Sexual selection of anther trichomes and sexual dimorphism in Ibervillea lindheimeri (Cucurbitaceae: Melothrieae)

Ibervillea lindheimeri is a dioecious member of the Cucurbitaceae whose male flowers possess a number of sex-specific characteristics including eglandular trichomes on the anther connective. A 2-year study (1989 and 1990) was undertaken to assess the potential for sexual selection of anther trichome number as a male floral trait that enhances pollen removal (a male fitness component). Correlation analysis of ten reproductive and floral traits showed that only the mean number of anther trichomes per flower was significantly associated with mean pollen removal per flower. Anther trichomes are two-celled, consisting of a small, caplike, apical cell and a large, bulbous basal cell. The basal cell is under tension and produces a sticky polysaccharide that is forcefully ejected upward when the apical cell is broken off by visiting bees. The sticky polysaccharide accumulates on the bees and aids in adherence of pollen. We propose that there is directional selection on individual males for number of anther trichomes per flower. The more anther trichomes per flower, the more pollen exported, and the greater the likelihood of siring seeds. Males differed significantly in mean number of anther trichomes per flower and were relatively consistent in their rank order over a 2-year period; both are prerequisites for sexual selection to operate. Selection coefficients and differentials for 1989 and 1990 were 0.005 and 0.007, and 0.22 and 0.32, respectively, and suggest moderate to strong directional selection on anther trichome number.     

Economical strategies in the Upper Palaeolithic in the Cantabrian region

The aim of this paper is to survey the economic approach in relation to animal use during Upper Palaeolithic times in Northern Spain. The animals present in the archaeological record can be separated into main groups, like those present by natural reasons and those introduced by human groups. Also in the anthropic aported animals, some of them are related to food procurements and others to economic reasons. Animals like deer, bovids, equids and so on, were mainly related to nutrition, while some others like mustelids, canids or felines were more related to the obtention of furs or other non-alimentary uses. The analysis of the “main-six” (red deer, roe deer, big bovids, horse, ibex and wild boar) showed that all of them were used throughout the Upper Palaeolithic without many changes in time.     

Performance of marking techniques in the field and laboratory for Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae)

A reliable marking technique was needed for a mark–release–recapture experiment with adults of Diabrotica speciosa (Germar). Four marking techniques, acrylic paint (spattered or brushed on the surface of the insect); and fluorescent pigments (dusted on surfaces or mixed with diet to produce an ingested marker), were tested. Fluorescent pigment durability for the dusting and ingested techniques was evaluated for laboratory conditions and under simulated field conditions. The impact of the techniques on beetle survival was also assessed. Both acrylic paint techniques caused mobility problems in the beetles, and neither technique lasted for more than 48 h. Both fluorescent pigment techniques were more reliable, but the dusting technique showed a significantly higher mortality than the control, and duration variations between laboratory and field conditions. Use of fluorescent pigments added to the diet was the most reliable technique. This technique allowed the manipulation of the marking period, and provided reliable timing of marker persistence in the field.     

Natural genetic variation drives microbiome selection in the Caenorhabditis elegans gut

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The biological consequences of altered MHC class I expression in tumours.

The identification of different mechanisms by which tumours escape from the immune system has helped to evaluate the clinical relevance of a variety of phenotypic changes that occur during tumour development. Among them, changes in HLA class I expression play a leading role in the tumour-host environment since HLA class I molecules interact with T lymphocytes for antigen presentation and with NK cells for inhibition/activation of these immune effector cells. Our laboratory has proposed a classification of the altered HLA class I phenotypes frequently found in human tumours, into five major groups. This review focuses on the tumour phenotypes found in primary and metastatic lesions, the molecular mechanisms that give rise to each phenotype and the clinical implications of these findings.     

