Molecular and biochemical characterization of the Neurospora crassa glycogen synthase encoded by the gsn cDNA

Glycogen synthases catalyze the transfer of a glucosyl moiety from a nucleotide phosphosugar to a nascent glycogen chain via an alpha1-->4 linkage. Although many genes coding for glycogen synthases have been described, the enzymes from rabbit and yeast are the best characterized. The fungus Neurospora crassa accumulates glycogen during exponential growth, and mobilizes it at the onset of stationary phase, or when placed at high temperature or starved for carbon. Through a PCR methodology, the gsn cDNA coding for the N. crassa glycogen synthase was isolated, and the amino acid sequence of the protein was deduced. The product of the cDNA seems to be the only glycogen synthase present in N. crassa. Characterization of the gsn cDNA revealed that it codes for a 706-amino acids protein, which is very similar to mammalian and yeast glycogen synthases. Gene expression increased during exponential growth, reaching its maximal level at the end of the exponential growth phase, which is consistent with the pattern of glycogen synthase activity and glycogen level. Expression of the gsn is highly regulated at the transcriptional level. Under culture conditions that induce heat shock, conidiation, and carbon starvation, expression of the gsn gene was decreased, and glycogen synthase activity and glycogen content behaved similarly.

Purification and biochemical characterization of an endoxylanase from Aspergillus versicolor

An endoxylanase (beta-1,4-xylan xylanohydrolase, EC 3.2.1.8) was purified from the culture filtrate of a strain of Aspergillus versicolor grown on oat wheat. The enzyme was purified to homogeneity by chromatography on DEAE-cellulose and Sephadex G-75. The purified enzyme was a monomer of molecular mass estimated to be 19 kDa by SDS-PAGE and gel filtration. The enzyme was glycoprotein with 71% carbohydrate content and exhibited a pI of 5.4. The purified xylanase was specific for xylan hydrolysis. The enzyme had a K-m of 6.5 mg ml(-1) and a V-max of 1440 U (mg protein)(-1). (C) 1998 Federation of European Microbiological Societies. Published by Elsevier B.V. B.V. All rights reserved.

Biological and biochemical properties of the Brazilian Potamotrygon stingrays : Potamotrygon cf. scobina and Potamotrygon gr. orbignyi

Stingrays of the family Potamotrygonidae are widespread throughout river systems of South America that drain into the Atlantic Ocean. Some species are endemic to the most extreme freshwater environment of the Brazil and cause frequent accidents to humans. The envenomation causes immediate, local, and intense pain, soft tissue edema, and a variable extent of bleeding. The present study was carried out in order to describe the principal biological and some biochemical properties of the Brazilian Potamotrygon fish venoms (Potamotrygon cf. scobina and P. gr. orbignyi). Both stingray venoms induced significant edematogenic and nociceptive responses in mice. Edematogenic and nociceptive responses were reduced when the venom was incubated at 37 or 56 degrees C. The results showed striking augments of leukocytes rolling and adherent cells to the endothelium of cremaster mice induced by both venoms. The data also presented that injection of both venoms induced necrosis, low level of proteolytic activity, without inducing haemorrhage. But when the venoms of both stingray species were injected together with their mucus secretion, the necrotizing activity was more vigorous. The present study provided in vivo evidence of toxic effects for P. cf. scobina and P. gr. orbignyi venoms. (c) 2006 Elsevier Ltd. All fights reserved.

Genetic and phenotypic trends for growth traits of buffaloes in Brazil

The objectives this paper were to estimate genetic parameters and genetic and phenotypic trends of birth weight (BWT) and weights adjusted to 205 (WT205), 365 (WT365) and 550 (P550) days of age of beef buffaloes born from 1985 to 2003 in Brazil. For BWT and WT205 the model included direct and maternal genetic and maternal environment as random effects and contemporary and genetic groups as fixed effects. For WT365 and WT550 the same model was used except without direct maternal and maternal environmental effects. The genetic and phenotypic trends were estimated by regression of means of dependent variables on birth year of animals Regressions were obtained by using two methodologies: 1) linear regression; and 2) non-parametric splined regression. The direct heritability estimates were 0.09, 0.45, 0.46 and 0.58 for BWT, WT205, WT365 and WT550, respectively. The direct genetic trends from linear regression were 0.01, 0.23, 0.58 and 1.40 kg per year for PN, WT205, VVT365 and WT550, respectively (P<0.001 for all). Phenotypic trends were strongly positive while genetic trends were consistently positive but small. Genetic parameters indicate potential for increased rate of genetic change with full implementation of genetic improvement programs.

