Region-specific expression of young small-scale duplications in the human central nervous system

BMC Evolutionary Biology

article

Brohard-Julien, Solène¹  Frouin, Vincent²  Meyer, Vincent¹  Chalabi, Smahane¹  Deleuze, Jean-François¹  Le Floch, Edith¹  Battail, Christophe¹ 

[1] Centre National de Recherche en Génomique Humaine (CNRGH), Institut François Jacob, Université Paris-Saclay;Institut Joliot, Université Paris-Saclay;Université Paris-Sud, Université Paris-Saclay;Centre d’Etude du Polymorphisme Humain;Centre de Référence;CEA, Univ. Grenoble Alpes, INSERM, IRIG, Biology of Cancer and Infection UMR

关键词: Paralog;    Small scale duplication;    Brain region-specific expression;    Human central nervous system;    Gene co-expression network;   

DOI  :  10.1186/s12862-021-01794-w

学科分类：护理学

来源: BioMed Central

【 摘 要 】

The duplication of genes is one of the main genetic mechanisms that led to the gain in complexity of biological tissue. Although the implication of duplicated gene expression in brain evolution was extensively studied through comparisons between organs, their role in the regional specialization of the adult human central nervous system has not yet been well described. Our work explored intra-organ expression properties of paralogs through multiple territories of the human central nervous system (CNS) using transcriptome data generated by the Genotype-Tissue Expression (GTEx) consortium. Interestingly, we found that paralogs were associated with region-specific expression in CNS, suggesting their involvement in the differentiation of these territories. Beside the influence of gene expression level on region-specificity, we observed the contribution of both duplication age and duplication type to the CNS region-specificity of paralogs. Indeed, we found that small scale duplicated genes (SSDs) and in particular ySSDs (SSDs younger than the 2 rounds of whole genome duplications) were more CNS region-specific than other paralogs. Next, by studying the two paralogs of ySSD pairs, we observed that when they were region-specific, they tend to be specific to the same region more often than for other paralogs, showing the high co-expression of ySSD pairs. The extension of this analysis to families of paralogs showed that the families with co-expressed gene members (i.e. homogeneous families) were enriched in ySSDs. Furthermore, these homogeneous families tended to be region-specific families, where the majority of their gene members were specifically expressed in the same region. Overall, our study suggests the involvement of ySSDs in the differentiation of human central nervous system territories. Therefore, we show the relevance of exploring region-specific expression of paralogs at the intra-organ level.

【 授权许可】

CC BY|CC0