By Lynne FriedmannBiologists at UC San Diego have identified eight genes — never before suspected of having a role in healing — that spring into action when a wound occurs.
The discovery was made in the laboratory fruit fly Drosophila, which serves as an experimental model because many of the genes that regulate a Drosophila’s exoskeleton (cuticle) are the same as those controlling biological processes in human skin.
Puncturing the cuticle of fruit fly embryos, researchers examined 162 genes that either turn on or turn off in response to healing. Of these, eight genes were identified that expressed at very low levels or not at all during development, but became activated near an injury site. The response begins immediately,
releasing antimicrobial peptides and other compounds that protect the fly should bacteria or fungi enter the wound. The next step is to see if these genes in human play a comparable healing role.
Details of the discovery found in the journal
- News release at
Transforming stem cells directly into brain cellsIn a serendipitous discovery, scientists at The Scripps Research Institute have found a way to turn bone marrow stem cells directly into brain cells. Current techniques for turning patients’ marrow cells into cells of some other desired type are relatively cumbersome, risky, and confined to the lab dish.
Researchers discovered the new method while looking for lab-grown antibodies that activate a growth-stimulating receptor on marrow cells. One antibody turned out to activate the receptor in a way that induces marrow stem cells (which normally develop into white blood cells) to become neural progenitor cells, a type of almost-mature brain cell. These results highlight the potential of antibodies as versatile manipulators of cellular functions and challenge the current view of antibodies as simply molecules for binding.
Findings published in the
Proceedings of the National Academy of Sciences
- News release at
The ability of sea spray to seed cloudsTiny air bubbles form when ocean waves break, and rise to the surface and burst, releasing gases and aerosols whose chemical make-up affects their ability to take up water, seed clouds and react in the atmosphere. But that ability is altered by the presence of biological life found in water.
By engineering breaking waves of natural ocean water under purified air in the lab, atmospheric chemists at UC San Diego were able to isolate and analyze aerosols and determine how life within the water impacts the chemistry of the particles.
Over five days, the team systematically altered biological communities within the flume by adding various combinations of cultures of marine bacteria and microscopic marine algae (phytoplankton). Then a hydraulic paddle sent waves breaking over an artificial shoal.
As the seawater changed and bacteria levels increased, the composition of the aerosols changed in ways that reduced their ability to form clouds. In particular, a day after new cultures were added, bacteria levels rose fivefold and cloud-seeding potential fell by about a third.
This is an important finding because current estimates of biological activity in surface waters of the ocean rely on satellite instruments that measure the color of the sea surface, signaling a change of chlorophyll levels, but that would miss blooms of other organisms, such as bacteria.
The findings are reported in the
Proceedings of the National Academy of Science
- News release at
Lynne Friedmann is a science writer based in Solana Beach.