Restriction map and location/nature of mahoganoid mutations. (a) Restriction map of normal fragment sizes. (b) md, md^2J, and md^5J mutations are all due to retroviral insertions. md^5J and md are due to an approximately 5 kb insertion located in the intronic region 3′ of exon 2 and 5′ of exon 12, respectively. md^2J is due to an approximately 8 kb insertion within exon 12. Fragment sizes shown above the inserted sequences represent the sizes from the new restriction sites located within retrovirus insertion to the normal restriction site in the direction of the arrow. RF indicates the location of the RING finger domain located in exon 10. GenBank numbers for md with retrovirus insertions are indicated in parentheses adjacent to new sequences. Sequences in bold are normal sequences. The inserted sequences are underlined.