Repeated intraspecific divergence in life span and aging of African annual fishes along an aridity gradient

Life span and aging are substantially modified by natural selection. Across species, higher extrinsic (environmentally related) mortality (and hence shorter life expectancy) selects for the evolution of more rapid aging. However, among populations within species, high extrinsic mortality can lead to extended life span and slower aging as a consequence of condition‐dependent survival. Using within‐species contrasts of eight natural populations of Nothobranchius fishes in common garden experiments, we demonstrate that populations originating from dry regions (with short life expectancy) had shorter intrinsic life spans and a greater increase in mortality with age, more pronounced cellular and physiological deterioration (oxidative damage, tumor load), and a faster decline in fertility than populations from wetter regions. This parallel intraspecific divergence in life span and aging was not associated with divergence in early life history (rapid growth, maturation) or pace‐of‐life syndrome (high metabolic rates, active behavior). Variability across four study species suggests that a combination of different aging and life‐history traits conformed with or contradicted the predictions for each species. These findings demonstrate that variation in life span and functional decline among natural populations are linked, genetically underpinned, and can evolve relatively rapidly.     

Species assemblages of ladybirds including the harlequin ladybird <Emphasis Type="Italic">Harmonia axyridis</Emphasis>: a comparison at large spatial scale in urban habitats

We evaluated the status of native ladybird assemblages in the presence of the non-native ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) in three European countries. To achieve this, we assessed the abundance of ladybirds from common host plants in urban areas of Great Britain, Czech Republic and Slovak Republic in 2014. We determined (i) the effects of season, host plant, location, abundance of H. axyridis and aphids on the ladybird species assemblage, (ii) the relationship between ladybird abundance and aphid density, (iii) the relationship between diversity of native ladybird species and the abundance of H. axyridis. There was a non-linear relationship between abundance of ladybirds and abundance of aphids but we found the abundance of other ladybird species was not correlated with H. axyridis. We highlight the value of large-spatial scale studies for revealing patterns in community assemblages and ultimately informing understanding of ecosystem resilience.     

Aquarium molluscs as a case study in risk assessment of incidental freshwater fauna

Because biological invasions may cause loss of biodiversity, accurate predictions are necessary for implementing effective restrictions aimed at specific high-risk taxa. The majority of freshwater macroinvertebrate invaders are molluscs and crustaceans. The pet trade has been considered one of the main pathways for new introductions of such species. Risk assessment is usually focused on traded ornamental species whereas, despite their potential importance, incidental “hitchhiking” molluscs are usually given only minimal consideration. We surveyed the Czech Republic, which is one of the leading markets for aquarium species in the European Union (EU), and found 41 freshwater mollusc species (25 ornamental gastropods, 6 ornamental clams, and 10 “hitchhiking” gastropods) representing 13 families. We extrapolated data from the Czech Republic and, using Climatch v. 1.0, matched the climate in each species’ native range to the entire territory of the EU. We also assessed the risk associated with each species by FI-ISK. “Hitchhiking” gastropods were found to be significantly more hazardous and with higher potential to become established within the EU than were ornamental gastropods and bivalves. Many “hitchhikers” may be easily overlooked due to their small size and cryptic coloration or shape. Thus, they easily can be accidentally imported in association with aquarium plants. Therefore, we recommend here to disinfect imported ornamental plants to eradicate these unwanted faunal assemblages.     

Investigation of new acyloxy derivatives of cholic acid and their esters as drug absorption modifiers

Skin penetration enhancers are used in the formulation of transdermal delivery systems for drugs that are otherwise not sufficiently skin-permeable. Intestinal absorption promoters/enhancers are used as excipients in oral formulations of poorly oral-bioavailable drugs. Series of fourteen acyloxy derivatives of 5β-cholic acid as potential drug absorption modifiers was generated by multistep synthesis. The synthesis of all newly prepared compounds is presented here. Structure confirmation of all generated compounds was accomplished by (1)H NMR, (13)C NMR, IR and MS spectroscopy methods. All the prepared compounds were analyzed using RP-TLC, and their lipophilicity (R(M)) was determined. The hydrophobicity (logP) and solubility (logS) of the studied compounds were also calculated using two commercially available programs. All the target compounds were tested for their in vitro transdermal penetration activity and as potential intestinal absorption enhancers. The anti-proliferative activity of all the final compounds was also assessed against the human cancer cell lines: T-lymphoblastic leukemia cell line and the breast adenocarcinoma cell line. Their cytotoxicity was also evaluated against the normal human skin fibroblast cells. Two compounds showed anti-proliferative effect on cancer cells without affecting the growth of normal cells, which should be promising in potential development of new drugs. Most of the target compounds showed minimal anti-proliferative activity (IC(50)>37 μM), indicating they would have low cytotoxicity when administered as chemical absorption modifiers. The relationships between the lipophilicity and the chemical structure of the studied compounds as well as the relationships between their chemical structure and enhancement effects are discussed in this article.     

