The brush rabbit, Sylvilagus bachmani, is one of several species of cottontail rabbits. They have a short, fluffy tails that may be white or gray in color. Inhabiting the western costal region of North America, brush rabbits may be found foraging through shrub-lands, woodlands, and coniferous forests. Though they rarely leave the brush for long, they may be seen basking in the sun in nice weather. If they’re feeling particularly excited or playful, brush rabbits can binky, jumping up in the air while twisting their bodies and kicking their feet [1]!
The brush rabbit are prolific breeders, producing around 3 litters with an average of four offspring a year [2]. The population is kept in check by their many predators, including snakes, foxes, coyotes, and bobcats. When startled, brush rabbits may thump their back feet on the ground in surprise! Brush rabbits avoid predators by running at speeds of 40 km/hr in zig zag patterns [3].
Originally sampled in 1976, this assembly was created from primary fibroblasts obtained from T.C. Hsu CryoZoo at the University of Texas MD Anderson Cancer Center. 44 years later, we share the chromosome length assembly of the brush rabbit. This is a $1K genome assembly with contig N50 = 58 Kb and scaffold N50 = 116 Mb. See Dudchenko et al., 2018 for details on the procedure.
This is only a second chromosome-length genome assembly for a rabbit in our collection: previously we shared a few tweaks to the European rabbit genome assembly from the Broad institute (Lindblad-Toh et al., 2011), here. The second genome gives us the first opportunity to compare karyotypes within the rabbit family. Included below is the whole-genome alignment plot between the two rabbit genomes: the genome appear to be highly collinear, with two fusion events (circled in blue) apparent responsible for the difference in karyotypes: 2n=44 in the European rabbit vs 2n=48 in the brush rabbit!
