Conservation of centromere proteins in vertebrates

The chicken genome comprises 78 chromosomes which include several macrochro mosomes and many microchromosomes. Very little information is currently ava ilable concerning chicken centromere structure and function and it is uncle ar if the two types of chromosomes share a common centromere mechanism or w hether this mechanism resembles those in other species. Immunofluorescence studies using antibodies to mammalian constitutive centromere proteins CENP -A, CENP-B, and CENP-C and the passenger proteins CENP-E, and CENP-F reveal ed the presence of each of these proteins at the centromeres of both macro- and microchromsomes. CENP-A, CENP-B, and CENP-E levels showed variability between metaphase centromeres while CENP-C and CENP-F levels were relativel y constant. These results suggest a common centromere mechanism for both ty pes of chromosomes as well as indicating a high degree of conservation of i ndividual proteins between widely divergent vertebrate classes and an overa ll conservation of centromere function throughout vertebrate evolution.