Fine-Scale Spatial Genetic Structure in Perennial Grasses in Three Environments

Past research has shown that changes in grazing-resistance traits may be associated with genetic changes in plant populations. Little is known about spatial genetic relationships within plant populations (spatial genetic structure) and any grazing effects on these relationships. Here we present observations of the fine-scale spatial genetic structure in three grass species in semiarid environments (Arizona, Mexico, and Argentina). In each environment, populations of a dominant grass species were sampled from two sites with contrasting livestock grazing histories. Plant genotypes were described with the use of amplified fragment length polymorphism markers. In Arizona, populations of sideoats grama (Bouteloua curtipendula var. caespitosa Gould and Kapadia) differed in that one has never experienced livestock grazing, whereas cattle have grazed the other. In the other two environments, populations exposed to long-term heavy grazing were examined, along with those that experienced either moderate grazing (Mexico, blue grama [Bouteloua gracilis {Willd. ex Kunt} Lag. ex Griffiths]) or extended exclusion of livestock (Argentina [Poa ligularis Nees ex Steud.]). Based on independent analysis of each population, we observed no differences in average gene diversity between populations of each species. With the use of analysis of molecular variance we found slight but significant genetic differentiation between populations with different grazing histories in Arizona and Argentina. Significant genetic structure was present in all populations and indicated an inverse relationship between spatial and genetic distance. Interestingly, this relationship was most pronounced in the cattle-free sideoats grama population, suggesting larger genetic neighborhood areas in the absence of livestock. Less distinct differences in spatial genetic structure associated with grazing history were evident in the other two species. We hypothesize that livestock grazing may lead to increased homogeneity in genetic structure at the landscape scale. Effectively examining this hypothesis presents many experimental challenges.     

Effect of colostrum treated by heat on immunological parameters in newborn lambs

Seventeen newborn lambs were fed with untreated colostrum (group A) and 18 lambs were fed with colostrum treated by heat (56 °C, 30 min) (group B). Blood samples were obtained at seven time points from day 0 to 38 of life. Clinical status and body weight were recorded and serum protein fractions and IgG levels were determined in blood. Phagocytosis of neutrophils from the lambs and opsonic capacity of their serum were examined using a flow cytometry method. As an indicator of in vivo cellular immunity, reactions to intradermal injection of phytohemagglutinin (PHA) were examined at 8 and 16 days of age. There were no clinical signs of disease and no significant differences in body weight between groups. Lambs from group B had lower total protein initially and lower γ-globulin and IgG levels until day 32 compared to lambs from group A (P < 0.01). Heat treatment of colostrum had no significant effect on serum opsonic capacity or phagocytosis by neutrophils and these functions increased with age. However, responses to PHA in lambs from group B were lower (P < 0.01) than group A at day 8 of life, but not at day 16, suggesting that cellular immunity was affected by the treatment of colostrum. These results showed that colostrum treated by heat impaired cellular and IgG levels in lambs, but not phagocytic function. However, these changes did not affect the health or performance of the lambs.     

Stress response of extensively reared young bulls being transported to growing-finishing farms under Spanish summer commercial conditions

To evaluate the effect of Spanish summer commercial journeys on the stress response of young bulls born and reared under extensive conditions, 2 replicates of a transport from an assembly centre to a growing-finishing farm were studied. Journeys lasted 27 h, involving a total of 62 young bulls. Variables under study included haematocrit, red blood cell count (RBC), total white blood cell count (WBC), differential WBC counts, serum haptoglobin (Hp), cortisol, glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), total protein, and albumin at loading, at the end of an intermediate market stop, and at the unloading. Before the beginning of the journey elevated WBC and neutrophil counts, and high Hp values were detected, reflecting high stress levels probably as a consequence of previous procedures associated with the grouping at the assembly centre. Some stress was also detected at the end of the market stop, with cortisol increasing from 6.5 to 12.6 ± 2.0 ng/mL (P < 0.001), although a change in Hp concentration was not observed. Neither CPK and LDH activities, related to muscular tissue damage, nor haematocrit and RBC count, related to dehydration revealed a significant effect of this first stage of the journey on the physical stress of the young bulls. Subsequent 13 h transport to the growing-finishing farm induced an increase in Hp levels from 0.48 to 0.78 ± 0.16 mg/mL (P < 0.001), reflecting an onset of the acute stress response, although cortisol levels immediately after the unloading were similar to those found before loading at the market, suggesting that calves got accustomed to transport. At the end of the journey some dehydration and physical stress were also detected. Overall, our study provides new information to the discussion of the effect of temperatures during cattle transport. Although an improvement in pre-transport conditions is essential if the welfare of assembled and transported cattle is to be improved, the stress-related alteration of cattle physiology under Spanish summer commercial transport conditions is similar to that observed under colder conditions.     

A recombinant-based ELISA evaluating the efficacy of netobimin and albendazole in ruminants with naturally acquired fascioliasis

The therapeutic efficacy of albendazole and netobimin in ruminants with naturally occurring fascioliasis was investigated using a recombinant-based ELISA. The variation in the IgG response against a 2.9-kDa recombinant protein (FhrAPS), termed efficacy index (EI) 1, and the egg-output changes, termed EI 2, were used to evaluate drug efficacy.The values of EI 1 ranged between 0% and 50% in sheep, and between 0% and 30% in cattle after treatment with albendazole and netobimin. Similar EI 2 values were observed in sheep receiving albendazole or netobimin, but the highest values were found in cattle treated with netobimin. The significant reduction in the IgG response to FhrAPS found in this study shows promise in terms of developing alternative methods for evaluating the efficacy of chemotherapy against Fasciola hepatica in grazing ruminants.     

