Search bioRxiv⌕ Search

bioRxiv · 10.1101/2025.09.11.675639

Fine-scale recombination rates inferred using the canFam4 assembly are strongly correlated with previous maps of dog recombination

Abstract

BackgroundGenetic maps are a key resource for the analysis of genetic variation. Prior maps in dogs were based on the canFam3.1 genome assembly, which contains thousands of sequence gaps that include functional elements. Although long-read technologies have enabled the generation of updated reference assemblies, updated maps are required to take full advantage of these new resources. MethodsWe inferred fine-scale recombination maps that consider population demographic history for four populations of village dogs sequenced by the Dog10K Consortium. We compare properties among the newly generated and previously published maps and assess the effects of genetic map choice on genotype phasing accuracy. ResultsThe newly inferred maps are broadly consistent with previous studies of recombination in dogs. At small scales, stronger correlations are observed among maps inferred using linkage disequilibrium than with a pedigree-based map. The position of recombination hotspots showed significant overlap among inferred maps and were enriched for sequences that were gaps in a previous canine genome assembly. When using the Dog10K samples as a reference panel, a phase error rate of approximately 2% was found with the choice of genetic map having little effect. ConclusionsWe describe genetic maps based on the canFam4 assembly which will be useful for future studies of genetic variation that rely on updated dog genome references.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kidd, J. M.. 2025-09-13. Fine-scale recombination rates inferred using the canFam4 assembly are strongly correlated with previous maps of dog recombination. https://doi.org/10.1101/2025.09.11.675639

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↗