COMPLEX INTERACTIONS BETWEEN PATERNAL AND MATERNAL EFFECTS: PARENTAL EXPERIENCE AND AGE AT REPRODUCTION AFFECT FECUNDITY AND OFFSPRING PERFORMANCE IN A BUTTERFLY

Parental effects can greatly affect offspring performance and are thus expected to impact population dynamics and evolutionary trajectories. Most studies have focused on maternal effects, whereas fathers are also likely to influence offspring phenotype, for instance when males transfer nutrients to females during mating. Moreover, although the separate effects of maternal age and the environment have been documented as a source of parental effects in many species, their combined effects have not been investigated. In the present study, we analyzed the combined effects of maternal and paternal age at reproduction and a mobility treatment in stressful conditions on offspring performance in the butterfly Pieris brassicae. Both paternal and maternal effects affected progeny traits but always via interactions between age and mobility treatment. Moreover, parental effects shifted from male effects expressed at the larval stage to maternal effects at the adult stage. Indeed, egg survival until adult emergence significantly decreased with father age at mating only for fathers having experienced the mobility treatment, whereas offspring adult life span decreased with increasing mother age at laying only for females that did not experience the mobility treatment. Overall, our results demonstrate that both parents’ phenotypes influence offspring performance through nongenetic effects, their relative contribution varying over the course of progeny's life.     

TMEM165 deficiency causes a congenital disorder of glycosylation

Protein glycosylation is a complex process that depends not only on the activities of several enzymes and transporters but also on a subtle balance between vesicular Golgi trafficking, compartmental pH, and ion homeostasis. Through a combination of autozygosity mapping and expression analysis in two siblings with an abnormal serum-transferrin isoelectric focusing test (type 2) and a peculiar skeletal phenotype with epiphyseal, metaphyseal, and diaphyseal dysplasia, we identified TMEM165 (also named TPARL) as a gene involved in congenital disorders of glycosylation (CDG). The affected individuals are homozygous for a deep intronic splice mutation in TMEM165. In our cohort of unsolved CDG-II cases, we found another individual with the same mutation and two unrelated individuals with missense mutations in TMEM165. TMEM165 encodes a putative transmembrane 324 amino acid protein whose cellular functions are unknown. Using a siRNA strategy, we showed that TMEM165 deficiency causes Golgi glycosylation defects in HEK cells.     

A case-control study estimating accident risk for alcohol, medicines and illegal drugs

Background

The aim of the present study was to assess the risk of having a traffic accident after using alcohol, single drugs, or a combination, and to determine the concentrations at which this risk is significantly increased.

Methods

A population-based case-control study was carried out, collecting whole blood samples of both cases and controls, in which a number of drugs were detected. The risk of having an accident when under the influence of drugs was estimated using logistic regression adjusting for gender, age and time period of accident (cases)/sampling (controls). The main outcome measures were odds ratio (OR) for accident risk associated with single and multiple drug use. In total, 337 cases (negative: 176; positive: 161) and 2726 controls (negative: 2425; positive: 301) were included in the study.

Results

Main findings were that 1) alcohol in general (all the concentrations together) caused an elevated crash risk; 2) cannabis in general also caused an increase in accident risk; at a cut-off of 2 ng/mL THC the risk of having an accident was four times the risk associated with the lowest THC concentrations; 3) when ranking the adjusted OR from lowest to highest risk, alcohol alone or in combination with other drugs was related to a very elevated crash risk, with the highest risk for stimulants combined with sedatives.

Conclusion

The study demonstrated a concentration-dependent crash risk for THC positive drivers. Alcohol and alcohol-drug combinations are by far the most prevalent substances in drivers and subsequently pose the largest risk in traffic, both in terms of risk and scope.     

Lactoferrin and host defence: an overview of its immuno-modulating and anti-inflammatory properties

Lactoferrin is a member of the transferrin family of iron-binding glycoproteins that is abundantly expressed and secreted from glandular epithelial cells. In secretions, such as milk and fluids of the intestinal tract, lactoferrin is an important component of the first line of host defence. During the inflammatory process, lactoferrin, a prominent component of the secondary granules of neutrophils (PMNs), is released in infected tissues and in blood and then it is rapidly cleared by the liver. In addition to the antimicrobial properties of lactoferrin, a set of studies has focused on its ability to modulate the inflammatory process and the overall immune response. Though many in vitro and in vivo studies report clear regulation of the immune response and protective effect against infection and septic shock by lactoferrin, elucidation of all the cellular and molecular mechanisms of action is far from being achieved. At the cellular level, lactoferrin modulates the migration, maturation and function of immune cells. At the molecular level and in addition to iron binding, interactions of lactoferrin with a plethora of compounds, either soluble or membrane molecules, account for its modulatory properties. This paper reviews our current understanding of the cellular and molecular mechanisms that explain the regulatory properties of lactoferrin in host defence.     

