Extreme heterochiasmy and nascent sex chromosomes in European tree frogs.

We investigated sex-specific recombination rates in Hyla arborea, a species with nascent sex chromosomes and male heterogamety. Twenty microsatellites were clustered into six linkage groups, all showing suppressed or very low recombination in males. Seven markers were sex linked, none of them showing any sign of recombination in males (r=0.00 versus 0.43 on average in females). This opposes classical models of sex chromosome evolution, which envision an initially small differential segment that progressively expands as structural changes accumulate on the Y chromosome. For autosomes, maps were more than 14 times longer in females than in males, which seems the highest ratio documented so far in vertebrates. These results support the pleiotropic model of Haldane and Huxley, according to which recombination is reduced in the heterogametic sex by general modifiers that affect recombination on the whole genome.

A hybrid zone with coincident clines for autosomal and sex-specific markers in the Sorex araneus group.

In hybrid zones, endogenous counter-selection of hybrids is usually first expressed as reduced fertility or viability in hybrids of the heterogametic sex, a mechanism known as Haldane's rule. This phenomenon often leads to a differential of gene flow between sex-linked markers. Here, we address the possibility of a differential gene flow for Y chromosome, mtDNA and autosomal markers across the hybrid zone between the genetically and chromosomally well-differentiated species Sorex antinorii and Sorex araneus race Vaud. Intermarker comparison clearly revealed coincidental centre and very abrupt clines for all three types of markers. The overall level of genetic differentiation between the two species must be strong enough to hinder asymmetric introgression. Cyto-nuclear mismatches were also observed in the centre of hybrid zone. The significantly lower number of mismatches observed in males than in females possibly results from Y chromosome-mtDNA interactions. Results are compared with those previously reported in another hybrid zone between S. antinori and S. araneus race Cordon.

Distribution of neuronal and metabolic markers in the human auditory cortex

SUMMARY The human auditory cortex, located on the supratemporal plane of the temporal lobe, is divided in a primary auditory area and several non-primary areas surrounding it. These different areas show anatomical and functional differences. Many studies have focussed on auditory areas in non-human primates, using investigation techniques such as electrophysiological recordings, tracing of neural connections, or immunohistochemical and histochemical staining. Some of these studies have suggested parallel and hierarchical organization of the cortical auditory areas as well as subcortical auditory relays. In humans, only few studies have investigated these regions immunohistochemically, but activation and lesion studies speak in favour of parallel and hierarchical organization, very similar to that of non-human primates. Calcium-binding proteins and metabolic markers were used to investigate possible correlates of hierarchical and parallel organization in man. Calcium-binding proteins, parvalbumin, calretinin and calbindin, modulate the concentration of intracellular free calcium ions and were found in distinct subpopulations of GABAergic neurons in non-human primates species. In our study, their distribution showed several differences between auditory areas: the primary auditory area was darkly stained for both parvalbumin and calbindin, and their expression rapidly decreased while moving away from the primary area. This staining pattern suggests a hierarchical organization of the areas, in which the more darkly stained areas could correspond to an earlier integration level and the areas showing light staining may correspond to higher level integration areas. Parallel organization of primary and non-primary auditory areas was suggested by the complementarity, within a given area, between parvalbumin and calbindin expression across layers. To investigate the possible differences in the energetic metabolism of the cortical auditory areas, several metabolic markers were used: cytochrome oxidase and LDH1 were used as oxidative metabolism markers and LDH5 was used as glycolytic metabolism marker. The results obtained show a difference in the expression of enzymes involved in oxidative metabolism between areas. In the primary auditory area the oxidative metabolism markers were maximally expressed in layer IV. In contrast, higher order areas showed maximal staining in supragranular layers. The expression of LDH5 varied in patches, but did not differ between the different hierarchical auditory areas. The distribution of the two LDH enzymes isoforms also provides information about cellular aspects of metabolic organization, since neurons expressed the LDH1 isoform whereas astrocytes express primarily LDH5, but some astrocytes also contained the LDH1 isoform. This cellular distribution pattern supports the hypothesis of the existence of an astrocyte-neuron lactate shuttle, previously suggested in rodent studies, and in particular of lactate transfer from astrocytes, which produce lactate from the glucose obtained from the circulation, to neurons that use lactate as energy substrate. In conclusion, the hypothesis of parallel and hierarchical organization of the auditory areas can be supported by CaBPs, cytochrome oxidase and LDH1 distribution. Moreover, the two LDHs cellular distribution pattern support the hypothesis of an astrocyte-neuron lactate shuttle in human cortex.

