Conservation implications for dingoes from the maternal and paternal genome: Multiple populations,dog introgression,and demography

It is increasingly common for apex predators to face a multitude of complex conservation issues. In Australia, dingoes are the mainland apex predator and play an important role in ecological functioning. Currently, however, they are threatened by hybridization with modern domestic dogs in the wild. As a consequence, we explore how increasing our understanding of the evolutionary history of dingoes can inform management and conservation decisions. Previous research on whole mitochondrial genome and nuclear data from five geographical populations showed evidence of two distinct lineages of dingo. Here, we present data from a broader survey of dingoes around Australia using both mitochondrial and Y chromosome markers and investigate the timing of demographic expansions. Biogeographic data corroborate the presence of at least two geographically subdivided genetic populations, southeastern and northwestern. Demographic modeling suggests that dingoes have undergone population expansion in the last 5,000 years. It is not clear whether this stems from expansion into vacant niches after the extinction of thylacines on the mainland or indicates the arrival date of dingoes. Male dispersal is much more common than female, evidenced by more diffuse Y haplogroup distributions. There is also evidence of likely historical male biased introgression from domestic dogs into dingoes, predominately within southeastern Australia. These findings have critical practical implications for the management and conservation of dingoes in Australia; particularly a focus must be placed upon the threatened southeastern dingo population.     

Effect of cultural conditions on the protein and lipopolysaccharide profiles of Haemophilus ducreyi analysed by SDS-PAGE

Abstract A comparative study of the protein and lipopolysaccharide (LPS) profiles of 8 strains of Haemophilus ducreyi revealed that protein patterns remained unaffected by changes in medium composition, atmospheric conditions and temperature. In contrast, the LPS patterns exhibited marked variations under the different cultural conditions.     

Evaluation of DNA Variants Associated with Androgenetic Alopecia and Their Potential to Predict Male Pattern Baldness

Androgenetic alopecia, known in men as male pattern baldness (MPB), is a very conspicuous condition that is particularly frequent among European men and thus contributes markedly to variation in physical appearance traits amongst Europeans. Recent studies have revealed multiple genes and polymorphisms to be associated with susceptibility to MPB. In this study, 50 candidate SNPs for androgenetic alopecia were analyzed in order to verify their potential to predict MPB. Significant associations were confirmed for 29 SNPs from chromosomes X, 1, 5, 7, 18 and 20. A simple 5-SNP prediction model and an extended 20-SNP model were developed based on a discovery panel of 305 males from various European populations fitting one of two distinct phenotype categories. The first category consisted of men below 50 years of age with significant baldness and the second; men aged 50 years or older lacking baldness. The simple model comprised the five best predictors: rs5919324 near AR, rs1998076 in the 20p11 region, rs929626 in EBF1, rs12565727 in TARDBP and rs756853 in HDAC9. The extended prediction model added 15 SNPs from five genomic regions that improved overall prevalence-adjusted predictive accuracy measured by area under the receiver characteristic operating curve (AUC). Both models were evaluated for predictive accuracy using a test set of 300 males reflecting the general European population. Applying a 65% probability threshold, high prediction sensitivity of 87.1% but low specificity of 42.4% was obtained in men aged <50 years. In men aged ≥50, prediction sensitivity was slightly lower at 67.7% while specificity reached 90%. Overall, the AUC=0.761 calculated for men at or above 50 years of age indicates these SNPs offer considerable potential for the application of genetic tests to predict MPB patterns, adding a highly informative predictive system to the emerging field of forensic analysis of externally visible characteristics.     

Multiple Myeloma Involving Skin and Pulmonary Parenchyma after Autologous Stem Cell Transplantation

Pulmonary involvement and skin involvement are rare complications of plasma cell neoplasms. Here we describe what may be the first reported case of a patient with relapse in both of these sites following autologous peripheral blood stem cell transplantation.     

A reappraisal of the evidence for regulation of wolf populations

The dogma that gray wolf (Canis lupus) population densities in naturally occurring systems are limited almost solely by available ungulate biomass is based upon studies that fit straight line linear regressions (Type 1 numerical response) to data collected at 32 sites across North America. We fit Type 1, 2, and 3 response functions to the data using linear and nonlinear regression as appropriate and found that the evidence supported wolf population regulation by density-dependence as much as limitation by prey availability. When we excluded 4 of 32 points from the original data set because those points represented exploited or expanding wolf populations the data suggested that wolf populations are self regulated rather than limited by prey biomass by at least a 3:1 margin. In establishing goals for sustainable wolf population levels, managers of wolf reintroductions and species recovery efforts should account for the possibility that some regulatory mechanism plays an important role in wolf population dynamics. © 2011 The Wildlife Society.     

Insulin-like growth factor (IGF)-I and IGF-II binding to an IGF binding protein. An investigation using chemical modification of tyrosine residues as a structural probe for the sites of interaction.

