Chromosome X News and Research

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The X chromosome is one of the two sex chromosomes in humans (the other is the Y chromosome). The sex chromosomes form one of the 23 pairs of human chromosomes in each cell. The X chromosome spans about 155 million base pairs (the building blocks of DNA) and represents approximately 5 percent of the total DNA in cells.

Each person normally has one pair of sex chromosomes in each cell. Females have two X chromosomes, while males have one X and one Y chromosome. Early in embryonic development in females, one of the two X chromosomes is randomly and permanently inactivated in somatic cells (cells other than egg and sperm cells). This phenomenon is called X-inactivation or Lyonization. X-inactivation ensures that females, like males, have one functional copy of the X chromosome in each body cell. Because X-inactivation is random, in normal females the X chromosome inherited from the mother is active in some cells, and the X chromosome inherited from the father is active in other cells.

Some genes on the X chromosome escape X-inactivation. These genes are located at the tip of the short (p) arm of the X chromosome in an area known as the pseudoautosomal region. Although many genes are unique to the X or Y chromosome, genes in the pseudoautosomal region are present on both chromosomes. As a result, men and women each have two functional copies of these genes. Many genes in the pseudoautosomal region are essential for normal development.

Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. The X chromosome likely contains between 900 and 1,400 genes.

Genes on the X chromosome are among the estimated 20,000 to 25,000 total genes in the human genome.

NPHS1 is a disease-susceptibility gene for steroid-sensitive nephrotic syndrome, reveals study

An international research collaboration, including Professor IIJIMA Kazumoto et al. (of the Department of Pediatrics, Kobe University Graduate School of Medicine) has revealed that NPHS1 is a disease-susceptibility gene for steroid-sensitive nephrotic syndrome in children.

3 Jul 2020

New scanner to detect early signs of bladder cancer could save thousands of lives

Thousands of lives lost to bladder cancers each year could be saved thanks to a new scanner that uses photonics to illuminate parts of the tissue that are currently impossible to visualize.

3 Jul 2020

Glitches in DNA replication have important implications for treating cancer

USC researchers peering deep inside a living cell have discovered something surprising: Its system for preventing genetic damage linked to diseases can fail so badly that the cell would be better off without it.

30 Jun 2020

Scientists discover osmotic stress as stimulator of cellular waste disposal

Cellular waste disposal, where autophagy and lysosomes interact, performs elementary functions, such as degrading damaged protein molecules, which impair cellular function, and reintroducing the resulting building blocks such as amino acids into the metabolic system.

29 Jun 2020

Researchers identify new protein complex that regulates chromosome separation

Researchers from the University of Tsukuba have identified a novel protein complex that regulates Aurora B localization to ensure that chromosomes are correctly separated during cell division

26 Jun 2020

A metabolic enzyme drives B cell lymphomas and could be a potential drug target

Scientists at the Sloan Kettering Institute have found that increased activity of a normal metabolic enzyme can lead to cancer. The enzyme, SHMT2, is a driver of a large portion of B cell lymphomas and could be a potential drug target.

24 Jun 2020

ACE inhibition in kidney could influence pathogenesis of SARS-CoV-2

The dynamics of angiotensin-converting enzyme 2 (ACE2) expression in the kidney could have implications for the infectivity and pathogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), say researchers.

24 Jun 2020

Tomocube holotomography microscopy reveals novel cholesterol membrane transport system in erythrocytes infected with fatal malaria parasite

The first study to elucidate the dynamics of membrane cholesterol transport in erythrocytes has been successfully concluded using holotomography microscopy.

From Tomocube Inc. 24 Jun 2020

Evidence of link between ACE2 genotype and COVID-19 disease severity

A new study published on the preprint server medRxiv in June 2020 shows that variants in the ACE2 gene which encodes the enzyme receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19 disease, are linked to the risk of severe disease.

24 Jun 2020

Blood types and COVID-19 risk confirmed

Blood type may play a pivotal role in driving disease severity among coronavirus disease (COVID-19) patients. Genetic analysis of COVID-19 patients has shown that people with blood type O seemed to be protected against severe disease. In contrast, those with blood type A may experience complications tied to the viral infection.

18 Jun 2020

Persistent DNA damage in the placenta can affect embryonic growth

Scientists at the Stowers Institute for Medical Research have shown that a dysfunctional placenta can play a previously unrecognized role during the earliest stages of development in mouse models of Cornelia de Lange syndrome.

16 Jun 2020

MGH researchers identify key mechanism in X chromosome inactivation

Researchers at Massachusetts General Hospital have identified a key mechanism in X chromosome inactivation, a phenomenon that may hold clues that lead to treatments for certain rare congenital disorders.

12 Jun 2020

New insights on DNA replication can help develop novel cancer treatments

A study by the Centre for Chromosome Biology at NUI Galway, Ireland, in partnership with the University of Zurich, has uncovered new insights into how the replication of DNA occurs which can be applied to help develop novel cancer treatments.

10 Jun 2020

New Canadian study investigates how cancer adapts its metabolism to overcome therapies

Knowing what cancer will do next could lessen the likelihood of it becoming resistant to treatment. A new Canadian study investigates how cancer adapts its metabolism to potentially overcome therapies still in development.

8 Jun 2020

New images of LSD1 enzyme in action shed light on gene regulation

New images of an enzyme in action as it interacts with the chromosome could provide important insight into how cells--including cancer cells--regulate their genes.

5 Jun 2020

SARS-CoV-2 gene deletions may cause milder infections and increase human-to-human transmission

In their recent paper released on the bioRxiv preprint server, a research group from Spain demonstrated how genome changes and deletions in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could represent a strategy of natural selection used for lessening the impact of infection in order to increase viral transmission potential.

4 Jun 2020