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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Can the proliferative ability of chicken cardiomyocytes be assessed using flow cytometry?

Karlsson, Mathilda January 2016 (has links)
The study of the formation of new cardiac muscle cells during postnatal development is a relatively new field. During fetal development, new cells are formed as the heart grows. However, the proliferative ability of postnatal cardiomyocytes is still debated. While several studies have been made on mammals, less is known about the chicken cardiac cells and their postnatal proliferation. As almost all previous studies have used microscopy-based cell counting methods, there has been some limitations on accuracy and amounts of cells that could be counted. The aim of this study is to develop a method for using flow cytometry to analyze proliferative ability of chicken cardiomyocytes and to investigate if any postnatal proliferation exists. For this study, 4 weeks old Red Junglefowl (Gallus gallus) chickens were used for isolating cardiomyocytes. In addition, 19 days old Red Junglefowl embryos were used to asses if a longer incubation time would yield a higher number of proliferative cells. Cells were stained using a commercial EdU imaging kit and analyzed using flow cytometry and imaging flow cytometry. The produced results could not be used for determining the proliferative ability of the cardiomyocytes, but provides crucial information for possible method improvements. In conclusion, this study has laid important groundwork for future studies on the proliferative ability of chicken cardiomyocytes.
22

Social environment influences impulsivity in red junglefowl (Gallus gallus) chicks

Andersson, Emelie January 2019 (has links)
Cognition (i.e. how individuals perceive, process and react to environmental cues) is fundamental to all animals’ life. Despite this, what explains variation in cognitive abilities is still mainly unclear. Environment is assumed to influences cognitive variation, but the mechanisms for this are still unknown. According to the social intelligence hypothesis, living in a group with a rich social environment, generate challenges that can enhance cognitive abilities. Impulsivity (to not be able to inhibit impulses), one aspect of cognition, may be influenced by the social environment, however this has not yet been experimentally tested. Impulsivity can complicate life, both for humans and animals. In humans, high levels of impulsivity and lack of self-control are associated with addictions and psychiatric disorders, thus is considered to be maladaptive. In animals, impulsivity correlates with stereotypies. To improve our understanding of impulsivity, I experimentally investigated how early social environment affects individual variation in impulsivity. To test this, red junglefowl chicks were used because their group living nature, and our accumulated knowledge on their cognition and behaviour. To manipulate the social environment, chicks either grew up in larger groups (with 17 individuals) or smaller groups (with 7 individuals). During the chicks’ first five weeks of life, three aspects of impulsivity were tested; impulsive action, persistence (in a detour reaching test) and routine formation (in a reversal learning test). Chicks that grew up in larger groups tended to perform less impulsive actions, while social environment did not explain variation in persistence. Chicks from larger groups had less strong routine formation compared to chicks raised in smaller groups. This partially supports the social intelligence hypothesis, and suggest that early social life can affect cognitive traits and explain individual variation in such.
23

Identificação e análise de etiquetas de seqüências expressas (ESTs) na hipófise e hipotálamo de Gallus gallus / Identification and characterization of expressed sequence tags (ESTs) in pituitary and hypothalamus in Gallus gallus

