Assessment of hybridisation between the endangered Chatham Island black robin (<Emphasis Type="Italic">Petroica traversi</Emphasis>) and the Chatham Island tomtit (<Emphasis Type="Italic">Petroica macrocephala chathamensis</Emphasis>)

Hybridisation between an endangered species and a more common species can facilitate population decline and extinction of the endangered species due to wasted reproductive effort, outbreeding depression and/or swamping of alleles due to widespread or complete admixture. The Chatham Island black robin (Petroica traversi) is an endangered songbird species, which was reduced to only five individuals in 1980. Intensive cross-fostering, whereby black robin offspring were placed into nests of the closely related Chatham Island tomtit (Petroica macrocephala chathamensis) to increase reproductive output, contributed to the rapid recovery of the species within 10 years. Several hybridisation events occurred and although those hybrids were successfully eliminated from the population, concerns remained for the possibility of introgression between the two species that may have gone unnoticed. In this study, we genotyped seven microsatellite loci in both species from the two islands where they coexist, to assess the level of hybridisation and the extent of introgression between the two species. The two species shared no alleles at five of the seven loci genotyped, and cluster analysis, AMOVA and admixture analysis of a total of 174 black robins and 78 Chatham Island tomtits showed no evidence of hybridisation or introgression on either of the two islands where they co-exist. As a result, there is no evidence that black robins are currently in any danger of population decline or extinction through hybridisation with tomtits, although small population size and skewed sex ratio, particularly in the smaller of the two populations, may facilitate future hybridisation events.     

The reduced form of the antibody CH2 domain

Among the immunoglobulin domains, the CH2 domain has the lowest thermal stability, which also depends on amino acid sequence and buffer conditions. To further identify factors that influence CH2 folding and stability, we characterized the domain in the reduced form using differential scanning fluorimetry and nuclear magnetic resonance. We show that the CH2 domain can fold, similarly to the disulfide‐bridged form, without forming a disulfide‐bridge, even though the protein contains two Cys residues. Although the reduced form exhibits thermal stability more than 15°C lower than the disulfide‐bridged form, it does not undergo immediate full oxidization. To explain this phenomenon, we compared CH2 oxidization at different conditions and demonstrate a need for significant fluctuation of the folded conformation to enhance CH2 disulfide‐bridge formation. We conclude that, since CH2 can be purified as a folded, semi‐stable, reduced protein that can coexist with the oxidized form, verification of the level of oxidization at each step is critical in CH2 engineering studies.     

Strain differentiation of Staphylococcus aureus by means of direct MALDI TOF mass spectrometry profiling

Staphylococcus aureus is one of the most interesting microbial species in clinical studies. It is characterized by a wide extent of strain diversity, first of all, due to variability in virulence and pathogenicity. The aim of this study was to test the method of rapid Staphylococcus strain differentiation by a certain sign based on registration of characteristics features of MALDI mass spectra accumulated during direct protein profiling of the bacterial cell. The model signs registered as strain differences included production of β-lactamase and α-hemolysin encoded by blaZ and hla genes, respectively. The mathematical analysis of MALDI mass spectra accumulated for 53 S. aureus isolates using the clustering genetic algorithm resulted in generation of two independent classification models, which could differentiate the strains by the considered features. Using statistical contribution of each mass peak to the model, the most significant peaks (masses), which could be considered as the markers of Staphylococcus strain differences, were found. The generated diagnostic models were characterized by the following sensitivity and specificity coefficients: 97.5 and 82.5%, respectively, for strain differentiation by β-lactamase production and 90.0 and 88.7% by the presence of α-hemolysin.     

