Genetics & Molecular Biology

New human heart muscle cells can be formed, but this mainly happens during the first ten years of life, according to a new study from Karolinska Institutet in Sweden. Other cell types, however, are replaced more quickly. The study, which is published in the journal Cell, demonstrates that the heart muscle is regenerated throughout a person's life, supporting the idea that it is possible to stimulate the rebuilding of lost heart tissue.


Plants can undergo the same extreme 'chromosome shattering' seen in some human cancers and developmental syndromes, UC Davis researchers have found. Chromosome shattering, or 'chromothripsis,' has until now only been seen in animal cells.

The process could be applied in plant breeding as a way to create haploid plants with genetic material from only one parent, said Ek Han Tan, a postdoctoral researcher in the UC Davis Department of Plant Biology and first author on the paper. Although plants don't get cancer, it might also allow cancer researchers to use the laboratory plant Arabidopsis as a model to study chromosome behavior in cancer.


Dengue is a virus spread via the Aedes aegypti mosquito that infects as many as 100 million people annually in more than 100 tropical countries worldwide.

It causes fevers, extreme headaches, and muscle and joint pains. In a few extreme cases, leakage of blood plasma through the walls of small blood vessels into the body cavity occurs, resulting in bleeding.

This is known as dengue hemorrhagic fever.

A study in mice reveals that hormones that dictate a female's attraction towards males do so in part by controlling her sense of smell. 

The investigators analyzed female mice at various stages of the ovulation cycle and found that when a female is not ready for reproduction, her hormones (specifically progesterone) block her ability to sense the smell of male pheromones.

These hormones diminish during ovulation, eventually allowing a female mouse to smell a potential partner. When ovulation ends, the cycle repeats, and she is again rendered "odor-blind" to males.


In many animal species, the chromosomes differ between the sexes - the male has a Y chromosome. This contains genes which result in the development of male characters and reproductive organs. If there is no Y chromosome, the organism will be a female.

But in birds and some other animals, it is the other way round and females have their own sex chromosome, the W chromosome. 


Until now, de novo genetic mutations, alterations in a gene found for the first time in one family member, were believed to be mainly the result of new mutations in the sperm or eggs (germline) of one of the parents and passed on to their child.

Researchers from The Netherlands have now succeeded in determining that at least 6.5% of de novo mutations occur during the development of the child (post-zygotic) rather than from the germline of a parent.  


Researchers have identified individual stem cells that can regenerate tissue, cartilage and bone.

The stem cells are mixed within human bone marrow stromal cells (MSCs) but are similar in appearance and previously, scientists had difficulty in distinguishing between them. The researchers isolated individual MSCs and analyzed their different properties.

This allowed researchers to identify those stem cells which are capable of repairing damaged cartilage or joint tissue opening the way for improved treatment for arthritis.


In the animal kingdom, predators use a full range of strategies, such as camouflage, speed and optical illusions, to catch their prey. Meanwhile, prey species resort to the same tactics to escape from their predators. Such tricks are also used at the molecular level, as discovered by researchers from the CNRS, INRA, CEA and INSERM in one of the most devastating bacterial plant pathogens in the world, which bypasses plant cell defenses by preventing an immune signaling from being triggered.

Even more surprising is the fact that plant cells have developed a receptor incorporating a decoy intended to catch the invader in its own trap. 

A long noncoding RNA (lncRNA), which might give an impact on tyrosine kinase-targeted leukemia therapy, was found to be expressed in a leukemia cell line.

The function of the lncRNA CCDC26 is not fully understood; however, researchers found the mechanisms by which CCDC26 controls the receptor tyrosine kinase KIT expression. Recent transcriptomic studies have revealed the existence of numerous RNAs that are relatively long but not translated into proteins. Some of such lncRNAs are suggested to regulate the expression of other genes. Mutations or imbalances in the noncoding RNA repertoire within the body can therefore cause a variety of diseases such as cancer. However, the molecular functions of lncRNAs remain to be fully elucidated.

Researchers have unraveled one of the mysteries of how a small group of immune cells work: That some inflammation-fighting immune cells may actually convert into cells that trigger disease. 

White blood cells, called T-cells, iare one of the body's critical disease fighters. Regulatory immune cells, called "Tregs," direct T-cells and control unwanted immune reactions that cause inflammation. They are known to produce only anti-inflammatory proteins to keep inflammation caused by disease in check.