The mouse genome in 88 sequence-based ultracontigs. The position and extent of the 88 ultracontigs of the MGSCv3 assembly are shown adjacent to ideograms of the mouse chromosomes. All mouse chromosomes are acrocentric, with the centromeric end at the top of each chromosome. The supercontigs of the sequence assembly were anchored to the mouse chromosomes using the MIT genetic map. Neighbouring supercontigs were linked together into ultracontigs using information from single BAC links and the fingerprint and radiation-hybrid maps, resulting in 88 ultracontigs containing 95% of the bases in the euchromatic genome.