Clinical characteristics of canine fibrocartilaginous embolic myelopathy (FCE): a systematic review of 393 cases (1973-2013).

Fibrocartilaginous embolic myelopathy (FCE) is common in dogs; however, there is conflicting information in the veterinary literature regarding clinical characteristics and data on recovery in severe cases is sparse. A systematic review of canine FCE was performed to delineate the natural history of this disease. 322 previously reported cases and 71 previously unreported cases were identified for inclusion. Source publications were identified via PubMed central search and by references from review articles. Previously unreported cases were identified via computerised medical records search at two veterinary institutions. FCE was most common in middle-aged large breed dogs (30 per cent); however, the miniature schnauzer was the most frequently reported individual breed and small breeds comprised 24 per cent of all reported cases. The most common neuroanatomical localisation was a T3-L3 myelopathy (33.1 per cent). Prognosis for recovery of ambulation was good to excellent with 85 per cent of cases regaining the ability to walk unassisted, most within 3 weeks. Persistent neurological deficits were common in patients that recovered ambulation (49.1 per cent). When nociception was absent in the affected limbs at initial presentation, rate of recovery was lower (10 per cent); however, this data is likely biased by limited follow-up in more severe cases. Future prospective studies should evaluate prognosis for more severely affected patients.

Cloning and sequencing of a gene encoding cellobiose dehydrogenase from Trametes versicolor.

Cellobiose dehydrogenase (CDH) is an enzyme produced under lignocellulose-degrading conditions by Trametes versicolor strain 52J (Tv) and several other wood-degrading fungi, including Phanerochaete chrysosporium (Pc). In order to understand better the nature and properties of this enzyme, we isolated a genomic clone of Tv cdh using heterologous probes derived from the sequence of Pc cdh. DNA sequence analysis revealed that Tv cdh consists of 3091 bp of coding sequence interrupted by 14 introns. Southern blotting showed that the gene was present in a single copy in the strain of Tv analyzed. Tv cdh was shown by Northern blot analysis to be expressed as a single transcript under cellulolytic conditions. RT-PCR of poly(A)+ RNA isolated under cellulolytic conditions was used to generate a near full-length cDNA copy of the cdh mRNA. The deduced protein encoded by Tv cdh consists of 768 amino acids (aa), including a predicted 19 aa signal peptide. The protein had 73% identity to the corresponding protein from Pc, which is the only other CDH-encoding gene that has been cloned. Based upon its deduced primary structure and alignment to similar sequences, Tv CDH shares a general structural organization with Pc CDH and other hemoflavoenzymes. Amino acid residues H-109 and M-61 in the N-terminal heme domain are hypothesized to function in heme binding; the C-terminal flavin domain contained a consensus sequence for flavin binding between residues 217-222. Although the protein is known to bind to cellulose, no obvious homology to bacterial or fungal cellulose binding domains was observed. However, a strong homology was observed to a region of Pc CDH that is hypothesized to be involved in cellulose binding.

Deletion of the Schizophyllum commune A alpha locus: the roles of A alpha Y and Z mating-type genes.

The A alpha locus is one of four master regulatory loci that determine mating type and regulate sexual development in Schizophyllum commune. We have made a plasmid containing a URA1 gene disruption of the A alpha Y1 gene. Y1 is the sole A alpha gene in A alpha 1 strains. We used the plasmid construction to produce an A alpha null (i.e., A alpha delta) strain by replacing the genomic Y1 gene with URA1 in an A alpha 1 strain. To characterize the role of the A alpha genes in the regulation of sexual development, we transformed various A alpha Y and Z alleles into A alpha delta strains and examined the acquired mating types and mating abilities of the transformants. These experiments demonstrate that the A alpha Y gene is not essential for fungal viability and growth, that a solitary Z A alpha mating-type gene does not itself activate development, that A beta proteins are sufficient to activate the A developmental pathway in the absence of A alpha proteins and confirm that Y and Z genes are the sole determinants of A alpha mating type. The data from these experiments support and refine our model of the regulation of A-pathway events by Y and Z proteins.

The A alpha mating-type locus of Schizophyllum commune: structure and function of gene X.

Gene X maps immediately right of gene Y at the A alpha mating-type locus in Schizophyllum commune. Alleles X1, X3 and X4 were isolated, subcloned, and sequenced. The structure of the alleles and their relationship to the A alpha locus is described. The deduced X isoforms possess no recognized motifs common to other polypeptides and no significant similarity to any sequences in the protein data-bases. X alleles do not activate A-regulated development when transformed into recipient strains possessing different A alpha mating types or when these transformants are mated with tester strains. An X1-disrupted construction yielded a high frequency (33%) of homologous gene replacements. X-disrupted mutants have wild-type phenotypes and mate normally. Both the functional analyses and sequence data for X1, X3, and X4 suggest that the right boundary of the A alpha mating-type locus falls between A alpha Y and X. We propose that the Z and Y genes constitute the A alpha locus in its entirety.