Analysis of the Glycyrrhizic Acid-Binding Sites with Phage Display

Phages that expose peptides specifically interacting with glycyrrhizic acid (GA) were selected from a phage peptide library by affinity selection and ELISA. Amino acid sequence analysis of the selected peptides and human proteins with the SIM program revealed homology to tyrosine protein kinases, serine/threonine protein kinases, tyrosine phosphatases, and some receptors. Analysis of the peptide and virus protein sequences with the BLAST program showed that GA has affinity for various surface proteins of several human viruses such as HIV-1, hepatitis C virus, and herpesviruses.     

Immunohistochemical Assessment of Phosphorylated mTORC1-Pathway Proteins in Human Brain Tumors

BackgroundCurrent pathological diagnostics include the analysis of (epi-)genetic alterations as well as oncogenic pathways. Deregulated mammalian target of rapamycin complex 1 (mTORC1) signaling has been implicated in a variety of cancers including malignant gliomas and is considered a promising target in cancer treatment. Monitoring of mTORC1 activity before and during inhibitor therapy is essential. The aim of our study is to provide a recommendation and report on pitfalls in the use of phospho-specific antibodies against mTORC1-targets phospho-RPS6 (Ser235/236; Ser240/244) and phospho-4EBP1 (Thr37/46) in formalin fixed, paraffin embedded material.ConclusionHere we provide a recommendation for phospho-specific immunohistochemistry for patient-orientated therapy decisions and monitoring treatment response.     

Investigating assumptions of vulnerability: A case study of the exclusion of psychiatric inpatients as participants in genetic research in low‐ and middle‐income contexts

Psychiatric genetic research investigates the genetic basis of psychiatric disorders with the aim of more effectively understanding, treating, or, ultimately, preventing such disorders. Given the challenges of recruiting research participants into such studies, the potential for long‐term benefits of such research, and seemingly minimal risk, a strong claim could be made that all non‐acute psychiatric inpatients, including forensic and involuntary patients, should be included in such research, provided they have capacity to consent. There are tensions, however, regarding the ethics of recruiting psychiatric inpatients into such studies. In this paper our intention is to elucidate the source of these tensions from the perspective of research ethics committee interests and decision‐making. We begin by defining inpatient status and outline some of the assumptions surrounding the structures of inpatient care. We then introduce contemporary conceptions of vulnerability, including Florencia Luna’s account of vulnerability which we use as a framework for our analysis. While psychiatric inpatients could be subject to consent‐related vulnerabilities, we suggest that a particular kind of exploitation‐related vulnerability comes to the fore in the context of our case study. Moreover, a subset of these ethical concerns takes on particular weight in the context of genetic research in low‐ and middle‐income countries. At the same time, the automatic exclusion of inpatients from research elicits justice‐related vulnerabilities.     

Cys-Flanked Cationic Peptides For Cell Delivery of the Herpes Simplex Virus Thymidine Kinase Gene for Suicide Gene Therapy of Uterine Leiomyoma

Molecular Biology - Uterine leiomyoma (UL) is the most common benign tumor in women of reproductive age. Gene therapy using suicidal genes appears to be a promising approach for UL treatment. One...     

Pre-crystallization phase formation of thermolysin hexamers in solution close to crystallization conditions

Communicated by Ramaswamy H. Sarma     

Human aqueous humor proteome in cataract,glaucoma, and pseudoexfoliation syndrome

Twenty‐nine human aqueous humor samples from patients with eye diseases such as cataract and glaucoma with and without pseudoexfoliation syndrome were characterized by LC–high resolution MS analysis. In total, 269 protein groups were identified with 1% false discovery rate including 32 groups that were not reported previously for this biological fluid. Since the samples were analyzed individually, but not pooled, 36 proteins were identified in all samples, comprising the constitutive proteome of the fluid. The most dominant molecular function of aqueous humor proteins as determined by GO analysis is endopeptidase inhibitor activity. Label‐free protein quantification showed no significant difference between glaucoma and cataract aqueous humor proteomes. At the same time, we found decrease in the level of apolipoprotein D as a marker of the pseudoexfoliation syndrome. The data are available from ProteomeXchange repository (PXD002623).