We present here the results of regional mapping of neurofibromatosis 1 (NF1) gene with the use of microdissection of chromosome 12 (SSC12) in pigs. Previously we mapped this gene by Southern blot hybridization and PCR analyses of pig-mink and pig-hamster cell lines containing intact SSC12 or SSC12p. Specific DNA fragments and PCR product were present in SSC12 and absent in SSC12p. To confirm our suggestion about localization of NF1 in SSC12q we dissected 8 copies of p and q arms from pig metaphase spreads and amplified them with primers specific to NF1. Q-arm was positive for this gene. Then, we dissected 8 copies of SSC12cen-q1.2, SSC12q1.3, and SSC12q1.4-ter. The results showed the presence of specific PCR product in SSC12cen-q1.2. Since, we can not exclude the contamination of this fragment with small part of neighbor one, we believe the NF1 gene to be mapped on SSC12cen-q1.3.1 (Fig.1). NF1 locates in humans on HSA17q considering homeologous to SSC12p and tightly links with RARA gene which we localized in SSC12p, so we can suggest the intrachromosomal rearrangements in pigs with breakpoint between NF1 and RARA genes.

The method described allows to localize regionally any genes for which primers design is possible and does not require the production of cell hybrids.