Explaining the wide range of animal colouration in the natural world is a key issue in evolutionary biology. Bumble bees are often brightly coloured and show a range of colours and colour patterns in different species as well as considerable variation within species. The large garden bumble bee, Bombus ruderatus, is highly variable in its degree of black (melanic) colouration, with morphs ranging from the familiar yellow and black bands (banded) through intermediate forms to morphs that are totally melanic. The aim of this research was to determine what might be maintaining the colour polymorphism in populations of B. ruderatus in the South Island, New Zealand. Colouration of worker bees was measured using a digital photography method and found to be significantly different across sample sites. To look at potential adaptive functions of body colour in B. ruderatus, three hypotheses of thermoregulation, desiccation tolerance and Müllerian mimicry were tested by comparing patterns of variation in melanism to patterns of variation in climatic variables (temperature, rainfall, humidity) and abundance of conspecifics. In order to address the possibility that selectively neutral processes were more important than selection, the genetic structure of B. ruderatus populations was characterised and compared to the pattern of variation in melanism. The colouration of individuals from the same population collected at different times in the season was compared to evaluate whether body colour was plastic and any support for the genetic basis of melanism in B. ruderatus was also assessed by determining any relationship between relatedness and degree of melanism. The results suggest that differences in the degree of melanism between populations are greater than the differences expected through selectively neutral forces alone and, therefore, that the pattern of variation in melanism is likely a result of selection and/or phenotypic plasticity in addition to gene flow and genetic drift. Although a global model consisting of four climatic variables and the abundance of conspecifics explained a small proportion of the variation in melanism, no support was found for any specific hypothesis relating to the adaptive function for body colour. Instead the results suggest that some combination of factors, most likely including factors not measured in this study, is influencing the frequency of melanic morphs. In addition, there was evidence that body colour was influenced by phenotypic plasticity and that melanism has a low heritability in B. ruderatus. Taken together, these results imply that patterns of melanism across B. ruderatus populations are complex and it is likely that multiple factors are influencing melanism in concert.

Analysis of mitochondrial DNA (mtDNA) sequence variation among 244 American shad (Alosa sapidissima) from 14 rivers spanning the (Florida-Quebec) range of the species revealed several unusual features of shad mtDNA polymorphism. Two types of heteroplasmy, one involving a length polymorphism and the other a restriction site are common in shad. The length polymorphism involves a novel tandem triplication of a 1.5-kb sequence in the D-loop region. Both forms of heteroplasmy stem from multiple mutational events. The mtDNA data indicate that shad populations are reproductively discrete, and suggest that differences in the reproductive traits of northern and southern shad populations have evolved since the Pleistocene. Low mtDNA sequence variation in shad may stem at least in part from Pleistocene population reductions. A fossil calibration supports an mtDNA divergence rate in shad at least one order of magnitude slower than the prevailing estimate for vertebrates.

No description available.

