homogeneously staining regions (hsr) or double minute chromosomes (dmin) are autonomously replicating extra-chromosomal elements that are frequently associated with gene amplifi cation in a variety of cancers. the diagnosis of leukemia patients was based on characterization of the leukemic cells obtained from bone marrow cytogenetics. this study report two cases, one with acute myeloblastic leu...

To accomplish the precise segregation of chromosomes, kinetochore must be form incentive interaction with motor proteins. Any error happens in chromosome led to aneuploidy that consider as main factor cause cancers and many birth defects. Kinetochore is a proteinous complex structure consist hundred It’s performed functions such it connects movement chromosomes microtubule, acts observer for bi...

The gene order of chromosomes can be rearranged by chromosomal inversions that reverse the order of segments. Motivated by a comparative study of two Drosophila species, we investigate the number of reversals that are needed to scramble the gene order when all reversals are equally likely and when the segments reversed are never more than L genes. In studying this question we prove some new res...

The chromatin threads, which we described briefly several years ago (1), have since then been studied carefully both morphologically and chemically. We now consider these microscopic threads of chromatin to be isolated chromosomes (2). From certain animal cells such masses of isolated chromosomes can be prepared that, with respect to quantity of material available, no special methods are requir...

The genus Odontophrynus, composed of ten species, is found in practically the entire south South America. Odontophrynus americanus was first vertebrate registered to present natural polyploidy, considering that most individuals have 2N = 4x 44 chromosomes, although having 2x 22 chromosomes considered ancestral condition for all genera family Odontophrynidae. study aimed analyze karyotype O. ame...