定量电子束显微分析中生物薄样品的质量损失

对多种生物薄样品和标样进行电子探针X射线能谱显微定量分析,分别以电子束轰击后样品的O Kα峰计数和介于4.2-6.2keV区间的连续X－射线计数变化监测质量损失,结果显示样品O Kα峰计数减少幅度大于连续X－射线计数减少幅度,在相同的分析条件下,各样品质量损失程度不相同（P＜0.05）。培养肝癌细胞冷冻干燥超薄切片、明胶冷冻干燥超薄切片、BSA薄膜、氨基塑料超薄切片、红细胞冷冻干燥超薄切片和卵黄高磷蛋白薄膜样品的质量损失分别为33％、28％、26％、18％、13％和13％,以上结果提示：以O Kα峰计数的减少监测样品的质量损失较敏感,在进行生物薄试样定量EPMA时应对各样品的质量损失进行相应校正。     

Identification of the enzymatic active site of tobacco caffeoyl-coenzyme A O-methyltransferase by site-directed mutagenesis.

Animal catechol O-methyltransferases and plant caffeoyl-coenzyme A O-methyltransferases share about 20% sequence identity and display common structural features. The crystallographic structure of rat liver catechol O-methyltransferase was used as a template to construct a homology model for tobacco caffeoyl-coenzyme A O-methyltransferase. Integrating substrate specificity data, the three-dimensional model identified several amino acid residues putatively involved in substrate binding. These residues were mutated by a polymerase chain reaction method and wild-type and mutant enzymes were each expressed in Escherichia coli and purified. Substitution of Arg-220 with Thr resulted in the total loss of enzyme activity, thus indicating that Arg-220 is involved in the electrostatic interaction with the coenzyme A moiety of the substrate. Changes of Asp-58 to Ala and Gln-61 to Ser were shown to increase K(m) values for caffeoyl coenzyme A and to decrease catalytic activity. Deletions of two amino acid sequences specific for plant enzymes abolished activity. The secondary structures of the mutants, as measured by circular dichroism, were essentially unperturbed as compared with the wild type. Similar changes in circular dichroism spectra were observed after addition of caffeoyl coenzyme A to the wild-type enzyme and the substitution mutants but not in the case of deletion mutants, thus revealing the importance of these sequences in substrate-enzyme interactions.     

Mycobacterium tuberculosis Phylogeny Reconstruction Based on Combined Numerical Analysis with IS1081, IS6110, VNTR, and DR-Based Spoligotyping Suggests the Existence of Two New Phylogeographical Clades

This paper deals with phylogenetic relationships among a set of 90 clinical strains representative of the worldwide diversity of the Mycobacterium tuberculosis complex (Kremer et al. 1999) using eight independent genetic markers: IS6110, IS1081, the direct repeat (DR) locus, and five variable number of tandem DNA repeat loci (VNTR). In a preliminary experiment, phylogenetic trees based on single markers were constructed that led to the detection of some similarities between the VNTR-based and the spoligotyping-based phylogenetic trees. In the second step, a more global phenetic approach based on pairwise comparison of strains within each typing system was used, followed by calculations of mean genetic distances based on all the eight loci and the use of the neighbor-joining algorithm for tree reconstruction. This analysis confirmed our preliminary observations and suggested the existence of at least two new phylogeographical clades of M. tuberculosis, one defined as the ``East African–Indian family' (EA-I), which may find its origin on the African or Asian continents, and the other as the ``Latin American and Mediterranean' (LA-M) family. The existence of these two families was also validated by an independent phylogenetic analysis of spoligotyping on a larger set of shared types (n= 252) and further corroborated by VNTR and katG–gyrA results. The potential origin of these families of bacilli is discussed based on cattle domestication and human migration history. In conclusion, the information contained in insertion sequence and repetitive DNAs may serve as a model for the phylogenetic reconstruction of the M. tuberculosis complex.