title: DNA content and expression of cell cycle proteins in caterpillar nuclei from fetal human cardiac myocytes.
abstract: Caterpillar nuclei (CN) are characterized by their peculiar morphology, with chromatin distributed in clusters and running along the longitudinal axis of the nucleus. They can be observed in normal hearts of fetuses as well as in hearts of children and adults with rheumatic heart disease. This study has demonstrated by means of ploidy studies with digital image analysis that in the fetal heart (20.5+/-1.8 weeks) the CN (diploid = 5.6+/-8.4%; tetraploid = 46.2+/-24.2%; hypertetraploid = 46.9+/-26.3%) present higher DNA content than non-caterpillar myocyte nuclei (diploid = 89.4+/-6.2%; tetraploid = 10.0+/-4.1%; hypertetraploid = 1.5+/-1.3%) (P=0.000001, 0.00013, and 0.000038, respectively). Expression of proliferation cell nuclear antigen (PCNA; 30.6+/-11.7% in CN and 13.4+/-7.3% in non-caterpillar myocyte nuclei; P=0.0115) and cyclin B1 (2.8+/-3.8% and 12.6+/-15.6%, respectively; P=n.s.) was also positive in these nuclei. In conclusion, these results suggest that there exists a relationship between CN morphology and myocyte replication phenomena.
authors.affiliation: Facultad de Ciencias Médicas and CONICET, Universidad Nacional de La Plata, Prov. de Buenos Aires, Argentina.
authors.forename: Rivello Hernán
authors.initials: RH
authors.lastname: García
authors.forename: Meckert Patricia
authors.initials: MP
authors.lastname: Cabeza
authors.forename: Amelia
authors.initials: A
authors.lastname: Gallo
authors.forename: Luis
authors.initials: L
authors.lastname: Palacios
authors.forename: Rubén P
authors.initials: RP
authors.lastname: Laguens
mesh_terms: D002467:Cell Nucleus / Q000648:ultrastructure*; D019926:Cyclin B / Q000032:analysis*; D056744:Cyclin B1; D004247:DNA / Q000032:analysis*; D005260:Female; D005318:Fetal Heart / Q000737:chemistry / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D011003:Ploidies; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*
chemical_list: C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D018809:Proliferating Cell Nuclear Antigen; D004247:DNA