Identification of Polymorphisms in the Osteopontin Gene and Their Associations with Certain Semen Production Traits of Water Buffaloes in the Brazilian Amazon

The osteopontin gene may influence the fertility of water buffaloes because it is a protein present in sperm. The aim of this work was to identify polymorphisms in this gene and associate them with fertility parameters of animals kept under extensive grazing. A total of 306 male buffaloes older than 18 months, from two farms, one in the state of Amapá and the other in the state of Pará, Brazil were used in the study. Seven SNPs were identified in the regions studied. The polymorphisms were in gene positions 1478, 1513 and 1611 in the region 5′upstrem and positions 6690, 6737, 6925 and 6952 in the region amplified in intron 5. The SNPs were associated with the traits, namely scrotal circumference, scrotal volume, sperm motility, sperm concentration and sperm pathology. There were significant SNPs (p < 0.05) for all the traits. The SNP 6690 was significant for scrotal circumference, sperm concentration, sperm motility and sperm pathology and the SNP 6737 for scrotal volume. The genotype AA of SNP 6690 presented the highest averages for scrotal circumference, sperm concentration and motility and the lowest total number of sperm pathologies. For the scrotal volume trait, the animals with the largest volume were correlated with the presence of the genotype GG of SNP 6737. These results indicate a significance of the osteopontin gene as it seems to exert a substantial influence on the semen production traits of male buffaloes.     

Massive liver hemorrhage in Ontario broiler chickens

A massive liver hemorrhage (MLH) recognized in Ontario broiler chickens had a characteristic clinical course and pathological lesions. Affected flocks had a higher death rate than normal, with no obvious clinical signs. Deaths from MLH began at two weeks of age; the mortality rate returned to a normal level by four weeks. The main necropsy finding was massive multiple liver hemorrhage with consequent profuse hemoperitoneum.     

Morphologic and immunohistochemical features of two spontaneous peripheral nerve tumors in Wistar rats

Morphologic features and S-100 protein immunoreactivity of a benign and malignant peripheral nerve sheath tumor were studied in two Wistar rats. Neoplasms that developed in untreated control rats from tumor bioassays were S-100 protein positive and had similar histopathologic features. Each peripheral nerve sheath tumor was encapsulated and composed of spindle cells arranged around small thin-walled blood vessels. Palisaded tumor cells were in the benign peripheral nerve sheath tumor while cells of the malignant peripheral nerve sheath tumor had cellular atypia and moderate numbers of mitoses. Ultrastructural examination of the malignant peripheral nerve sheath tumor revealed cells with external lamina and interdigitation of cytoplasmic processes. Intracytoplasmic concentric lamellae were seen; they were regularly spaced with a periodicity of about 15 nm. Such structures, indistinguishable from myelin sheaths, have not been commonly associated with peripheral nerve sheath tumors in man. Electron microscopy and immunohistochemistry were useful in the diagnosis of these tumors as Schwannomas and in differentiation from other spindle cell tumors.     

Belowground carbon dynamics in loblolly pine (Pinus taeda) immediately following diammonium phosphate fertilization

Forest soils store an immense quantity of labile carbon (C) and a may be a large potential sink for atmospheric C. Forest management practices such as fertilization may enhance overall C storage in soils, yet changes in physiological processes following nutrient amendments have not been widely investigated. We intensively monitored belowground C dynamics for nearly 200 days following diammonium phosphate fertilization of pot-grown loblolly pine (Pinus taeda L.) seedlings in an effort to examine the short-term effects of fertilization on processes involved in soil C sequestration. Soil respiration rates initially increased in fertilized pots relative to controls, followed by a brief reversal in this trend and then a final sustained pattern of elevated rates of soil respiration in the fertilized treatment. Patterns in soil respiration rates over time reflected changes in autotrophic (root) and heterotrophic (microbial) components of soil respiration. Root respiration rates were greater in the fertilized treatment 49 days following fertilization and returned to control rates by the end of the study. In contrast, microbial respiration rates and microbial activity per soil C concentration remained depressed over the same time period. Compared with control seedlings, total root biomass was 27% greater in fertilized seedlings harvested at the end of the study, indicating that the elevated soil respiration rates observed toward the end of the study were a result of increased respiring root biomass. We conclude that fertilization, at least over the short-term, may increase soil C sequestration by increasing belowground biomass production and reducing microbial driven C turnover.     

Competitive assembly of South Pacific invasive ant communities

Background  

The relative importance of chance and determinism in structuring ecological communities has been debated for nearly a century. Evidence for determinism or assembly rules is often evaluated with null models that randomize the occurrence of species in particular locales. However, analyses of the presence or absence of species ignores the potential influence of species abundances, which have long been considered of major importance on community structure. Here, we test for community assembly rules in ant communities on small islands of the Tokelau archipelago using both presence-absence and abundance data. We conducted three sets of analyses on two spatial scales using three years of sampling data from 39 plots on 11 islands.