The domestic dog, Canis lupus familiaris, has emerged as a model system for the study of human hereditary diseases. Of the approximately 450 hereditary diseases described in the dog, half have clinical presentations that are quite similar to specific human diseases. Understanding the genetic bases of canine hereditary diseases will not only complement comparative genetics studies but also facilitate selective breeding practices to reduce incidences in the dog. Whole genome screens have great potential to identify the marker(s) that segregate with canine hereditary diseases for which no reasonable candidate genes exist. The Minimal Screening Set-1 (MSS-1) was the first set of microsatellite markers described for linkage analysis in the dog and was, until recently, the best tool for genome screens. The MSS-2 is the most recently described screening set and offers increased density and more polymorphic markers. The first objective of this work was to develop tools to streamline genomic analyses in the study of canine hereditary diseases. This was achieved through the development of 1) multiplexing strategies for the MSS-1, 2) a multiplex of microsatellite markers for use in canine forensics and parentage assays and 3) chromosome-specific multiplex panels for the MSS-2. Multiplexing is the simultaneous amplification and analysis of markers and significantly reduces the expense and time required to collect genotype information. Pancreatic acinar atrophy (PAA) is a disease characterized by the degeneration of acinar cells of the exocrine pancreas and is the most important cause of exocrine pancreatic insufficiency (EPI) in the German Shepherd Dog (GSD). Although the prognosis for dogs having EPI is typically good with treatment, many dogs are euthanized because the owners are unable to afford the expensive enzyme supplements. The second objective of this work was to determine the mode of transmission of EPI in the GSD and conduct a whole genome screen for linkage. Two extended families of GSDs having PAA were assembled and used to determine the pattern of transmission. The results of this indicate that PAA is an autosomal recessive disease. The multiplexed MSS-1 was used to conduct an initial whole genome screen, although no markers were suggestive of linkage.

In certain diseases, like Multiple Sklerosis and Alzheimer's disease, the progression of the disease can be measured by whole brain atrophy. A difficulty with this is that all people have very different scull sizes, thus also very different brain sizes. This makes it almost impossible to establish "normal values" for brain size. The spread is very large and the method is not practical to use for individual patients. A method with less spread in healthy persons is to use the ratio of the Brain Parenchymal Fraction (BPF). The use of Brain Parenchymal Fraction has increased steadily since it was first introduced in 1999.  BPF = BPV/ICV This study was performed to increase the knowledge of what is normal and to evaluate the robustness of the BPF as a measurement for brain atrophy. Among other things, the change in the BPF when calculated from incomplete volumes (parts of the scull missing in the set of MR images) was evaluated.  The results show that when parts are missing from the top (superior) of the scull the resulting BPF is strictly higher than the correct PBF and when parts are missing from the lower (inferior) part of teh scull the resulting BPF is stritly lower than teh correct value.  Two different methods where tried to compensate for missing parts. The first method was to find a variable factor to compensate with, the size of this factor was depending on how much of the scull that was missing. The second method was to interpolate the ICV and BPV curves and from the new interpolated curves, calculate a new BPF. The method of compensating incomplete volumes using a factor calculated as a function of the intercranial volume of the first/last available slice turned out to be the better.

Spinobulbar muscular atrophy (SBMA) is a neurodegenerative disease caused by the expansion of a polyglutamine (polyGln) tract in the human androgen receptor (hAR). One mechanism by which polyGln-expanded proteins are believed to cause neuronotoxicity is through aberrant interaction(s) with, and possible sequestration of, critical cellular protein(s). / Our goal was to confirm and further characterize the interaction between hAR and cytochrome c oxidase subunit Vb (COXVb), a nuclear-encoded mitochondrial protein. We had previously isolated COXVb as an AR-interacting protein in a yeast two-hybrid search to identify candidates that interact with normal and polyGln-expanded AR. Using the mammalian two-hybrid system, we confirm that COXVb interacts with normal and mutant AR and demonstrate that the COXVb-normal AR interaction is stimulated by heat shock protein 70 (Hsp70). Also, BFP-tagged AR specifically co-localizes with cytoplasmic aggregates formed by GFP-labelled polyGln-expanded AR in androgen-treated cells. / Mitochondrial dysfunction may precede neuropathological findings in polyGln-expanded disorders and may thus represent an early event in neuronotoxicity. Interaction of COXVb and hAR, with subsequent sequestration of COXVb, may provide a mechanism for putative mitochondrial dysfunction in SBMA.

