The centromere is a specific chromosomal locus that organizes the assembly of the kinetochore. It plays a fundamental role in accurate chromosome segregation. In most eukaryotic organisms, each chromosome contains a single centromere the position and function of which are epigenetically specified. Occasionally, centromeres form at ectopic loci, which can be detrimental to the cell. However, the...

We have demonstrated in Saccharomyces cerevisiae the transposition of a gene coding for an efficient ochre (UAA) suppressor from a centromere-linked site on chromosome III to two new sites in the yeast genome. One site is on chromosome VI, very close to, if not allelic with, SUP11, one of eight genes coding for a tyrosine-inserting suppressor. The second site is on chromosome III, unlinked to t...

Abstract This research was motivated by the potential sources of genetic diversity shallot cultivars, originated from several districts in Southeast Sulawesi. Sources are one defining factors success plant breeding programs to develop new cultivars with desired traits. The purpose this study identify characteristics Sulawesi through Karyotype Analysis. conducted at Agrotechnology Laboratory, In...

Centromere that plays a pivotal role in chromosome segregation is composed of repetitive elements in many eukaryotes. Although chromosomal regions containing repeats are the hotspots of rearrangements, little is known about the stability of centromere repeats. Here, by using a minichromosome that has a complete set of centromere sequences, we have developed a fission yeast system to detect gros...

B chromosomes of corn are stable at all mitotic and meiotic divisions of the plant except the second pollen mitosis. In the latter division, B chromosomes undego mitotic nondisjunction at rates as high as 98%. Studies by several workers on B-A translocation chromosomes have provided evidence for the existence of four factors on the B chromosome that control nondisjunction and are separable from...

Using in situ hybridisation, we identified interstitial telomeric sequences in seven chromosomal translocations present in normal and in syndromic subjects. Telomeric sequences were also found at the centromeric ends of a 4p and a 4q caused by centric fission of one chromosome 4. We found that rearrangements leading to interstitial telomeric sequences were of three types: (1) termino-terminal r...

Chromosomes are known to contain local hot and cold spots that undergo quite different rates of meiotic recombination. The question of why such regional variation in recombination rates exists on chromosomes holds a strange mix of intrigue and frustration for geneticists. One of the human chromosomes that has been carefully studied over the years in this regard is the X chromosome. These studie...

Pericentric heterochromatin, while often considered as "junk" DNA, plays important functions in chromosome biology. It contributes to sister chromatid cohesion, a process mediated by the cohesin complex that ensures proper genome segregation during nuclear division. Long stretches of heterochromatin are almost exclusively placed at centromere-proximal regions but it remains unclear if there is ...