Molecular characterisation of Cryptosporidium isolates from pet reptiles

In this study, we investigated the presence of Cryptosporidium in 171 faecal samples from reptiles commonly used as pet animals. These include lizards belonging to the genera Eublepharis, Pogona, Chlamydosaurus, Hemiteconyx, Teratoscincus, Tiliqua, Iguana, and Chamaeleo, snakes of the genera Lampropeltis, Elaphe, Python, Boa and Corallus, and tortoises belonging to the genera Testudo and Kinixys. Cryptosporidium oocysts were detected by immunofluorescence using a commercially available kit and cryptosporidial DNA by amplification of a polymorphic fragment of the 18S rDNA and the HSP70 locus.Cryptosporidium was detected in 38.6% and 25.1% of the samples analysed by immunofluorescence and PCR, respectively. Molecular characterisation of the isolates confirmed that C. serpentis and C. varanii (syn. C. saurophilum) are the main species involved in infection in pet reptiles but also showed the presence of C. parvum and C. muris, as well as other species or genotypes of this parasite including the Cryptosporidium mouse genotype and Cryptosporidium tortoise genotype previously described in reptiles. In addition, a Cryptosporidium sp. was isolated from a chameleon and a python.     

Cytochrome P450 3A, NADPH cytochrome P450 reductase and cytochrome b5 in the upper airways in horse

Gene and protein expression as well as catalytic activity of cytochrome P450 (CYP) 3A were studied in the nasal olfactory and respiratory mucosa and the tracheal mucosa of the horse. We also examined the activity of NADPH cytochrome P450 reductase (NADPH P450 reductase), the amount of cytochrome b(5) and the total CYP content in these tissues. Comparative values for the above were obtained using liver as a control. The CYP3A related catalytic activity in the tissues of the upper airways was considerably higher than in the liver. The CYP3A gene and protein expression, on the other hand, was higher in the liver than in the upper airway tissues. Thus, the pattern of CYP3A metabolic activity does not correlate with the CYP3A gene and protein expression. Our results showed that the activity of NADPH P450 reductase and the level of cytochrome b(5) in the relation to the gene and protein expression of CYP3A were higher in the tissues of the upper airways than in the liver. It is concluded that CYP3A related metabolism in horse is not solely dependent on the expression of the enzyme but also on adequate levels of NADPH P450 reductase and cytochrome b(5).     

Identification of carcass and meat quality quantitative trait loci in a Landrace pig population selected for growth and leanness

The identification of QTL related to production traits that are relevant for the pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.     

Immunoglobulin G and E responses in various stages of canine leishmaniosis

Pathogenesis in visceral leishmaniosis is associated with depressed cellular immunity and a significant rise of antileishmanial antibodies. We assessed the relative levels of immunoglobulin E anti-Leishmania infantum, together with those of IgG, IgG1 and IgG2, using the enzyme-linked immunosorbent assay (ELISA) test, in non-infected and infected dogs with or without symptoms, and their association with symptoms to differentiate the stages of the infection. The expression of all immunoglobulins (IgG, IgG1, IgG2 and IgE) was higher in symptomatic dogs than in all other categories. IgG and IgG2 expression was higher in the infected asymptomatic group than in the non-infected group, whereas IgG1 and IgE expression was only higher in symptomatic animals. This correlation between the expression of IgG1 and IgE and the pathology of leishmaniosis points to their potential role as markers of the active disease.     

Cyclooxygenase-2 expression is related with localization, proliferation, and overall survival in canine melanocytic neoplasms

A direct relationship has been firmly established between cyclooxygenase-2 (COX-2) expression and malignant behavior in human melanoma. This report examines the relationship between COX-2 expression and tumor location, mitotic and proliferative indices, degree of T CD3(+) lymphocyte infiltration, overall survival, and frequency of recurrence and metastasis of 57 melanocytic tumors (25 oral and 32 cutaneous). COX-2 was highly or moderately expressed in 88% of oral neoplasms (22 of 25), whereas for their cutaneous counterparts, COX-2 expression was low or insignificant in 75% of cases (24 of 32). High and moderate COX-2 expression levels were observed in 73% of melanocytic tumors with a mitotic index ≥ 3 per 10 high-power fields (26 of 36), whereas in 81% of tumors with a mitotic index < 3 (17 of 21), expression was mild or absent. There were 41 cases with known clinical outcomes; of those showing high, moderate, and mild COX-2 expression, 83.3% (10 of 12), 37.5% (3 of 8), and 25% (2 of 8) died, respectively, whereas 100% of animals showing no COX-2 expression (13 of 13) were still alive at the last follow-up. COX-2 expression was statistically correlated with tumor location, mitotic and percentage Ki-67 proliferative indices, and overall survival, frequency of neoplastic recurrence and metastasis. Regression analysis also showed disease-specific predictive value for COX-2 expression for subjects with melanocytic neoplasms. Additionally, only high COX-2 expression showed significant differences in overall survival, in comparison with moderate, mild, or absent expression. These results suggest that high COX-2 expression may be considered a prognostic biomarker and potentially as a target for therapeutic and preventive strategies in canine melanocytic neoplasms.