Biology subjects

McLain, A.

Publications and source records attributed to McLain, A..

3 recordsLinked to original sources

bioRxiv2026

A Telomere-to-telomere genome of the hibernating fat-tailed dwarf lemur (Cheirogaleus medius)

Madagascars dwarf lemurs (genus Cheirogaleus) are the only obligate-hibernating primates and closest relative to humans capable of hibernation. Endemic to the increasingly fragmented dry forests of Madagascar, the fat tailed dwarf lemur (Cheirogaleus medius) represents a unique model for understanding primate physiology and tropical hibernation. Here we present FatTail1, a highly contiguous diploid genome assembly generated from a male C. medius at the Duke Lemur Center using Oxford Nanopore Technologies PromethION sequencing. The assembly spans 2.3 Gb, with an N50 of 103Mb, L50 of 10, and a BUSCO completeness score of over 99%. In addition to a complete mitogenome, we generated allele-specific DNA methylation profiles and annotated 23,925 genes using NCBIs EGAPX. FatTail1 exceeds the gap-free contiguity of previously published strepsirrhine genomes, representing the first telomere-to-telomere genome of a Strepsirrhine primate, and providing a foundation for future studies of primate hibernation, epigenetic regulation, and conservation genomics. ARTICLE SUMMARYDwarf lemurs are the only primates and closest relative to humans capable of months-long hibernation, making them an important model for understanding metabolic adaptations with relevance to human physiology. Here we present FatTail1, the first telomere-to-telomere genome assembly of a strepsirrhine primate, generated from a fat-tailed dwarf lemur (Cheirogaleus medius) using Oxford Nanopore Technologies PromethION sequencing. In addition to a highly complete nuclear genome, we assembled the mitogenome, identified allele-specific DNA methylation profiles and annotated 23,925 genes. FatTail1 exceeds the gap-free contiguity of previously published strepsirrhine genomes and provides an improved genomic resource for studies of hibernation, comparative genomics, epigenetic regulation, evolutionary biology, and conservation of this threatened primate.

genomics↗

bioRxiv2022

Chromosome-level, nanopore-only genome and allele-specific DNA methylation of Pallas's cat, Otocolobus manul

Pallass cat, or the manul cat (Otocolobus manul), is a small felid native to the grasslands and steppes of central Asia. Population strongholds in Mongolia and China face growing challenges from climate change, habitat fragmentation, poaching, and other sources. These threats, combined with O. manuls zoo collection popularity and value in evolutionary biology, necessitate improvement of species genomic resources. We used standalone nanopore sequencing to assemble a 2.5 Gb, 61-contig nuclear assembly and 17,097 bp mitogenome for O. manul. The primary nuclear assembly had 56x sequencing coverage, a contig N50 of 118 Mb, and a 94.7% BUSCO completeness score for Carnivora-specific genes. High genome collinearity within Felidae permitted alignment-based scaffolding onto the fishing cat (Prionailurus viverrinus) reference genome. Manul contigs spanned all 19 felid chromosomes with an inferred total gap length of less than 400 kilobases. Modified basecalling and variant phasing produced an alternate pseudohaplotype assembly and allele-specific DNA methylation calls; sixty-one differentially methylated regions were identified between haplotypes. Nearest features included classical imprinted genes, non-coding RNAs, and putative novel imprinted loci. The assembled mitogenome successfully resolved existing discordance between Felinae nuclear and mtDNA phylogenies. All assembly drafts were generated from 158 Gb of sequence using seven minION flow cells.

genomics↗

bioRxiv2021

The Mitochondrial Genome and Epigenome of the Golden Lion Tamarin from Fecal DNA using Nanopore Adaptive Sequencing

The golden lion tamarin (Leontopithecus rosalia) is an endangered Platyrrhine primate endemic to the Atlantic coastal forests of Brazil. Despite ongoing conservation efforts, genetic data on this species remains scarce. Complicating factors include limitations on sample collection and a lack of high-quality reference sequences. Here, we used nanopore adaptive sampling to resequence the L. rosalia mitogenome from feces, a sample which can be collected non-invasively. Adaptive sampling doubled the fraction of both host-derived and mitochondrial sequences compared to sequencing without enrichment. 258x coverage of the L. rosalia mitogenome was achieved in a single flow cell by targeting the unfinished genome of the distantly related emperor tamarin (Saguinus imperator) and the mitogenome of the closely related black lion tamarin (Leontopithecus chrysopygus). The L. rosalia mitogenome has a length of 16,597 bp, sharing 99.68% sequence identity with the L. chrysopygus mitogenome. A total of 38 SNPs between them were identified, with the majority being found in the non-coding D-loop region. DNA methylation and hydroxymethylation were directly detected using a neural network model applied to the raw signal from the MinION sequencer. In contrast to prior reports, DNA methylation was negligible in mitochondria in both CpG and non-CpG contexts. Surprisingly, a quarter of the 642 CpG sites exhibited DNA hydroxymethylation greater than 1% and 44 sites were above 5%, with concentration in the 3 side of several coding regions. Overall, we report a robust new mitogenome assembly for L. rosalia and direct detection of cytosine base modifications in all contexts.

genomics↗