Phenotypic plasticity in female mate choice behavior is mediated by an interaction of direct and indirect genetic effects in Drosophila melanogaster

Female mate choice is a complex decision‐making process that involves many context‐dependent factors. In Drosophila melanogaster, a model species for the study of sexual selection, indirect genetic effects (IGEs) of general social interactions can influence female mate choice behaviors, but the potential impacts of IGEs associated with mating experiences are poorly understood. Here, we examined whether the IGEs associated with a previous mating experience had an effect on subsequent female mate choice behaviors and quantified the degree of additive genetic variation associated with this effect. Females from 21 different genetic backgrounds were housed with males from one of two distinct genetic backgrounds for either a short (3 hr) or long (48 hr) exposure period and their subsequent mate choice behaviors were scored. We found that the genetic identity of a previous mate significantly influenced a female's subsequent interest in males and preference of males. Additionally, a hemiclonal analysis revealed significant additive genetic variation associated with experience‐dependent mate choice behaviors, indicating a genotype‐by‐environment interaction for both of these parameters. We discuss the significance of these results with regard to the evolution of plasticity in female mate choice behaviors and the maintenance of variation in harmful male traits.     

Determination of nicotine and two major metabolites in serum by solid-phase extraction and high-performance liquid chromatography, and high-performance liquid chromatography—particle beam mass spectrometry

A rapid and selective assay of nicotine, cotinine and rans-3'-hydroxycotinine in human serum, based on high-performance liquid chromatography with UV detection has been developed. The compounds were subjected to solid-phase extraction, using Extrelut 1 cartridges. Recoveries were ca. 95% for nicotine, 90% for cotinine and 50–55% for trans-3'-hydroxycotinine. The limit of quantitation observed with this method was 10 ng/ml for nicotine and 5 ng/ml for each of the metabolites. The compounds were also identified using high-performance liquid chromatography with particle beam mass spectrometry, to confirm their presence in human serum.     

Twenty years of percutaneous treatments for cystic echinococcosis: a preliminary assessment of their use and safety

Image-guided percutaneous treatments for echinococcal cysts were introduced in the mid-eighties. Today they represent a third therapeutic option, after surgery and benzimidazole derivatives. Two types of percutaneous treatments are available, based on the destruction of the germinal layer or the evacuation of the endocyst. To assess the extent of their use and their safety, a Medline search of the literature on this subject was performed. The number of cysts treated, their anatomical sites, the complications and, length of follow-up (when available), were all examined. The results show that percutaneous treatments for cystic echinococcosis are safe and efficacious in selected anatomical sites, provided basic safety issues are correctly addressed. However, before drawing final conclusions, a more detailed analysis of the literature is needed. Percutaneous treatments could be simplified and made more effective if a scolecidal agent could be found that melts the entire endocyst without causing harm to the biliary epithelium.     

Glucose-free/high-protein diet improves hepatomegaly and exercise intolerance in glycogen storage disease type III mice

Glycogen disease type III (GSDIII), a rare incurable autosomal recessive disorder due to glycogen debranching enzyme deficiency, presents with liver, heart and skeletal muscle impairment, hepatomegaly and ketotic hypoglycemia. Muscle weakness usually worsens to fixed myopathy and cardiac involvement may present in about half of the patients during disease. Management relies on careful follow-up of symptoms and diet. No common agreement was reached on sugar restriction and treatment in adulthood.We administered two dietary regimens differing in their protein and carbohydrate content, high-protein (HPD) and high-protein/glucose-free (GFD), to our mouse model of GSDIII, starting at one month of age. Mice were monitored, either by histological, biochemical and molecular analysis and motor functional tests, until 10?months of age.GFD ameliorated muscle performance up to 10?months of age, while HPD showed little improvement only in young mice. In GFD mice, a decreased muscle glycogen content and fiber vacuolization was observed, even in aged animals indicating a protective role of proteins against skeletal muscle degeneration, at least in some districts. Hepatomegaly was reduced by about 20%. Moreover, the long-term administration of GFD did not worsen serum parameters even after eight months of high-protein diet. A decreased phosphofructokinase and pyruvate kinase activities and an increased expression of Krebs cycle and gluconeogenesis genes were seen in the liver of GFD fed mice.Our data show that the concurrent use of proteins and a strictly controlled glucose supply could reduce muscle wasting, and indicate a better metabolic control in mice with a glucose-free/high-protein diet.     

Mitochondrial dysfunction in fibroblasts of Multiple System Atrophy

Multiple System Atrophy is a severe neurodegenerative disorder which is characterized by a variable clinical presentation and a broad neuropathological spectrum. The pathogenic mechanisms are almost completely unknown. In the present study, we established a cellular model of MSA by using fibroblasts' primary cultures and performed several experiments to investigate the causative mechanisms of the disease, with a particular focus on mitochondrial functioning.Fibroblasts' analyses (7 MSA-P, 7 MSA-C and 6 healthy controls) displayed several anomalies in patients: an impairment of respiratory chain activity, in particular for succinate Coenzyme Q reductase (p?<?0.05), and a reduction of complex II steady-state level (p?<?0.01); a reduction of Coenzyme Q10 level (p?<?0.001) and an up-regulation of some CoQ10 biosynthesis enzymes, namely COQ5 and COQ7; an impairment of mitophagy, demonstrated by a decreased reduction of mitochondrial markers after mitochondrial inner membrane depolarization (p?<?0.05); a reduced basal autophagic activity, shown by a decreased level of LC3 II (p?<?0.05); an increased mitochondrial mass in MSA-C, demonstrated by higher TOMM20 levels (p?<?0.05) and suggested by a wide analysis of mitochondrial DNA content in blood of large cohorts of patients.The present study contributes to understand the causative mechanisms of Multiple System Atrophy. In particular, the observed impairment of respiratory chain activity, mitophagy and Coenzyme Q10 biosynthesis suggests that mitochondrial dysfunction plays a crucial role in the pathogenesis of the disease. Furthermore, these findings will hopefully contribute to identify novel therapeutic targets for this still incurable disorder.     

