Double-color fluorescence in situ hybridization was performed on chicken chromosomes using seven unique clones from the human chromosome 3-specific NotI linking libraries. Six of them (NL1-097, NL2-092, NL2-230, NLM- 007, NLM-118, and NLM-196) were located on the same chicken microchromosome and NL1-290 on another. Two chicken microchromosome GGA15-specific BAC clones, JE024F14 containing the IGVPS gene and JE020G17 contain- ing the ALDH1A1 gene, were cytogenetically mapped to the same microchromosome that carried the six NotI linking clones, allowing identification of this chromosome as GGA15. Two GGA14-specific clones, JE027C23 and JE014E08 con- taining the HBA gene cluster, were co-localized on the same microchromosome as NL1-290, suggesting that this chromo- some was GGA14. The results indicated that the human chro- mosomal region HSA3q13 → q23 is likely to be orthologous to GGA15 and GGA14. The breakpoint of evolutionary conser- vation of human and chicken chromosomes was detected on HSA3q13.3 → q23 between NL1-290, on the one hand, and six other NotI clones, on the other hand. Considering the available chicken-human comparative mapping data, another break- point appears to exist between the above NotI loci and four oth- er genes, TFRC, EIF4A2, SKIL and DHX36 located on HSA3q24 → qter and GGA9. Based on human sequences with- in the NotI clones, localization of the six new chicken coding sequences orthologous to the human/rodent genes was suggest- ed to be on GGA15 and one on GGA14. Microchromosomal location of seven NotI clones from the HSA3q21 T-band region can be considered as evidence in support of our hypothesis about the functional analogy of mammalian T-bands and avian microchromosomes.