A proteomic analysis of the Pichia pastoris secretome in methanol-induced cultures

The secreted proteome of Pichia pastoris X-33 was investigated in methanol-induced cultures with a goal to enhance the secretion and purification of recombinant proteins. In a fed-batch fermentation at 30 °C, more host proteins were found in greater concentrations compared to cultures grown at 25 °C. Protein samples collected directly from the culture media at 25 °C, as well as separated by two-dimensional (2D) gel, were subjected to ESI-MS/MS analysis. A total of 75 proteins were identified in the media from different conditions including pre- and post-methanol induction and in a strain overexpressing a recombinant schistosomiasis vaccine, Sm14-C62V. The identified proteins include native secreted proteins and some intracellular proteins, most of which have low isoelectric points (pI < 6). 2D gel analyses further revealed important characteristics, such as abundance, degradation, and glycosylation of these identified proteins in this proteome. Cell wall-associated proteins involved in cell wall biogenesis, structure, and modification comprised the majority of the secreted proteins which have been identified. Intracellular proteins such as alcohol oxidase and superoxide dismutase were also found in the proteome, suggesting some degree of cell lysis. However, both protocols show that their concentrations are significantly lower than the native secreted proteins. This study identifies proteins secreted or released into the culture media in the methanol-induced fermentation cultures of P. pastoris X-33 and suggests potential biotechnology applications based on the discovery of this proteome.     

Inbreeding depression of sperm traits in the zebra finch Taeniopygia guttata

Inbreeding depression, or the reduction in fitness due to mating between close relatives, is a key issue in biology today. Inbreeding negatively affects many fitness‐related traits, including survival and reproductive success. Despite this, very few studies have quantified the effects of inbreeding on vertebrate gamete traits under controlled breeding conditions using a full‐sib mating approach. Here, we provide comprehensive evidence for the negative effect of inbreeding on sperm traits in a bird, the zebra finch Taeniopygia guttata. We compared sperm characteristics of both inbred (pedigree F = 0.25) and outbred (pedigree F = 0) individuals from two captive populations, one domesticated and one recently wild‐derived, raised under standardized conditions. As normal spermatozoa morphology did not differ consistently between inbred and outbred individuals, our study confirms the hypothesis that sperm morphology is not particularly susceptible to inbreeding depression. Inbreeding did, however, lead to significantly lower sperm motility and a substantially higher percentage of abnormal spermatozoa in ejaculate. These results were consistent across both study populations, confirming the generality and reliability of our findings.     

Immunohistochemical analysis of nerve growth factor receptor expression in normal and malignant human tissues

Nerve growth factor (NGF) is a polypeptide important for normal development of the nervous system and promotion of survival and differentiation of sensory and sympathetic neurons in culture. The cellular effects of NGF are mediated by a specific cell surface molecule, nerve growth factor receptor (NGF-R). In the present study we have used a monoclonal antibody against human NGF-R to examine, by the avidin-biotin-immunoperoxidase method, the receptor distribution in a wide range of normal tissues and in more than 200 malignant tumors. Our results show that (a) human NGF-R is expressed in the peripheral nervous system but not in any of the central nervous system areas tested; (b) NGF-R expression is not restricted to neural tissues but is also found in a number of normal epithelial, mesenchymal, and lymphoid tissues; (c) NGF-R expression changes during normal development; and (d) NGF-R expression in malignant tumors generally parallels its normal tissue distribution. Thus, NGF-R is detected in a proportion of neuroectoderm-derived tumors, carcinomas, and lymphomas, and also in a characteristic group of small round-cell tumors (Ewing's sarcomas and embryonal rhabdomyosarcomas). These findings suggest a normal regulatory role for NGF in both neuronal and non-neuronal cells and identify a range of human tumors in which the NGF/NGF-R system may contribute to the malignant phenotype.