%0 Journal Article
%A Vargas-Chávez, Carlos
%A Benítez-Álvarez, Lisandra
%A Martínez-Redondo, Gemma I.
%A Álvarez-González, Lucía
%A Salces-Ortiz, Judit
%A Eleftheriadi, Klara
%A Escudero, Nuria
%A Guiglielmoni, Nadège
%A Flot, Jean-François
%A Novo Rodríguez, Marta
%A Ruiz-Herrera, Aurora
%A McLysaght, Aoife
%A Fernández, Rosa
%T An episodic burst of massive genomic rearrangements and the origin of non-marine annelids
%D 2025
%@ 2397-334X
%U https://hdl.handle.net/20.500.14352/123316
%X The genomic basis of cladogenesis and adaptive evolutionary change has intrigued biologists for decades. Here we show that the tectonics of genome evolution in clitellates, a clade composed of most freshwater and all terrestrial species of the phylum Annelida, is characterized by extensive genome-wide scrambling that resulted in a massive loss of macrosynteny between marine annelids and clitellates. These massive rearrangements included the formation of putative neocentromeres with newly acquired transposable elements and preceded a further period of genome-wide reshaping events, potentially triggered by the loss of genes involved in genome stability and homoeostasis of cell division. Notably, whereas these rearrangements broke short-range interactions observed between Hox genes in marine annelids, they were reformed as long-range interactions in clitellates. Our findings reveal extensive genomic reshaping in clitellates at both the linear (2D) and three-dimensional (3D) levels, suggesting that unlike in other animal lineages where synteny conservation constrains structural evolution, clitellates exhibit a remarkable tolerance for chromosomal rearrangements. Our study thus suggests that the genomic landscape of Clitellata resulted from a rare burst of genomic changes that ended a long period of stability that persists across large phylogenetic distances.
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