Phylogenetics support an ancient common origin of two scientific icons: Devils Hole and Devils Hole pupfish

The Devils Hole pupfish (Cyprinodon diabolis; DHP) is an icon of conservation biology. Isolated in a 50 m² pool (Devils Hole), DHP is one of the rarest vertebrate species known and an evolutionary anomaly, having survived in complete isolation for thousands of years. However, recent findings suggest DHP might be younger than commonly thought, potentially introduced to Devils Hole by humans in the past thousand years. As a result, the significance of DHP from an evolutionary and conservation perspective has been questioned. Here we present a high‐resolution genomic analysis of DHP and two closely related species, with the goal of thoroughly examining the temporal divergence of DHP. To this end, we inferred the evolutionary history of DHP from multiple random genomic subsets and evaluated four historical scenarios using the multispecies coalescent. Our results provide substantial information regarding the evolutionary history of DHP. Genomic patterns of secondary contact present strong evidence that DHP were isolated in Devils Hole prior to 20–10 ka and the model best supported by geological history and known mutation rates predicts DHP diverged around 60 ka, approximately the same time Devils Hole opened to the surface. We make the novel prediction that DHP colonized and have survived in Devils Hole since the cavern opened, and the two events (colonization and collapse of the cavern's roof) were caused by a common geologic event. Our results emphasize the power of evolutionary theory as a predictive framework and reaffirm DHP as an important evolutionary novelty, worthy of continued conservation and exploration.     

Effects of high doses of dexamethasone on hemodynamic and immunohistochemical characteristics of acute paraquat intoxication in rat kidneys

Paraquat (1,1’-dimethyl-4,4’-bipyridinium) (PQ), is a nonselective contact herbicide that is highly toxic to humans. The kidney is affected during PQ intoxication. Dexamethasone (Dexa) has anti-inflammatory effects and is used to treat cases of PQ poisoning. We investigated in rat kidney hemodynamic effects and immunohistochemical characteristics of Dexa treatment in acute PQ poisoning. Adult male rats were divided into four groups: 1, untreated control; 2, treated with 100 mg/kg Dexa; 3, treated with 25 mg/kg PQ; 4, treated with PQ + Dexa. Mean arterial pressure (MAP) and heart rate (HR) were recorded during the experimental period (2 h). Tissues were removed after 2 h and immunohistochemistry was performed after 24 h. Paraffin sections of kidney were prepared and anti-cyclo-oxygenase-1 (COX-1), anti-cyclo-oxygenase-2 (COX-2), anti-angiotensin converting enzyme (ACE), anti-aquaporin-1 (AQU-1), anti-vascular cell adhesion molecule (VCAM) primary antibodies were used for immunohistochemical examination. Immunoreactivities were scored as: (1) minimal, (2) weak, (3) mild, (4) moderate, (5) strong and (6) very strong. MAP and HR were measured at 10 min, 20 min, 1 h and 2 h. MAP at 10 and 20 min and 1 h was increased in the Dexa group. HR also was increased in all groups compared to controls at 2 h. Compared to groups 2 and 4, MAP values decreased significantly in group 3 at 1 h. The intensity of all of immunoreactivities was decreased in group 2. In group 3, immunoreactivities of COX-1, COX-2 and ACE were decreased compared to the control and the other groups, whereas AQU-1 and VCAM immunoreactivities were the same as the control group. ACE and VCAM immunoreactivities were decreased in group 4 compared to the control group, while COX-1, COX-2 and AQU-1 immunoreactivities were close to those of the control group. Dexa appears to be useful for treating PQ intoxication.     

Effect of Cytokinins on In Vitro Propagation of Ajuga xylorrhiza Kit Tan (Critically Endangered), Endemic to Turkey

In Vitro Cellular & Developmental Biology - Plant - Ajuga xylorrhiza Kit Tan is a rare endemic perennial species growing in the stony habitats in Southeastern Anatolia region, Turkey. An...     

