Biometric conversion factors as a unifying platform for comparative assessment of invasive freshwater bivalves

Invasive bivalves continue to spread and negatively impact freshwater ecosystems worldwide. As different metrics for body size and biomass are frequently used within the literature to standardise bivalve-related ecological impacts (e.g. respiration and filtration rates), the lack of broadly applicable conversion equations currently hinders reliable comparison across bivalve populations. To facilitate improved comparative assessment among studies originating from disparate geographical locations, we report body size and biomass conversion equations for six invasive freshwater bivalves (or species complex members) worldwide: Corbicula fluminea, C. largillierti, Dreissena bugensis, D. polymorpha, Limnoperna fortunei and Sinanodonta woodiana, and tested the reliability (i.e. precision and accuracy) of these equations. Body size (length, width and height) and biomass metrics of living-weight (LW), wet-weight (WW), dry-weight (DW), dry shell-weight (SW), shell free dry-weight (SFDW) and ash-free dry-weight (AFDW) were collected from a total of 44 bivalve populations located in Asia, the Americas and Europe. Relationships between body size and individual biomass metrics, as well as proportional weight-to-weight conversion factors, were determined. For most species, although inherent variation existed between sampled populations, body size directional measurements were found to be good predictors of all biomass metrics (e.g. length to LW, WW, SW or DW: R2 = 0.82–0.96), with moderate to high accuracy for mean absolute error (MAE): ±9.14%–24.19%. Similarly, narrow 95% confidence limits and low MAE were observed for most proportional biomass relationships, indicating high reliability for the calculated conversion factors (e.g. LW to AFDW; CI range: 0.7–2.0, MAE: ±0.7%–2.0%). Synthesis and applications. Our derived biomass prediction equations can be used to rapidly estimate the biologically active biomass of the assessed species, based on simpler biomass or body size measurements for a wide range of situations globally. This allows for the calculation of approximate average indicators that, when combined with density data, can be used to estimate biomass per geographical unit-area and contribute to quantification of population-level effects. These general equations will support meta-analyses, and allow for comparative assessment of historic and contemporary data. Overall, these equations will enable conservation managers to better understand and predict ecological impacts of these bivalves.Fil: Coughlan, Neil E.. The Queens University of Belfast; Irlanda. University College Cork; IrlandaFil: Cunningham, Eoghan M.. The Queens University of Belfast; IrlandaFil: Cuthbert, Ross N.. The Queens University of Belfast; Irlanda. Geomar-Helmholtz Centre for Ocean Research Kiel; AlemaniaFil: Joyce, Patrick W. S.. The Queens University of Belfast; IrlandaFil: Anastácio, Pedro. Universidade de Évora; PortugalFil: Banha, Filipe. Universidade de Évora; PortugalFil: Bonel, Nicolás. Université Montpellier II; Francia. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Bradbeer, Stephanie J.. University of Leeds; Reino UnidoFil: Briski, Elizabeta. Geomar-Helmholtz Centre for Ocean Research Kiel; AlemaniaFil: Butitta, Vince L.. University of Wisconsin; Estados UnidosFil: Cadková, Zuzana. Czech University of Life Sciences; República ChecaFil: Dick, Jaimie T. A.. The Queens University of Belfast; IrlandaFil: Douda, Karel. Czech University of Life Sciences; República ChecaFil: Eagling, Lawrence E.. The Queens University of Belfast; IrlandaFil: Ferreira Rodríguez, Noé. Universidad de Vigo; EspañaFil: Hünicken, Leandro Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Johansson, Mattias L.. University of North Georgia; Estados UnidosFil: Kregting, Louise. The Queens University of Belfast; IrlandaFil: Labecka, Anna Maria. Jagiellonian University; PoloniaFil: Li, Deliang. Hunan Agricultural University; ChinaFil: Liquin, Florencia Fernanda. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Marescaux, Jonathan. University of Namur; Bélgica. e-biom; BélgicaFil: Morris, Todd J.. Fisheries and Ocean Canada; CanadáFil: Nowakowska, Patrycja. University of Gdansk; PoloniaFil: Ozgo, Malgorzata. Kazimierz Wielki University; PoloniaFil: Paolucci, Esteban Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Peribáñez, Miguel A.. Universidad de Zaragoza; EspañaFil: Riccardi, Nicoletta. Consiglio Nazionale delle Ricerche; ItaliaFil: Smith, Emily R. C.. University College London; Estados UnidosFil: Sylvester, Francisco. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentin

