Btau_4.0, released on 4 October 2007, is a 7x preliminary assembly of the bovine, Bos taurus, Hereford breed.
The Btau_4.0 assembly used a combined strategy as developed for the rat genome (Nature 428:493-521, 2004)
and used more recently for the sea urchin genome (Science 314:941-952, 2006). The combined strategy is a
hybrid of the Whole Genome Shotgun (WGS) approach used for the mouse genome and the hierarchical (BAC clone)
approach used for the human genome. The sequencing combines BAC shotgun reads with whole-genome-shotgun (WGS)
reads from small insert libraries as well as BAC end sequences.
This assembly adds relatively little new sequence data, and thus contigs and scaffolds are not significantly changed. However it uses different map information to place the contigs and scaffolds in the genome, resulting in more accurate chromosome structures.
The N50 size is the median sequence length, i.e. 50% of the assembled genome lies in blocks of the N50 size or longer. The N50 size of the contigs is 48.7 kb and the N50 of the scaffolds is 1,922 kb. The total length of all contigs is 2.73 Gb. When the gaps between contigs in scaffolds are included, the total span of the assembly is 2.87 Gb. The coverage is 7x.
The project coordination and genome sequencing and assembly is provided by the Human Genome Sequencing Center at Baylor College of Medicine