Caractérisation des bases moléculaires de l'isolement reproducteur post-zygotique intrinsèque chez le Grand Corégone (Coregonus clupeaformis)
|Abstract:||While high throughput sequencing has led to significant progress towards the understanding of the genomic architecture of speciation, molecular mechanisms responsible for reproductive isolation remain unclear. The main objective of this thesis is to contribute to elucidate the molecular basis of reproductive isolation in a nascent species complex : the Lake Whitefish. In particular, the approach was to examine the mechanisms associated with genome stability and instability in a context of divergence and hybridization. Using transcriptomics, we documented a profound deregulation at the transcriptome scale in hybrids between dwarf and normal Lake Whitefish, including transposable element and non-coding RNA derepression. Then, we found that hybrids show significant signs of meiosis and mitosis breakdown, despite the absence of karyotype changes between parental forms. Finally, we observed conspicuous sub-chromosomal polymorphism in three sympatric Lake Whitefish species pairs, mainly associated with earlier allopatry. This work shows that genome-scale reorganization occurs early during divergence, and may lead to profound dysregulation in hybrids. This thesis also shows that integrative biology promotes a better understanding of the mechanisms linked to divergence and speciation.|
|Document Type:||Thèse de doctorat|
|Open Access Date:||23 April 2018|
|Collection:||Thèses et mémoires|
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