Corn snake genome v3

This is our final effort to improve the corn snake genome as we have now achieved a nearly-chromosome length quality. We combined linked reads of 10x Genomics sequencing with the robust genomic maps previously generated with BioNano (see version 2) to produce a hybrid assembly. You can access our own corn snake annotation via our JBrowse or directly enquire the NCBI corn snake annotation.

The high continuity of this genome (see statistics in the table below), coupled with extensive annotation, will greatly facilitate the objectives of our ‘corn snake skin colour project’: the identification of the causative mutations of the multiple corn snake color and color pattern morphs, as well as the effect of these mutations on the development of chromatophores and/or their interactions.

One example is our recently-published study in which we show that the Lavender corn snake color variant is due to a mutation in the lysosomal trafficking regulator (LYST) gene. We show that this mutation affects all chromatophores and that, not only melanosomes in melanophores, but also red-pigment vesicles in xanthophores and guanine-crystal compartments in reflective iridophores are ‘Lysosome-Related Organelles’ (LROs).

Corn snake genome statistics
Version No. of sequences (>1 kbp) N50 (kbp) L50 (seqs) Total length (Gbp)
1 1,781,284 3.7 94,091 1.53
2 114,644 1,378.4 279 1.94
3 34,268 16,790 24 1.71

Associated Publication
Ullate-Agote A., Burgelin I., Debry A., Langrez C., Montange F., Peraldi R., Daraspe J., Kaessmann H., Milinkovitch, M. C. M. & Tzika A. C.*
“Genome mapping of a LYST mutation in corn snakes indicates that vertebrate chromatophore vesicles are lysosome-related organelles ”
Proceedings of the National Academy of Sciences (PNAS) (2020)

BUSCO comparison
BUSCO results for the three versions of the corn snake genome. The genome completeness assessment was performed using the 3,950 single-copy genes of the Tetrapoda set.