The current epidemic of obesity poses a substantial threat to public health worldwide. Obesity is associated with many deleterious health conditions, including type 2 diabetes, hypertension, dyslipidaemia, respiratory conditions, arthritis, and some forms of cancer. Moreover, the rising prevalence of obesity has been accompanied by a substantial increase in the cost of treating these conditions. Obesity results from a complex interaction between behavioural, environmental, and genetic factors. While the recent increase in the prevalence of obesity is largely due to behavioural factors (for example, physical inactivity); it has also been observed that genetic factors make a large contribution to individual susceptibility. In fact, studies indicate that as much as 50 - 80% of the variation in measures of obesity can be attributed to the effects of genes. Furthermore, closer examination of this genetic component using segregation analysis has indicated the presence of common genes for obesity, with large effects on the phenotype. However, these putative major genes for obesity have not yet been identified. The aim of this thesis was to investigate the role of three distinct genetic loci in obesity and related cardiovascular factors, including type 2 diabetes and dyslipidaemia. The aim of the first investigation was to test whether a common polymorphism (Pro12Ala) in the gene encoding peroxisome proliferator-activated receptor gamma 2 (PPAR-γ2) was associated with obesity and other cardiovascular risk factors in a large group of Caucasian subjects. PPAR-γ2 is an adipogenic transcription factor, which also regulates insulin sensitivity in adipose tissue. No association was observed between the Pro12Ala polymorphism and obesity in Caucasians, but obese subjects carrying the Ala allele displayed an altered blood lipid profile compared with obese Pro/Pro subjects. As the Pro12Ala polymorphism may exacerbate the risk of cardiovascular disease by modifying blood lipid profile in obesity, this relationship was examined further in a separate population. The aim of the second investigation was to determine whether the Pro12Ala polymorphism was associated with obesity, dyslipidaemia, diabetes and carotid intima-medial wall thickening in a population at high risk of developing cardiovascular disease. Australian Aboriginal people display high rates of mortality from cardiovascular disease, and it is possible that their increased susceptibility is due to genetic factors. However, the results from the Aboriginal population confirmed the results of the first study: there was no intrinsic association between the Pro12Ala variant and obesity. In addition, the Ala allele was not associated with deleterious changes in blood lipid profile, as it was in Caucasians. The aim of the third investigation was to confirm the presence of a quantitative trait locus (QTL) for obesity on chromosome 20q13. Highly polymorphic genetic markers in this region were tested for linkage and association with several measures of obesity in a Caucasian population. None of the measures of obesity were linked to or associated with markers spanning 20q13, suggesting that this chromosomal region does not contain a major locus for obesity in this Caucasian population. In the fourth investigation, the 5' sequence of Agouti Signalling Protein (ASIP) was identified. ASIP is a candidate gene for obesity, as it is expressed at high levels in adipocytes, and may participate in several obesity-related processes. Three new exons and two alternative promoters were identified for the ASIP gene. These results may lead to greater understanding of the role of ASIP in obesity and adipocyte metabolism; and may also be used to direct further research into genetic variation within this candidate gene. In conclusion, extensive study of two established candidate genetic loci revealed no association with measures of obesity. Therefore, it is likely that loci other than these make significant contributions to obesity in humans. Further investigation of novel candidate genes, such as ASIP, may allow the identification of novel genetic polymorphisms and new pathways important for the genetic basis of obesity.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2009. / Härtill 5 uppsatser.

Thesis (M.S.)--University of Akron, Dept. of Biology, 2005. / "May, 2005." Title from electronic thesis title page (viewed 09/24/2005) Includes bibliographical references.

