Publications by authors named "James Mickelson"

(1) Background: An adult dog was presented to a board-certified veterinary neurologist for evaluation of chronic weakness, exercise intolerance and lactic acidemia. (2) Methods: A mitochondrial myopathy was diagnosed based on the histological and histochemical phenotype of numerous COX-negative muscle fibers. Whole-genome sequencing established the presence of multiple extended deletions in the mitochondrial DNA (mtDNA), with the highest prevalence between the 1-11 kb positions of the approximately 16 kb mitochondrial chromosome.

View Article and Find Full Text PDF

(1) Background: Muscle hypertrophy, swallowing disorders, and gait abnormalities are clinical signs common to many muscle diseases, including muscular dystrophies, non-dystrophic myotonias, genetic myopathies associated with deficiency of myostatin, and acquired inflammatory myopathies. Here, we investigated underlying causes of this triad of clinical signs in four young French bulldogs via muscle histopathology coupled with whole genome and Sanger sequencing. (2) Methods: Dogs were evaluated by veterinary clinical internists and neurologists, and biopsies were obtained for histopathological diagnosis.

View Article and Find Full Text PDF

Miniature Schnauzers are predisposed to primary hypertriglyceridemia (HTG). In this study, we performed whole genome sequencing (WGS) of eight Miniature Schnauzers with primary HTG and screened for risk variants in six HTG candidate genes: , , , , , and . Variants were filtered to identify those present in ≥2 Miniature Schnauzers with primary HTG and uncommon (<10% allele frequency) in a WGS variant database including 613 dogs from 61 other breeds.

View Article and Find Full Text PDF

ARSACS (autosomal recessive spastic ataxia of Charlevoix-Saguenay) is a human neurological disorder characterized by progressive cerebellar ataxia and peripheral neuropathy. A recently recognized disorder in Great Pyrenees dogs is similarly characterized by widespread central nervous system degeneration leading to progressive cerebellar ataxia and spasticity, combined with peripheral neuropathy. Onset of clinical signs occurred in puppies as young as 4 months of age, with slow progression over several years.

View Article and Find Full Text PDF

Two (male and female) 10-month-old American Staffordshire Terrier littermates presented for progressive weakness, joint contracture, and distal limb joint hyperlaxity beginning around 6 months of age. Neurological examination, serum creatine kinase activity, infectious disease titers, cerebrospinal fluid analysis, and electrodiagnostic testing were performed. Muscle biopsies were collected for histopathology and immunofluorescence staining for localization of dystrophy associated proteins.

View Article and Find Full Text PDF
Article Synopsis
  • The identification of canine muscular dystrophies has increased, revealing more affected breeds and mutations tied to these conditions.
  • Key genetic defects include those related to muscle cell membranes and the extracellular matrix, leading to various types of muscular dystrophy in dogs.
  • This report discusses ongoing advancements in genetic testing methods and highlights new findings, including mutations causing X-linked muscular dystrophy in Brittany spaniels and French bulldogs.
View Article and Find Full Text PDF

DP915635 maize was genetically modified (GM) to express the IPD079Ea protein for corn rootworm (Diabrotica spp.) control. DP915635 maize also expresses the phosphinothricin acetyltransferase (PAT) protein for tolerance to glufosinate herbicide and the phosphomannose isomerase (PMI) protein that was used as a selectable marker.

View Article and Find Full Text PDF

A form of dystrophinopathy with mild or subclinical neuromuscular signs has been previously reported in a family of Labrador retrievers. Markedly and persistently elevated creatine kinase activity was first noted at 6 months of age. Skeletal muscle biopsies revealed a dystrophic phenotype, with dystrophin non-detectable on western blotting and immunohistochemical staining, and with increased utrophin expression.

View Article and Find Full Text PDF

In this report, we describe a novel genetic basis for congenital dyserythropoietic anemia and polymyopathy in Labrador Retriever littermates characterized by incidental detection of marked microcytosis, inappropriate metarubricytosis, pelvic limb weakness and muscle atrophy. A similar syndrome has been described in English Springer Spaniel littermates with an early onset of anemia, megaesophagus, generalized muscle atrophy and cardiomyopathy. Muscle histopathology in both breeds showed distinctive pathological changes consistent with congenital polymyopathy.

View Article and Find Full Text PDF
Article Synopsis
  • Dogs, particularly large breeds like the Leonberger, are valuable models for studying osteosarcoma (OSA), a common bone cancer that closely resembles the form found in humans.
  • A genome-wide analysis of 273 Leonberger cases revealed significant genetic associations on chromosome 11, reinforcing previous studies in other high-risk breeds like greyhounds.
  • The study determined a heritability of 20.6% for OSA, identifying 2563 SNPs that influence cancer risk, highlighting the importance of genetic factors in OSA predisposition in dogs.
View Article and Find Full Text PDF

An episodic nervous system disorder triggered by strenuous exercise, termed border collie collapse (BCC), exists in border collies and related breeds. The genetic basis of BCC is unknown but is believed to be a complex genetic disorder. Our goal was to estimate the heritability (h) of BCC, define its underlying genetic architecture, and identify associated genomic loci using dense whole-genome single-nucleotide polymorphism (SNP) genotyping data.

