Molecular genetic analysis of a cattle population to reconstitute the extinct Algarvia breed

Background

Decisions to initiate conservation programmes need to account for extant variability, diversity loss and cultural and economic aspects. Molecular markers were used to investigate if putative Algarvia animals could be identified for use as progenitors in a breeding programme to recover this nearly extinct breed.

Methods

46 individuals phenotypically representative of Algarvia cattle were genotyped for 27 microsatellite loci and compared with 11 Portuguese autochthonous and three imported breeds. Genetic distances and factorial correspondence analyses (FCA) were performed to investigate the relationship among Algarvia and related breeds. Assignment tests were done to identify representative individuals of the breed. Y chromosome and mtDNA analyses were used to further characterize Algarvia animals. Gene- and allelic-based conservation analyses were used to determine breed contributions to overall genetic diversity.

Results

Genetic distance and FCA results confirmed the close relationship between Algarvia and southern Portuguese breeds. Assignment tests without breed information classified 17 Algarvia animals in this cluster with a high probability (q > 0.95). With breed information, 30 cows and three bulls were identified (q > 0.95) that could be used to reconstitute the Algarvia breed. Molecular and morphological results were concordant. These animals showed intermediate levels of genetic diversity (MNA = 6.0 ± 1.6, R_t = 5.7 ± 1.4, H_o = 0.63 ± 0.19 and H_e = 0.69 ± 0.10) relative to other Portuguese breeds. Evidence of inbreeding was also detected (F_is = 0.083, P < 0.001). The four Algarvia bulls had Y-haplotypes H6Y2 and H11Y2, common in Portuguese cattle. The mtDNA composition showed prevalence of T3 matrilines and presence of the African-derived T1a haplogroup. This analysis confirmed the genetic proximity of Algarvia and Garvonesa breeds (F_st = 0.028, P > 0.05). Algarvia cattle provide an intermediate contribution (CB = 6.18, CW = -0.06 and D1 = 0.50) to the overall gene diversity of Portuguese cattle. Algarvia and seven other autochthonous breeds made no contribution to the overall allelic diversity.

Conclusions

Molecular analyses complemented previous morphological findings to identify 33 animals that can be considered remnants of the Algarvia breed. Results of genetic diversity and conservation analyses provide objective information to establish a management program to reconstitute the Algarvia breed.     

A review of recent non-target toxicity testing of vertebrate pesticides: establishing generic guidelines

Abstract

An analysis of the range, extent and importance of New Zealand-based ecotoxicology studies has been completed to better understand the hazards and non-target risks associated with new toxins and baits. This review focuses on compounds that have been recently developed for incorporation into bait for terrestrial vertebrate pest control, namely cholecalciferol, para-aminopropiophenone (PAPP) and zinc phosphide and the effects of these toxins on non-target species. Testing of these compounds has included cage and pen toxicity and bait acceptance studies. Locally conducted acute toxicity studies clarify overseas data and enhance risk assessments. Consistency in approach and selection of surrogate species, and careful selection of native non-target species for acute toxicity testing in cage and pen trials are recommended as important steps before field trials. We propose a systematic approach to cage and pen trials and offer guidelines on species selection.     

Tim-1 promotes cisplatin nephrotoxicity

Nephrotoxicity is a frequent complication of cisplatin-based chemotherapy, in which T cells are known to promote acute kidney injury. In this study, we examined the role of T cell immunoglobulin mucin 1 (Tim-1) in cisplatin-induced acute kidney injury using an inhibitory anti-Tim-1 antibody. Tim-1 acts to modulate T cell responses, but it is also expressed by damaged proximal tubules in the kidney, where it is known as kidney injury molecule-1 (Kim-1). Anti-Tim-1 antibodies attenuated cisplatin nephrotocity, with less histologic damage, improved renal function, and fewer leukocytes infiltrating the kidney compared with control antibody-treated mice. Renal NF-κB activation and apoptosis were reduced, and proinflammatory renal cytokine and chemokine mRNA expression was decreased. Renal Kim-1 expression was reduced, consistent with the diminished kidney injury after anti-Tim-1 antibody treatment. Furthermore, anti-Tim-1 antibodies reduced early systemic CD4+ and CD8+ T cell activation, apoptosis, and cytokine production. To determine whether the protective actions of anti-Tim-1 antibodies were due to effects on renal tubular cells, cisplatin nephrotoxicity was studied in Rag1(-/-) mice. Anti-Tim-1 antibodies did not affect renal dysfunction or histologic damage in Rag1(-/-) mice, showing that the benefits of inhibiting Tim-1 come from T cell effects. As Tim-1 plays an important role in promoting cisplatin nephrotoxicity, inhibiting Tim-1 may be a therapeutic strategy to prevent cisplatin-induced acute kidney injury.     

