Group items matching

in title, tags, annotations or url

Explore the cycling of carbon among carbon reservoirs! Then discover the importance of nitrogen, essential for amino acids and nucleotides, and learn about the nitrogen cycle! Vocabulary discussed includes ammonification and denitrification.

In the August 1 issue of CELL, researchers from the Gene and Stem Cell Therapy Program at Sydney's Centenary Institute revealed another function of introns, or noncoding nucleotide sequences, in DNA. They reported that gene-sequencing techniques and computer analysis allowed them to demonstrate how granulocytes use noncoding DNA to regulate the activity of a group of genes that determines the cells' shape and function.

Genetic differences among ethnically diverse individuals are largely due to structural elements called copy number variants (CNVs), according to a study published today (August 6) in Science. Compared with other genomic features, such as single nucleotide variants (SNVs), CNVs have not previously been studied in as much detail because they are more difficult to sequence. Covering 125 distinct human populations around the world, geneticist Evan Eichler at the University of Washington in Seattle and an international team of colleagues studied the genomes of 236 people-analyzing both SNVs and CNVs. "The take-home message is that we continue to find a lot more genetic variation between humans than we appreciated previously," Eichler told The Scientist.

This video segment adapted from NOVA scienceNOW examines the realm of personal DNA testing. It describes the latest tests, which look for single-nucleotide polymorphisms (SNPs). These single-letter differences in DNA sequence make humans unique from one another but may also predispose people to certain diseases. The video also discusses the Personal Genome Project, an extension of the Human Genome Project aimed at determining the root causes of many common diseases. The Personal Genome Project takes into account personal genomics as well as lifestyle information, such as one's living environment, habits, and behaviors.

At least 140 alternative RNA nucleotide forms exist. On mRNA, the most common is the methylation of adenosine on the N6 position (m6A).

Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs) and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a "risk" allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders.

"This modular case study tells the story of Dan and Annie, a married couple of Acadian ancestry who have a genetic form of deafblindness called Usher syndrome. They live in Southwest Louisiana, home of the largest population of DeafBlind citizens in the United States. Acadian Usher syndrome is caused by an allele of the USH1C gene that came to Louisiana with the first Acadian settlers from Canada who founded today's Cajun population. This allele's single nucleotide substitution creates an erroneous splice site that produces a defective cytoskeletal protein (harmonin) of the cochlear and vestibular hair cells and retinal photoreceptors. This splice site is the target of a promising gene therapy. The case study applies and connects Mendelian inheritance, chromosomes, cell division, vision and hearing, DNA sequences, gene expression, gene therapy and population genetics to a specific gene and its movement through generations of Dan and Annie's families.  After the introduction, each of the remaining sections can be used independently either for in-class team activities or out-of-class extensions or assignments over an entire year of introductory undergraduate biology. "

Gangnam stype take on biomolecules

3:09 video RNA may have been the origin of life on Earth. Go on a whirlwind tour of RNA's evolving role through billions of years of evolutionary history. Play the RNA Lab: http://www.pbs.org/wgbh/nova/labs/lab...

4:47 video Over the past few weeks, the Nobel committees have been announcing the 2015 laureates. This year's winners in the physics and chemistry categories made discoveries about the tiny neutrinos flying through all of us, and the ways our bodies repair DNA.