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.

New genetic engineering technique sets the stage for advances in medicine and beyond

From bacteria-made insulin that obviates the use of animal pancreases to a better understanding of infectious diseases and improved treatments, genetic engineering of bacteria has redefined modern medicine. Yet, serious limitations remain that hamper| progress in numerous other areas.

30 May 2020

Targeted therapy pralsetinib shows high response rates in patients with RET fusion-positive cancers

The targeted therapy pralsetinib appears to have high response rates and durable activity in patients with a broad variety of tumors harboring RET gene fusions, according to results from the international Phase I/II ARROW trial, led by researchers at The University of Texas MD Anderson Cancer Center.

29 May 2020

Study sheds light on homologous recombination of DNA strands

As chromosomes go, X and Y make an unlikely pair. The X is large and contains thousands of genes critical for life. The Y, by contrast, is little more than a nub.

29 May 2020

Mouse model mimics clinical course and pathology observed in COVID-19 patients

A mouse model of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reproduces features observed in human patients, researchers report May 26 in the journal Cell Host & Microbe.

27 May 2020

Researchers investigate the early development of ovarian cancer

Researchers from the group of Hans Clevers at the Hubrecht Institute have modeled the development and progression of high-grade serous ovarian cancer in mini-versions of the female reproductive organs of the mouse.

27 May 2020

New genomic method helps obtain high-resolution maps of DNA in the cell nucleus

Researchers at Karolinska Institutet in Sweden have developed a new sequencing method that makes it possible to map how DNA is spatially organised in the cell nucleus - revealing which genomic regions are at higher risk of mutation and DNA damage.

26 May 2020

Researchers recombine entire chromosomes with CRISPR/Cas technology

The CRISPR/Cas molecular scissors work like a fine surgical instrument and can be used to modify genetic information in plants.

25 May 2020

Study uncovers the role of DNA repair in preserving egg quality

A Monash University study has uncovered the role DNA repair plays in preserving egg quality, offering hope for women whose eggs may be damaged through treatments such as radiation and chemotherapy.

22 May 2020

Novel biomarkers linked to improved outcomes with immunotherapy in metastatic breast cancer

Two novel biomarkers have been found to correlate with improved outcomes with immunotherapy in metastatic breast cancer and may help to identify the patients most likely to benefit from this treatment, according to exploratory studies reported at the ESMO Breast Cancer Virtual Meeting 2020.

22 May 2020

Research demonstrates self-synthesis and assembly of 30S subunit of ribosome

As the cell's protein factory, the ribosome is the only natural machine that manufactures its own parts. That is why understanding how the machine, itself, is made, could unlock the door to everything from understanding how life develops to designing new methods of drug production.

21 May 2020

DZD researchers discover additional genetic cause for non-alcoholic fatty liver disease

In Germany about 18 million people suffer from non-alcoholic fatty liver. The causes of this disease are manifold and include environmental as well as genetic factors.

19 May 2020

Gene variants can increase risk of schizophrenia, shows study

Variants in a gene of the human immune system cause men and women to have different vulnerabilities to the autoimmune diseases lupus and Sjögren's syndrome, according to findings published in the journal Nature.

19 May 2020

Takeda to present oncology pipeline data at upcoming virtual scientific congresses

Takeda Pharmaceutical Company Limited today announced that the company will present data from its expanding oncology pipeline and established product portfolio at two upcoming virtual scientific congresses: the 56th Annual Meeting of the American Society of Clinical Oncology, May 29-31 and the 25th Virtual Congress of the European Hematology Association, June 11-14.

18 May 2020

Variations in genome’s 'dark matter' region can make patients susceptible to inflammatory diseases

A study led by researchers at the Babraham Institute in collaboration with the Wellcome Sanger Institute has uncovered how variations in a non-protein coding 'dark matter' region of the genome could make patients susceptible to complex autoimmune and allergic diseases such as inflammatory bowel disease.

14 May 2020

Researchers use “gene drive” technology to eliminate malaria mosquitoes in lab experiments

A modification that creates more male offspring was able to eliminate populations of malaria mosquitoes in lab experiments.

13 May 2020

Scientists uncover important functions of a special protein during cell division

In a new study, researchers from the University of Copenhagen have discovered two important functions of a protein called RTEL1 during cell division.

12 May 2020

Woman's genetic make-up may play a role in weight gain from birth control

A woman's genetic make-up may cause her to gain weight when using a popular form of birth control, according to a study from researchers at the University of Colorado Anschutz Medical Campus.

12 May 2020

Study: Recombination is crucial for proper segregation of chromosomes into germs cells

From avocado plants to baker's yeast, humans to zebras, sexually reproducing organisms must create germ cells that contain half the number of chromosomes found in a typical body cell.

7 May 2020

Harmful effects of BPA can be reversed by administering coenzyme Q10

Exposure to bisphenol A (BPA), an industrial chemical used to make certain plastics and resins, inner coatings for food cans and bottle tops, thermal paper used in store receipts, dental sealants and so on, is a concern because of possible adverse health effects, including a reduction in fertility.