Cassoli, Clarissa Sanches da Silva 25 April 2007 (has links)
A avicultura brasileira tem alcançado altos índices de desempenho na produção de carne e ovos, como resultado da atualização constante de tecnologias no setor. A biotecnologia vem contribuindo nesse sentido, atuando especialmente em programas de seleção de animais com maior potencial de desenvolvimento e crescimento. Como toda a fisiologia animal é controlada direta e/ou indiretamente pela hipófise e hipotálamo, este trabalho propôs identificar e analisar genes expressos nestas estruturas de galinhas de duas linhagens divergentes quanto ao potencial de crescimento e avaliar a expressão dos genes correspondentes a transcritos cuja identidade não pôde ser revelada (sem similar nos bacos de dados), uma vez que estes podem representar possíveis genes novos. Para isto, foram construídas e analisadas bibliotecas a partir da hipófise e hipotálamo de aves de 21 dias de idade de uma linha macho de corte (TT) e uma linhagem de postura (CC), provenientes da Embrapa Suínos e Aves. Um total de 4.286 ESTs válidas foi obtido (no mínimo150 pb com qualidade PHRED acima de 20), correspondendo a 2.133 ESTs da biblioteca da linhagem TT e 2.153 ESTs da biblioteca da linhagem CC. O exercício de montagem, via programa Cap3, revelou 3.074 seqüências únicas, sendo 1.643 da biblioteca da linhagem TT e 1.649 da CC. Estas seqüências únicas foram automaticamente classificadas, de acordo com as categorias do GeneOntology, sendo que as seqüências de ambas as bibliotecas apresentaram uma distribuição similar entre os termos. Após montagem das ESTs e análise do padrão de expressão digital das seqüências constituintes, dos 389 contigs obtidos, 194 foram compostos por seqüências diferencialmente expressas entre as bibliotecas. Foram detectados 28 contigs contendo SNPs linhagem específicos, sendo 52 SNPs TT específicos e 25 CC específicos. Um total de 146 ESTs não pôde ter sua identidade revelada, porém destas, 133 puderam ser localizadas no genoma da galinha e apresentaram pelo menos uma fase de leitura aberta (ORF). Após análise de expressão gênica, os genes correspondentes a 78 destas ESTs sem identidade apresentaram-se diferencialmente expressos entre pelo menos dois dos tecidos de aves de uma linhagem comercial de corte de 21 dias de idade estudados: hipófise, hipotálamo, cérebro, fígado e músculo. Os resultados apresentados são promissores e merecem ser investigados em estudos futuros com o objetivo de identificar marcadores moleculares para programas de seleção e melhoramento animal. / The brazilian aviculture has reached a high development level in both meat and egg production as a result of constant technological atualization in the sector. Biotechnology can contribute in this way acting in selection programs of animals that show higher growth and development potential. The global animal physiology is direct or indirectly controlled by pituitary and hypothalamus. The aim of this work was to identify and analyse genes expressed in these structures of two divergent line chickens according to growth potential and evaluate the gene expression of corresponding transcripts classified as "no hit", once these ESTs could represent new genes. In this way, two pituitary and hypothalamus libraries of 21 days broiler (TT) and a layer (CC) chickens supplied by Embrapa Swine and Poultry National Research Center were constructed and analysed. A total of 4,286 valid ESTs was obtained (showing at least 150 bp with PHRED quality above 20) corresponding to 2,133 ESTs of TT line library and 2,153 ESTs of CC line library. The clustering process by Cap3 resulted in 3,074 unique sequences corresponding to 1,643 TT library sequences and 1,649 of CC sequences. These unique sequences were automatically annotated according GeneOntology categories and both library sequences showed a similar distribution between the terms. After ESTs clustering and northern digital analysis, 389 contigs were obtained – 194 of them showed differentially expressed sequences between the libraries. A total of 28 contigs showed line specific SNPs, corresponding to 52 TT specific SNPs and 25 CC specific SNPs. 146 ESTs were classified as "no hit" but 133 of these sequences were localized in chicken genome and showed open reading frame (ORF). After gene expression analysis, the genes of 78 "no hit" ESTs showed different expression level between the five tissues of commercial broilers with 21 days old: pituitary, hypothalamus, brain, liver and muscle. These results are promising and must be more investigated in future studies to identify molecular markers for use in animal selection and improvement programs.
24

Foraging and exploratory behaviour in Red Junglefowl (<em>Gallus gallus</em>) selected for fear of humans

