The genome sequencing of the saltwater crocodile had just been completed.

This offers a more accurate, faster and economical selection of “breeders” which could take place as soon as the eggs hatch. Researchers at the University of Sydney say the information from the genome sequence could be used to “perfect crocodile breeding techniques.”

The development has the potential of benefitting the crocodile industry in Australia which is worth an estimated $8.8 million in exports. Crocodile skin is turned into leather for belts, wallets, shoes and bags and has a huge demand due to their durability. In some country like Australia, crocodile meat is even consumed.

Advances in DNA sequencing technology, so-called nextgen sequencing, have provided between 1,000 and 10,000-fold reductions in cost, and comparable increases in the speed with which whole genome sequences can be generated.

"It cost many millions of dollars and many years of work by a huge international collaboration to produce the first human genome sequence in 2002," Professor Moran said.

"Now a complete genome sequence can be produced for a complex organism for several thousands of dollars and in a relatively few months of work; this is what has been achieved with the finalisation of the saltwater crocodile genome sequence."

A crocodile reaches sexual maturity when it’s seven years old. This means that breeders have to wait that long before they can choose suitable breeding stock. At present, the Australian saltwater crocodile population is estimated at around 100, 000- 200,000 adults.

"We had previously completed a genome map for the saltwater crocodile but this is a huge leap forward," said Professor Chris Moran from the Faculty of Veterinary Science at the University of Sydney.

"Genome sequencing is the next step. The difference between genome mapping and genome sequencing is the difference between having a map of Australia on a single page and a detailed street directory."

"The genome sequencing revolutionises that process."

"So the Darwin Crocodile Farm, one of our industry partners, will be able to take DNA samples as soon as the crocodiles hatch and use them to decide which animals will be suitable for breeding."

"This is possible because the genome sequence identifies genetic 'markers' which provide information on the likely health and breeding quality of an animal."

Professor Moran worked on the genome sequence with his University of Sydney colleague Dr Jaime Gongora, PhD students Amanda Chong and Pauline Dalzell together with research affiliates (and former PhD students of the University), Dr Sally Isberg and Dr Lee Miles.

They have been working on the genetics and genomics of farmed saltwater crocodiles since 2001 with funding from the Rural Industries Research and Development Corporation.

Other outcomes of the genome sequencing work include a better understanding of the evolutionary relationships among crocodylians, especially between the alligator family and crocodile family. It will also improve our understanding of crocodylians' relationships to other reptiles including their closest living relatives, the birds.

The research was recently outlined in an article in Genome Biology.

UPDATE: The research was funded Rural Industries Research and Development Corporation, which "was established by the Australian Government to work with industry to invest in research and development for a more profitable, sustainable and dynamic rural sector."

Source: University of Sydney.