Spatial segregation of two vole species (Arvicola sapidus and Microtus cabrerae) within habitat patches in a highly fragmented farmland landscape

Spatial segregation is one of the common mechanisms allowing the co-existence of similar interacting species in heterogeneous environments. Analysing spatial segregation requires information on individual home-range sizes and their degree of spatial overlap. In this study, we used radio-tracking to report for the first time the home-range and core-area sizes of sympatric Cabrera and water voles and to analyse intra- and inter-specific space sharing within habitat patches in a highly fragmented landscape. Results indicated that both species exhibited strong fine-scale site fidelity and reduced variation in range size across sexes and seasons. Monogamous mating system seemed to prevail for both species, although water voles may also exhibit polygynous breeding strategies. Mean home-range and core-area sizes of water voles (946.3 and 156.6 m²) were about twice that of Cabrera voles (418.2 and 55.1 m²). Within habitat patches, individuals of both species often overlapped their home ranges, particularly during the dry season (May–September), though intra-specific home-range overlap was generally higher than inter-specific overlap. Inter-specific space sharing was restricted to areas outside the centre of activity of animals, as no core-area overlap was ever recorded between Cabrera and water voles. Taken together, results support the view that co-existence of Cabrera and water voles in Mediterranean patchy habitats may in part result from spatial segregation among individuals, which may reflect competitive displacement or small-scale habitat partitioning. Results highlight the need to account for species interactions when designing conservation management strategies for sympatric Cabrera and water voles in fragmented landscapes.     

Deep Sequencing of Target Linkage Assay-Identified Regions in Familial Breast Cancer: Methods,Analysis Pipeline and Troubleshooting

Background

The classical candidate-gene approach has failed to identify novel breast cancer susceptibility genes. Nowadays, massive parallel sequencing technology allows the development of studies unaffordable a few years ago. However, analysis protocols are not yet sufficiently developed to extract all information from the huge amount of data obtained.

Methodology/Principal Findings

In this study, we performed high throughput sequencing in two regions located on chromosomes 3 and 6, recently identified by linkage studies by our group as candidate regions for harbouring breast cancer susceptibility genes. In order to enrich for the coding regions of all described genes located in both candidate regions, a hybrid-selection method on tiling microarrays was performed.

Conclusions/Significance

We developed an analysis pipeline based on SOAP aligner to identify candidate variants with a high real positive confirmation rate (0.89), with which we identified eight variants considered candidates for functional studies. The results suggest that the present strategy might be a valid second step for identifying high penetrance genes.     

Mitigation of unwanted direct and indirect land‐use change – an integrated approach illustrated for palm oil,pulpwood, rubber and rice production in North and East Kalimantan,Indonesia

The widespread production of cash crops can result in the decline of forests, peatlands, rice fields and local community land. Such unwanted land‐use and land‐cover (LULC) change can lead to decreased carbon stocks, diminished biodiversity, displaced communities and reduced local food production. In this study, we analysed to what extent four main commodities, namely, palm oil, pulpwood, rice and rubber, can be produced in North and East Kalimantan in Indonesia without such unwanted LULC change. We investigated the technical potential of four measures to mitigate unwanted LULC change between 2008 and 2020 under low, medium and high scenarios, referring to the intensities of the mitigation measures compared with those implemented in 2008. These measures are related to land sparing through (i) the improvements of yields, (ii) chain efficiencies, (iii) chain integration and (iv) the steering of any expansion of these commodities to suitable and available underutilised (potentially degraded) lands. Our analyses resulted in a land‐sparing potential of 0.4–1.2 Mha (i.e. 24–62% of the total land demand of the commodities) between 2008 and 2020, depending on the land‐use projection of the four commodities and the scenario for implementing the mitigation measures. Additional expansion on underutilised land is the most important mitigation measure (45–62% of the total potential), followed by yield improvements as the second most important mitigation measure (32–46% of the total potential). Our study shows that reconciling the production of palm oil, pulpwood, rice and rubber with the maintenance of existing agricultural lands, forests and peatlands is technically possible only (i) under a scenario of limited agricultural expansion, (ii) if responsible land zoning is applied and enforced and (iii) if the yields and chain efficiencies are strongly improved.     

Metabolic profiling of maternal urine can aid clinical management of gestational diabetes mellitus

Introduction

The clinical management of Gestational diabetes mellitus (GDM) would benefit from enhanced metabolic knowledge both at the time of diagnosis and during therapy.