Walett, Emma January 2010 (has links)
<p>Domestication is a process in which animals become adapted to a life among humans by means of selection. A reduced fear of humans is probably one of the first aims of selection, intentionally or unintentionally. Animals that have undergone the process of domestication have a different appearance than animals in the wild (domestic phenotype) and behave in a different way towards humans. In this study I have looked at foraging and explorative behaviours in an unselected parental generation of red junglefowl and their offspring. The parental generation were bred in three lines, a high line, with birds displaying a strong fear of humans, an intermediate line, birds showing a modest fear, and one low line, with birds performing a more tame behaviour towards humans. I presented the birds with three different feeding alternatives, familiar chicken food, meal worms camouflaged with wood shavings and just wood shavings. I counted number of pecks in the different food options, number of changes between sites and how many sites a bird visited. The results show that females of both generations were more explorative than males, by pecking more in cups of meal worms hidden in wood shavings whereas the males pecked more in cups containing chicken food. Females also moved around more in the arena. Results from the first selected generation show significant differences between the selection lines among the females, with females from the high and low groups being the most explorative.</p>
25

Behavioural aspects of conservation breeding : Red junglefowl (Gallus gallus) as a case study

Håkansson, Jennie January 2007 (has links)
Ett stort antal utrotningshotade djurarter ingår idag i bevarandeprogram världen över. Små populationer hålls då i skyddade miljöer, exempelvis i djurparker, och i många fall är målet att återintroducera djur till naturen. Dessvärre är det vanligt att det uppstår problem när djur återintroduceras vilket kan bero på beteendemässiga anpassningar som uppkommit under tiden i fångenskap. Syftet med den här studien var därför att undersöka beteendemässiga aspekter på bevarandeavel och försöka ta reda på om och hur djur påverkas beteendemässigt av att hållas i skyddade fångenskapsmiljöer. I projektet användes röda djungelhöns (Gallus gallus) som en fallstudie. En granskning av beteendevariation mellan olika populationer av röda djungelhöns i fångenskap konstaterade skillnader i antipredatorbeteende, socialt beteende och födosöksbeteende. Vid en genetisk studie av samma populationer upptäcktes dessutom ett samband mellan genetisk diversitet och beteendevariation som potentiellt kan vara intressant ur ett bevarandeperspektiv. Socialt beteende, födosöksbeteende och olika aspekter av rädsla studerades vidare i populationer med olika bakgrund som fick växa upp tillsammans i en grupp. Resultaten visade att populationerna bara skilde sig åt i rädslebeteenden vilket antyder att denna typ av beteende i större utsträckning påverkas av långvarig avel i en viss fångenskapsmiljö medan socialt beteende och födosöksbeteende istället kan bero på den omedelbara sociala eller fysiska miljön. Antipredatorbeteende studerades också i en longitudinell studie av två populationer över fyra generationer och det visade sig att populationerna blev mer lika varandra ju längre tiden gick då de hölls under likadana miljöförhållanden. Det verkar alltså som om antipredatorbeteende kan förändras av avel i en viss miljö efter bara ett fåtal generationer. Utöver detta studerades även dagliga beteendemönster i olika djurparksmiljöer samt dygnsrytm av galanden hos både vilda populationer och djurparkspopulationer inom artens naturliga utbredningsområde. Resultaten tyder på att sådana beteendemönster inte påverkas nämnvärt av att djur hålls i fångenskap. Fallstudien som presenteras här är ett av de första försöken att, ur ett bevarandeperspektiv, studera hur fångenskapsmiljöer kan påverka djurs beteende och resultaten talar för att dessa aspekter är viktiga att ta hänsyn till vid planering av bevarandeavel. / A number of endangered species are currently involved in conservation breeding programs worldwide. Conservation breeding deals with propagation of captive populations, often with the ultimate aim of releasing animals into the wild. However, an alarmingly high proportion of reintroductions have not been successful in establishing viable populations, possibly due to behavioural problems caused by genetic adaptation to captivity. The main aim of this thesis was to study behavioural aspects of conservation breeding and investigate whether, and how, maintenance of small populations in captivity cause behavioural modifications, which could affect the success of reintroductions. Throughout the project, the red junglefowl (Gallus gallus) was used as a case study, representing animals maintained in captive populations. A screening of behavioural variation revealed that captive populations differ in antipredator, social and exploratory behaviours, all of which are central components of life in the wild. A correlation was also found between genetic diversity and behavioural variation. This has not been reported before and may potentially have interesting implications for conservation breeding. When studying the behaviour of populations with different backgrounds being raised together as one group, the results suggested that fear-related behaviours may be more affected by long-term breeding in a certain captive environment than social and exploratory behaviours which seem to be more influenced by the immediate social or physical environment. A longitudinal study of antipredator behaviour in two populations across four generations revealed that the populations became more similar over time when maintained under identical conditions. This demonstrates that effects of a new environment can appear after only a few generations. Furthermore, daily behavioural routines in different captive environments as well as diurnal crowing rhythms in both wild and captive populations were studied in the species’ natural region of distribution and the results suggest that such behavioural patterns are not affected by the captive environments to any notable extent. The present case study is one of the first attempts to, from a conservation perspective, study how captive environments can affect behaviour and the results imply that these aspects are important to take into consideration in conservation breeding programs.
26

