RFLP and linkage analysis of the porcine casein loci—CASAS1, CASAS2, CASB and CASK

Restriction fragment length polymorphisms (RFLPs) were revealed at the porcine casein loci with the following combinations of restriction endonucleases and porcine cDNA clones: α_s1,-casein (TaqI); α_s2-casein (BamHI); and ß-casein (Sacl). These RFLPs were shown to be under simple monogenic control by segregation analysis of two- and three-generation families. The CASAS1, CASAS2 and CASB casein loci were also shown to be linked with no recombinant haplotypes observed amongst 77 meioses in Large White and Meishan F₁ and F₂ crosses. No recombinants were observed in a further 106 meioses that were informative for linkage between CASAS1 and CASAS2.     

Inclusion of phytosociological data in an index of vegetation fire danger: application and mapping on the Karst area around Trieste (Italy)

In this paper we propose a method to produce maps of fire danger index (FDI). The index includes in the formula a vegetation pyrogenic potential index (VPPI) based on floristic phytosociological data. The map of FDI is produced by integrating available phytosociological maps of vegetation, geomorphology and climate, using the Geographic Information System technology. The method is applied to an area of the coastal Classical Karst (NE-Italy). While fire risk maps based on the incidence of previous fires are useful for facilitating emergency operations, e.g. the allocation of fire fighting resources, we conclude that the proposed index offers an effective tool to plan actions for fire prevention.     

Production of keto-disaccharides from aldo-disaccharides in subcritical aqueous ethanol

Isomerization of disaccharides (maltose, isomaltose, cellobiose, lactose, melibiose, palatinose, sucrose, and trehalose) was investigated in subcritical aqueous ethanol. A marked increase in the isomerization of aldo-disaccharides to keto-disaccharides was noted and their hydrolytic reactions were suppressed with increasing ethanol concentration. Under any study condition, the maximum yield of keto-disaccharides produced from aldo-disaccharides linked by β-glycosidic bond was higher than that produced from aldo-disaccharides linked by α-glycosidic bond. Palatinose, a keto-disaccharide, mainly underwent decomposition rather than isomerization in subcritical water and subcritical aqueous ethanol. No isomerization was noted for the non-reducing disaccharides trehalose and sucrose. The rate constant of maltose to maltulose isomerization almost doubled by changing solvent from subcritical water to 80 wt% aqueous ethanol at 220 °C. Increased maltose monohydrate concentration in feed decreased the conversion of maltose and the maximum yield of maltulose, but increased the productivity of maltulose. The maximum productivity of maltulose was ca. 41 g/(h kg-solution).     

Characterization of five new bovine dinucleotide repeats

Five new bovine (TG)n microsatellite sequences were characterized. During the screening procedure, one-third of the clones had essentially the same flanking sequences. A fast technique was devised to eliminate these clones.     

Linkage of hyperkalaemic periodic paralysis in Quarter horses to the horse adult skeletal muscle sodium channel gene

A genetic disease observed in certain Quarter horses is hyperkalaemic periodic paralysis (HYPP). This disease causes attacks of paralysis which can be induced by ingestion of potassium. Recent studies have shown that HYPP in humans is due to single base changes within the adult skeletal muscle sodium channel gene. A large Quarter horse pedigree segregating dominant HYPP was studied to determine if mutations of the sodium channel gene are similarly responsible for HYPP in horses. We used cross-species, PCR-mediated, cDNA cloning and sequencing of the horse adult skeletal muscle sodium channel alpha-subunit gene to identify a polymorphism, and then used this polymorphism to see if the horse sodium channel gene was genetically linked to HYPP in horses. The sodium channel gene was indeed found to be tightly linked to HYPP (LOD = 2.7, theta = 0). Our results suggest that HYPP in horses involves the same gene as the clinically similar human disease, and indicates that these are homologous disorders. The future identification of the specific sodium channel mutation causing HYPP in Quarter horses will permit the development of accurate molecular diagnostics of this condition, as has been recently shown for humans.     

Mapping markers linked to porcine salmonellosis susceptibility

The goal of this study was to identify pig chromosomal regions associated with susceptibility to salmonellosis. Genomic DNA from pig reference populations with differences in susceptibility to Salmonella enterica serovar Choleraesuis as quantified by spleen and liver bacterial colonization at day 7 post-infection (dpi; Van Diemen et al. 2002 ) was used. These samples belonged to the offspring of a sire thought to be heterozygous for genes involved in susceptibility to salmonellosis. Amplified fragment length polymorphism (AFLP) markers were created and used to determine associations with spleen or bacterial counts at 7 dpi. To position linked markers, two mapping populations, the Roslin and Uppsala PiGMaP pedigrees were used to create an integrated map which included the AFLP markers associated with salmonellosis. Twenty-six AFLP markers located in 14 different chromosomal regions in the porcine genome were found to be significantly associated with susceptibility (Chi-square P  < 0.05). More than one linked marker was found on chromosomes 1, 7, 13, 14 and 18. It is likely that these regions contain genes involved in Salmonella susceptibility. Regions on chromosomes 1, 7 and 14 were significantly associated with Salmonella counts in the liver and regions on chromosomes 11, 13 and 18 with counts in spleen. The identification of these chromosomal regions highlights specific areas to search for candidate genes that may be involved in innate or adaptive immunity. Further investigation into these chromosomal regions would be useful to improve our understanding of host responses to infection with this widespread pathogen.     

The distribution of carbohydrate side chains along the polypeptide chain of glucoamylase

Glucoamylase is a starch-hydrolyzing enzyme with a glycoprotein structure, used industrially for the conversion of starch to glucose, citric acid, corn syrups, and high-fructose sweeteners. This enzyme possesses an unusual type of structure in which many carbohydrate side chains are linked O-glycosidically to serine and threonine residues of the polypeptide chain. The carbohydrate side chains may be single monosaccharide residues or oligosaccharides of mannose, glucose, galactose, and in some cases N-acetylglucosamine. New data from experiments on the CNBr fragmentation of glucoamylase followed by chemical and immunological characterization of the fragments show that the carbohydrate side chains are distributed randomly along the polypeptide chain. Such a structure is appropriately termed a random model reprensentation for the glucoamylase molecule.     

A new allele at the Pgd locus in pigs

A new electrophoretic variant of porcine 6-phosphogluconate dehydrogenase (PGD) is described. The new variant, PGD C, has been shown to be controlled by a third allele, PgdC, at the Pgd locus.     

Construction of a genetic linkage map for silver carp (Hypophthalmichthys molitrix)

For silver carp (Hypophthalmichthys molitrix), a combined microsatellite (or simple sequence repeat) and amplified fragment length polymorphism (AFLP) sex average linkage map was constructed. A total of 483 markers (245 microsatellites and 238 AFLPs) were assigned to 33 linkage groups. The map spanned 1352.2 cM, covering 86.4% of the estimated genome size of silver carp. The maximum and average spaces between 420 loci were 21.5 cM and 3.2 cM, respectively. The length of linkage groups ranged from 3.6 cM to 98.5 cM with an average of 41.0 cM. The number of markers per group varied from 2 to 44 with an average of 14.6. The AFLP markers significantly improved the integrity of microsatellite-based linkage groups and increased the genome coverage and marker evenness. A genome-wide recombination suppression was observed in male. In an extreme case, six microsatellites co-segregated in male, but spanned a 45.1 cM region in female.