Localization of seven HSA3q13-q23 NotI linking clones on the chicken microchromosomes 14 and 15 by double-color FISH

Double-color fluorescence in situ hybridization was performed on chicken chromosomes using seven unique clones from human chromosome 3-specific NotI linking libraries. Six of them (NL1-097, NL2-092, NL2-230, NLM-007, NLM-118, and NLM-196) hybridized to the same chicken microchromosome, while NL1-290 hybridized to another one. Two chicken microchromosome GGA15-specific BAC clones, JE024F14 containing the IGVPS gene and JE020G17 containing the ALDH1A1 gene, were cytogenetically mapped to the same microchromosome that contained the six NotI linking clones, allowing identification of this chromosome as GGA15. Two GGA14-specific clones, JE027C23 and JE014E08, containing the HBA gene cluster, were co-localized on the same microchromosome with NL1-290, marking this chromosome as GGA14. The results indicate that the human chromosome region HSA3q13-q23 is likely to be orthologous to GGA15 and GGA14. The synteny breakpoint between the human and chicken gene segments was detected on HSA3q13.3-q23 between NL1-290 and the six other NotI clones. Previously available comparative mapping data suggest another breakpoint between all the above NotI clones and four genes, TFRC, EIF4A2, SKIL and DHX36, located on HSA3q24-qter and GGA9. Microchromosomal location of seven NotI clones from the HSA3q21 T-band region can be considered as an evidence in support of our hypothesis regarding the functional analogy of mammalian T-bands and avian microchromosomes.