First Draft Genome of the Sable, Martes zibellina

Abstract

Members of genus Martes provide early warning signals about forest ecosystem health and are designated as a Management Indicator Species. As one of the most widespread members in Martes, the sable (Martes zibellina) is a circumboreal small predator found throughout all taiga zoogeographical zones of Eurasia and shows distinct population differentiation and morphological variations. To support further studies on striking local adaptation and population evolution, we present the first sable genome, assembled de novo from an individual originating in the Great Khingan Mountains (China). The assembled genome is 2.42 Gb, consisting of 15,814 scaffolds with a scaffold N50 of 5.20 Mb. Searches for complete Mammalia BUSCO (Benchmarking Universal Single-Copy Ortholog) gene groups found that 95.15% of the curated single-copy orthologs were assembled as complete, suggesting a high level of completeness of the genome. We totally predicted 19,413 protein-coding genes, and 0.82 Gb of repeat sequences was annotated. We also detected 1,257 olfactory receptor genes and found more functional olfactory receptor genes in sable than in other Mustelidae species, which provide a possible genetic explanation for the acute sense of smell of the sable for searching the preys under deep snow. Phylogenetic analyses revealed that the ferret (Mustela putorius furo) and sea otter (Enhydra lutris) form a clade that is sister to the sable, which was dated ∼16.4 Ma. Overall, our study provided the first reference genome for research in a broad range of areas including local adaptations, population evolution, conservation, and management for sable.

Multiple types of genomic variation contribute to adaptive traits in the mustelid subfamily Guloninae

“…The overall repeat landscape of the tayra genome assembly is comparable to other carnivore genomes (Liu et al, 2020;Peng et al, 2018). It is similar to that of the sable genome, differing mostly in the number of L1 LINE elements, which have been recently proliferating and accumulating within the tayra genome more than in other Guloninae genomes.…”

“…This allowed us to verify the sex of the animals using a coverage-based approach (Figure S5), which confirmed morphological sexing for the tayra (male) and wolverine (female) individuals. While the sable individual is referred to as a male (Liu et al, 2020), our analysis suggests it is a female (further details given in Supporting Information).…”

“…The Mustelidae are the most ecologically and taxonomically diverse family within the mammalian order Carnivora, representing a remarkable example of adaptive radiation among mammals that is rich with recent speciation events (Koepfli et al, 2008; Liu et al, 2020). Closely related mustelid species often inhabit vastly different ecosystems, where they experience diverse environmental challenges and are thus exposed to different evolutionary pressures.…”

“…The sable ( Martes zibellina ) is distributed in the taiga and deciduous forests of north central and northeastern Eurasia. The sable is solitary and omnivorous, relying on hearing and olfaction to locate prey, even under snow cover during winter months (Liu et al, 2020; Monakhov, 2011). Unlike wolverines, seasonal changes do not cause dramatic fluctuations in resource availability for sables as they are able to exploit a wider variety of food sources, and are adapted to tolerate short‐term food scarcity (Mustonen et al, 2006).…”

“…To date, only a few studies have investigated adaptive variation in mustelids using comparative genomics (Abduriyim et al, 2019; Beichman et al, 2019; Liu et al, 2020; Miranda et al, 2021). Here, we generated a highly contiguous genome assembly of the tayra, an early diverging gulonine (Koepfli et al, 2008; Law et al, 2018), and compared it to previously published genomes of the wolverine and sable to identify the genetic basis underlying the adaptations to the diverse environments inhabited by these species.…”