Swallowing is an important physiological function leading to nourishment of the organism, controlled by complicated interactions between the muscles, the cranial nerves and multiple brain structures. Swallowing impairments, also called dysphagia, are a major health burden for patients with neurological diseases such as stroke, Parkinson’s disease as well as community dwelling elderly individuals. It has been shown that activation of undamaged swallowing motor cortex compensates for the initial lost swallowing function in stroke patients. Non-invasive brain stimulation provides a tool to explore excitability within the areas of the motor cortex responsible for swallowing muscles. Repetitive transcranial magnetic stimulation (rTMS) is one such technique, with defined frequency parameters, however the underlying reasons for the heterogeneity is responses to low (1Hz) and high (5Hz) frequencies is unclear. These physiological interactions affecting the neurological control of swallowing may be influenced by multiple genes and proteins. Insights into the molecular basis of swallowing through genetic interactions could provide a source of information which can be further used in understanding and treating swallowing impairments. Existing evidence is limited in terms of candidate proteins, genes and pathways which might drive the neural control of swallowing. The aim of my doctoral research was to explore genes which might be involved in swallowing neurophysiology and pathophysiology. My hypothesis is that swallowing due to its complicated physiology is most likely affected by multiple genes and interactions between genes and proteins. To study this hypothesis I used two experimentally distinct study designs. Firstly I explored a number of single nucleotide polymorphisms (SNPs) and potential candidate genes presented in the existing literature. Then, I performed a SNP- and gene-based Genome-Wide Association Study (GWAS) of self-reported swallowing impairments compared with over 500,000 single nucleotide changes. For GWAS I used a group of 555 community dwelling individuals from the Dyne Steel Cohort from the areas of Manchester and Newcastle. Further research involved replication of selected genes and SNPs from literature screening and GWAS using two rTMS paradigms on the largest to date cohort of healthy young volunteers. Forty one volunteers (were assessed for corticobulbar excitability after single-pulse TMS. Repeated measurements of motor evoked potentials from the pharynx and the hand were recorded after the interventions of 1Hz and 5Hz rTMS. The subjects’ individual responses were grouped according to multiple criteria and then associated with factors such as gender, ethnicity, time of day of the stimulation and individual genetic information. GWAS analysis for association with swallowing impairment identified one SNP rs17601696 which achieved genome-wide significance (P-value=5×10(-8)) within a non-coding region of chromosome 10. Gene-based analysis did not result in any genome-wide significant association. In replication of these findings and following a priori selected genes from the literature (BDNF, COMT, TRKB, APOE, DRD2, GRIN2B and GRIN1) from neurophysiological studies applying TMS, two main conclusions were formed. Firstly, rTMS paradigms showed high variability in responses which made the phenotype more complicated. Secondly the result from GWAS could not be confirmed. By contrast, SNP rs6269 from the COMT gene was associated with responsiveness of the pharyngeal MEPs after delivering 1Hz paradigm and rs1800497 from the DRD2 gene with responsiveness after 5Hz rTMS.Lack of replication of the findings between two experiments might be caused by high variability in responsiveness with complex molecular networks of swallowing control where multiple genes with small genetic effects are involved. Although our findings support the hypothesis that molecular markers can be associated with swallowing, more studies are needed to understand the individual factors that determine responsiveness and effectiveness of treatment therapies of swallowing impairments.

Submitted by ALINE APARECIDA DEL'VESCOVO null (alinedelvescovo@yahoo.com.br) on 2016-03-11T17:46:30Z No. of bitstreams: 1 Defesa Oficial Aline Ap. Del Vescovo.pdf: 1253963 bytes, checksum: c4bb222d0eaddb9111ac9d6ffcf287e1 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-03-14T18:20:06Z (GMT) No. of bitstreams: 1 vescovo_aa_me_bot.pdf: 1253963 bytes, checksum: c4bb222d0eaddb9111ac9d6ffcf287e1 (MD5) / Made available in DSpace on 2016-03-14T18:20:06Z (GMT). No. of bitstreams: 1 vescovo_aa_me_bot.pdf: 1253963 bytes, checksum: c4bb222d0eaddb9111ac9d6ffcf287e1 (MD5) Previous issue date: 2016-02-22 / Os Astrocitomas são tumores de Sistema Nervoso Central (SNC) caracterizado, quanto à sua nomenclatura e grau de malignidade, conforme seu tipo histológico e seu potencial proliferativo, presença de necrose e invasão cortical. Os interferons (IFNs) foram inicialmente associados à resposta antiviral, contudo, estudos posteriores evidenciaram o envolvimento dessas citocinas na regulação do crescimento celular e no efeito imunomodulatório. A Interleucina 28B (IL28B), membro da família dos IFNs do tipo III, parece estar envolvida na resposta imune antiviral e antitumoral. Sendo assim, o objetivo do presente estudo foi avaliar a frequência de variações genéticas em IL28B em pacientes acometidos por Astrocitomas. Cinquenta e sete pacientes tratados pelo serviço de Neurocirurgia da UNESP de Botucatu/SP foram incluídos neste estudo. A análise do polimorfismo rs12979860 C/T não teve significância estatística quando comparou-se a frequência genotípica da população brasileira em relação a presente casuística. Foi descrito a detecção de novas variações genéticas (missense e silent) no gene IL28B ao comparar com a sequência referência disponível em banco de dados (NCBI). Estes dados sugerem uma importante relação destas variações genéticas em relação a estrutura e função das proteínas envolvidas, entretanto um estudo mais aprofundado das consequências dessas alterações na gênese e/ou progressão dos astrocitomas devem ser considerado. / The astrocytomas are tumors of the central nervous system (CNS) characterized as to its nomenclature and degree of malignancy, according to their histological type and their proliferative potential, presence of necrosis and cortical invasion. Interferons (IFNs) were originally associated with the antiviral response, however, subsequent studies revealed the involvement of these cytokines in the regulation of cell growth and immunomodulatory effect. Interleukin 28B (IL28B), member of the family of IFNs type III appears to be involved in the antiviral and anti-tumor immune response. Thus, the aim of this study was to evaluate the frequency of genetic variation in IL28B in patients suffering from astrocytomas. Fifty-seven patients treated by our service at UNESP in Botucatu / SP were included in this study. Rs12979860 C / T polymorphism analysis was not statistically significant when compared to genotypic frequency of the population in relation to this study. It described the detection of new genetic variants (missense and silent) in IL28B gene to compare with the reference sequence available in the database (NCBI). These data suggest an important relationship between these genetic variations regarding the structure and function of the proteins involved, however further study of the consequences of these changes in the genesis and / or progression of astrocytomas should be considered.