In vivo characterization of lung morphology and function in anesthetized free-breathing mice using micro-computed tomography.

Lung morphology and function in human subjects can be monitored with computed tomography (CT). Because many human respiratory diseases are routinely modeled in rodents, a means of monitoring the changes in the structure and function of the rodent lung is desired. High-resolution images of the rodent lung can be attained with specialized micro-CT equipment, which provides a means of monitoring rodent models of lung disease noninvasively with a clinically relevant method. Previous studies have shown respiratory-gated images of intubated and respirated mice. Although the image quality and resolution are sufficient in these studies to make quantitative measurements, these measurements of lung structure will depend on the settings of the ventilator and not on the respiratory mechanics of the individual animals. In addition, intubation and ventilation can have unnatural effects on the respiratory dynamics of the animal, because the airway pressure, tidal volume, and respiratory rate are selected by the operator. In these experiments, important information about the symptoms of the respiratory disease being studied may be missed because the respiration is forced to conform to the ventilator settings. In this study, we implement a method of respiratory-gated micro-CT for use with anesthetized free-breathing rodents. From the micro-CT images, quantitative analysis of the structure of the lungs of healthy unconscious mice was performed to obtain airway diameters, lung and airway volumes, and CT densities at end expiration and during inspiration. Because the animals were free breathing, we were able to calculate tidal volume (0.09 +/- 0.03 ml) and functional residual capacity (0.16 +/- 0.03 ml).     

Mutability Dynamics of an Emergent Single Stranded DNA Virus in a Na?ve Host

Quasispecies variants and recombination were studied longitudinally in an emergent outbreak of beak and feather disease virus (BFDV) infection in the orange-bellied parrot (Neophema chrysogaster). Detailed health monitoring and the small population size (<300 individuals) of this critically endangered bird provided an opportunity to longitudinally track viral replication and mutation events occurring in a circular, single-stranded DNA virus over a period of four years within a novel bottleneck population. Optimized PCR was used with different combinations of primers, primer walking, direct amplicon sequencing and sequencing of cloned amplicons to analyze BFDV genome variants. Analysis of complete viral genomes (n = 16) and Rep gene sequences (n = 35) revealed that the outbreak was associated with mutations in functionally important regions of the normally conserved Rep gene and immunogenic capsid (Cap) gene with a high evolutionary rate (3.41×10⁻³ subs/site/year) approaching that for RNA viruses; simultaneously we observed significant evidence of recombination hotspots between two distinct progenitor genotypes within orange-bellied parrots indicating early cross-transmission of BFDV in the population. Multiple quasispecies variants were also demonstrated with at least 13 genotypic variants identified in four different individual birds, with one containing up to seven genetic variants. Preferential PCR amplification of variants was also detected. Our findings suggest that the high degree of genetic variation within the BFDV species as a whole is reflected in evolutionary dynamics within individually infected birds as quasispecies variation, particularly when BFDV jumps from one host species to another.     

Functional and biochemical characterisation of the Escherichia coli major facilitator superfamily multidrug transporter MdtM

Multidrug resistance (MDR) occurs when bacteria simultaneously acquire resistance to a broad spectrum of structurally dissimilar compounds to which they have not previously been exposed. MDR is principally a consequence of the active transport of drugs out of the cell by proteins that are integral membrane transporters. We characterised and purified the putative Escherichia coli MDR transporter, MdtM, a 410 amino acid residue protein that belongs to the large and ubiquitous major facilitator superfamily. Functional characterisation of MdtM using growth inhibition and whole cell transport assays revealed its role in intrinsic resistance of E. coli cells to the antimicrobials ethidium bromide and chloramphenicol. Site-directed mutagenesis studies implied that the MdtM aspartate 22 residue and the highly conserved arginine at position 108 play a role in proton recognition. MdtM was homologously overexpressed and purified to homogeneity in dodecyl-β-D-maltopyranoside detergent solution and the oligomeric state and stability of the protein in a variety of detergent solutions was investigated using size-exclusion HPLC. Purified MdtM is monomeric and stable in dodecyl-β-D-maltopyranoside solution and binds chloramphenicol with nanomolar affinity in the same detergent. This work provides a firm foundation for structural studies on this class of multidrug transporter protein.     

Extracts of brewer's yeast contain GABA which enhances activation of glycogen synthetase by insulin in isolated rat hepatocytes

Extracts of brewer's yeast have been fractionated, and the effects of fractions on the incorporation of 14C-labelled precursors into glycogen by hepatocytes have been studied. Purification of fractions which enhanced response to insulin resulted in the isolation of gamma-aminobutyric acid (GABA) which stimulated glycogen synthetase activity in the presence but not in the absence of suboptimal insulin concentrations.