An investigation of the potential of DIP-STR markers for DNA mixture analyses

The genetic characterization of unbalanced mixed stains remains an important area where improvement is imperative. In fact, using the standard tools of forensic DNA profiling (i.e., STR markers), the profile of the minor contributor in mixed DNA stains cannot be successfully detected if its quantitative share of DNA is less than 10% of the mixed trace. This is due to the fact that the major contributor's profile "masks" that of the minor contributor. Besides known remedies to this problem, such as Y-STR analysis, a new compound genetic marker that consists of a Deletion/Insertion Polymorphism (DIP) linked to a Short Tandem Repeat (STR) polymorphism, has recently been developed and proposed [1]. These novel markers are called DIP-STR markers. This paper compares, from a statistical and forensic perspective, the potential usefulness of these novel DIP-STR markers (i) with traditional STR markers in cases of moderately unbalanced mixtures, and (ii) with Y-STR markers in cases of female-male mixtures. This is done through a comparison of the distribution of 100,000 likelihood ratio values obtained using each method on simulated mixtures. This procedure is performed assuming, in turn, the prosecution's and the defence's point of view.

Assessing the vulnerability of women to sexually transmitted diseases STDS/ HIV: construction and validation of markers

Objective To construct and validate markers of vulnerability of women to STDs/HIV, taking into consideration the importance of STDs/HIV. Method Methodological study carried out in three stages: 1) systematic review and identification of elements of vulnerability in the scientific production; 2) selection of elements of vulnerability, and development of markers; 3) establishment of the expert group and validation of the markers (content validity). Results Five markers were validated: no openness in the relationship to discuss aspects related to prevention of STDs/HIV; no perception of vulnerability to STDs/HIV; disregard of vulnerability to STDs/ HIV; not recognizing herself as the subject of sexual and reproductive rights; actions of health professionals that limit women’s access to prevention of STDs/HIV. Each marker contains three to eleven components. Conclusion The construction of such markers constituted an instrument, presented in another publication, which can contribute to support the identification of vulnerabilities of women in relation to STDs/HIV in the context of primary health care services. The markers constitute an important tool for the operationalization of the concept of vulnerability in primary health care and to promote inter/multidisciplinary and inter/multi-sectoral work processes.


Frequent clonal loss of heterozygosity but scarcity of microsatellite instability at chromosomal breakpoint cluster regions in adult leukemias.

Microsatellites are important highly polymorphic genetic markers dispersed in the human genome. Using a panel of 22 (CA)n repeat microsatellite markers mapped to recurrent breakpoint cluster regions specifically involved in leukemia, we investigated 114 adult leukemias (25 acute lymphocytic leukemia [ALL], 32 acute myeloid leukemia [AML], 36 chronic lymphocytic leukemia [CLL], and 21 chronic myeloid leukemia [CML] in chronic phase) for somatic mutations at these loci. In each patient, DNA from fresh leukemia samples was analyzed alongside normal constitutive DNA from buccal epithelium. We detected loss of heterozygosity (LOH) in 81 of 114 patients (ALL 16/25, AML 25/32, CLL 30/36, CML 10/21). Deletions were most often seen in ALL at 11q23 and 19p13; in AML at 8q22 and 11q23; in CLL at 13q14.3, 11q13, and 11q23; and in CML at 3q26. Only six deletions were reported in 74 karyotypes analyzed, whereas in these same cases, 91 LOH events were detected by microsatellites. Of 26 leukemias with a normal karyotype, 16 nevertheless showed at least one LOH by microsatellite analysis. Replication errors were found in 10 of 114 patients (8.8%). Thus, microsatellite instability is rare in leukemia in contrast to many solid tumors. Our findings suggest that in adult leukemia, LOH may be an important genetic event in addition to typical chromosomal translocations. LOH may point to the existence of tumor suppressor genes involved in leukemogenesis to a degree that has hitherto been underestimated.