Reactivation of covalently immobilized lipase from Thermomyces lanuginosus

Lipase from Thermomyces lanuginosus (TLL) immobilized on cyanogen bromide agarose (CNBr) may be fully inactivated when incubated in saturated solutions of guanidine. When this inactivated enzyme is re-incubated in aqueous medium, 20% of the activity may be recovered for several cycles. However, if the activity was determined in the presence of a detergent (CTAB, an activator of this enzyme), 100% of the initial activity in the presence of detergent was recovered. The enzyme was also inactivated in the presence of organic solvents and at high temperatures. Inactivations were more rapid when the activity was determined in absence of detergent. In both cases, some activity could be recovered just by incubation under mild conditions, and this increase was higher if the activity measurements were performed in the presence of CTAB. These results suggested that the opening of the lipase could be a critical step in the inactivation or reactivation of immobilized TLL. In inactivations in the presence of solvents, 100% of activity could be recovered during several cycles, while in thermal inactivations, the recovered activity decreased in each inactivation–reactivation cycle. The incubation of the enzyme inactivated by temperature in guanidine improved the results, but still 100% could not be achieved during several cycles even measured in the presence of CTAB.Thus, the simple incubation of the partially or fully inactivated enzyme under mild conditions permitted to recover some activity (enhancing the half life of the biocatalysts), even in thermal inactivations.     

Forest soil organic carbon dynamics as affected by plant species and their corresponding litters: a fluorescence spectroscopy approach

Background and aims

The effect of forest cover distribution and plant litter input on soil organic carbon were analyzed to better understand the dynamics of carbon cycling across ecosystems on the “Natural Oriented Reserve Bosco delle Pianelle”. Fluorescence spectroscopy represents a very useful tool to characterize soil organic matter properties, since it allows to directly monitor the molecular status of a fluorophore depending on its chemical environment, as well as on its structure, substituents of the aromatic moieties, and molecular weight. Here, fluorescence analysis was performed on humic acids isolated from four litters (HALs) and their underlying soils (HAs) at three depths.

Methods

All samples were collected from a protected forest area, Southern Italy, under different plant covering: Quercus ilex L. (Q), mixed Carpinus betulus L. and Carpinus orientalis Mill. (CC), Pinus halepensis L. (P), and mixed Quercus trojana Webb. and Quercus ilex L. (QQ).

Results

Data obtained showed a fast decomposition process for P and QQ litters, with HAs in the underlying soils characterized by the presence of simple, highly fluorescent structural components also in the deepest layers. On the contrary, a slow decomposition process was observed for Q and CC litters, whose underlying soil HAs were characterized by an increasing aromatic polycondensation and humification degree from the surface to the deepest layers, as supported by low values of fluorescence intensity and high wavelength maxima.

Conclusions

Results obtained indicate that P and QQ species promote C accumulation and stock in the underlying soils, thanks to a greater decomposition of their litter, and fluorescence spectroscopy is a very simple and suitable method to evaluate the influence of three species distribution on soil organic carbon pools.     

The role of p21 Waf1/Cip1 in large airway epithelium in smokers with and without COPD

Airway epithelium alterations, including squamous cell metaplasia, characterize smokers with and without chronic obstructive pulmonary disease (COPD). The p21 regulates cell apoptosis and differentiation and its role in COPD is largely unknown. Molecules regulating apoptosis (cytoplasmic p21, caspase-3), cell cycle (nuclear p21), proliferation (Ki67/PCNA), and metaplasia (survivin) in central airways from smokers (S), smokers-COPD (s-COPD) and non-smokers (Controls) were studied. The role of cigarette smoke extracts (CSE) in p21, survivin, apoptosis (caspase-3 and annexin-V binding) and proliferation was assessed in a bronchial epithelial cell line (16HBE). Immunohistochemistry, image analysis in surgical samples and flow-cytometry and carboxyfluorescein succinimidyl ester proliferative assay in 16HBE with/without CSE were applied. Cytoplasmic and nuclear p21, survivin, and Ki67 expression significantly increased in large airway epithelium in S and in s-COPD in comparison to Controls. Caspase-3 was similar in all the studied groups. p21 correlated with epithelial metaplasia, PCNA, and Ki67 expression. CSE increased cytoplasmic p21 and survivin expression but not apoptosis and inhibited the cell proliferation in 16HBE. In large airway epithelium of smokers with and without COPD, the cytoplasmic p21 inhibits cell apoptosis, promotes cell proliferation and correlates with squamous cell metaplasia thus representing a potential pre-oncogenic hallmark.