Tonic immobility and effects of early stress on chickens (Gallus gallus)

Hjelm, Jonas January 2010 (has links)
Tonic immobility, TI, is an innate fear response in many vertebrate animals, induced by brief physical restraint. It is a widespread theory that chickens (Gallus gallus) reared under stressful conditions react stronger in tonic immobility tests, i.e. stay still and lay still for a longer period of time, than individuals reared under more stress-free conditions. In our study we attempted to see if stressful conditions early in life (temporary isolation from the flock on a daily basis) had any effect on how the individuals handled the stressful and fear-evoking experience of tonic immobility tests. A total of 77 chickens of the HyLine strain of White Leghorn were used. Three sets of tests were performed; first at the hatchery facility at Linköpings universitet; second after a stressful experience – the moving to the Wood-Gush facility at Vreta jordbruksgymnasium; and a random sample with about half of the birds the third time, also at Vreta. The results were inconclusive, but pointed more in the direction of the early-in-life stress having no effect on TI tests rather than the other way around.
27

Foraging and exploratory behaviour in Red Junglefowl (Gallus gallus) selected for fear of humans

Walett, Emma January 2010 (has links)
Domestication is a process in which animals become adapted to a life among humans by means of selection. A reduced fear of humans is probably one of the first aims of selection, intentionally or unintentionally. Animals that have undergone the process of domestication have a different appearance than animals in the wild (domestic phenotype) and behave in a different way towards humans. In this study I have looked at foraging and explorative behaviours in an unselected parental generation of red junglefowl and their offspring. The parental generation were bred in three lines, a high line, with birds displaying a strong fear of humans, an intermediate line, birds showing a modest fear, and one low line, with birds performing a more tame behaviour towards humans. I presented the birds with three different feeding alternatives, familiar chicken food, meal worms camouflaged with wood shavings and just wood shavings. I counted number of pecks in the different food options, number of changes between sites and how many sites a bird visited. The results show that females of both generations were more explorative than males, by pecking more in cups of meal worms hidden in wood shavings whereas the males pecked more in cups containing chicken food. Females also moved around more in the arena. Results from the first selected generation show significant differences between the selection lines among the females, with females from the high and low groups being the most explorative.
28

Heart and ventilation rate changes during tonic immobility in Ornate Tinamou (Nothoprocta ornata) and High Andean chicken (Gallus gallus) compared to Chilean Tinamou (Nothoprocta perdicaria)

Greder, Cecilia Alexis January 2015 (has links)
Animals can show different responses to fear for example by playing dead when there is no possibility to escape. This response is called tonic immobility (TI) and is a well-established test of fear to evaluate fearfulness. Long durations of TI are generally considered as high levels of fearfulness. Physiological changes observed during tonic immobility suggest that there are changes in the autonomic nervous system (ANS) strongly involved in this process. The main objective for this study was to analyse duration of tonic immobility and heart and ventilation rate during tonic immobility in three different species; domesticated High Andean chickens (Gallus gallus), wild-caught Ornate Tinamous (Nothoprocta ornata) and Chilean Tinamous born in captivity (Nothoprocta perdicaria). In this study needle electrodes were used to measure heart and ventilation rate. The time following induction of tonic immobility (i.e. after holding the bird on its back for 15 s) was characterized by a large increase in heart and ventilation rate. During tonic immobility a progressive decrease in heart and ventilation rate was observed in all species, significant in all cases except for heart rate between start and end of TI in chickens. The duration of TI was significantly longer in Ornate Tinamou compared to Chilean Tinamou and chickens. The same was observed in latency to first head movement. TI is probably controlled by the autonomic nervous system, but a heart rate variability analysis has to be done in order to determine the different relative contributions of the sympathetic and parasympathetic systems in these species.
29