The human body consists of about 40 % skeletal muscles which control the body’s movement, ability to stand up, force generation, locomotion, heat production and are also the body’s protein reservoir. Muscle mass is controlled by the relationship between protein synthesis and protein degradation. Atrophy, a decrease in muscle mass, can be trigged by disuse, immobilization, inflammation and cancer. Hypertrophy, an increase in muscle mass, can occur after increased mechanical load, high usage and/or anabolic stimulation. The aim of this thesis was to investigate changes in expression and post translational modifications of some factors involved in the regulation of protein synthesis and protein degradation in 6-days denervated atrophic hind-limb muscles (anterior tibial and pooled gastrocnemius and soleus muscles) and in 6-days denervated hypertrophic hemidiaphragm muscle in mice. Protein expression and post translational modifications were studied semi-quantitatively using Western blots with whole muscle homogenates and separated nuclear and cytosolic fractions from both innervated and denervated muscles.  An increase in protein synthesis after denervation in both atrophic and hypertrophic muscles was suggested after studies of factors downstream of mTOR (paper I).  Other results suggest that FoxO1 and MuRF1 (paper II) participate in the tissue remodeling that occurs after denervation. A differential response of MK2 phosphorylation in denervated hypertrophic and atrophic muscles was confirmed (paper III). An increase in phosphorylation of the MK2 substrate Hsp 25 in all denervated muscles studied (paper III) indicates that other factors than MK2 are involved in regulating this phosphorylation. eIF4G phosphorylation at S1108 was investigated (paper IV) and a decrease was observed in atrophic muscle but an increase in hypertrophic muscle. The results in this thesis suggest that there are several factors that control protein degradation and protein synthesis in denervated atrophic and hypertrophic skeletal muscles. This is an intricate labyrinth with many different cell signaling factors, the function of which are still far from fully understood.

Licentiatavhandling (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 2 uppsatser.

Thesis (Ph. D.)--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. Vita. "December 2006" Includes bibliographical references.

Dissertation (Ph.D.).--University of Texas Graduate School of Biomedical Sciences at San Antonio, 2008. / Vita. Includes bibliographical references.

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. [215]-219.

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. [215]-219.

Spinal Muscular Atrophy (SMA), traditionally described as a predominantly childhood form of motor neuron disease, is a leading genetic cause of infant mortality. Although motor neurons are undoubtedly the primary affected cell type, SMA is now widely recognised as a multisystem disorder, where a variety of organs and systems in the body are also affected. Vascular perfusion abnormalities have previously been reported in both patients and mouse models of SMA, however it remains unclear whether these defects are secondary to the motor neuron pathology for which this disease is known. Through analysis of the 'Taiwanese' murine model of severe SMA (Smn-/-;SMN2tg/0, Smn-/+) we report significant vascular defects in the retinas of SMA mice, a tissue devoid of motor neurons, thus providing strong evidence that these vascular defects are independent of motor neuron pathologies. We show that restoration of Smn levels by antisense oligonucleotide treatment at birth significantly ameliorates retinal vascular defects. Next, we report defects in the neural retina, with a significant decrease in key neural cells in SMA mice. A similar vascular pathology was expected in the spleen of SMA mice given that the spleen is small and pale in appearance; however, the density of the intrinsic vasculature remained unchanged. We report that the spleen is disproportionately small in SMA mice, correlated to low levels of cell proliferation, increased cell death, and multiple lacunae. The SMA spleen lacks its distinctive red appearance and presents with a degenerated capsule and a disorganized fibrotic architecture. Histologically distinct white pulp fails to form and this is reflected in an almost complete absence of B lymphocytes necessary for normal immune function. Taken together, these results highlight both the vascular and immune systems as key targets of SMA pathology that should be considered during treatment of this disease.