MRI visualized neo-intimal dissection and co-localization of novel apoptotic markers apolipoprotein C-1, ceramide and caspase-3 in a Watanabe hyperlipidemic rabbit model

PURPOSE: Apoptotic arterial wall vascular smooth muscle cell death is known to contribute to plaque vulnerability and rupture. Novel apoptotic markers like apolipoprotein C-I have been implicated in apoptotic human vascular smooth muscle cell death via recruiting a neutral sphingomyelinase (N-SMase)-ceramide pathway. In vivo relevance of these observations in an animal model of plaque rupture has not been shown. METHODS AND RESULTS: Using Watanabe rabbits, we investigated three different groups (group 1, three normal Watanabe rabbits; group 2, six Watanabe rabbits fed with high cholesterol diet for 3 months; group 3, five Watanabe rabbits with similar diet but additional endothelial denudation). We followed progression of atherosclerosis to pharmacologically induced plaque rupture non-invasively using novel 3D magnetic resonance Fast-Field-Echo angiography (TR=7.2, TE=3.6 ms, matrix=512 x 512) and Fast-Spin-Echo vessel wall imaging methods (TR=3 heart beats, TE=10.5 ms, matrix=304 x 304) on 1.5 T MRI. MRI provided excellent image quality with good MRI versus histology vessel wall thickness correlation (r=0.8). In six animals of group 2/3 MRI detected neo-intimal dissection in the abdominal aorta which was accompanied by immuno-histochemical demonstration of concomitant aforementioned novel apoptotic markers, previously implicated in the apoptotic smooth muscle cell death in vitro. CONCLUSIONS: Our studies suggest a potential role for the signal transduction pathway involving apolipoprotein C-I for in vivo apoptosis and atherosclerotic plaque rupture visualized by MRI.

Maturation-dependent effects of chlorpyrifos and parathion and their oxygen analogs on acetylcholinesterase and neuronal and glial markers in aggregating brain cell cultures.

An in vitro model, the aggregating brain cell culture of fetal rat telencephalon, has been used to study the maturation-dependent sensitivity of brain cells to two organophosphorus pesticides (OPs), chlorpyrifos and parathion, and to their oxon derivatives. Immature (DIV 5-15) or differentiated (DIV 25-35) brain cells were treated continuously for 10 days. Acetylcholinesterase (AChE) inhibitory potency for the OPs was compared to that of eserine (physostigmine), a reversible AChE inhibitor. Oxon derivatives were more potent AChE inhibitors than the parent compounds, and parathion was more potent than chlorpyrifos. No maturation-dependent differences for AChE inhibition were found for chlorpyrifos and eserine, whereas for parathion and paraoxon there was a tendency to be more effective in immature cultures, while the opposite was true for chlorpyrifos-oxon. Toxic effects, assessed by measuring protein content as an index of general cytotoxicity, and various enzyme activities as cell-type-specific neuronal and glial markers (ChAT and GAD, for cholinergic and GABAergic neurons, respectively, and GS and CNP, for astrocytes and oligodendrocytes, respectively) were only found at more than 70% of AChE inhibition. Immature compared to differentiated cholinergic neurons appeared to be more sensitive to OP treatments. The oxon derivates were found to be more toxic on neurons than the parent compounds, and chlorpyrifos was more toxic than parathion. Eserine was not neurotoxic. These results indicate that inhibition of AChE remains the most sensitive macromolecular target of OP exposure, since toxic effects were found at concentrations in which AChE was inhibited. Furthermore, the compound-specific reactions, the differential pattern of toxicity of OPs compared to eserine, and the higher sensitivity of immature brain cells suggest that the toxic effects and inhibition of AChE are unrelated.

Combining bone resorption markers and heel quantitative ultrasound to discriminate between fracture cases and control

