Changes in the morphological character of appendages are essential to arthropod diversification and adaptation to a variety of living conditions. For instance, the fruit fly Drosophila melanogaster possesses cylindrical, uniramous (unbranched) walking legs that are well suited for terrestrial life, while Triops longicaudatus possesses paddle-like, multiramous (multibranched) limbs adapted to aquatic life. Comparative studies of limb patterning between different species of arthropods suggest that most animals utilize a conserved set of genes to construct a limb. How is this common set of genes used to produce morphological divergence? This question is addressed here by examining the spatiotemporal expression patterns of genes shown to establish distinct domains along the proximodistal (P/D) axis in arthropod species with legs morphologically distinct from Drosophila legs.In this dissertation, I investigate the role of the limb patterning genes, dachshund (dac) and homothorax (hth), in patterning the appendages of the crustacean Triops longicaudatus. I examine the spatiotemporal relationships of the expression of these two essential limb-patterning genes individually and simultaneously with two previously reported leg patterning genes, extradenticle (exd) and Distal-less (Dll). I discovered that Triops dac and hth, as expected, are expressed during leg development. I verified a cell-to-cell association between HTH and nuclear-EXD (n-EXD), a spatial relationship that had only been conjectured to exist outside of Drosophila. This spatial relationship represents an ancient unchangeable constraint on limb patterning. HTH expression reported here in addition to previously reported EXD and DLL expressions suggests a common, early subdivision of the leg into broad proximal and distal domains. However, the reiterated stripes of DAC expression found along the ventral axis do not support establishment of an intermediate leg domain but instead suggest that the ventral branches of the Triops limb are generated by a mechanism of segmentation not previously observed in other arthropod limbs. Additionally, I present a record of my attempts aimed at functional determination of genes believed to specify, pattern, or modify branchiopod appendages. Finally, I demonstrated that dac functions in the dung beetle leg to properly segment the tarsus as well as producing a structural modification, such as spiked protrusions.

Esta pesquisa foi realizada com o intuito de descrever o protocolo de obtenção da imagem termográfica, definir o padrão térmico normal da coluna vertebral e também descrever os valores cinemáticos durante a locomoção em 17 cães condrodistróficos da raça Dachshund. Foram analisadas as imagens tomográficas de toda a extensão da coluna; e também foram avaliadas as regiões dorsal e lateral de todos as regiões da coluna vertebral por meio da termografia. Para a realização da análise cinemática, foram aderidos em pontos anatômicos específicos de cada um dos cães marcadores reflexivos e foram obtidos os valores de máxima extensão, mínima flexão e a amplitude articular durante a locomoção das articulações dos membros torácicos e pélvicos do lado direito e esquerdo do animal. Foi testada a normalidade dos dados e comparados os lados direito e esquerdo, e as regiões da coluna vertebral de cada cão. Nenhum dos 17 cães mostrou evidencia tomográfica de compressão extradural da medula espinhal. Houve diferença estatística entre os pontos da região cervical e torácica e entre a região cervical e toracolombar; o ponto médio de maior temperatura encontrado foi na região toracolombar. Foram obtidos os dados cinemáticos de 5 passagens válidas de cada animal, a velocidade foi mantida entre 1,2 e 1,5m/seg. Os valores cinemáticos apresentaram uma distribuição normal e a simetria entre os lados de cada uma das articulações foi constatada. O mapa térmico em cães da raça Dachshund hígidos se caracteriza por apresentar uma maior temperatura na região torácica e toracolombar. Em toda a extensão da coluna o mapa térmico se caracteriza por uma zona central mais quente com diminuição simétrica da temperatura nas áreas mais laterais. A análise cinemática da locomoção permitiu a obtenção dos valores simétricos do movimento de flexão, extensão e amplitude articular da articulação coxofemoral, joelho, tibiotársica, ombro e cotovelo bilateral. Não foi possível a obtenção dos valores da articulação radiocárpica. Conclui-se que a termografia é uma ferramenta útil e não invasiva para medir a temperatura da coluna vertebral em cães da raça Dachshund e que estes apresentam um padrão de movimento articular simétrico durante a locomoção. / This research was conducted with the purpose of describing the protocol to obtain the thermographic image, to define the normal thermal pattern of the spine and to describe the kinematic data during locomotion in 17 Dachshund breed dogs. The tomographic images of the entire spine were analyzed; and the dorsal and lateral view of all the regions of the spine were also evaluated using thermography. To perform the kinematic analysis, reflective markers were attached to specific anatomical landmarks and the numeric values of maximum extension, minimum flexion and range of motion were obtained during locomotion for the joints of the fore and hind limbs of the right and left side of the animal. The normality of the data was tested and the right and left side, and the regions of the spine of each dog were compare. None of the 17 dogs showed tomographic evidences of extradural compression of the spinal cord. There was statistical difference between the points of the cervical and thoracic region and between the cervical and thoracolumbar region; the midpoint with the highest temperature was found in the thoracolumbar region. Kinematic data of 5 valid passages of each animal were obtained, velocity was maintained between 1.2 and 1.5 m/sec. The kinematic data had normal distribution and the symmetry between the sides of each joint was verified. The thermal map in healthy Dachshund dogs is characterized by presenting the higher temperature in the thoracic and thoracolumbar regions. Throughout the whole extension of the spine the thermal map is characterized by a warmer central zone with symmetrical decrease of temperature in the lateral areas. The kinematic gait analysis allowed us to obtain the symmetrical bilateral values of flexion, extension and range of motion of the hip, knee, tibiotarsal, shoulder and elbow joints. It was not possible to obtain the values of the radiocarpal joint. It was concluded that thermography is a useful and non-invasive tool to measure the spinal temperature in Dachshund breed dogs and that they have a pattern of symmetrical joint movement during locomotion.

No description available.

Master of Science / Department of Clinical Sciences / James K. Roush / Objective – To evaluate the value of thermography in a clinical setting for dogs with thoracolumbar disease. Animal Population – Thirteen client-owned short-haired Dachshunds presented to Kansas State University Veterinary Medical Teaching Hospital for paraparesis/paraplegia and diagnosed with thoracolumbar disease via myelogram/CT and confirmed during surgical decompression. Procedures - Thermal images were obtained with a hand-held infrared camera with a focal plane array uncooled microbolometer. Images were obtained after physical exam and client consultation and prior to any pre-anesthetic medications, approximately 30+ minutes after entering the hospital. Additional images were obtained in the same manner at 24 hour intervals following surgery until discharge. Six regions of interest (ROI) were identified and recorded. The ROIs identified were right and left thoracic, lumbar and pelvic regions. From each of these regions average temperatures were taken. Results - Temperatures in the pelvic region were significantly cooler (p< 0.001) over all days as compared to the thoracic and lumbar regions and to the overall mean temperature. The lumbar region temperature was significantly greater on day 0 as compared to thoracic and pelvic regions but was not significantly different on any of the following days. The thoracic temperatures were significantly greater than the lumbar and pelvic regions on day 2 but there was no significant difference on any of the preceding or following days. There was no significant difference between left and right on any of the days. There was a correlation of the pelvic region temperatures on day 3 in relation to the presenting neurological grade. Conclusion - Although there were varied heat patterns detected in dachshunds with IVDD, these patterns did not correlate with neurological grade, lesion site or lateralization of the lesion. Although there was a correlation between neurological grades and the pelvic region temperatures on day 3, this time period is unlikely to provide clinical utility. Clinical Relevance - The results of this study suggest that thermography is not a useful tool for the diagnosis or prognosis of thoracolumbar disease in dogs in a clinical setting.