Snake genomes

Why do we need to sequence snake genomes?

For most people, snakes are objects of fear and fascination in roughly equal measure, but for scientists especially, this the balance tips in favour of fascination. The list of evolutionary novelties and adaptations exhibited by snakes is extensive, and includes: elongated bodies and loss of limbs; an ability to go long periods without eating (and to cope with infrequent large meals); extensive variation in pigmentation patterning, including warning coloration, mimicry, and camouflage; heat-sensing abilities; venom and venom delivery systems; wide variation in locomotion, including gliding and side-winding; and adaptation to an aquatic environment in sea snakes. To fully understand these and other processes within snakes, and to determine how snakes are similar or different to other vertebrates, we need to understand their genomes. What genes are present in each species, or have been lost? When, where and to what extent are they switched on or off? How are they organised in the genome, and could this organisation be important for how they are used?

Unfortunately, there are currently very few good quality genomic resources available for snakes. Given recent advances in DNA sequencing technologies and other relevant approaches, now if the perfect time to remedy this.

We’re currently sequencing the genome of the painted saw-scaled viper (Echis coloratus), which by virtue of its small size and (relatively) mild venom, we believe represents an excellent “model” venomous snake, one which is easy to maintain in the laboratory.

Echis coloratus

There is also some genome sequence data available for a few other snake species, including the king cobra (Ophiophagus hannah), Burmese python (Python molurus bivittatus), boa constrictor (Boa constrictor), some rattlesnakes, and a few others. However, these genomes have all been sequenced using different technologies, and to different levels, meaning they are not only often very fragmentary, but also difficult to compare.

 

Luckily, help is at hand in the form of the Vertebrate Genome Project (VGP), part of the Genome10K initiative. The VGP has provided standards on the best combination of approaches to use to produce a “Platinum” quality genome, and, since everyone will be adhering to these standards, we will end up with a large number of genome sequences of comparable coverage and quality. Within the Genome10K project, there are subsections targeting particular groups of species, such as the Bird 10,000 Genomes (B10K) Project and the BAT 1K project. Perhaps it is also time for a 1KSnake project…?

 

 

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