A new program for neural stem cells. Neural stem cells can do a lot, but not everything. For example, brain and spinal cord cells are not usually generated by neural stem cells of the peripheral nervous system, and it is not possible to produce cells of the peripheral nervous system from the stem cells of the brain. However, researchers from the Max Planck Institute for Brain Research in Frankfurt and the Max Planck Institute of Immunobiology and Epigenetics in Freiburg have now succeeded in producing central nervous system cells from neural stem cells of the peripheral nervous system. They found that if peripheral stem cells are maintained under defined growth conditions, they generate oligodendrocytes, which form the myelin layer that surrounds the neurons found in the brain and spinal cord. The mammalian nervous system consists of a central (brain, spinal cord) and peripheral nervous system (e.g. nerves and sensory ganglia).
Scientists observe single gene activity in living cells in detail for first time. Researchers at Albert Einstein College of Medicine of Yeshiva University have for the first time observed the activity of a single gene in living cells. In an unprecedented study, published in the April 22 online edition of Science, Einstein scientists were able to follow, in real time, the process of gene transcription, which occurs when a gene converts its DNA information into molecules of messenger RNA (mRNA) that go on to make the protein coded by the gene. Robert Singer, Ph.D., co-director of the Gruss Lipper Biophotonics Center at Einstein and professor and co-chair of anatomy and structural biology, is senior author of the paper.
The study's lead author is Daniel Larson, Ph.D., previously a member of Dr. Singer's lab and now an investigator at the National Cancer Institute and head of the institute's Systems Biology of Gene Expression Section. Using florescent proteins, the researchers were able to follow mRNA activity by inserting DNA sequences into a gene in live yeast cells. Can a Simple Model Explain the Advent of Cells? Scientists still don't know how a few biomolecules got together to kick-start life. Now a pair of theoretical biophysicists have come up with a simple mathematical model of two interacting chemicals that seems to replicate an essential part of the rise of life: the emergence of primitive, reproducing "protocells. " The first task in sparking life, or at least lifelike chemical interactions, would be to coax complex molecules to reproduce themselves from the other chemicals in solution around them.
Under the right conditions, some proteins and other complex molecules can produce copies of themselves by purely chemical means. But making such a process run on as reliably as, say, bacteria multiplying in a petri dish is harder than one might guess. That's because in the process, numerous copying errors, or mutations, arise. Of course, nature found a way around this problem, and over the years scientists have proposed several refinements to make their models more stable.
#20: AIDS Virus Has an Ancient History | HIV & AIDS. HIV is a newcomer among human pathogens, having caused the first known cases of aids within the past few decades. So scientists suspected that SIV, the primate virus that spawned HIV, was just a few hundred years older. Tulane University virologist Preston Marx published research in September that suggests otherwise: SIV seems to be at least 32,000 years old, meaning it coexisted with people nearly all that time before HIV emerged.
Marx’s team did SIV tests on monkeys from Bioko Island, which was cut off from the African continent 10,000 years ago. The Bioko SIV strains all shared ancestry with strains from the African mainland, indicating the virus is at least that old and probably much older. If we do not figure out what triggered the HIV epidemic, it will be hard to prepare for what might come next.
Molecular biology.