A microspectrophotometric evaluation of the DNA content of tumor cell nuclei was undertaken in 24 cases of fibroadenomas and 30 cases of carcinomas of the human breast. There was a general trend that fibroadenomas of the breast showed the DNA values lying in a diploid range, with limited deviation among the cells, while in carcinomas of the breast, the DNA values were slightly or definitely hig...

We report a 3 month old boy with tetraploidy, found in peripheral blood and skin fibroblast cultures, with severely delayed growth and neurodevelopment, and with a cleft lip; these findings have not been described before. This report brings to seven the total number of liveborn infants with a 92,XXYY karyotype.

Endopolyploidy and genomic instability are shared features of both stress-induced cellular senescence and malignant growth. Here, we examined these facets in the widely used normal human fibroblast model of senescence, IMR90. At the presenescence stage, a small (2-7%) proportion of cells overcome the 4n-G1 checkpoint, simultaneously inducing self-renewal (NANOG-positivity), the DNA damage respo...

Rotifers of Class Bdelloidea are abundant freshwater invertebrates known for their remarkable ability to survive desiccation and their lack of males and meiosis. Sequencing and annotation of approximately 50-kb regions containing the four hsp82 heat shock genes of the bdelloid Philodina roseola, each located on a separate chromosome, have suggested that its genome is that of a degenerate tetrap...

We have shown previously that mitotic spindle inhibitors allow the c-Myc oncoprotein to uncouple mitosis from DNA synthesis, resulting in the acquisition of tetraploidy. This can also occur in the absence of spindle inhibition if c-Myc deregulation is combined with inactivation of the p53 tumor suppressor. Under these conditions, cyclin B1 protein is induced but retains its normal cell cycle re...

Tetraploidization has been proposed as an intermediate step toward aneuploidy in human cancer but a general mechanism for the induction of tetraploidy during tumorigenesis is lacking. We report that tetraploidization occurs in p53-deficient cells experiencing a prolonged DNA damage signal due to persistent telomere dysfunction. Live-cell imaging revealed that these cells have an extended G2 due...

Whole genome duplications, or tetraploidies, are an important source of increased gene content. Following whole genome duplication, duplicate copies of many genes are lost from the genome. This loss of genes is biased both in the classes of genes deleted and the subgenome from which they are lost. Many or all classes are genes preferentially retained as duplicate copies are engaged in dose sens...