A chromosome-scale genome assembly of the okapi (Okapia johnstoni)

The okapi (Okapia johnstoni), or forest giraffe, is the only species in
its genus and the only extant sister group of the giraffe within the
family Giraffidae. The species is one of the remaining large vertebrates
surrounded by mystery because of its elusive behavior as well as the armed
conflicts in the region where it occurs, making it difficult to study.
Deforestation puts the okapi under constant anthropogenic pressure, and it
is currently listed as “Endangered” on the IUCN Red List. Here, we present
the first annotated de novo okapi genome assembly based
on PacBio continuous long reads, polished with short reads, and anchored
into chromosome-scale scaffolds using Hi-C proximity ligation sequencing.
The final assembly (TBG_Okapi_asm_v1) has a length of 2.39 Gbp, of which
98% are represented by 28 scaffolds >3.9 Mbp. The contig N50 of 61
Mbp and scaffold N50 of 102 Mbp, together with a BUSCO score of 94.7%, and
23,412 annotated genes, underline the high quality of the assembly. This
chromosome-scale genome assembly is a valuable resource for future
conservation of the species and comparative genomic studies among the
giraffids and other ruminants.