mirmap package. Discoveries that 55 of the miRNA sequences generated more than 28,570 target genes, pointing to a new creation of miRNAs interacting with mRNA targets. Cloister all SNPs for a target prediction for miRNAs in pigs. / Mestre

Typescript (photocopy). Thesis submitted under title: Biochemical aspects of early pregnancy in the pig; but doctorate conferred to title: Biochemical aspects of early pregnancy in the sow Includes bibliographical references (leaves 178-205) and list of personal publications related to pig physiology (leaves vi-vii) Examines aspects of early pregnancy in pigs, aimed to identify determinants of the high level of embryonic mortality which occurs prior to implantation

Thesis (M.S.)--Ohio State University, 1983. / Includes bibliographical references (leaves 84-85). Available online via OhioLINK's ETD Center

Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 7, 2007) Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 9, 2007) Includes bibliographical references.

Little information exists on the nutrient composition and value of wheat millrun as an opportunity feedstuff for swine. The nutritional value of millrun and ways to improve it were investigated in 4 studies. In Chapter 1, 2 experiments were conducted to determine if dietary enzymes increased the digestibility of nutrients bound by non-starch polysaccharides (NSP) and phytate in millrun and consequently improved performance. Xylanase improved (P < 0.05) total tract energy digestibility, DE content and G:F. Phytase reduced (P < 0.05) ADFI, and xylanase tended to reduce (P = 0.07) ADFI. In Chapter 2, effects of xylanase on nutrient digestibility were studied in a wheat control diet and 5 diets containing 30% by-product (millrun, middlings, shorts, screenings, and bran). Xylanase improved (P < 0.05) total tract energy digestibility of the millrun, shorts, screenings, and bran diets. Xylanase did not affect hindgut fermentation but reduced (P < 0.05) hindgut fermentable DE. In Chapter 3, effects of supplementing xylanase and (or) phytase on nutrient digestibility, digesta passage rate and mean digesta retention time (MRT) of a wheat-based diet containing 20% millrun were investigated. The enzymes interacted to increase (P < 0.05) total tract nutrient digestibility and DE content of the negative control diet, but did not affect passage rate and MRT. In Chapter 4, effects of xylanase and phytase supplementation on site of nutrient digestibility in weaned pigs, pH content in the gastrointestinal tract and on growth performance were studied in diets with reduced nutrient specifications (negative control: NC). Xylanase improved (P < 0.01) energy digestibility of the NC in the mid jejunum and over the total tract by 63.0 and 4.6%, respectively. Diet tended to reduce (P = 0.074) the pH content of the upper small intestine, and phytase raised (P < 0.01) the pH content of the upper mid small intestine. Both enzymes improved total tract DE content and performance of weaned pigs. Phytase inclusion led to a more rapid return to alkaline conditions in the upper part of the small intestine. In conclusion, the nutritional value of millrun can be improved with exogenous enzymes thereby improving its status as an opportunity feedstuff in swine diets.

Swine influenza (SI) is an acute, highly contagious, respiratory disease of swine. The causative agent of SI infections is swine influenza virus (SIV). SIV is a type A influenza virus classified into the Orthomyxoviridae family and is an enveloped particle with a genome composed of eight negative-orientated RNA segments.<p> The mortality rate of influenza disease in pigs is generally low but morbidity can reach up to 100%. SI infections considerably contribute to respiratory disease in post-weaning pigs, causing significant economic losses due to an increase in the number of days pigs need to reach market weight. In addition, SI infections possess significant human public health concerns. Vaccination is the primary method for the prevention of SI. Currently available vaccines against SI are a combination of two inactivated antigenically distinct SIVs with oil adjuvant. The application of these vaccines induce mainly humoral immune responses. In contrast, application of live attenuated influenza vaccines (LAIV) mimics natural infection and induce strong, long-lived cell-mediated and humoral immunity. Furthermore, LAIV induces cross-protective immunity against different subtypes of influenza A viruses. LAIVs are developed for human and equine influenza viruses but at present no LAIV is available for SIVs.<p> The critical step in influenza virus infection is an initial interaction between virus and cell surface carbohydrates followed by receptor-mediated endocytosis and fusion of the viral and endosomal membranes. Influenza virus entry into cells is mediated by the viral surface glycoprotein hemagglutinin (HA). HA is primary synthesized as a polypeptide in HA0 form. In order to be infectious, HA0 must be cleaved by host proteases into HA1 and HA2 subunits. Therefore, this process is crucial determinant for virus pathogenicity.<p> Our objective was to generate a live attenuated SIVs, particularly a viruses with a modified HA cleavage site resistant to activation during natural infection but which can be activated in vitro by an exogenous protease. Using the reverse genetics technique, we generated two mutant SIVs of strain A/SW/SK/18789/02 (H1N1) containing a modified cleavage site within their HA. Mutant A/SW/SK-R345V (R345V) contained a mutation within HA segment at amino acid (AA) position 345 from Arginine (Arg) to Valine (Val) while the second mutant, A/SW/SK-R345A (R345A) encoded Alanine (Ala) instead of Arginine (Arg) at position AA345 on HA. We showed that HA cleavage in both mutants was strictly dependent on the presence of human neutrophil elastase in tissue culture. These tissue-culture grown mutant SIVs showed similar growth properties in terms of plaque size and growth kinetics, compared to the wild type virus. Both mutant SIVs were able to preserve introduced mutations after multiple passages in tissue culture suggesting that AA substitution within HA cleavage site did not alter genetic stability in the presence of appropriate protease. Furthermore, these mutant SIVs were highly attenuated in pigs but capable of inducing significant cell-mediated and humoral immune responses after two vaccinations via intratracheal (IT) and intranasal (IN) routes. Immune responses induced by vaccination with elastase dependent SIV were sufficient to confer full protection against parental homologous and antigenic variant of H1N1 SIVs and partial protection from heterologous subtypic H3N2 after the challenge. Therefore, elastase-dependent mutant SIV could serve as live vaccine against antigenically distinct swine influenza viruses in pigs.

