Lamya Chaoui
University of Montpellier
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Featured researches published by Lamya Chaoui.
Molecular Ecology | 2012
Lamya Chaoui; Pierre-Alexandre Gagnaire; Bruno Guinand; Jean-Pierre Quignard; Costas S. Tsigenopoulos; M. Hichem Kara; François Bonhomme
The genetic basis and evolutionary implications of local adaptation in high gene flow marine organisms are still poorly understood. In several Mediterranean fish species, alternative migration patterns exist between individuals entering coastal lagoons that offer favourable conditions for growth and those staying in the sea where environmental conditions are less subject to rapid and stressful change. Whether these coexisting strategies are phenotypically plastic or include a role for local adaptation through differential survival needs to be determined. Here, we explore the genetic basis of alternate habitat use in western Mediterranean populations of the gilthead sea bream (Sparus aurata). Samples from lagoonal and open‐sea habitats were typed for three candidate gene microsatellite loci, seven anonymous microsatellites and 44 amplified fragment length polymorphism markers to test for genotype–environment associations. While anonymous markers globally indicated high levels of gene flow across geographic locations and habitats, non‐neutral differentiation patterns correlated with habitat type were found at two candidate microsatellite loci located in the promoter region of the growth hormone and prolactin genes. Further analysis of these two genes revealed that a mechanism based on habitat choice alone could not explain the distribution of genotype frequencies at a regional scale, thus implying a role for differential survival between habitats. We also found an association between allele size and habitat type, which, in the light of previous studies, suggests that polymorphisms in the proximal promoter region could influence gene expression by modulating transcription factor binding, thus providing a potential explanatory link between genotype and growth phenotype in nature.
Royal Society Open Science | 2015
I. D. Pivotto; David Nerini; Mauatassem Billah Masmoudi; H. Kara; Lamya Chaoui; Didier Aurelle
Climate change has a strong impact on marine ecosystems, including temperate species. Analysing the diversity of thermotolerance levels within species along with their genetic structure enables a better understanding of their potential response to climate change. We performed this integrative study on the Mediterranean octocoral Eunicella cavolini, with samples from different depths and by means of a common garden experiment. This species does not host photosynthetic Symbiodinium, enabling us to focus on the cnidarian response. We compared the thermotolerance of individuals from 20 m and 40 m depths from the same site and with replicates from the same colony. On the basis of an innovative statistical analysis of necrosis kinetics and risk, we demonstrated the occurrence of a very different response between depths at this local scale, with lower thermotolerance of deep individuals. Strongly thermotolerant individuals were observed at 20 m with necrosis appearing at higher temperatures than observed in situ. On the basis of nine microsatellite loci, we showed that these marked thermotolerance differences occur within a single population. This suggests the importance of acclimatization processes in adaptation to these different depths. In addition, differences between replicates demonstrated the occurrence of a variability of response between fragments from the same colony with the possibility of an interaction with a tank effect. Our results provide a basis for studying adaptation and acclimatization in Mediterranean octocorals in a heterogeneous environment.
Ecology and Evolution | 2016
Moutassem Billah Masmoudi; Lamya Chaoui; Nur Eda Topçu; Pachka Hammami; Mohamed Hichem Kara; Didier Aurelle
Abstract Understanding the factors explaining the observed patterns of genetic diversity is an important question in evolutionary biology. We provide the first data on the genetic structure of a Mediterranean octocoral, the yellow gorgonian Eunicella cavolini, along with insights into the demographic history of this species. We sampled populations in four areas of the Mediterranean Sea: continental France, Algeria, Turkey, and the Balearic and Corsica islands. Along French coasts, three sites were sampled at two depths (20 and 40 m). We demonstrated a high genetic structure in this species (overall FST = 0.13), and most pairwise differentiation tests were significant. We did not detect any difference between depths at the same site. Clustering analyses revealed four differentiated groups corresponding to the main geographical areas. The levels of allelic richness and heterozygosity were significantly different between regions, with highest diversity in Algeria and lowest levels in Turkey. The highest levels of private allelic richness were observed in Algeria followed by Turkey. Such contrasted patterns of genetic diversity were not observed in other Mediterranean octocorals and could be the result of different evolutionary histories. We also provide new empirical evidence of contrasting results between tests and model‐based studies of demographic history. Our results have important consequences for the management of this species.
Zoologica Scripta | 2017
Didier Aurelle; Isabelle D. Pivotto; Marine Malfant; Nur Eda Topçu; Mauatassem Billah Masmoudi; Lamya Chaoui; Hichem M. Kara; Márcio A.G. Coelho; Rita Castilho; Anne Haguenauer
The study of the interplay between speciation and hybridization is of primary importance in evolutionary biology. Octocorals are ecologically important species whose shallow phylogenetic relationships often remain to be studied. In the Mediterranean Sea, three congeneric octocorals can be observed in sympatry: Eunicella verrucosa, Eunicella cavolini and Eunicella singularis. They display morphological differences and E. singularis hosts photosynthetic Symbiodinium, contrary to the two other species. Two nuclear sequence markers were used to study speciation and gene flow between these species, through network analysis and Approximate Bayesian Computation (ABC). Shared sequences indicated the possibility of hybridization or incomplete lineage sorting. According to ABC, a scenario of gene flow through secondary contact was the best model to explain these results. At the intraspecific level, neither geographical nor ecological isolation corresponded to distinct genetic lineages in E. cavolini. These results are discussed in the light of the potential role of ecology and genetic incompatibilities in the persistence of species limits.
Scientia Marina | 2006
Lamya Chaoui; Mohamed Hichem Kara; Eric Faure; Jean Pierre Quignard
Cybium | 2006
Lamya Chaoui; M. Hichem Kara; Eric Faure; Jean-Pierre Quignard
Cahiers De Biologie Marine | 2005
Lamya Chaoui; Farid Derbal; M. Hichem Kara; Jean Pierre Ouignard
Estuarine Coastal and Shelf Science | 2016
A. S. Boudinar; Lamya Chaoui; Jean-Pierre Quignard; Didier Aurelle; Mohamed Hichem Kara
Cybium | 2004
Lamya Chaoui; M. Hichem Kara
Comptes Rendus Biologies | 2018
Almudena Cánovas-Molina; Monica Montefalcone; Giorgio Bavestrello; Mauatassem Billah Masmoudi; Anne Haguenauer; Pachka Hammami; Lamya Chaoui; Mohammed Hichem Kara; Didier Aurelle