Abstract
Morphology and H3-thymidine incorporation patterns of chromosomes were compared in 6 species of the order Passeriformes for the elucidation of karyotypic relatedness. With the exception of sex elements, karyotypes were indistinguishable in L. striata, T. castanotis and P. oryzivora of the family Ploceidae and corresponding chromosomes showed similar late replicating patterns. In spite of apparent karyotypic divergence and late replicating profiles in the remaining 2 species of Ploceidae, S. amandava and B. ruficauda, macrochromosomes of these species seemed to share labeling characteristics with those of above 3 species, which favored the elucidation of involved chromosomal alterations.
The karyotype of C. spinus of the family Fringillidae appeared distinctively different from that of the above 5 species of the family Ploceidae. However, the identical relative length of macrochromosomes together with the characteristic autoradiographic patterns suggested that the intrachromosomal rearrangements had been largely contributed to the karyotypic diversification between C. spinus and L. striata.
