Walrus (Odobenus rosmarus)

Walrus are easily recognized by their prominent tusks, whiskers, and bulk. Walrus and walruses are both acceptable plurals for walrus! Read more about walrus in Wikipedia.

Photo by skeeze from Pixabay

Chromosome-length genome assembly

Download the Oros_1.0_HiC.fasta.gz file containing the chromosome-length (2n=32) assembly of the walrus genome. All modifications with respect to the draft (see below) are annotated in the Oros_1.0_HiC.assembly file. Some basic stats associated with the new reference, Oros_1.0_HiC, are listed below. The full data release can be explored here.

Draft

The chromosome-length genome assembly is based on the draft assembly Oros_1.0 (GCF_000321225.1), credited below.

Foote, Andrew D., Yue Liu, Gregg W. C. Thomas, Tomas Vinar, Jessica Alfoldi, Jixin Deng, Shannon Dugan, et al. 2015. "Convergent Evolution of the Genomes of Marine Mammals." Nature Genetics 47 (3): 272-75. https://doi.org/10.1038/ng.3198.

Method

3D Assembly was performed using 3D-DNA pipeline (Dudchenko et al., Science, 2017). The genome was reviewed using Juicebox Assembly Tools  (Dudchenko et al., bioRxiv, 2018). See Methods for more information.

Hi-C sample

The blood sample for in situ Hi-C preparation was donated by a male individual named Garfield, and provided to us by SeaWorld.

Hi-C Contact maps

Hi-C data was aligned to the draft reference using Juicer (Durand, Shamim et al., Cell Systems, 2016), and contact maps visualizing the alignments with respect to the draft and the new reference were built using 3D-DNA (Dudchenko et al., Science, 2017). The contact maps can be explored below via Juicebox.js interactive tool (Robinson et al., Cell Systems, 2018). (Please note that the interactive figures are scaled 1:2.) To explore the assembly in greater detail, please download the .hic and .assembly files from the data release folder and use Juicebox Assembly Tools  (Dudchenko et al., bioRxiv, 2018).

References

If you use this genome assembly in your research, please check that the conditions of use associated with the draft permit it, and acknowledge the following work.

Foote, Andrew D., Yue Liu, Gregg W. C. Thomas, Tomas Vinar, Jessica Alfoldi, Jixin Deng, Shannon Dugan, et al. 2015. "Convergent Evolution of the Genomes of Marine Mammals." Nature Genetics 47 (3): 272-75. https://doi.org/10.1038/ng.3198.

Dudchenko, O., Batra, S.S., Omer, A.D., Nyquist, S.K., Hoeger, M., Durand, N.C., Shamim, M.S., Machol, I., Lander, E.S., Aiden, A.P., Aiden, E.L., 2017. De novo assembly of the Aedes aegypti genome using Hi-C yields chromosome-length scaffolds. Science 356, 92–95. https://doi.org/10.1126/science.aal3327.

Dudchenko, O., Shamim, M.S., Batra, S., Durand, N.C., Musial, N.T., Mostofa, R., Pham, M., Hilaire, B.G.S., Yao, W., Stamenova, E., Hoeger, M., Nyquist, S.K., Korchina, V., Pletch, K., Flanagan, J.P., Tomaszewicz, A., McAloose, D., Estrada, C.P., Novak, B.J., Omer, A.D., Aiden, E.L., 2018. The Juicebox Assembly Tools module facilitates de novo assembly of mammalian genomes with chromosome-length scaffolds for under $1000. bioRxiv 254797. https://doi.org/10.1101/254797.

Disclaimer

This is a work in progress. If you notice any discrepancies in the map or have data that confirms or contradicts the suggested reference, please email us at theaidenlab@gmail.com or leave a comment on the Forum.

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© 2018-2019 by the Aiden Lab.