You won't believe these cat pix - #1 is a total blast!!!

Cacomistle (Bassariscus sumichrasti) is a nocturnal animal native to Central America, with its habitat spanning from Southern Mexico to Panama [1]. The name cacomistle comes from the Nahuatl language meaning “half-cat” [2], but don't be fooled by the name! Cacomistles aren’t related to cats. In fact, the black ringed tail of the cacomistle hints on its family resemblance to the common racoon, a species we’ve recently assembled at the DNA Zoo alongside the white-nosed coati and kinkajou in the same family.

Today, we share a chromosome length assembly for a cacomistle using a fibroblast cell line provided to us by the T.C. Hsu CryoZoo at the University of Texas MD Anderson Cancer Center. These were originally frozen all the way back in the summer of 1976! Fast-forward 45 years, and the cells feel great: pictured below is the confluent cell line after just 6 days of culturing. We thank Drs. Asha Multani, Sen Pathak, Richard Behringer, Liesl Nel-Themaat and Arisa Furuta in the Department of Genetics at the MD Anderson Cancer Center for their help with the samples!

This is a $1K genome assembly with contig N50 = 45kb and scaffold N50 = 125Mb. See Dudchenko et al., 2018 for details on the procedure!

44 year old cacomistle fibroblasts from the T.C. Hsu CryoZoo at MD Anderson Cancer Center.

Moves like jaguar

The jaguar (Panthera onca) is a large felid species, and the only remaining member of the Panthera genus native to the Americas [1]. These amazing animals have the most powerful bite of all big cats, and are aptly named. The word ‘jaguar’ comes from the Tupian word ‘yaguara’ which means ‘beast of prey’. The jaguar is listed as near threatened on the ICUN’s red list due to loss of habitat [2]. Read more about the jaguar on panthera.org website and learn about the Jaguar Corridor Initiative to preserve the genetic integrity and future of the jaguar by connecting and protecting core jaguar populations from Mexico to Argentina!

Today, we share the chromosome-length assembly for the jaguar named Cocoy from the Houston Zoo. Sadly, Cocoy passed away in 2015, but her genome lives on in the digital form and will hopefully help the jaguar species in the years to come. This is a $1K genome assembly, see Dudchenko et al., 2018 for strategy details.

This is the sixth felid assembly in our collection alongside the cheetah, leopard, tiger, cougar, and clouded leopard. As pointed out before (see, e.g. this blog post) the Felidae karyotype is very highly conserved, confirmed once again in the whole-genome alignment plot between the domestic cat genome assembly, from Pontius et al., Genome Res., 2007, and the new jaguar genome assembly.

Whole genome alignment between the new jaguar genome assembly (Panthera_onca_HiC) and the domestic cat genome assembly (felCat9, NCBI accession number GCF_000181335.3).

Selfish genes, or shellfish genes?

Often known as the Great Scallop, King Scallop or Coquille St Jacques, the scallop Pecten maximus is widespread around northern Europe, and is an important human food source.

The genome of this species has just been made available (see Kenny et al. 2020 and this dnazoo.org webpage) as part of a collaboration with the Wellcome Sanger 25 Genomes project. As well as being the best assembled bivalve genome to date, it contains a large number of surprises. Approximately 70,000 of them, in fact - an exceptionally high number of genes packed into a relatively normal (circa 1.1 Gbp) sized genome. This is more than double the number of genes found in humans and in most commonly studied species!

These genes have been generated from widespread gene duplication, together with relatively little gene loss. The cause of this is not yet known, but echos what has been seen in some other mollusk genomes (e.g. Li et al 2018). Scallops therefore seem to need lots of new genes!

The genome contains a number of clues that will be useful for managing fisheries of this species. For example, Scallops are resistant to domoic acid, which they can accumulate when filter feeding. A potential cause of this resistance has been identified in our data, which could stop people from getting sick with Amnesic shellfish poisoning.

Scallops also have beautiful and unique eyes, and are some of the most mobile shellfish (able to swim surprisingly big distances). The Pecten maximus genome will therefore be interesting to evolutionary biologists, pharmaceutical companies, and anyone who likes to eat seafood. It is sure to be the basis for many sorts of work in the future - the world is its oyster (oops, no, scallop!).

References:

Kenny et al. 2020 Scallop preprint: https://www.biorxiv.org/content/10.1101/2020.01.08.887828v1.full

Li, C., Liu, X., Liu, B., Ma, B., Liu, F., Liu, G., Shi, Q. and Wang, C., 2018. Draft genome of the Peruvian scallop Argopecten purpuratus. GigaScience, 7(4), p.giy031.