background: high-energy ionizing radiation is harmful and changes the genetic makeup of dna, which can lead to increased risk of cancer. thus, the exposure of radiation dose should be under control and limited. ionizing radiation might lead to some chromosome aberrations like dicentric. there is a strong relation between the frequency of dicentric chromosome in metaphase, and the received dose....

A woman with first trimester abortion and a dicentric chromosome formed from a 4 and a 21 is described. The dicentric chromosome was stable and in the majority of cells the 21 centromere was active, while in a minority the chromosome 4 centromere was active. This shows that both centromeres were functional, but that only one functioned in any given cell. Suppression of the activity of one centr...

The B chromosome of maize has been used in a study of dicentric chromosomes. TB-9Sb is a translocation between the B and chromosome 9. The B-9 of TB-9Sb carries 60% of the short arm of 9. For construction of dicentrics, a modified B-9 chromosome was used, B-9-Dp9. It consists of the B-9 chromosome plus a duplicated 9S region attached to the distal end. In meiosis, fold-back pairing and crossing...

BACKGROUND In most mammals, sex is determined at the beginning of gestation by the constitution of the sex chromosomes, XY in males and XX in females. CASE Here we report an interesting case characterized by ambiguous genitalia and ovotestis in a newborn carrying an apparently female karyotype (46 XX). Array Comparative Genomic Hybridization (Array-CGH) revealed an unbalanced rearrangement re...

We present a patient with partial monosomy of the short arm of chromosome 18 caused by de novo translocation t(Y;18) and a generalized form of keratosis pilaris (keratosis pilaris affecting the skin follicles of the trunk, limbs and face-ulerythema ophryogenes). Two-color FISH with centromere-specific Y and 18 DNA probes identified the derivative chromosome 18 as a dicentric with breakpoints in...

During the eukaryotic cell cycle, genetic material must be accurately duplicated and faithfully segregated to each daughter cell. Segregation of chromosomes is dependent on the centromere, a region of the chromosome which interacts with mitotic spindle microtubules during cell division. Centromere function in the budding yeast, Saccharomyces cerevisiae, can be regulated by placing an inducible ...

Much of the Y chromosome consists of large palindromic arrays harboring genes that are critical for spermatogenesis. In this issue, Lange et al. (2009) show that although gene conversion within these arrays maintains their integrity, it also permits rare unequal sister chromatid-exchange events within palindromes that create unstable dicentric chromosomes, resulting in infertility, sex reversal...