Hal will be stopped for maintenance from friday on june 10 at 4pm until monday june 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Unusual composition of a yeast chromosome arm is associated with its delayed replication.

Abstract : Yeast species from the Lachancea genus belong to a phylogenetic clade within the Saccharomycetacae that was established before the ancestral whole genome duplication event that molded the genomes of Saccharomyces species. The 11.3 Mb genome of Lachancea (Saccharomyces) kluyveri displays an intriguing compositional heterogeneity: a region of ca. 1Mb, covering almost the whole left arm of chromosome C (C-left), has an average GC content of 52.9%, significantly higher than the 40.4% global GC content of the rest of the genome. This region contains the MAT locus, which remains normal in composition. The excess of GC base pairs affects both coding and non-coding sequences, and thus is not due to selective pressure acting on protein sequences. It leads to a strong codon usage bias and alters the amino acid composition of the proteins encoded on C-left. The 457 genes on C-left do not show obvious bias for functional categories, presence of paralogs or orthologs of essential genes of S. cerevisiae. They share significant synteny conservation with other species of Saccharomycetaceae, and phylogenetic analysis indicates that this chromosomal arm originates from a Lachancea species. In contrast, there is a complete absence of transposable elements in C-left, whereas 18 elements per Mb are distributed across the rest of the genome. Comparative hybridization of synchronized cells using high density genome arrays reveals that C-left is replicated later during the S-phase than the rest of the genome. Two possible primary causes of this major compositional heterogeneity are discussed: an ancient hybridization of two related species with very distinct GC composition, or an intrinsic mechanism, possibly associated with the loss of the silent cassettes (HML and HMR) from C-left that progressively increased the GC content and generated the delayed replication of this chromosomal arm.
Complete list of metadata

Cited literature [55 references]  Display  Hide  Download

Contributor : David James Sherman Connect in order to contact the contributor
Submitted on : Sunday, May 31, 2020 - 2:11:00 PM
Last modification on : Thursday, April 7, 2022 - 10:10:30 AM


2009_Payen_Genome Reseach_1.pd...
Publisher files allowed on an open archive



Célia Payen, Gilles Fischer, Christian Marck, Caroline Proux, David James Sherman, et al.. Unusual composition of a yeast chromosome arm is associated with its delayed replication.. Genome Research, Cold Spring Harbor Laboratory Press, 2009, 19, pp.1710-1721. ⟨10.1101/gr.090605.108⟩. ⟨inria-00407518⟩



Record views


Files downloads