Authors:	Rücklé, Cornelia
Title:	Analysis of m6A mRNA modifications and their role in dosage compensation
Online publication date:	9-Aug-2023
Year of first publication:	2023
Language:	english
Abstract:	m6A mRNA modifications play a crucial role in mRNA metabolism, in- cluding the degradation of m6A-mRNA via the YTHDF2 reader protein. To specifically understand which mRNAs are degraded in an m6A-dependent way, it is essential to locate the modification in a high-confidence and transcriptome-wide manner. m6A is commonly detected with antibody- based methods. These approaches have been shown to suffer several lim- itations due to insufficient antibody selectivities. To investigate the distri- bution of m6A, we focused in the first part of this work on improving the accurate detection of the modification. We specifically overcame limitations of m6A detection using the miCLIP protocol and established an improved miCLIP2 protocol. This was specifically coupled with an extensive bioinfor- matic pipeline and a machine learning classifier, allowing the accurate detec- tion of m6A transcriptome-wide in a single-nucleotide resolution. Using this novel high-confidence annotation, we present in the second part of the work a novel role of m6A modifications in X-to-autosome dosage compensation. X-to-autosome dosage compensation aims to balance the gene expression of autosomes and the X chromosome: While the X chromosome is present in one copy, autosomes are present in two copies. It has been proposed that X-chromosomal genes are upregulated and reach similar expression lev- els as autosomal genes. It has been shown that X-chromosomal transcripts have higher half-lives than autosomal transcritps, however, how this is ac- complished is not known. Here, we show that X-chromosomal transcripts are significantly depleted of m6A and thereby more stable than autosomal transcripts. When depleting m6A, autosomal transcripts become more stable and reach similar stabilities as the X-chromosomal transcripts. Collectively, our work firstly provides an enhanced tool for the detection of m6A in a transcriptome-wide manner and, secondly, gives novel insights into a global function of the modification in the regulation of gene expression.
DDC:	500 Naturwissenschaften 500 Natural sciences and mathematics 570 Biowissenschaften 570 Life sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 10 Biologie
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-9315
URN:	urn:nbn:de:hebis:77-openscience-e8dc6280-b3a7-4eaa-8597-317383f81c907
Version:	Original work
Publication type:	Dissertation
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Extent:	Getrennte Zählungen ; Illustrationen, Diagramme
Appears in collections:	JGU-Publikationen