Mapeamento de locos de características quantitativas associados a desempenho e carcaça nos cromossomos 11 e 13 de Gallus gallus /

Boschiero, Clarissa. January 2006 (has links)
Orientador: Ana Sílvia Alves Meira Tavares Moura / Banca: Heraldo César Gonçalves / Banca: Mônica Corrêa Ledur / Resumo: O objetivo deste trabalho foi identificar locos controladores de características quantitativas (QTLs) nos cromossomos 11 e 13 de galinhas (Gallus gallus) para características de desempenho e carcaça. A partir do cruzamento entre uma linhagem de corte e uma de postura, foi gerada a população experimental F2 na Embrapa Suínos e Aves. Foram avaliadas as seguintes informações fenotípicas: peso ao nascer, peso aos 35, 41 e 42 dias, ganho de peso, consumo de ração, eficiência e conversão alimentar dos 35 aos 41 dias e valores de hematócrito. As carcaças foram evisceradas e avaliados: o comprimento do intestino, peso dos pulmões, do fígado, do coração e da moela. Foram obtidos após quatro horas de resfriamento: peso da carcaça, gordura abdominal, peso de partes: peito, coxas, dorso, asas, cabeça e pés. Quatro e cinco marcadores microssatélites dos cromossomos 11 e 13, respectivamente, foram genotipados num total aproximado de 330 animais F2 em quatro famílias de irmãos-completos. Os mapas de ligação para ambos os cromossomos foram construídos e a análise de mapeamento de QTLs baseada no modelo genético de F2 foi realizada. No cromossomo 11 foram mapeados dois QTLs sugestivos: para peso de pés e de moela, ambos posicionados no intervalo entre ADL0123 e ADL0210. No cromossomo 13 foi mapeado um QTL sugestivo para peso de coração posicionado no intervalo entre MCW0110 e MCW0104. / Abstract: The objective of this study was to identify quantitative trait loci (QTLs) for performance and carcass traits in chicken (Gallus gallus) chromosomes 11 and 13. From the crossbreeding of a broiler and a layer line, an F2 experimental population was generated at the Embrapa Suínos e Aves. The following phenotypic data were recorded: body weights at birth, 35, 41 and 42 d; weight gain, feed consumption and feed conversion from 35 to 41 d; weights of carcass, carcass parts, organs and abdominal fat, hematocrit and length of intestine. Four and five microsatellite markers from chromosomes 11 and 13, respectively, were genotyped in approximately 330 F2 chickens from four full-sib families. The linkage maps for both chromosomes were constructed and the QTL mapping analyses were carried out based on an F2 genetic model. Two suggestive QTLs were mapped to chromosome 11: for feet and gizzard weights, both located in the interval between ADL0123 and ADL0210. On chromosome 13 one suggestive QTL for heart weight was detected in the interval between MCW0110 and MCW0104. / Mestre
30

Identificação e análise de etiquetas de seqüências expressas (ESTs) na hipófise e hipotálamo de Gallus gallus / Identification and characterization of expressed sequence tags (ESTs) in pituitary and hypothalamus in Gallus gallus