Multi-scale finite element modelling at the posterior lumbar vertebra: analysis of pedicle stresses due to pars fracture

Multi-scale finite element (FE) model is a cost-effective way to analyse stress response of micro-level structures to the changes in loading at macro-level. This study deals with the development of a multi-scale model of a human vertebra and stress changes in the pedicle at high resolution after a gross fracture at the posterior neural arch. Spondylolysis (pars fracture) is a painful condition occurring in the vertebral neural arch and common especially among the athletic young population. The fracture of the pars significantly alters load distribution and load transfer characteristics at the neural arch. Structural changes in the posterior vertebra due to the new loading patterns can trigger secondary complications. Clinical reports have shown the association of pedicle hypertrophy or pedicle fracture with unilateral pars fractures. However, the biomechanical consequences of pars fracture and its effect on the pedicle have never been studied in detail. Therefore, we prepared a multi-scale model of posterior vertebra with continuum laminar complex model combined with micro-FE model of a pedicle section. The results showed that stress at the contralateral pars and pedicle increased after unilateral pars fracture simulation. High-stress regions were found around the outer boundaries of the pedicle. This model and information are helpful in understanding the stress changes in the pedicle and can be used for adaptive remodelling studies.     

Synthesis and characterization of ether-derivatized aminophosphines and their application in C-C coupling reactions

Four new bis(phosphino)amine ligands (Ph₂P)₂N-C₆H₃-R, where R = 3,5-OMe (1), 2,5-OMe (2), 2,4-OMe (3) or 3,4-OMe (4), were prepared via aminolysis of the corresponding dimethoxyanilines with 2 equiv. of diphenylphosphine chloride in the presence of triethyl amine. Oxidation of these ligands with aqueous H₂O₂, elemental S₈ or Se powder afforded the corresponding chalcogen oxides 1a-4a, sulfides 1b-4b and selenides 1c-4c in good yields. Reaction of 1-4 with [MCl₂(cod)] (M = Pt, Pd; cod = cycloocta-1,5-diene) in equimolar ratios afforded cis-[MCl₂{(Ph₂P)₂N-C₆H₃-R}] (M = Pt; R = 3,5-OMe 1d, R = 2,5-OMe 2d, R = 2,4-OMe 3d, and R = 3,4-OMe 4d. M = Pd; R = 3,5-OMe 1e, R = 2,5-OMe 2e, R = 2,4-OMe 3e, and R = 3,4-OMe 4e). Similarly, reaction of [Cu(CH₃CN)₄]PF₆ with the 1-4 in 1:2 ratio gave [Cu{(Ph₂P)₂N-C₆H₃-R}₂]PF₆ (R = 3,5-OMe 1f, 2,5-OMe 2f, 2,4-OMe 3f and 3,4-OMe 4f). All new compounds were fully characterized by spectroscopy and elemental analysis and the molecular structures of seven representative compounds were determined by single-crystal X-ray crystallography. In addition, the palladium complexes were investigated as pre-catalysts in C-C coupling reactions.     

Bacterial Communities in the Rhizosphere of Biofuel Crops Grown on Marginal Lands as Evaluated by 16S rRNA Gene Pyrosequences

Microbes are key components of the soil environment and are important contributors to the sustainability of agricultural systems, which is especially significant for biofuel crops growing on marginal lands. We studied bacterial communities in the rhizosphere of five biofuel crops cultivated in four locations in Michigan to determine which factors were correlated to changes in the structure of those communities. Three of these sites were marginal lands in that two were not suitable for conventional agriculture and one was regulated as a brownfield due to prior industrial pollution. Bacterial community composition and structure were assessed by 454 sequencing of the 16S rRNA gene. A total of 387,111 sequences were used for multivariate statistical analysis and to test for correlation between community structure and environmental variables such as plant species, soil attributes, and location. The most abundant bacterial phyla found in the rhizosphere of all crops were Acidobacteria, Proteobacteria, Actinobacteria, and Verrucomicrobia. Bacterial communities grouped by location rather than by crop and their structures were correlated to soil attributes, principally pH, organic matter, and nutrients. The effect of plant species was low but significant, and interactions between locations, plant species, and soil attributes account for most of the explained variation in the structure of bacterial communities, showing a complex relationship between bacterial populations and their environment. Bacterial diversity was higher in the agricultural sites compared to adjacent forest sites, indicating that the cultivation of those biofuel crops increased the rRNA diversity.     