Objectives

This work aimed at unveiling metabolic markers of GDM and of the subjects’ response to therapy.

Methods

Urine NMR metabolomics was used with a variable selection methodology to reduce uninformative variability. The NMR data was analysed by multivariate and univariate analysis methodologies.

Results

The results showed that urine NMR metabolomics enables a metabolic signature of GDM to be identified at the time of diagnosis. This signature comprises relevant changes in 12 NMR metabolites/resonances and qualitative variations in a number of additional metabolites. The metabolite changes characterizing GDM suggest adaptations in a number of different pathways and highlight the relevance of gut microflora disturbances in relation to the disease. The impact of diet and insulin treatments on the excreted metabolome of pregnant GDM women was measured and enabled responsive and resistant metabolic pathways to be identified, as well as side-effects of treatment i.e. metabolic changes induced by treatment and previously unrelated to the disease (including changes in the gut microflora). Furthermore, treatment duration was found to be associated to urine metabolic profile, thus emphasizing the possible future use of urine metabolomics in treatment follow-up and efficacy evaluation. Finally, a possible association of a priori urinary metabolome with future treatment requirements is reported, albeit requiring demonstration in larger cohorts. This result supports the hypothesis of different metabotypes characterizing different subjects and relating to individual response to treatment.

Conclusion

A 12-resonance metabolic signature of GDN at the time of diagnosis was identified and the evaluation of the impact of insulin and/or diet therapies enabled responsive/resistant metabolic pathways and treatment side-effects to be identified.

     

Genetic non-invasive sampling (gNIS) as a cost-effective tool for monitoring elusive small mammals

Genetic non-invasive sampling (gNIS) may provide valuable information for population monitoring, as it allows inferences of population density and key behavioural traits such as dispersal, kinship and reproduction. Despite its enormous potential, gNIS has rarely been applied to small mammals, for which live-trapping is still the most commonly used sampling method. Here we evaluated the applicability and cost-effectiveness of gNIS compared with live-trapping, to monitor a metapopulation of an Iberian endemic and elusive rodent: the Cabrera vole (Microtus cabrerae). We compared the genetic diversity, kinship and dispersal movements inferred using both methods. For that, we optimised microsatellite markers for individual identification of M. cabrerae, using both tissue (n?=?31) and faecal samples (n?=?323) collected from a metapopulation in south-western Iberia. An initial set of 20 loci was optimised for tissue samples, from which 11 were selected to amplify in faecal samples. Overall, gNIS revealed a higher number of identified individuals (65) than live-trapping (31), and the estimated genetic diversity was similar using data from tissues and gNIS. Kinship analysis showed a higher number of inferred relationships and dispersal events when including gNIS, and indicated absence of sex-biased dispersal. The total cost (fieldwork and genetic analysis) of each genotype obtained through live-trapping was three times greater than for gNIS. Our data strongly supports the high potential and cost-effectiveness of gNIS for monitoring populations of elusive and/or threatened small mammals. We also illustrate how this genetic tool can be logistically feasible in conservation.     

Kinetochore microtubule numbers of different sized chromosomes

For three species of grasshoppers the volumes of the largest and the smallest metaphase chromosome differ by a factor of 10, but the microtubules (MTs) attached to the individual kinetochores show no corresponding range in numbers. Locusta mitotic metaphase chromosomes range from 2 to 21 μm, and the average number of MTs per kinetochore is 21 with an SD of 4.6. Locusta meiotic bivalents at late metaphase I range from 4 to 40 μm(3), and the kinetochore regions (= two sister kinetochores facing the same spindle pole) have an average of 25 kinetochore microtubules (kMTs) with an SD of 4.9. Anaphase velocities are the same at mitosis and meiosis I. The smaller mitotic metaphase chromosomes of neopodismopsis are similar in size, 6 to 45 μm(3), to Locusta, but they have an average more kMTs, 33, SD = 9.2. The four large Robertsonian fusion chromosomes of neopodismopsis have an average of 67 MTs per kinetochore, the large number possibly the result of a permanent dicentric condition. Chloealtis has three pairs of Robertsonian fusion chromosomes which, at late meiotic metaphase I, form bivalents of 116, 134, and 152 μm (3) with an average of 67 MTs per kinetochore similar to Locusta bivalents, but with a much higher average of 42 MTs per kinetochore region. It is speculated that, in addition to mechanical demands of force, load, and viscosity, the kMT numbers are governed by cell type and evolutionary history of the karyotype in these grasshoppers.