Clarissa Sanches da Silva Cassoli 25 April 2007 (has links)
A avicultura brasileira tem alcançado altos índices de desempenho na produção de carne e ovos, como resultado da atualização constante de tecnologias no setor. A biotecnologia vem contribuindo nesse sentido, atuando especialmente em programas de seleção de animais com maior potencial de desenvolvimento e crescimento. Como toda a fisiologia animal é controlada direta e/ou indiretamente pela hipófise e hipotálamo, este trabalho propôs identificar e analisar genes expressos nestas estruturas de galinhas de duas linhagens divergentes quanto ao potencial de crescimento e avaliar a expressão dos genes correspondentes a transcritos cuja identidade não pôde ser revelada (sem similar nos bacos de dados), uma vez que estes podem representar possíveis genes novos. Para isto, foram construídas e analisadas bibliotecas a partir da hipófise e hipotálamo de aves de 21 dias de idade de uma linha macho de corte (TT) e uma linhagem de postura (CC), provenientes da Embrapa Suínos e Aves. Um total de 4.286 ESTs válidas foi obtido (no mínimo150 pb com qualidade PHRED acima de 20), correspondendo a 2.133 ESTs da biblioteca da linhagem TT e 2.153 ESTs da biblioteca da linhagem CC. O exercício de montagem, via programa Cap3, revelou 3.074 seqüências únicas, sendo 1.643 da biblioteca da linhagem TT e 1.649 da CC. Estas seqüências únicas foram automaticamente classificadas, de acordo com as categorias do GeneOntology, sendo que as seqüências de ambas as bibliotecas apresentaram uma distribuição similar entre os termos. Após montagem das ESTs e análise do padrão de expressão digital das seqüências constituintes, dos 389 contigs obtidos, 194 foram compostos por seqüências diferencialmente expressas entre as bibliotecas. Foram detectados 28 contigs contendo SNPs linhagem específicos, sendo 52 SNPs TT específicos e 25 CC específicos. Um total de 146 ESTs não pôde ter sua identidade revelada, porém destas, 133 puderam ser localizadas no genoma da galinha e apresentaram pelo menos uma fase de leitura aberta (ORF). Após análise de expressão gênica, os genes correspondentes a 78 destas ESTs sem identidade apresentaram-se diferencialmente expressos entre pelo menos dois dos tecidos de aves de uma linhagem comercial de corte de 21 dias de idade estudados: hipófise, hipotálamo, cérebro, fígado e músculo. Os resultados apresentados são promissores e merecem ser investigados em estudos futuros com o objetivo de identificar marcadores moleculares para programas de seleção e melhoramento animal. / The brazilian aviculture has reached a high development level in both meat and egg production as a result of constant technological atualization in the sector. Biotechnology can contribute in this way acting in selection programs of animals that show higher growth and development potential. The global animal physiology is direct or indirectly controlled by pituitary and hypothalamus. The aim of this work was to identify and analyse genes expressed in these structures of two divergent line chickens according to growth potential and evaluate the gene expression of corresponding transcripts classified as &#34;no hit&#34;, once these ESTs could represent new genes. In this way, two pituitary and hypothalamus libraries of 21 days broiler (TT) and a layer (CC) chickens supplied by Embrapa Swine and Poultry National Research Center were constructed and analysed. A total of 4,286 valid ESTs was obtained (showing at least 150 bp with PHRED quality above 20) corresponding to 2,133 ESTs of TT line library and 2,153 ESTs of CC line library. The clustering process by Cap3 resulted in 3,074 unique sequences corresponding to 1,643 TT library sequences and 1,649 of CC sequences. These unique sequences were automatically annotated according GeneOntology categories and both library sequences showed a similar distribution between the terms. After ESTs clustering and northern digital analysis, 389 contigs were obtained &#150; 194 of them showed differentially expressed sequences between the libraries. A total of 28 contigs showed line specific SNPs, corresponding to 52 TT specific SNPs and 25 CC specific SNPs. 146 ESTs were classified as &#34;no hit&#34; but 133 of these sequences were localized in chicken genome and showed open reading frame (ORF). After gene expression analysis, the genes of 78 &#34;no hit&#34; ESTs showed different expression level between the five tissues of commercial broilers with 21 days old: pituitary, hypothalamus, brain, liver and muscle. These results are promising and must be more investigated in future studies to identify molecular markers for use in animal selection and improvement programs.

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