The clonogenic potential of hematopoietic stem cells and mesenchymal stromal cells in various hematologic diseases: a pilot study

Background aimsMesenchymal stromal cells (MSC) are the most popular cells used in regenerative medicine and biotechnology. The clonogenic potential of these cells is defined by colony-forming unit-fibroblasts (CFU-F). It is well known that there is an interaction between hematopoietic cells and stromal cells in disease formation pathogenesis. Therefore we hypothesized that there should be a quantitative and qualitative relationship between MSC colonies (CFU-F) and hematopoietic stem cell colonies (colony-forming unit-granulocyte-macrophages; CFU-GM) among patients with and without hematologic diseases.MethodsForty-two patients were included in this study. Patients were divided into three groups: group A, patients with hematologic malignancies (n = 20); group B, patients with bone marrow (BM) failure (n = 11); group C, patients without hematologic diseases (n = 11). BM aspirates were plated in different densities for CFU-F culture. The plating density was the same for CFU-GM culture.ResultsCFU-GM colonies grew in 90% of group A cells and all of group B and C cells (P = 0.0001). CFU-F colonies became visible on the ninth day of plating in group A and on the eight day in groups B and C. There was no statistically significant difference between the groups for the duration of CFU-F colony formation (P = 0.12). There were differences in the morphology of the colonies among the groups.ConclusionsThis is the first study that has compared the clonogenic potential of stromal cells and hematopoietic stem cells in the same subjects with and without hematologic diseases. No correlation was shown between the clonogenic potential of stromal cells and hematopoietic cells.     

Alterations in p16 and p53 genes and chromosomal findings in patients with lung cancer: Fluorescence in situ hybridization and cytogenetic studies

Background: Chromosomal aberrations and instability of gene(s) are two factors related to the genetic instability of cancer cells. A loss of the tumor-suppressor function of the genes p16 and p53 is the most common event leading to the development of human cancers. Carcinoma of the lung is the leading cause of cancer deaths in the world. Chromosomal abnormalities in lung cancer may provide a valuable clue to the identification of target loci and culminate in a successful search for the major genes. The aim of this study was to investigate (i) alterations of the p16 and p53 genes and (ii) chromosomal aberrations in patients with small cell and non-small cell lung cancer by fluorescence in situ hybridization (FISH) and cytogenetic studies. Methods: We carried out cytogenetic analysis by Giemsa-banding in 18 cases. FISH probes for the p16 and p53 genes were also used on interphase nuclei to screen the alterations in these genes in lung cancer (LC).Results: We observed a high frequency of losses of the p16 – in 8/18 (44%) – and p53 – in 7/18 (39%) – genes in the cases with LC. A total of 18 patients showed predominantly numerical and structural aberrations. Among these two types, structural aberrations predominated and usually consisted of deletions, breaks, and fragilities in various chromosomes. Both structural and numerical changes were observed in almost all patients. Chromosomes 3 and 1 were found to be most frequently involved in structural abnormalities, followed by chromosomes 6, 9, and 8. Autosomal aneuploidies were also observed to be the most frequent (chromosomes 22, 19, 18, 20, 9, and 17), followed by those of the X and Y chromosomes. The expression of fragile sites was also found to be significantly higher in seven chromosomal regions: 3p14, 1q21, 1q12, 6q26, 9q13, 8q22, and 8q24. Conclusion: Our data confirmed that DNA damage and genomic instability may be factors contributing to the mutation profile and development of lung cancer. The patients who developed lung cancer showed a high frequency of loss of both p16 and p53, in addition to chromosomal aberrations. Tobacco could be a major carcinogenic factor in lung-cancer progression. The loss of p16 and p53, and increased incidence of autosomal aneuploidy and chromatid breaks, along with other chromosomal alterations, can contribute to the progression of the disease.