Local adaptations of Mediterranean sheep and goats through an integrative approach

Small ruminants are suited to a wide variety of habitats and thus represent promising study models for identifying genes underlying adaptations. Here, we considered local Mediterranean breeds of goats (n = 17) and sheep (n = 25) from Italy, France and Spain. Based on historical archives, we selected the breeds potentially most linked to a territory and defined their original cradle (i.e., the geographical area in which the breed has emerged), including transhumant pastoral areas. We then used the programs PCAdapt and LFMM to identify signatures of artificial and environmental selection. Considering cradles instead of current GPS coordinates resulted in a greater number of signatures identified by the LFMM analysis. The results, combined with a systematic literature review, revealed a set of genes with potentially key adaptive roles in relation to the gradient of aridity and altitude. Some of these genes have been previously implicated in lipid metabolism (SUCLG2, BMP2), hypoxia stress/lung function (BMPR2), seasonal patterns (SOX2, DPH6) or neuronal function (TRPC4, TRPC6). Selection signatures involving the PCDH9 and KLH1 genes, as well as NBEA/NBEAL1, were identified in both species and thus could play an important adaptive role

Decadal shifts of coastal microphytoplankton communities in a semi-enclosed bay of NW Mediterranean Sea subjected to multiple stresses

International audienceLong-term evolution of microphytoplankton communities remains poorly studied in anthropized coastal zones submitted to multiple stressors. Here, we investigate decadal (2005-2017) microphytoplankton community changes, focusing on abundance and biovolume of major taxa related to both local abiotic conditions (rainfall rate, temperature and salinity) and regional convection events (wintering deep mixing) in the highly urbanized and semi-enclosed Toulon Bay (NW Mediterranean Sea). Results showed that persistent variations in local rainfall regime were followed by major changes in microphytoplankton community composition. Wet period (P ⁠ 2) (increase of wintering precipitations observed between late 2008 and early 2015) was associated to an increase of large heterotrophic dinoflagellates and disappearance of dominant diatom taxa, while dry periods (2005-2008 (P ⁠ 1) and 2015-2017 (P ⁠ 3)) promoted diatoms, microflagellates and small mixotrophic/heterotrophic dinoflagel-lates including potentially toxic species. Concomitance between intense deep mixing events, reported in open Ligurian Basin (particularly during winters 2005 and 2006) and higher values in the total microphytoplankton abundance and in spring diatom abundance regardless of rainfall conditions, presents this meso-scale process as the main fertilization mechanism in Toulon Bay. Although no change was detected in the chlorophyll a concentration during the 2006-2017 period, its trend was negatively correlated to the total microphytoplankton abundance. This negative relation as well as a change of size in dinoflagellates suggested a shift in the primary producer nature, from large autotrophic cells (diatoms and microflagellates) to smaller ones, driven by a runoff intensification. Finally, different communities composition were observed during both dry periods (i.e. diatoms-dominated and autotrophic microflagellate-dominated communities during P ⁠ 1 and P ⁠ 3 , respectively), suggesting another environmental driver of change for phytoplankton communities of this coastal ecosystem

Proposition of indicators of anthropogenic pressure in the Bay of Toulon (Mediterranean Sea) based on zooplankton time-series

International audienceZooplankton present characteristics of high interest in the frame of investigation for organisms sensitive to environmental changes and/or anthropogenic pressures. Such indicators are particularly needed in the present context of European legislation (Marine Strategy Framework Directive). However, zooplankton have not been given the interest they should have in regards to these issues. The aim of the present study is to provide an attempt of proposition of indicators of good environmental status and associated thresholds based on zooplankton data. Zooplankton time-series (2002–2013) from the Toulon Bay in the Mediterranean was used. This time-series presents the great characteristics that the sampling has be done jointly in two areas of the Bay of Toulon known to differ in term of anthropogenic pressures. The study focus on the copepod assemblage and different potential indicators are tested: ratio of copepod families on total copepod and diversity index (Piélou's evenness). The indicators relevance was evaluated per season by looking at the importance of the overlapping region between density's distributions for each indicator in both bays. This methodology well-recognized is commonly used, particularly in the medical sector, for a long time. The results show that the Oithonidae relative abundance and the Piélou's evenness index are the best indicators of anthropogenic pollution for this case study. Thresholds related to the selected indicators are also proposed in order to characterize the degree of anthropogenic pressure for the Toulon Bay and to provide a first evaluation for potential environmental management. Applicability of the selected indicators and future development needed are also discussed. This study is a first step in the investigation for operational zooplankton indicators and should open the way for additional studies in coastal anthropized area such as the Mediterranean coast where it is more urgently needed.