Aug 20, 2014 The green anole lizard (Anolis carolinensis), when caught by a predator, can lose its tail and then grow it back. Researchers have discovered the genetic 'recipe' as to how this happens. Credit: Joel Robertson

By understanding the secret of how lizards regenerate their tails, researchers may be able to develop ways to stimulate the regeneration of limbs in humans. Now, a team of researchers from Arizona State University is one step closer to solving that mystery. The scientists have discovered the genetic "recipe" for lizard tail regeneration, which may come down to using genetic ingredients in just the right mixture and amounts.

An interdisciplinary team of scientists used next-generation molecular and computer analysis tools to examine the genes turned on in tail regeneration. The team studied the regenerating tail of the green anole lizard (Anolis carolinensis), which when caught by a predator, can lose its tail and then grow it back.

The findings are published today in the journal PLOS ONE.

"Lizards basically share the same toolbox of genes as humans," said lead author Kenro Kusumi, professor in ASU's School of Life Sciences and associate dean in the College of Liberal Arts and Sciences. "Lizards are the most closely-related animals to humans that can regenerate entire appendages. We discovered that they turn on at least 326 genes in specific regions of the regenerating tail, including genes involved in embryonic development, response to hormonal signals and wound healing."

Other animals, such as salamanders, frog tadpoles and fish, can also regenerate their tails, with growth mostly at the tip. During tail regeneration, they all turn on genes in what is called the 'Wnt pathway'a process that is required to control stem cells in many organs such as the brain, hair follicles and blood vessels. However, lizards have a unique pattern of tissue growth that is distributed throughout the tail.

"Regeneration is not an instant process," said Elizabeth Hutchins, a graduate student in ASU's molecular and cellular biology program and co-author of the paper. "In fact, it takes lizards more than 60 days to regenerate a functional tail. Lizards form a complex regenerating structure with cells growing into tissues at a number of sites along the tail."

"We have identified one type of cell that is important for tissue regeneration," said Jeanne Wilson-Rawls, co-author and associate professor with ASU's School of Life Sciences. "Just like in mice and humans, lizards have satellite cells that can grow and develop into skeletal muscle and other tissues."

"Using next-generation technologies to sequence all the genes expressed during regeneration, we have unlocked the mystery of what genes are needed to regrow the lizard tail," said Kusumi. "By following the genetic recipe for regeneration that is found in lizards, and then harnessing those same genes in human cells, it may be possible to regrow new cartilage, muscle or even spinal cord in the future."

The researchers hope their findings will help lead to discoveries of new therapeutic approaches to spinal cord injuries, repairing birth defects, and treating diseases such as arthritis.

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How lizards regenerate their tails: Researchers discover genetic 'recipe'

7 hours ago

(Phys.org) There's an old saying in the biofuels industry: "You can make anything from lignin except money." But now, a new study may pave the way to challenging that adage. The study from the Energy Department's National Renewable Energy Laboratory (NREL) demonstrates a concept that provides opportunities for the successful conversion of lignin into a variety of renewable fuels, chemicals, and materials for a sustainable energy economy.

"Lignin Valorization Through Integrated Biological Funneling and Chemical Catalysis" was recently published in the Proceedings of the National Academy of Sciences. The NREL-led research project explores an innovative method for upgrading lignin.

The process for converting glucose from biomass into fuels such as ethanol has been well established. However, plants also contain a significant amount of lignin up to 30 percent of their cell walls. Lignin is a heterogeneous aromatic polymer that plants use to strengthen cell walls, but it is typically considered a hindrance to cost-effectively obtaining carbohydrates, and residual lignin is often burned for process heat because it is difficult to depolymerize and upgrade into useful fuels or chemicals.

"Biorefineries that convert cellulosic biomass into liquid transportation fuels typically generate more lignin than necessary to power the operation," NREL Senior Engineer and a co-author of the study Gregg Beckham said. "Strategies that incorporate new approaches to transform the leftover lignin to more diverse and valuable products are desperately needed."

Although lignin depolymerization has been studied for nearly a century, the development of cost-effective upgrading processes for lignin valorization has been limited.

In nature, some microorganisms have figured out how to overcome the heterogeneity of lignin. "Rot" fungi and some bacteria are able to secrete powerful enzymes or chemical oxidants to break down lignin in plant cell walls, which produces a heterogeneous mixture of aromatic molecules. Given this large pool of aromatics present in nature, some bacteria have developed "funneling" pathways to uptake the resulting aromatic molecules and use them as a carbon and energy source.

This new study shows that developing biological conversion processes for one such lignin-utilizing organism may enable new routes to overcome the heterogeneity of lignin. And, that may enable a broader slate of molecules derived from lignocellulosic biomass.

"The conceptual approach we demonstrate can be applied to many different types of biomass feedstocks and combined with many different strategies for breaking down lignin, engineering the biological pathways to produce different intermediates, and catalytically upgrading the biologically-derived product to develop a larger range of valuable molecules derived from lignin," Beckham said. "It holds promise for a wide variety of industrial applications. While this is very exciting, certainly there remains a significant amount of technology development to make this process economically viable."

A patent application has been filed on this research and NREL's Technology Transfer Office will be working with researchers to identify potential licensees of the technology.

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New process helps overcome obstacles to produce renewable fuels and chemicals

3 hours ago by David Stacey

(Phys.org) A problem that has puzzled canola breeders for years has been solved by researchers from The University of Western Australia - and the results could provide a vital breakthrough in understanding the impact of increasing global temperatures on crop flowering.

The key to understanding what makes Australian canola flower earlier than its Canadian and European counterparts lies in the genes.

Associate Professor Matthew Nelson from UWA's Institute of Agriculture and School of Plant Biology has identified that heat-responsive genes are responsible for flowering time in Australian spring-type and European summer-type canola. This is the first time such genes have been reported to influence flowering time in canola.

Australian canola is quite distinct from its Canadian and European counterparts - it flowers much earlier. Plant breeders cannot simply transfer varieties from Canada or Europe into Australia as they flower much too late for the Australian environment.

"We took a European summer-type canola, crossed it with Monty, a typical early flowering Australian variety, and analysed the progeny for variation in flowering time," Associate Professor Nelson said.

"There was a huge variation from about 30 days to 160 days in our typical Australian environment. This was totally unexpected and we showed there are several forms of these heat-responsive genes controlling flowering time."

The research indicated that the European plants required much more accumulated heat (thermal time) to flower than the Australian plants.

"Until now, most researchers assumed that long summer days in Europe and Canada triggered flowering, not heat," Associate Professor Nelson said. "Now we know that long days are only a minor part of the story."

"Understanding this complex process is important as breeders alter the adaptation of crops to a new and changing environment," research team leader Winthrop Professor Wallace Cowling said. "International canola breeders will use this information to re-establish the correct flowering time in canola when they cross between Australian types and summer annual types in the northern hemisphere.

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Canola flowers faster with heat genes