Experimental Trypanosoma evansii infection in South American coati (Nasua nasua): hematological, biochemical and histopathological changes

The course of an experimental Trypanosoma evansi infection in coatis (Nasua nasua, carnivora, Procyonidae) was followed for 262 days. Hematological analysis of the infected coatis revealed a marked decline in hemoglobin, packed-cell volume, and total erythrocyte count. An intense anemia followed the first wave of parasitemia and persisted until the end of the experimental period. Biochemical analysis showed increased serum levels of alanine aminotransferase and aspartate aminotransferase and decreased albumin. The main histopathological features consisted of myocarditis with the presence of degenerate cardiac fibers and meningoencephalitis. This study has shown that coatis infected with T. evansi develop a chronic disease. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Genetic evaluation of performance traits in Brazilian Quarter Horse

The aim of this study was to estimate genetic parameters for racing performance traits in Quarter Horses in Brazil. The data (provided by the Sorocaba Jockey Club) came from 3 Brazilian hippodromes in 1994-2003, with 11875 observations of race time and 7775 of the speed index (Sl), distributed in 2403 and 2169 races, respectively. The variance components were estimated by the MTGSAM program, under animal models including the random additive genetic effect, random permanent environmental effect, and the fixed effects of sex, age and race. Heritabilities for race time and the SI, for the 3 distances studied (301, 365 and 402 in), varied from 0.26 to 0.41 and from 0. 14 to 0. 19, respectively, whereas repeatabilities varied from 0.36 to 0.68 (time) and from 0.27 to 0.42 (SI) and the genetic correlations from 0.90 to 0.97 (time) and from 0.67 to 0.73 (SI).

A rapid procedure for the isolation of the Lys-49 myotoxin II from Bothrops moojeni (caissaca) venom: Biochemical characterization, crystallization, myotoxic and edematogenic activity

A, M. Soares, V, M, Rodrigues, M. I. Homsi-Brandeburgo, M. H. Toyama, F, R, Lombardi, K. Arni and J. R, Giglio. A rapid procedure for the isolation of the Lys-49 myotoxin II from Bothrops moojeni (caissaca) venom: Biochemical characterization, crystallization, myotoxic and edematogenic activity. Toxicon 36, 503-514, 1998.-Bothrops moojeni snake venom was fractionated on a CM-Sepharose column which was previously equilibrated with 0.05 M ammonium bicarbonate buffer at pH 8.0 and subsequently eluted with an ammonium bicarbonate concentration gradient from 0.05 to 0.5 M at constant pH (8.0) and temperature (25 degrees C). The fraction which eluted last (M-VI) showed, after direct lyophilization, a single band by polyacrylamide gel electrophoresis (PAGE) and SDS-PAGE, indicating an approximate M,. of 14 000 and 77 000, in the presence and absence of dithiothreitol, respectively. Its amino acid composition revealed a high level of hydrophobic and basic amino acids as well as 13 half-cystine residues. Its isoelectric point and extinction coefficient (E-1.0cm(1.0mg/ml) at 278 nm and pH 7.0) were 8.2 and 1.170, respectively. M-VI was devoid of phospholipase A(2) (PLA(2)) activity on egg yolk, as well as of hemorrhagic, anticoagulant and coagulant activities, but could induce drastic necrosis on skeletal muscle fibres as well as rapid and transient edema on the rat paw. Its N-terminal sequence: SLFELGKMILQETGKNPAKSYGVYGCNCGVGGRGKPKDATDRCCYVHKCCYK.... revealed high homology with other Lys 49 PLA(2)-like myotoxins from other bothropic venoms. Orthorhombic crystals of M-VI? which diffracted to a maximal resolution of 1.6 Angstrom. were obtained and indicated the presence of a dimer in the asymmetrical unit. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Univariate and bivariate distribution of growth traits in beef buffaloes from Brazil

The aim of this study was to analyze the weight at birth (BW) and adjusted at 205 (W205), 365 (W365) and 550 (W55O) days in beef buffaloes from Brazil, using two approaches: parametric, by normal distribution, and non-parametric, by kernel function, and thus estimating the genetic, environmental and phenotypic correlation among traits. Information of 5,169 animals at birth (BW), 3,792 at 205 days (W205), 3.883 at 365 days (W365) and 1,524 at 550 days of age (W550) were used. The birth weight distribution presented an evident discrepancy in relation to the normal distribution. However, W205, W365 and W550 presented normal distributions. The birth weight presented weak genetic, environmental, and phenotypic associations with the other weight measurements. on the other hand, the weight traits at 205, 365, 550 days of age showed a high genetic correlation.

