The first sheep genome assembly was created through the following steps:
- A new bovine assembly was created with an improved ordering of scaffolds.
- A mapping was created between this improved ordering of the bovine genome and the virtual sheep genome.
- This mapping was used to reorder bovine sequence into sheep order.
- Ovine contigs built from 454 sequencing were mapped onto the bovine sequence that is now in sheep order.
- The bovine sequence framework was replaced with sequence from the ovine contigs.
- The result is sheep chromosomes consisting of 100% sheep sequence.
