Increased cellular ploidy is widespread during developmental processes of multicellular organisms, especially in plants. Elevated ploidy levels are typically achieved either by endoreplication or endomitosis, which are often regarded as modified cell cycles that lack an M phase either entirely or partially. We identified GIGAS CELL1 (GIG1)/OMISSION OF SECOND DIVISION1 (OSD1) and established tha...

Unisexual (all female) salamanders in the genus Ambystoma are animals of variable ploidy (2N-5N) that reproduce via a unique system of 'leaky' gynogenesis. As a result, these salamanders have a diverse array of nuclear genome combinations from up to five sexual species: the blue-spotted (A. laterale), Jefferson (A. jeffersonianum), smallmouth (A. texanum), tiger (A. tigrinum) and streamside (A....

Direct determination of chromosome number in Saccharomyces is advantageous in the further development of yeast genetics. The enumeration of centromeres by deductions from tetrad analysis sets a minimum chromosome number (Lindegren, 1949; Lindegren and Lindegren, 1951b), but interchromosomal linkage (Shult and Lindegren, 1955) introduces complexities into the deduction of chromosomal numbers fro...

BACKGROUND DNA ploidy determination of carcinomas in radical prostatectomy specimens has shown significant correlation with patient outcome, but the predictive value of ploidy status of cancers obtained by transrectal ultrasound-guided needle biopsies has not been studied extensively. METHODS Eighty-nine paired needle biopsy specimens (NBX) and radical prostatectomy (RPX) specimens from patie...

The cyclin-dependent kinase inhibitor p21(Waf-1/Cip-1) is expressed at high level during megakaryocyte differentiation, but its precise function remains unknown. In this study, it is confirmed that p21 was expressed at a high level in hypoploid (2N and 4N) and polyploid (at least 8N) human megakaryocytes derived from CD34(+) cells. A high expression of p27(Kip1), p16, cyclin E, and cyclin D3 wa...

Abstract Polyploids with odd-ploidy levels may play an important evolutionary role as they enable backcrosses their parental cytotypes. We chose the ploidy-variable Senecio carniolicus species group to address overarching question if pentaploid individuals, which occur at high frequencies in immediate contact zones of tetraploids and hexaploids, mediate effective interploidy gene flow. employed...

PURPOSE Deoxyribonucleic acid ploidy correlates with the biological behavior of prostate carcinoma. However, the usefulness of ploidy on needle biopsies that show prostate cancer has not been established to our knowledge. MATERIALS AND METHODS We retrospectively determined ploidy on needle biopsies of 159 men with prostate carcinoma treated surgically at Johns Hopkins Hospital. Ploidy was det...

Tremendous diversity exists among organisms with respect to their ploidy level, defined as the number of sets of homologous chromosomes per cell. As differences in ploidy represent a potentially major genomic change affecting the evolution of a species, it might be thought that ploidy evolution would be well understood. In fact, our knowledge is fragmentary, and there are several open questions...