Rapport de synthèse : L'ostéoporose est reconnue comme un problème majeur de santé publique. Comme il existe actuellement des traitements préventifs efficaces pour minimiser le risque de fracture, il est essentiel de développer des nouvelles stratégies de détection des femmes à risque de fracture. Les marqueurs spécifiques du remodelage osseux dosés dans les urines ainsi que les ultrasons quantitatifs du talon ont été étudiés comme outils cliniques pour prédire le risque fracturaire chez les femmes âgées. Il n'existe cependant que très peu de donnée sur la combinaison de ces deux outils pour améliorer la prédiction du risque de fracture. Cette étude cas-contrôle, réalisée chez 368 femmes âgées de 76 ans en moyenne d'une cohorte suisse de femmes ambulatoires, évalue la capacité discriminative entre 195 femmes avec fracture non-vertébrale à bas traumatisme et 173 femmes sans fractures - de deux marqueurs urinaires de la résorption osseuse, les pyridinolines et les deoxypyridinolines, ainsi que deux ultrasons quantitatifs du talon, le Achilles+ (GE-Lunar, Madison, USA) et le Sahara (Hologic, Waltham, USA). Les 195 patientes avec une fracture ont été choisies identiques aux 173 contrôles concernant Page, l'indice de masse corporel, le centre médical et la durée de suivi jusqu'à la fracture. Cette étude montre que les marqueurs urinaires de la résorption osseuse ont une capacité environ identique aux ultrasons quantitatifs du talon pour discriminer entre les patientes avec fracture non-vertébrale à bas traumatisme et les contrôles. La combinaison des deux tests n'est cependant pas plus performante qu'un seul test. Les résultats de cette étude peuvent aider à concevoir les futures stratégies de détection du risque fracturaire chez les femmes âgées, qui intègrent notamment des facteurs de risque cliniques, radiologiques et biochimiques. Abstract : Summary : This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information. Introduction : Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture. Methods In a nested case-control analysis, we studied 368 women (mean age 76.213.2 years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS. Results : Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.560.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.600.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD. Conclusions : Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alone.

Biological markers of alcohol consumption in alcoholised drivers: Comparison of capillary electrophoresis (CZE CDT) and a direct immunoassay (N Latex CDT) with the traditional method of anion-exchange chromatography-immunoturbidimetry (%CDT TIA).

Objectives: The aim of this study was to compare specificity and sensitivity of different biological markers that can be used in a forensic field to identify potentially dangerous drivers because of their alcohol habits. Methods: We studied 280 Swiss drivers after driving while under the alcohol influence. 33 were excluded for not having CDT N results, 247 were included (218 men (88%) and 29 women (12%). Mean age was 42,4 (SD:12, min: 20 max: 76). The evaluation of the alcohol consumption concerned the month before the CDT test and was considered as such after the interview: Heavy drinkers (>3 drinks per day): 60 (32.7%), < 3 drinks per day and moderate: 127 (51.4%) 114 (46.5%), abstinent: 60 (24.3%) 51 (21%). Alcohol intake was monitored by structured interviews, self-reported drinking habits and the C-Audit questionnaire as well as information provided by their family and general practitioner. Consumption was quantified in terms of standard drinks, which contain approximately 10 grams of pure alcohol (Ref. WHO). Results: comparison between moderate (less or equal to 3 drinks per day) and excessive drinkers (more than 3 drinks) Marker ROC area 95% CI cut-off sensitivity specificity CDT TIA 0.852 0.786-0917 2.6* 0.93 LR+1.43 0.35 LR-0.192 CDT N latex 0.875 0.821-0.930 2.5* 0.66 LR+ 6.93 0.90 LR- 0.369 Asialo+disialo-tf 0.881 0.826-0.936 1.2* 0.78 LR+4.07 0.80 LR-0.268 1.7° 0.66 LR+8.9 0.93 LR-0.360 GGT 0.659 0.580-0.737 85* 0.37 LR+2.14 0.83 LR-0.764 * cut-off point suggested by the manufacturer ° cut-off point suggested by our laboratory Conclusion: With the cut-off point established by the manufacturer, CDT TIA performed poorly in term of specificity. N latex CDT and CZE CDT were better, especially if a 1.7 cut-off is used with CZE

Markers of atherosclerosis and inflammation for prediction of coronary heart disease in older adults.

Although both inflammatory and atherosclerosis markers have been associated with coronary heart disease (CHD) risk, data directly comparing their predictive value are limited. The authors compared the value of 2 atherosclerosis markers (ankle-arm index (AAI) and aortic pulse wave velocity (aPWV)) and 3 inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha)) in predicting CHD events. Among 2,191 adults aged 70-79 years at baseline (1997-1998) from the Health, Aging, and Body Composition Study cohort, the authors examined adjudicated incident myocardial infarction or CHD death ("hard" events) and "hard" events plus hospitalization for angina or coronary revascularization (total CHD events). During 8 years of follow-up between 1997-1998 and June 2007, 351 participants developed total CHD events (197 "hard" events). IL-6 (highest quartile vs. lowest: hazard ratio = 1.82, 95% confidence interval: 1.33, 2.49; P-trend < 0.001) and AAI (AAI </= 0.9 vs. AAI 1.01-1.30: hazard ratio = 1.57, 95% confidence interval: 1.14, 2.18) predicted CHD events above traditional risk factors and modestly improved global measures of predictive accuracy. CRP, TNF-alpha, and aPWV had weaker associations. IL-6 and AAI accurately reclassified 6.6% and 3.3% of participants, respectively (P's </= 0.05). Results were similar for "hard" CHD, with higher reclassification rates for AAI. IL-6 and AAI are associated with future CHD events beyond traditional risk factors and modestly improve risk prediction in older adults.