View Article and Find Full Text PDF

A 2-year-old female spayed dog was presented with a chronic history of short-strided gait and inability to completely open the jaw. Clinical signs were present since the dog was adopted from a humane society at a few months of age. Serum creatine kinase activity was abnormally high.

View Article and Find Full Text PDF

Alpha-dystroglycan (αDG) is a highly glycosylated cell surface protein with a significant role in cell-to-extracellular matrix interactions in muscle. αDG interaction with extracellular ligands relies on the activity of the LARGE1 glycosyltransferase that synthesizes and extends the heteropolysaccharide matriglycan. Abnormalities in αDG glycosylation and formation of matriglycan are the pathogenic mechanisms for the dystroglycanopathies, a group of congenital muscular dystrophies.

View Article and Find Full Text PDF
Article Synopsis
  • * The study identified four significant genetic variants associated with xanthinuria in various dog breeds, including Manchester Terriers, Cavalier King Charles Spaniels, an English Cocker Spaniel, a Dachshund, and a mixed-breed dog.
  • * These gene variants were found in a homozygous state among affected dogs, indicating they follow an autosomal recessive inheritance pattern, with implications for breeding and potential genetic testing in these breeds.
View Article and Find Full Text PDF

Distinctive colour patterns in dogs are an integral component of canine diversity. Colour pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves but important gaps remain in understanding how these patterns evolved and are genetically controlled. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments.

View Article and Find Full Text PDF

Support programs to improve higher education outcomes for former foster youths have emerged in the past 20 years, but literature to guide their development and implementation is limited. This conceptual article presents the program logic model for ACE [Achieving College Excellence] Scholars Services, the comprehensive, campus-based program supporting former foster youths grounded in social work values at California State University San Marcos (CSUSM). ACE has a noncompetitive application process that accepts an unrestricted number of students, known as ACE Scholars.

View Article and Find Full Text PDF
Article Synopsis
  • A group of miniature dachshunds showed symptoms of muscle weakness and exercise intolerance, prompting a detailed study.
  • Researchers used muscle biopsies, immunofluorescence, and genetic sequencing to investigate the underlying condition, identifying signs of a specific muscular dystrophy known as sarcoglycanopathy.
  • A new genetic mutation associated with this condition was found in the sarcoglycan A subunit gene, providing insights into canine muscular dystrophies and their relevance to human health.
View Article and Find Full Text PDF

Laryngeal paralysis associated with a generalized polyneuropathy (LPPN) most commonly exists in geriatric dogs from a variety of large and giant breeds. The purpose of this study was to discover the underlying genetic and molecular mechanisms in a younger-onset form of this neurodegenerative disease seen in two closely related giant dog breeds, the Leonberger and Saint Bernard. Neuropathology of an affected dog from each breed showed variable nerve fiber loss and scattered inappropriately thin myelinated fibers.

View Article and Find Full Text PDF
Article Synopsis
  • The Leonberger breed, established in the 1850s, has around 30,000 dogs today but suffers from genetic diversity issues that lead to high rates of neurodegenerative disorders and cancer.
  • Analysis of pedigree records and genomic data indicates significant inbreeding with an average inbreeding coefficient of 0.29 and a decline in lifespan from 9.4 years in 1989 to 7.7 years in 2004.
  • Although the study identified possible genetic variants linked to health issues, no definitive causal genetic indicators were found, suggesting that other factors may contribute to the breed's health problems.
View Article and Find Full Text PDF

DP23211 maize was genetically modified (GM) to express DvSSJ1 double-stranded RNA and the IPD072Aa protein for control of corn rootworm ( spp.). DP23211 maize also expresses the phosphinothricin acetyltransferase (PAT) protein for tolerance to glufosinate herbicide, and the phosphomannose isomerase (PMI) protein that was used as a selectable marker.

View Article and Find Full Text PDF

Altered melanosome transport in melanocytes, resulting from variants in the melanophilin () gene, are associated with inherited forms of coat color dilution in many species. In dogs, the gene corresponds to the D locus and two variants, c.-22G > A (d) and c.

View Article and Find Full Text PDF

The collagen VI-related muscular dystrophies in people include a broad spectrum of diseases ranging from the severe Ullrich congenital muscular dystrophy to the mild Bethlem myopathy. Clinical features are attributable to both muscle and connective tissue and include progressive muscle weakness and respiratory failure, hyperlaxity of distal joints, and progressive contracture of large joints. Here we describe two different COL6A3 pathogenic variants in Labrador Retriever dogs that result in autosomal recessive or autosomal dominant congenital myopathies with hyperlaxity of distal joints and joint contracture, similar to the condition in people.

View Article and Find Full Text PDF

Cutaneous lupus erythematosus (CLE) in humans encompasses multiple subtypes that exhibit a wide array of skin lesions and, in some cases, are associated with the development of systemic lupus erythematosus (SLE). We investigated dogs with exfoliative cutaneous lupus erythematosus (ECLE), a dog-specific form of chronic CLE that is inherited as a monogenic autosomal recessive trait. A genome-wide association study (GWAS) with 14 cases and 29 controls confirmed a previously published result that the causative variant maps to chromosome 18.

View Article and Find Full Text PDF