Everything is possum

The western ringtail possum refers to a marsupial, a species of possum, Pseudocheirus occidentalis, found in a small area of Southwest Australia (including Perth where DNA Zoo Australia headquarters is located). Western ringtail possums are critically endangered [1] and could be wiped out in 20 years unless something is done to save the species [2].

In order to help with the species conservation, we, in collaboration with the Mallarino Lab at Princeton University, share a de novo genome assembly for the western ringtail possum, here. The sample for generating the necessary sequencing libraries (short insert-size DNA-Seq and Hi-C) was donated by the Australian Biological Tissue Collection at the South Australian Museum. Included in the share are the homology-based annotations for the species, courtesy MacManes Lab.

The western ringtail possum is a member of the Diprotodontia (meaning “two front teeth”) order, in the Phalangeriformes suborder (possums, gliders and cuscus). The other two suborders of Diprotodontia are: Vombatiformes (wombats and koalas) and Macropodiformes (kangaroos and wallabies).

DNA Zoo has generated chromosome-length genome assemblies in all three of the listed suborders: ground cuscus in Phalangeriformes, common wombat in Vombatiformes and tammar wallaby, western grey kangaroo, eastern grey kangaroo and red kangaroo in the Macropodiformes. See some whole-genome alignment plots below for an idea on how the chromosomes of different Diprotodontia species spanning the last 28MY of evolution relate to each other: a rather plastic karyotype despite the deceivingly similar chromosome count!

Whole-genome alignment plots between the new western ringtail possum genome assembly (Pseudocheirus_occidentalis_HiC, 2n=20), to other Diprotodontia genome assemblies in the DNA Zoo: the ground cuscus (pg-2k, 2n=14), common wombat (vu-2k, 2n=16), tammar wallaby (me-1k, 2n=16), western grey kangaroo (mf-2k, 2n=16), eastern grey kangaroo (mg-2k, 2n=16) and red kangaroo (mr-2k, 2n=20).