The Effect of Magnesium and Calcium Ions on Adenosine Triphosphatases from Wheat and Oat Roots at Different pH

Microsomal fractions from wheat (Triticum vulgare) and oat (Avena sativa) roots were used to study Mg²⁺ and Ca²⁺ activated adenosine triphosphatases, their dependence of pH, and how Mg²⁺ and Ca²⁺ compete or add in stimulation and inhibition. Wheat gives a high proportion of Ca²⁺ stimulated ATPase. Less effect is obtained with Mg²⁺. The characteristics of oar ATPase are the reverse. The ATPase from the wheat roots depends on the mineral nutrition. A kinetïc analysis shows one site, where Mg²⁺ and Ca²⁺ at low concentrations (or complexes between the di-valents and ATP) cooperate in the activation of the ATPase. The action of this site is more dearly expressed at pH 6.0 than at 6.8, and more clearly in the preparations from low salt roots than in those from high salt conditions. In another site, which is particularly evident in preparations from high salt roots tested at pH 6.8, high concentrations of Mg²⁺ inhibit the ATPase; this inhibition is competitively relieved by Ca²⁺. The specific activity of the ATPase from high salt roots of wheat is higher than that from low salt roots, although the amount of protein of the fraction studied remains the same, when calculated per g fresh weight of the roots.     

The derivation of pelecypods: role of biomechanics, physiology and environment

A new model for the origin of pelecypods based on physiological and biomechanical viewpoints is presented. It seems that some early molluscs developed a bivalved shell in response to their migration from firm bottom onto soft sediments as epibenthic crawlers. Here a univalved shell cannot sufficiently protect the mantle cavity from getting clogged by sediment particles. The evolution of the pelecypod shell, of the necessary adductors and ligament, of the byssus and the change from grazing to filter-feeding life habit is explained as a step-by-step change, each stage providing an adaptational improvement.     

Low levels of taurine introgression in the current Brazilian Nelore and Gir indicine cattle populations

Background

Nelore and Gir are the two most important indicine cattle breeds for production of beef and milk in Brazil. Historical records state that these breeds were introduced in Brazil from the Indian subcontinent, crossed to local taurine cattle in order to quickly increase the population size, and then backcrossed to the original breeds to recover indicine adaptive and productive traits. Previous investigations based on sparse DNA markers detected taurine admixture in these breeds. High-density genome-wide analyses can provide high-resolution information on the genetic composition of current Nelore and Gir populations, estimate more precisely the levels and nature of taurine introgression, and shed light on their history and the strategies that were used to expand these breeds.

Results

We used the high-density Illumina BovineHD BeadChip with more than 777 K single nucleotide polymorphisms (SNPs) that were reduced to 697 115 after quality control filtering to investigate the structure of Nelore and Gir populations and seven other worldwide populations for comparison. Multidimensional scaling and model-based ancestry estimation clearly separated the indicine, European taurine and African taurine ancestries. The average level of taurine introgression in the autosomal genome of Nelore and Gir breeds was less than 1% but was 9% for the Brahman breed. Analyses based on the mitochondrial SNPs present in the Illumina BovineHD BeadChip did not clearly differentiate taurine and indicine haplotype groupings.

Conclusions

The low level of taurine ancestry observed for both Nelore and Gir breeds confirms the historical records of crossbreeding and supports a strong directional selection against taurine haplotypes via backcrossing. Random sampling in production herds across the country and subsequent genotyping would be useful for a more complete view of the admixture levels in the commercial Nelore and Gir populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-015-0109-5) contains supplementary material, which is available to authorized users.     

Interactions of Divalent Cations in Their Action on ATPases from Cucumber Roots

A microsomal fraction (10,000–30.000 g) was prepared from roots of Cucumis satirus L. (cv. Bestseller Fl) grown in solution culture. The ATPase activity was stimulated by Mg and Mn with optima between pH 6 and 7. Stimulation by Ca was obtained only above pH 7. Activations by Mg and Mn were inhibited by Ca, Mn and Mg interacted, so that Mn appeared strongly inhibitory for activation by Mg and Mg weakly inhibitory for activation by Mn: the simplest interpretation for this would be two separate enzymes. Cucumber accumulates and deposits Ca contrary to wheat and oat, which contain Ca-activated ATPase in the pH region 6 to 7. The Ca data for cucumber are compared with earlier findings from wheat and oat and are tentatively related to known physiological differences.     

Salivary and serum procalcitonin and C-reactive protein as biomarkers of periodontitis in United States veterans with osteoarthritis or rheumatoid arthritis

Serum procalcitonin (ProCT) is elevated in response to bacterial infections, whereas high sensitivity C-reactive protein (hsCRP) is a nonspecific inflammatory marker that is increased by excess adipose tissue. We examined the efficacy of ProCT and hsCRP as biomarkers of periodontitis in the saliva and serum of patients with arthritis, which is characterized by variable levels of systemic inflammation that potentially can confound the interpretation of inflammatory biomarkers. Blood and unstimulated whole saliva were collected from 33 patients with rheumatoid arthritis (RA) and 50 with osteoarthritis (OA). Periodontal status was assessed by full mouth examination and patients were categorized as having no/mild, moderate or severe periodontitis by standard parameters. Salivary and serum ProCT and hsCRP concentrations were compared. BMI, diabetes, anti-inflammatory medications and smoking status were ascertained from the patient records. Differences between OA and RA in proportionate numbers of patients were compared for race, gender, diabetes, adiposity and smoking status. Serum ProCT was significantly higher in arthritis patients with moderate to severe and severe periodontitis compared with no/mild periodontitis patients. There were no significant differences in salivary ProCT or salivary or serum hsCRP in RA patients related to periodontitis category. Most of the OA and RA patients were middle aged or older, 28.9% were diabetic, 78.3% were overweight or obese, and slightly more than half were either current or past smokers. The OA and RA groups differed by race, but not gender; blacks and males were predominant in both groups. The OA and RA groups did not differ in terms of controlled or uncontrolled diabetes, smoking status or BMI. The RA patients had been prescribed more anti-inflammatory medication than the OA patients. Our results demonstrate that circulating ProCT is a more discriminative biomarker for periodontitis than serum hsCRP in patients with underlying arthritis. Any elevation in salivary and serum hsCRP due to periodontitis apparently was overshadowed by differences among these patients in factors that influence CRP, such as the extent of inflammation between RA and OA, the extent of adipose tissue, the use of anti- inflammatory medications and smoking status. Although our study showed no differences in salivary ProCT related to severity of periodontitis, this biomarker also may be useful with further refinement.     

Brittle stars (Echinodermata: Ophiuroidea) from La Réunion and the systematic position of Ophiocanops Koehler, 1922

The ophiuroid fauna of La Réunion, Indian Ocean, is still incompletely known. We report 13 different species from coral reefs, including five new records and a probably undescribed species of Amphioplus , which increases the number of ophiuroids known from La Réunion to 25. The most important find consists of three individuals of a previously unknown representative of the genus Ophiocanops . Originally placed in Ophiomyxidae, its systematic position has long been debated, with some authors advocating a placement with the otherwise extinct Palaeozoic Oegophiurida, based on the absence of several skeletal characters. The new species, O. multispina sp. nov. , shows intermediate characters between its previously only known congener, O. fugiens , and the ophiomyxid Renetheo felli . The three species appear to represent a line of taxa with progressively reduced skeleton instead of an ancient condition. We propose to transfer Ophiocanops back to the Ophiomyxidae, to synonymize Renetheo with Ophiocanops , and to invalidate the Ophiocanopidae, for which there is no autapomorphy-based support. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 545–560.