Search bioRxiv⌕ Search

bioRxiv · 10.1101/2024.09.10.612032

Survey of gene, lncRNA and transposon transcription patterns in four mouse organs highlights shared and organ-specific sex-biased regulation

Abstract

BackgroundSex-biased gene regulation is the basis of sexual dimorphism in phenotypes and has been studied across different cell types and different developmental stages. However, sex-biased expression of transposable elements (TEs) that represent nearly half of the mammalian genome and have the potential of influencing genome integrity and regulation, remains underexplored. ResultsHere, we report a survey of gene, lncRNA and TE expression in four organs from mice with different combinations of gonadal and genetic sex. Data show remarkable variability among organs with respect to the impact of gonadal sex on transcription with the strongest effects observed in liver. In contrast, the X-chromosome dosage alone had modest influence on sex-biased transcription across different organs, albeit interaction between X-dosage and gonadal sex cannot be ruled out. The presence of the Y chromosome influenced TE, but not gene or lncRNA expression in liver. Notably, 90% of sex-biased TEs (sDETEs) reside in clusters. Moreover, 54% of these clusters overlap or reside close (<100 kb) to sex-biased genes or lncRNAs, share the same sex bias, and also have higher expression levels than sDETE clusters that do not co-localize with other types of sex-biased transcripts. We also tested the heterochromatic sink hypothesis that predicts higher expression of TEs in XX individuals and found no evidence to support it. ConclusionsOur data show that sex-biased expression of TEs varies among organs with highest numbers of sDETEs found in liver following the trends observed for genes and lncRNAs. It is enhanced by proximity to other types of sex-biased transcripts.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Zhuang, Q. K.-W., Bauermeister, K., Galvez Lopez, J. H., AlOgayil, N., Batdorj, E., Pardo-Manuel de Villena, F., Taketo, T., Bourque, G., Naumova, A. K.. 2024-09-13. Survey of gene, lncRNA and transposon transcription patterns in four mouse organs highlights shared and organ-specific sex-biased regulation. https://doi.org/10.1101/2024.09.10.612032

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Integrative Nanopore and Illumina sequencing reveals age-associated tRNA modification and CCA-tail dynamics in yeast

Aging is characterized by a progressive loss of proteostasis. Transfer RNAs (tRNAs) are essential regulators of translation, yet their dynamics during aging remain poorly understood due to challenges in sequencing highly modified RNAs. Here we present a benchmarked Nanopore direct RNA sequencing (RNA004 chemistry) resource that profiles the Saccharomyces cerevisiae tRNAome during replicative aging at single-molecule resolution. Using in vitro transcribed tRNA controls, we establish modification detection thresholds and validate key findings with orthogonal Illumina sequencing. While overall tRNA abundance remains largely stable, our resource reveals age-associated terminal A cleavage at the 3' CCA tail of mature tRNAs, targeted T-loop and anticodon modification changes, and single-molecule evidence of modification co-occurrence. This dataset provides a resource for exploring tRNA regulation, translation fidelity, and longevity.

genomics↗

A hydrogen-producing mitochondrion in an anaerobic eukaryotrophic rhizarian

Diverse eukaryotes thrive under low oxygen conditions, in part through highly modified mitochondrion-related organelles (MROs) that use alternate metabolic pathways to support ATP production and cofactor recycling. Anaerobic lifestyles have evolved repeatedly across the eukaryotic tree of life, each providing an independent opportunity to understand how eukaryotes adapt to life in low oxygen conditions. Here, we use single-cell transcriptomics to reconstruct the MRO metabolism of PCE SSF, a benthic eukaryotrophic flagellate and the first cultivated representative of Novel Clade 12 (NC12; Rhizaria), an independently anaerobic rhizarian lineage. PCE SSF possesses an anaerobic hydrogen-producing mitochondrion capable of hydrogenosome-type substrate-level phosphorylation. It also retains a nearly complete but likely branched tricarboxylic acid pathway that lacks citrate synthase and malate dehydrogenase. The function of citrate synthase may instead be fulfilled by the typically cytosolic ATP citrate lyase, previously reported in this context only in the anaerobic cercozoan, Brevimastigomonas motovehiculus. Unlike B. motovehiculus, however, PCE SSF retains only Complex II and the NuoE/NuoF subunits of the electron transport chain and lacks a mitochondrial genome. Together, these features indicate an atypical and reduced mitochondrial metabolism, highlighting the diversity of evolutionary solutions to anaerobic energy metabolism in eukaryotes.

genomics↗

Targeted CRISPRi screening reveals unexpected resilience across the RNA polymerase III transcriptome

Increased RNA polymerase III (Pol III) activity and tRNA abundance are widely linked to cancer cell growth, yet the functional requirement for individual Pol III genes and core components remains unclear, in part due to the difficulty of achieving gene-specific perturbation of highly conserved loci. Here, we developed an inducible CRISPR interference platform and a custom single-guide RNA (sgRNA) library enabling gene-specific targeting of Pol III-transcribed genes and Pol III machinery. Genome-wide screening identified several Pol III dependencies in diploid fibroblasts and HEK293T cells, including multiple initiator methionine tRNA genes among the strongest fitness dependencies. Unexpectedly, glioblastoma models remained largely insensitive to repression of both individual Pol III genes and core Pol III components, despite efficient target repression. These findings establish a general strategy for gene-specific interrogation of conserved Pol III genes and indicate that glioblastoma models tolerate extensive perturbation of Pol III genes and machinery.

genomics↗