Structural and functional correlates of a mutation in the malignant hyperthermia-susceptible pig ryanodine receptor.

The skeletal muscle ryanodine receptor of malignant hyperthermia-susceptible (MHS) pigs contains a mutation at residue 615 that is highly correlated with various abnormalities in the regulation of sarcoplasmic reticulum (SR) Ca2+ channel activity. In isolated SR membranes the Arg615 to Cys615 ryanodine receptor mutation is now shown to be directly responsible for an altered tryptic peptide map, due to the elimination of the Arg615 cleavage site. Furthermore, trypsin treatment released 86-99 kDa ryanodine receptor fragments encompassing residue 615 from the SR membranes. We conclude that the 86-99 kDa domain containing residue 615 is near the cytoplasmic surface of the ryanodine receptor and likely near important Ca2+ channel regulatory sites.     

Occurrence of long-finned pilot whales (Globicephala melas) and killer whales (Orcinus orca) in Icelandic coastal waters and their interspecific interactions

acta ethologica - Long-finned pilot whales and killer whales are widely distributed across the North Atlantic, but few studies have reported their occurrence in Icelandic coastal waters. Here, we...     

Effect of dental tool surface texture and material on static friction with a wet gloved fingertip

Hand injuries are an important cause of pain and disability among dentists and dental hygienists and may be due to the high pinch forces involved in periodontal work. The pinch forces required to perform scaling may be reduced by increasing the friction between the tool and fingers. The purpose of this study was to determine whether modifying the tool material, surface texture, or glove type altered the coefficient of static friction for a wet gloved finger. Seven tools with varying surface topography were machined from 13 mm diameter stainless steel and Delrin and mounted to a 6-component force plate. The textures tested were a fine, medium and coarse diamond knurled pattern and a medium and fine annular pattern (concentric rings). Thirteen subjects pulled their gloved, wet thumb pad along the long axis of the tool while maintaining a normal force of 40 N. Latex and nitrile gloves were tested. The coefficient of static friction was calculated from the shear force history. The mean coefficients of static friction ranged from 0.20 to 0.65. The coefficient of static friction was higher for a smooth tool of Delrin than one of stainless steel. Differences in the coefficient of static friction were observed between the coarse and medium knurled patterns and the fine knurled and annular patterns. Coefficients of static friction were higher for the nitrile glove than the latex glove for tools with texture. These findings may be applied to the design of hand tools that require fine motor control with a wet, gloved hand.     

Sitting height: An analysis of five measurement techniques

Five methods of obtaining sitting height were compared by taking triple trials of each. Three methods required that the subjects be seated on a table, the fourth had them sitting on the floor against a wall, and the fifth placed them in a recumbent position. Three trials of the first method were obtained without stretching and with the feet unsupported. These were followed by stretching techniques with subjects seated on the table, first with the feet unsupported and then with them supported, then with the subjects sitting on the floor, and finally with the subjects in the recumbent position. All methods were shown to be precise, with the smallest absolute measurements and highest technical error of measurement noted in the floor seated method. There was a tendency for females to yield greater values from being stretched, and for males to have greater values in the recumbent position.     

The hinge region between two ubiquitin-like domains destabilizes recombinant ISG15 in solution

Interferon-stimulated gene (ISG) 15 mediates antiviral responses and also is upregulated within the endometrium in response to the developing embryo during early pregnancy. Structurally, ISG15 resembles two ubiquitin domains (30% identical) that are separated by a hinge region. Recombinant (r) bovISG15 is not stable in solution. It was hypothesized that the hinge region contributed to the instability of rbovISG15. Within 24 h of dialysis, rbovISG15 formed complexes as detected by reducing and denaturing SDS-PAGE. However, chemical perturbations of cysteine prevented formation of rbovISG15 complexes over time. Furthermore, a site-directed mutant of rbovISG15 (Cys80Ser) was isomeric and more stable than rbovISG15. Neither wild-type nor mutant rbovISG15 was able to interact with the ISG15 E1 initiating enzyme, UBE1L, in an in vitro pull-down assay. Ovine (ov) ISG15 has three additional amino acids within the hinge region that were hypothesized to increase stability and the degree of interaction with UBE1L because of increased separation of the ubiquitin-like domains. Over time in solution, rovISG15 the level of rovISG15 secondary structure was diminished, whereas the Cys80Ser rovISG15 structure did not change. A GST-Cys80Ser rovISG15 fusion protein had increased structural stability and enhanced protein-protein interaction with UBE1L after dialysis for 48 h, when compared to the GST-rovISG15 fusion protein or rbovISG15. Models of bovISG15, Cys80Ser bovISG15, and ovISG15 were constructed, which confirmed that the hinge region between the two ubiquitin domains destabilizes rbovISG15 in solution.     

Genome‐wide association with delayed puberty in swine

An improvement in the proportion of gilts entering the herd that farrow a litter would increase overall herd performance and profitability. A significant proportion (10–30%) of gilts that enter the herd never farrow a litter; reproductive reasons account for approximately a third of gilt removals, with anestrous and failure to conceive the most common reasons for culling. Tools to select gilts for reproductive longevity through genomics or alternative phenotypes would be of great benefit to the producer. Ninety‐one gilts that failed to display behavioral estrus by 240 days (cases) and 127 pubertal littermates (controls) were genotyped with the Illumina Porcine SNP60 Beadchip. One hundred and seventy‐four SNPs with the most significant associations were genotyped in an additional 86 cases and 103 controls. Twelve of these associations were significant in the final analysis. The most significant (P < 1.5 × 10^?14) region associated with failure to attain puberty was on chromosome 4 surrounding the NHLH2 gene. Delayed pubertal development and age at first estrus have been associated with NHLH2 in mice. Because attainment of puberty is a complex trait, identifying genes that affect pubertal age would greatly contribute to our knowledge of reproductive development as well as overall fertility.