Little information exists on the nutrient composition and value of wheat millrun as an opportunity feedstuff for swine. The nutritional value of millrun and ways to improve it were investigated in 4 studies. In Chapter 1, 2 experiments were conducted to determine if dietary enzymes increased the digestibility of nutrients bound by non-starch polysaccharides (NSP) and phytate in millrun and consequently improved performance. Xylanase improved (P < 0.05) total tract energy digestibility, DE content and G:F. Phytase reduced (P < 0.05) ADFI, and xylanase tended to reduce (P = 0.07) ADFI. In Chapter 2, effects of xylanase on nutrient digestibility were studied in a wheat control diet and 5 diets containing 30% by-product (millrun, middlings, shorts, screenings, and bran). Xylanase improved (P < 0.05) total tract energy digestibility of the millrun, shorts, screenings, and bran diets. Xylanase did not affect hindgut fermentation but reduced (P < 0.05) hindgut fermentable DE. In Chapter 3, effects of supplementing xylanase and (or) phytase on nutrient digestibility, digesta passage rate and mean digesta retention time (MRT) of a wheat-based diet containing 20% millrun were investigated. The enzymes interacted to increase (P < 0.05) total tract nutrient digestibility and DE content of the negative control diet, but did not affect passage rate and MRT. In Chapter 4, effects of xylanase and phytase supplementation on site of nutrient digestibility in weaned pigs, pH content in the gastrointestinal tract and on growth performance were studied in diets with reduced nutrient specifications (negative control: NC). Xylanase improved (P < 0.01) energy digestibility of the NC in the mid jejunum and over the total tract by 63.0 and 4.6%, respectively. Diet tended to reduce (P = 0.074) the pH content of the upper small intestine, and phytase raised (P < 0.01) the pH content of the upper mid small intestine. Both enzymes improved total tract DE content and performance of weaned pigs. Phytase inclusion led to a more rapid return to alkaline conditions in the upper part of the small intestine. In conclusion, the nutritional value of millrun can be improved with exogenous enzymes thereby improving its status as an opportunity feedstuff in swine diets.

Swine influenza (SI) is an acute, highly contagious, respiratory disease of swine. The causative agent of SI infections is swine influenza virus (SIV). SIV is a type A influenza virus classified into the Orthomyxoviridae family and is an enveloped particle with a genome composed of eight negative-orientated RNA segments.<p> The mortality rate of influenza disease in pigs is generally low but morbidity can reach up to 100%. SI infections considerably contribute to respiratory disease in post-weaning pigs, causing significant economic losses due to an increase in the number of days pigs need to reach market weight. In addition, SI infections possess significant human public health concerns. Vaccination is the primary method for the prevention of SI. Currently available vaccines against SI are a combination of two inactivated antigenically distinct SIVs with oil adjuvant. The application of these vaccines induce mainly humoral immune responses. In contrast, application of live attenuated influenza vaccines (LAIV) mimics natural infection and induce strong, long-lived cell-mediated and humoral immunity. Furthermore, LAIV induces cross-protective immunity against different subtypes of influenza A viruses. LAIVs are developed for human and equine influenza viruses but at present no LAIV is available for SIVs.<p> The critical step in influenza virus infection is an initial interaction between virus and cell surface carbohydrates followed by receptor-mediated endocytosis and fusion of the viral and endosomal membranes. Influenza virus entry into cells is mediated by the viral surface glycoprotein hemagglutinin (HA). HA is primary synthesized as a polypeptide in HA0 form. In order to be infectious, HA0 must be cleaved by host proteases into HA1 and HA2 subunits. Therefore, this process is crucial determinant for virus pathogenicity.<p> Our objective was to generate a live attenuated SIVs, particularly a viruses with a modified HA cleavage site resistant to activation during natural infection but which can be activated in vitro by an exogenous protease. Using the reverse genetics technique, we generated two mutant SIVs of strain A/SW/SK/18789/02 (H1N1) containing a modified cleavage site within their HA. Mutant A/SW/SK-R345V (R345V) contained a mutation within HA segment at amino acid (AA) position 345 from Arginine (Arg) to Valine (Val) while the second mutant, A/SW/SK-R345A (R345A) encoded Alanine (Ala) instead of Arginine (Arg) at position AA345 on HA. We showed that HA cleavage in both mutants was strictly dependent on the presence of human neutrophil elastase in tissue culture. These tissue-culture grown mutant SIVs showed similar growth properties in terms of plaque size and growth kinetics, compared to the wild type virus. Both mutant SIVs were able to preserve introduced mutations after multiple passages in tissue culture suggesting that AA substitution within HA cleavage site did not alter genetic stability in the presence of appropriate protease. Furthermore, these mutant SIVs were highly attenuated in pigs but capable of inducing significant cell-mediated and humoral immune responses after two vaccinations via intratracheal (IT) and intranasal (IN) routes. Immune responses induced by vaccination with elastase dependent SIV were sufficient to confer full protection against parental homologous and antigenic variant of H1N1 SIVs and partial protection from heterologous subtypic H3N2 after the challenge. Therefore, elastase-dependent mutant SIV could serve as live vaccine against antigenically distinct swine influenza viruses in pigs.