Evolutionary change in Cepaea nemoralis shell colour over 43 years

We compared shell colour forms in the land snail Cepaea nemoralis at 16 sites in a 7 x 8 km section of the Province of Groningen, the Netherlands, between 1967 and 2010. To do so, we used stored samples in a natural history collection and resampled the exact collection localities. We found that almost all populations had experienced considerable evolutionary change in various phenotypes, possibly due to population bottlenecks and habitat change after repeated land consolidation schemes in the area. More importantly, we found a consistent increase in yellow effectively unbanded snails at the expense of brown snails. This is one of the expected adaptations to climate change (this area of the Netherlands has warmed by 1.52.0 degrees C over the time period spanned by the two sampling years), and the first clear demonstration of this in C. nemoralis

Effect of a low magnesium diet on magnesium status and gene expression in the kidneys of mice selected for high and low magnesium erythrocyte levels

International audienceThe magnesium concentrations in plasma and cells could be affected by diet, disease and genetic factors. To characterise the genetic factors involved in the regulation of magnesium homeostasis, Low (MgL) and High (MgH) magnesium status mice were developed by bidirectional selective breeding. The effects of a low-magnesium diet on the magnesium status parameters were analysed in these mice. Using a cDNA array, a screen for differential gene expression was performed in kidneys from these animals, fed either a magnesium adequate or deficient diet. The magnesium-deficient diet significantly affected the plasma, erythrocyte and urine magnesium concentrations in both strains, in similar proportions in the two strains. Furthermore, in response to the magnesium-deficient diet, both strains showed changes of the expression of genes belonging, for the majority of them, to the family of transcription and growth factors (down-regulated). Of the identified genes, five were of particular interest because they were differently expressed in response to the deficient diet in these two strains: osteopontin, the cholecystokinin A receptor, connexin 45, a growth hormone receptor and BAG1. These results suggest that the two strains exhibit different physiopathological responses to magnesium deficiency

Plasma proteome analysis : 2D gels and chips

ReviewInternational audienceThe knowledge of concentration, modification and interaction of proteins is fundamental in determining the phenotype of living organisms. Plasma, the primary clinical specimen, contains numerous and diverse proteins. The functions of these proteins are as manifold as the diversity of the protein themselves. Many of them have been largely used for many years as biomarkers of diseases and indicators of the physiological functions. The study of plasma proteome promises to be a significant advance in various areas of biological and clinical research. Two-dimensional polyacrylamide gel electrophoresis is considered as a primary tool in separating thousand of plasma proteins. This approach enables comparing normal and diseased samples revealing differently expressed proteins. Other proteomic techniques suitable for plasma analysis such as protein microarrays are now either established or are still being improved. This article briefly reviews the application of two-dimensional electrophoresis and the current status of technical aspects for plasma proteome

Inferring microevolution from museum collections and resampling: lessons learned from [i]Cepaea[i]

Studies documenting Human-Induced Rapid Evolutionary Change (HIREC) routinely compare contemporary allele or morph frequency distributions with historical baselines. All too often, this involves the re-sampling of a population that was sampled at a single time point in the past. However, year-to-year fluctuations in magnitude and direction of evolutionary response may make such studies prone to erroneous conclusions, where long-term evolutionary trends are inferred from what in fact are short-term fluctuations. Here, we explore this problem by re-sampling three Dutch populations of the land snail Cepaea nemoralis, whose shell colour polymorphism is known to be under thermal and predatory selection. Each of these three populations was originally sampled in at least two different years in the past. We show that conclusions on evolutionary change are strongly dependent on which of the historical sample dates is used for comparison with the contemporary sample. Our study highlights the fact that year-to-year variation in allele frequencies may often be so strong that a simple two-point comparison is unreliable to detect long-term evolutionary trends. 23 Here, we explore this problem by re-sampling three Dutch populations of the land snail 24 Cepaea nemoralis, whose shell colour polymorphism is known to be under thermal and 25 predatory selection. Each of these three populations was originally sampled in at least 26 two different years in the past. We show that conclusions on evolutionary change are 27 strongly dependent on which of the historical sample dates is used for comparison with 28 the contemporary sample. Our study highlights the fact that year-to-year variation in 29 allele frequencies may often be so strong that a simple two-point comparison is 30 unreliable to detect long-term evolutionary trends. 3