Epidemiology of castration resistant prostate cancer: A longitudinal analysis using a UK primary care database

Background: Castration resistant prostate cancer (CRPC) is defined clinically as a failure of castration to prevent an increase in circulating hormones which are associated with worsening prostate cancer. Published information on the frequency and characteristics of CRPC patients are lacking. This may be partly because there is no specific code which doctors can use to record CRPC, making research in existing data sources such as the General Practice Research Database (GPRD) difficult. Methods: The aim of this study was to firstly develop a method to accurately and thoroughly identify CRPC patients in the GPRD, using a combination of codes for treatments and diagnostic tests which these patients are likely to have received. Secondly, the anonymised electronic medical records were used to study the identified CRPC patient characteristics, such as age, treatments, comorbidity and expected survival. Results: After comprehensive exploratory research, the final algorithm was selected to identify patients’ assumed recording on the GPRD of either a rising prostate specific antigen (PSA) value (clinical definition of CRPC) or evidence of a switch in treatment after castration. Using the algorithm, over the 1999–2009 study period, 11 600 castrated prostate cancer patients were identified. Of these, 3277 (28%) developed CRPC during the study period, with an incidence rate of 8.3 per 100 person years in castrated prostate cancer patients, and 3.8 per 100 person years in all prostate cancer patients. Mean patient age at CRPC was 76.8 years, and mean survival duration from CRPC status was 13.5 months, and from first prostate cancer diagnosis was 48.2 months. The most common comorbidities among CRPC patients were hypertension, dyspnoea, and anaemia. Conclusions: Sensitivity analyses to test algorithms with differing inclusion criteria suggested that the primary algorithm was robust, reducing bias through missing data, while avoiding ‘false positives’ and retaining clinical credibility. Overall, our study has documented a reliable method for identifying CRPC patients in GPRD, and thus we have been able to characterise these patients more accurately.     

Mitochondrial DNA structure in the Arabian Peninsula

Background  

Two potential migratory routes followed by modern humans to colonize Eurasia from Africa have been proposed. These are the two natural passageways that connect both continents: the northern route through the Sinai Peninsula and the southern route across the Bab al Mandab strait. Recent archaeological and genetic evidence have favored a unique southern coastal route. Under this scenario, the study of the population genetic structure of the Arabian Peninsula, the first step out of Africa, to search for primary genetic links between Africa and Eurasia, is crucial. The haploid and maternally inherited mitochondrial DNA (mtDNA) molecule has been the most used genetic marker to identify and to relate lineages with clear geographic origins, as the African Ls and the Eurasian M and N that have a common root with the Africans L3.     

Inhibition of digestive trypsins by plant Kunitz proteins reduces the viability of Spodoptera cosmioides larvae

The acquired resistance by insects and the harmful environmental effects of chemical pesticides have encouraged the search of new tools for proper pest management. Among them, the use of protease inhibitors (PIs) obtained from plants has gained interest because they are a natural system against herbivory, are organic molecules with higher specificity and have the potential to cause less damage to nature. The aim of this work was to characterise the inhibitory potential of the proteins ApTI (Adenanthera pavonina trypsin inhibitor) and ILGA (Inga laurina trypsin inhibitor) on the digestive trypsins of Spodoptera cosmioides through molecular docking, enzymatic kinetics and biological survival analyses. The docking between trypsins and inhibitors was performed using the program CLUSPRO; the inhibitory constant Ki and the inhibition type were determined through chromogenic assays. In order to analyse survival, several concentrations of ApTI and ILTI inhibitors were included in the artificial diet of neonatal larvae. In this study, we determined that ILTI binds to the active site of the trypsins with a specificity similar to its natural substrate, whereas APTI showed that the inhibitor reactive site is not in contact with the trypsins catalytic site. The ILTI and APTI inhibitors were characterized as competitive and uncompetitive tight‐binding inhibitors, respectively. The survival curves obtained using Kaplan–Meier estimators indicated that the lowest percentage survival (20%) for all inhibitors tested was obtained using 1.0% doses at a development time of less than 20 days. We concluded that ILTI and APTI present biotechnological potential as agents against phytophagous Lepidoptera insects, inhibiting trypsins through tight‐binding inhibition, with competitive and non‐competitive mechanisms, respectively. The effect of ApTI and ILTI on the development of S. cosmioides larvae is shown to be toxic.