The arrival of Neolithic culture in North Africa, especially domestic animals has been essentially documented from archaeological records. As the data relative to sheep are scarce, we studied the genetic relationship between Moroccan sheep breeds and Mediterranean ones using the sequencing of 628 bp of the mitochondrial DNA control region in 193 Moroccan individuals, belonging to six breeds, and 652 sequences from other breeds in Europe and Middle East. Through Network analysis and an original phylogenetically derived method, the connection proportions of each Moroccan breed to foreign ones were estimated, highlighting the strong links between Moroccan and Iberian breeds. The first founders of Moroccan sheep population were issued at 79% from Iberia and 21% from a territory between Middle East and Africa. Their calculated expansion times were respectively 7,100 and 8,600 years B.P. This suggests that Neolithization was introduced by a double influence, from Iberia and from another route, maybe Oriental or Sub-Saharan. The consequence of the environmental changes encountered by founders from Iberia was tested using different neutrality tests. There are significant selection signatures at the level of Moroccan and European breeds settled in elevated altitudes, and an erosion of nucleotide diversity in Moroccan breeds living in arid areas.

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.

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.

In a context of climate change, identifying the genes underlying adaptations to extreme environments is essential. Small ruminants are adapted to a wide variety of habitats and thus, are promising study models. Here, we considered 17 goat and 25 sheep local Mediterranean breeds, in Italy, France and Spain. We proposed, and empirically tested a new methodology to highlight selection signatures in relation to the environments. Based on historical archives, we selected the breeds potentially most linked to a territory and defined their original geographical cradle, including transhumant pastoral areas. For both species, the cradles were arranged along latitudinal gradient of aridity and altitude. Then we used the programs PCAdapt and LFMM. Considering cradles, instead of current GPS coordinates, markedly improved the sensitivity of the LFMM analyses. All the results combined with a systematic literature review, revealed a set of genes with potentially key adaptive roles. Some of these genes, have been found implicated in lipid metabolism (SUCLG2, BMP2), hypoxia/heat stress (UBE2R2/UBAP2), lung function (BMPR2), seasonal patterns (SOX2, DPH6) or neuronal function (TRPC4, TRPC6). For the intergenic region between PCDH9 and KLH1, as well as NBEA, identified in both species, the adaptive role could be strong. We found for RXFP2, associated with sheep horn development, and MSRB3 and SLC26A4, both associated with hearing of sheep, a strong association with the environment gradient. We conclude that our new methodology, which considers breeds in their historical, environmental and anthropological context, provides novel and essential information on local breeds and their unique adaptations.