LIF and sIL-2R plasma concentrations in IVF patients on the day of embryo transfer: predictive markers of IVF outcome.

Successful implantation is still the limiting step in IVF. We hypothesized that maternal plasma concentrations of certain cytokines at the time of embryo transfer could predict the likelihood of successful implantation and pregnancy. sIL-2R, IL-6, LIF, and MMP2 concentrations were measured in plasma from 160 IVF patients (natural and stimulated IVF cycles) on the morning of the embryo transfer (ET0) and 14days later (ET+14). Patients were ultimately subdivided into four groups depending on the IVF treatment outcome (pregnancy failure, biochemical pregnancy, first-trimester miscarriage and normal term delivery). In natural and stimulated IVF cycles at ET0, sIL-2R concentrations were threefold higher in biochemical pregnancies than in pregnancy failures (P=0.020), and in natural cycles only, 2.5-fold higher in normal term deliveries than in pregnancy failures (P=0.023). Conversely, in natural and stimulated IVF cycles at ET0, LIF concentrations were one third lower in biochemical pregnancies/first-trimester miscarriages compared with pregnancy failures (P=0.042). We suggest that high sIL-2R and low LIF concentrations in maternal plasma on the morning of the embryo transfer might be associated with increased risks of early pregnancy loss, while a basal level of sIL-2R is necessary for normal term delivery outcome. Both cytokine measurements might therefore be useful in the management of IVF patients, and modulation of their concentrations could be investigated as a therapeutic alternative for women with abnormal concentrations at the time of embryo transfer.

Microsatellites reveal high population viscosity and limited dispersal in the ant Formica paralugubris

We used microsatellites to study the fine-scale genetic structure of a highly polygynous and largely uni-colonial population of the ant Formica paralugubris. Genetic data indicate that long-distance gene flow between established nests is limited and new queens are primarily recruited from within their natal nest. Most matings occur between nestmates and are random at this level. In the center of the study area, budding and permanent connections between nests result in strong population viscosity, with close nests being more similar generically than distant nests. In contrast, nests located outside of this supercolony show no isolation by distance, suggesting that they have been initiated by queens that participated in mating flights rather than by budding from nearby nests in our sample population. Recruitment of nestmates as new reproductive individuals and population viscosity in the supercolony increase genetic differentiation between nests. This in turn inflates relatedness estimates among worker nestmates (r = 0.17) above what is due to close pedigree links. Local spatial genetic differentiation may favor the maintenance of altruism when workers raise queens that will disperse on foot and compete with less related queens from neighboring nests or disperse on the wing and compete with unrelated queens.

Analysis of the genetic diversity in Metopolophium dirhodum (Walker) (Hemiptera, Aphididae) by RAPD markers

The emergence of host-races within aphids may constitute an obstacle to pest management by means of plant resistance. There are examples of host-races within cereals aphids, but their occurrence in Rose Grain Aphid, Metopolophium dirhodum (Walker, 1849), has not been reported yet. In this work, RAPD markers were used to assess effects of the hosts and geographic distance on the genetic diversity of M. dirhodum lineages. Twenty-three clones were collected on oats and wheat in twelve localitites of southern Brazil. From twenty-seven primers tested, only four primers showed polymorphisms. Fourteen different genotypes were revealed by cluster analysis. Five genotypes were collected only on wheat; seven only on oats and two were collected in both hosts. Genetic and geographical distances among all clonal lineages were not correlated. Analysis of molecular variance showed that some molecular markers are not randomly distributed among clonal lineages collected on oats and on wheat. These results suggest the existence of host-races within M. dirhodum, which should be further investigated using a combination of ecological and genetic data.