We have investigated insulin-like growth factor (IGF)-I and IGF-II binding to bovine insulin-like growth factor binding protein-2 (bIGFBP-2) using chemical modification to locate sites on the IGF involved in the binding interaction. bIGFBP-2 was incubated with either recombinant human (hIGF-I) or purified ovine (oIGF-II) to form a mixture of bound and free IGF. Sites of interaction between the binding protein and IGF were then probed by iodination of the available tyrosine residues. Subsequently, the mixture of free IGF and IGF.bIGFBP-2 complex was resolved by neutral chromatography, and the IGF component of the complex with bIGFBP-2 was recovered by reverse-phase high performance liquid chromatography at pH 2.1. The tyrosine labeling patterns of the two populations of IGF, one iodinated while free and the other iodinated while associated with binding protein, were determined following endoproteinase Glu-C peptide mapping. Binding of hIGF-I or oIGF-II to bIGFBP-2 resulted in reduced iodination of the tyrosines in both hIGF-I and oIGF-II that are near the carboxyl-terminal, Tyr-60 and Tyr-59, respectively. The reduction in labeling of these tyrosine residues was 2-fold and 6-fold for hIGF-I and oIGF-II, respectively. On the other hand, labeling of the other 2 tyrosines in hIGF-I and oIGF-II was not different between the free and complexed growth factors. From these results we conclude that Tyr-60 and Tyr-59 in the carboxyl-terminal regions of hIGF-I and oIGF-II, respectively, are either directly involved in the binding reaction or lie in a region of the IGF molecule encompassed by the association with bIGFBP-2. Conversely, the labeling pattern of the other tyrosines, Tyr-24 and Tyr-31 in hIGF-I and Tyr-2 and Tyr-27 in oIGF-II, implies that they are not involved in binding to bIGFBP-2. To examine the role of IGF tyrosine residues in the association with bIGFBP-2, we prepared nonradioactive 127I-labeled oIGF-II. In bIGFBP-2 competition binding assays, 127I-labeled oIGF-II was 2.5-fold and 5-fold less potent than native oIGF-II when competing for binding of 125I-labeled IGF-I or IGF-II tracers, respectively. We interpret these results as indicating that at least 1 tyrosine in oIGF-II is involved in binding to bIGFBP-2.     

Regulation of protein breakdown by epidermal growth factor in A431 cells

Addition of epidermal growth factor (EGF) to cultures of A431 human epidermoid carcinoma cells produces an increase in the rate of intracellular protein breakdown that cannot be accounted for by increased proteolysis in lysates from EGF-treated cells. In support of this observation, inhibition of protein synthesis with cycloheximide does not reduce the EGF response in cell monolayers. On the other hand, inhibitors of lysosomal proteolytic function such as leupeptin, vinblastine and especially the weak base, ammonia, are able to block the ability of EGF to increase protein breakdown. Additional results suggest that the EGF effect is mediated via a stimulation of autophagy. First, the autophagocytosis inhibitor, 3-methyladenine, reduces the EGF response, and second, the ability of insulin to inhibit protein breakdown by preventing the formation of autophagic vacuoles is overcome by EGF. Moreover, the actions of inhibitors and competing hormones are similar to those reported for glucagon, a hormone known to increase autophagy. The EGF response on protein breakdown persists for at least 6 h after thorough washing of the A431 monolayers. This result contrasts with the rapid reversal of EGF effects in other cell lines. Examination of the fate of bound EGF in cells washed and incubated for 2 h at 37 degrees C shows that some 500-fold more EGF per mg protein is retained on the surface of A431 cells compared to AG2804-transformed fibroblasts, a difference which probably explains the unusual persistence of the EGF effect on protein breakdown.     

Milk-derived growth factors as serum supplements for the growth of fibroblast and epithelial cells

Summary We have investigated the response of several epithelial and fibroblastic cells to a mitogenic extract of bovine milk. Cation exchange chromatography was used to produce a mitogen-rich fraction from an industrial whey source that, although comprising only 0.5% of total whey protein, contained the bulk of the growth factor activity. This fraction was a source of potent growth promoting activity for all mesodermal-derived cells tested, including human skin and embryonic lung fibroblasts, Balb/c 3T3 fibroblasts, and rat L6 myoblasts. Maximal growth of all these cell types exceeded that observed in 10% fetal bovine serum. Feline kidney and baby hamster fibroblasts and Chinese hamster ovary cells were less responsive, achieving a maximal growth response of 50–75% that observed in 10% fetal bovine serum. Maximal growth achieved in whey-extract-supplemented cultures of Balb/c 3T3 and human skin fibroblasts, and L6 myoblast cultures exceeded that seen in response to recombinant acidic or basic fibroblast growth factor, platelet-derived growth factor, insulin-like growth factor, or epidermal growth factor. Importantly, addition of low concentrations of fetal bovine serum to the whey-derived mitogenic fraction produced an additive response. However, concentrated milk-derived factors were found to be inhibitory to the growth of all epithelial lines tested, including rat intestinal epithelial cells, canine kidney epithelial cells, and mink lung cells. It is concluded that industrial whey extracted in this form constitutes an important source of potent growth-promoting agents for the supplementation of mesodermal-derived cell cultures.