Growth, carcass and meat quality traits of straightbred and crossbred Botucatu rabbits

The objective was to evaluate the effects of genetic group and age on growth, carcass, and meat traits of rabbits. A total of 144 straightbred Botucatu and White German Giant x Botucatu crossbred rabbits were involved. Rabbits were weaned at 35 d and sequentially, slaughtered, four per genetic group x sex combination, at: 42, 49, 56, 63, 70, 77, 84 and 91 d. A 2x2 factorial arrangement was employed in a completely randomized design with repeated measures for growth traits, and a split-plot for carcass and meat traits. Crossbred rabbits were heavier (2032 vs. 1962 g; P < 0.01), consumed more feed (143.5 vs. 131.0 g/d; P < 0.01), and presented higher slaughter weight (2169 vs. 2093 g, P=0.02) and dressing percentage (59.0 vs. 58.2%; P=0.07) than straightbreds throughout the experiment. No difference between genetic groups was detected for feed conversion and empty gastrointestinal weight corrected for slaughter weight (SW). Crossbreds showed higher skin weight (308.2 vs. 299.7 g, P = 0.06) and distal parts of leg weight (75.7 vs. 71.4 g; P < 0.01), both corrected for SW. No genetic group effect was detected on dissectible fat and hind part weights. Chilled commercial carcass (1284 vs. 1229 g: P=0.02), chilled reference carcass (1036 vs. 1000 g, P=0.06), fore part (297.9 vs. 283.3 g; P=0.01) and loin (308.7 vs. 295.5 g; P=0.05) were heavier in crossbreds than in straightbreds, but these differences were attributed to differences in SW. Uncorrected weights of head, kidneys, liver and thoracic viscera were higher in the crossbred group, but only head (116.6 vs. 113.6 g; P=0.06) and thoracic viscera (30.4 vs. 28.6 g; P=0.01) were, in fact, proportionately heavier in crossbreds than in straightbreds. No effect of genetic group was detected on meat to bone ratio, muscle ultimate pH and chemical composition of the Longissimus dorsi muscle. All traits, except for ash and fat contents of the Longissimus muscle, showed age effects (P < 0.01). Crossbreeding may be recommended for the production of whole commercial carcasses, but it is not clearly advantageous for the production of retail cuts. Slaughter should take place between 63 and 70 d of age for both genetic groups.

Inbreeding and its effects on some productive and reproductive traits in a Murrah buffalo herd

Data concerning genealogy, milk yield, lactation length, caving interval and lac at first calving, obtained from Murrah buffaloes on a farm In São Paulo state, Brazil, were studied in order to determine the presence of inbreeding in the herd and to evaluate its effects as well as the effects of some environmental factors on productive and reproductive traits. The mean inbreeding coefficient estimated for 2414 animals, born from 1965 to 1995 was 2.94%. of these animals, 47% mere considered inbred with a mean inbreeding coefficient equal 6.25%. Milk production, lactation length, calving interval and age at first calving averaged 1493.3 +/- 60.7 kg, 271.0 +/- 37.3 days, 385.0 +/- 53.4 days and 33.05 +/- 6.05 months, respectively. Among all four traits, only lactation length was affected by inbreeding.

Intraspecific variability in the basal metabolic rate: Testing the food habits hypothesis

Several competing hypotheses attempt to explain how environmental conditions affect mass-independent basal metabolic rate (BMR) in mammals. One of the most inclusive and yet debatable hypotheses is the one that associates BMR with food habits, including habitat productivity. These effects have been widely investigated at the interspecific level under the assumption that for any given species all traits are fixed. Consequently, the variation among individuals is largely ignored. Intraspecific analysis of physiological traits has the potential to compensate for many of the pitfalls associated with interspecific analyses and, thus, to be a useful approach for evaluating hypotheses regarding metabolic adaptation. In this study, we investigated the effects of food quality, availability, and predictability on the BMR of the leaf-eared mouse Phyllotis darwini. BMR was measured on freshly caught animals from the field, since they experience natural seasonal variations in environmental factors ( and, hence, variations in habitat productivity) and diet quality. BMR was significantly correlated with the proportion of dietary plants and seeds. In addition, BMR was significantly correlated with monthly habitat productivity. Path analysis indicated that, in our study, habitat productivity was responsible for the observed changes in BMR, while diet per se had no effect on this variable.