Different ploidy levels, diploid (2n=2x=24) to hexaploid (2n=6x=72) have been reported for Acorus calamus, a perennial medicinal plant. According to available information, there is a significant relationship between the ploidy level and essential oil compositions and medicinal properties of this important genetic resource. However, there is no information about the chromosome number of A. calam...

How are toxic proteins cleared by microglia? Since microglia are the macrophages of the CNS, the promotion of an increase in their ability to phagocytose highly toxic proteins is a promising new therapeutic approach to prevent many diseases. Toxic proteins are produced in a variety of brain diseases, such as Alzheimer’s disease (b-amyloid), amyotrophic lateral sclerosis (superoxide dismutase 1)...

In mammals, flies, and worms, sex is determined by distinctive regulatory mechanisms that cause males (XO or XY) and females (XX) to differ in their dose of X chromosomes. In each species, an essential X chromosome-wide process called dosage compensation ensures that somatic cells of either sex express equal levels of X-linked gene products. The strategies used to achieve dosage compensation ar...

The chromosome number (2n=5x=44+1B) of Tanacetum fisherae, as a new record from high mountains of southern Iran (Kerman province: Hazar mountain) is reported. A new ploidy level (pentaploidy) for the genus is presented for the first time. The studied population was aneuploid, having lost one chromosome out of the 45 expected in an x=9-based pentaploid. The distribution map, description and micr...

It is a well-known fact of popular science that nearly all tortoiseshell cats are female. Underlying this is X-chromosome inactivation, a phenomenon found in all mammals. In the sex-determining system of mammals — in which females carry two X chromosomes and males an X and a Y chromosome — the X chromosome is typically large and carries many genes unconnected with sex, whereas the Y chromosome ...

The X and Y chromosomes of placental and marsupial mammals originated from a pair of autosomes. Ohno hypothesised nearly 50 years ago that the expression levels of X-linked genes should be doubled to compensate for the degeneration of their Y-linked homologues during sex chromosome evolution. The advent of microarray and RNA (ribonucleic acid) sequencing technologies in the past decade prompted...

Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it ...