Orientador: Adriana Camargo Ferrasi / Resumo: Os Astrocitomas são tumores de Sistema Nervoso Central (SNC) caracterizado, quanto à sua nomenclatura e grau de malignidade, conforme seu tipo histológico e seu potencial proliferativo, presença de necrose e invasão cortical. Os interferons (IFNs) foram inicialmente associados à resposta antiviral, contudo, estudos posteriores evidenciaram o envolvimento dessas citocinas na regulação do crescimento celular e no efeito imunomodulatório. A Interleucina 28B (IL28B), membro da família dos IFNs do tipo III, parece estar envolvida na resposta imune antiviral e antitumoral. Sendo assim, o objetivo do presente estudo foi avaliar a frequência de variações genéticas em IL28B em pacientes acometidos por Astrocitomas. Cinquenta e sete pacientes tratados pelo serviço de Neurocirurgia da UNESP de Botucatu/SP foram incluídos neste estudo. A análise do polimorfismo rs12979860 C/T não teve significância estatística quando comparou-se a frequência genotípica da população brasileira em relação a presente casuística. Foi descrito a detecção de novas variações genéticas (missense e silent) no gene IL28B ao comparar com a sequência referência disponível em banco de dados (NCBI). Estes dados sugerem uma importante relação destas variações genéticas em relação a estrutura e função das proteínas envolvidas, entretanto um estudo mais aprofundado das consequências dessas alterações na gênese e/ou progressão dos astrocitomas devem ser considerado. / Abstract: The astrocytomas are tumors of the central nervous system (CNS) characterized as to its nomenclature and degree of malignancy, according to their histological type and their proliferative potential, presence of necrosis and cortical invasion. Interferons (IFNs) were originally associated with the antiviral response, however, subsequent studies revealed the involvement of these cytokines in the regulation of cell growth and immunomodulatory effect. Interleukin 28B (IL28B), member of the family of IFNs type III appears to be involved in the antiviral and anti-tumor immune response. Thus, the aim of this study was to evaluate the frequency of genetic variation in IL28B in patients suffering from astrocytomas. Fifty-seven patients treated by our service at UNESP in Botucatu / SP were included in this study. Rs12979860 C / T polymorphism analysis was not statistically significant when compared to genotypic frequency of the population in relation to this study. It described the detection of new genetic variants (missense and silent) in IL28B gene to compare with the reference sequence available in the database (NCBI). These data suggest an important relationship between these genetic variations regarding the structure and function of the proteins involved, however further study of the consequences of these changes in the genesis and / or progression of astrocytomas should be considered. / Mestre