The Sry-related high-mobility-group box transcription factor Sox9 recruits the redundant L-Sox5 and Sox6 proteins to effect chondrogenesis, but the mode of action of the trio remains unclear. We identify here a highly conserved 359-bp sequence 10 kb upstream of the Agc1 gene for aggrecan, a most essential cartilage proteoglycan and key marker of chondrocyte differentiation. This sequence directs expression of a minimal promoter in both embryonic and adult cartilage in transgenic mice, in a manner that matches Agc1 expression. The chondrogenic trio is required and sufficient to mediate the activity of this enhancer. It acts directly, Sox9 binding to a critical cis-acting element and L-Sox5/Sox6 binding to three additional elements, which are cooperatively needed. Upon binding to their specific sites, L-Sox5/Sox6 increases the efficiency of Sox9 binding to its own recognition site and thereby robustly potentiates the ability of Sox9 to activate the enhancer. L-Sox5/Sox6 similarly secures Sox9 binding to Col2a1 (encoding collagen-2) and other cartilage-specific enhancers. This study thus uncovers critical cis-acting elements and transcription factors driving Agc1 expression in cartilage and increases understanding of the mode of action of the chondrogenic Sox trio.
- American Society for Microbiology
- L-sox5 and sox6 drive expression of the aggrecan gene in ...
Construction site health and safety failures
As what is largely agreed to be the world’s most dangerous industry, construction site Health and Safety failures constitute potentially severe harm to worker wellbeing, with the capacity to severely impact quality of life or – put bluntly – end it. Running contrary to this doom-laden approach though, improvements to the industry typically arise from assessing HSE failures and implementing measures to reduce risks and control common hazards. In line with this thinking, in an effort to help...
Solar Light Towers for Remote Security
Lights are the most important components of security systems. Well-lit locations are generally avoided by trespassers, because such areas can disrupt stealthy movements. The isolated nature of far-flung locations, such as military bases, mining sites, agricultural operations and manufacturing plants, can be made secure with solar perimeter lighting, coupled with other security devices. Remote and Security Capabilities Solar light towers that are used to enhance security systems in remote locations are...
Major Considerations in Landfill Closure
Preparing for the closure and long-term care of a municipal solid waste landfill (MSWLF) can be an inordinate undertaking. Whether public or private, all landfills eventually reach the end of their active lifecycle. Before closure, a landfill must meet a series of criteria as determined by Subtitle D of the Resource Conservation and Recovery Act (RCRA). Following closure, those same regulations also require a minimum 30-year care period of monitoring and maintaining the landfill after it no longer generates...
What you need to know about Lone Working
Staying safe and being prepared for the unexpected With lone working on the rise lately a lot of people may be wondering; exactly what constitutes this practice and what are the health & safety requirements? A lone worker is essentially defined as an employee who works by themselves without direct supervision, perhaps on a remote site, in their own home or on the move. It can be carried out in a variety of occupations with the following being some of the most likely examples: Site Security guards. Nurses...
How three U.S. mini-farms are sowing the seeds of global food security
Tiny, biointensive operations show smallholder farmers from around the world how they can grow far more food than conventional approaches. Her face shaded by a wide-brimmed straw hat, Olawumi Benedict is cheerfully tending to her “little babies” — kale seedlings growing in shallow wooden flats until they’re hardy enough for transplantation into soil beds. Three miles over the hills on another small farm, Jonnes Mlegwah is double-digging the soil with a spading fork, preparing to plant...