Quels complexes protéiques plastidiques sont impliqués dans la dépression hybride chez Silene nutans ? // Hybrid breakdown in Silene nutans: which plastid protein complexes are involved?

Recent studies in evolutionary genomics have revealed the central role of cyto-nuclear interactions in the emergence of new species (Postel & Touzet 2020). Because plastid protein complexes have a dual origin (nuclear and plastid), mutations in one genome trigger selection in the other genome to maintain co-adaptation and functional plastids. The coevolution between plastid and nuclear genes involved in the same functional complexes generates strong patterns and could lead to hybrid breakdown between sister lineages as we demonstrated in the species complex Silene nutans (Postel et al. 2022). Silene nutans is composed of 4 genetic lineages. The hybrids between these lineages exhibit chlorosis leading to juvenile mortality pointing out to plastid-nuclear incompatibilities. Concordantly, the genomic analysis of both organellar genomes revealed a large number of specific mutations in plastid genes contrarily to the mitogenome (Postel et al. 2022, 2023).
The objective of the proposed PhD project is to identify which plastid protein complexes are functionally impaired in the inter-lineage hybrids. This will be conducted via an interdisciplinary approach, from in vivo fluorescence imaging (e.g. Johnson et al. 2009), biochemical methods (electrophoresis, native gels of proteomes from isolated plastids), mass spectrometry for the identification of plastid complexes, to the in silico prediction of the potential structural and functional impact of the observed modifications, all results being interpreted in the framework of evolutionary biology. This PhD project is part of the Cross Disciplinary Project PIE (Protein-Interaction-Evolution) (aiming to combine complementary approaches gathering plant physiologists, evolutionary biologists, structural biologists and biocomputer scientists to assess the role of protein-protein interaction in biological transitions.
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Recent studies in evolutionary genomics have revealed the central role of cyto-nuclear interactions in the emergence of new species (Postel & Touzet 2020). Because plastid protein complexes have a dual origin (nuclear and plastid), mutations in one genome trigger selection in the other genome to maintain co-adaptation and functional plastids. The coevolution between plastid and nuclear genes involved in the same functional complexes generates strong patterns and could lead to hybrid breakdown between sister lineages as we demonstrated in the species complex Silene nutans (Postel et al. 2022). Silene nutans is composed of 4 genetic lineages. The hybrids between these lineages exhibit chlorosis leading to juvenile mortality pointing out to plastid-nuclear incompatibilities. Concordantly, the genomic analysis of both organellar genomes revealed a large number of specific mutations in plastid genes contrarily to the mitogenome (Postel et al. 2022, 2023).
The objective of the proposed PhD project is to identify which plastid protein complexes are functionally impaired in the inter-lineage hybrids. This will be conducted via an interdisciplinary approach, from in vivo fluorescence imaging (e.g. Johnson et al. 2009), biochemical methods (electrophoresis, native gels of proteomes from isolated plastids), mass spectrometry for the identification of plastid complexes, to the in silico prediction of the potential structural and functional impact of the observed modifications, all results being interpreted in the framework of evolutionary biology. This PhD project is part of the Cross Disciplinary Project PIE (Protein-Interaction-Evolution) (aiming to combine complementary approaches gathering plant physiologists, evolutionary biologists, structural biologists and biocomputer scientists to assess the role of protein-protein interaction in biological transitions.
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Début de la thèse : 01/10/2025

Plan Investissement d'Avenir (Idex, Labex)

Université de Lille

104 Sciences de la Matière du Rayonnement et de l'Environnement

Master en omics, en physiologie végétale ou en biologie évolutive
Master in omics, plant physiology or evolutionary biology