IMAGE:This is the skull of an extinct short-faced kangaroo (Simosthenurus occidentalis). Ancient DNA from these animals reveals they are a highly distinct evolutionary lineage. view more Credit: Mike Lee / South Australian Museum Scientists have finally managed to extract DNA from Australia's extinct giant kangaroos - the mysterious marsupial megafauna that roamed Australia over 40,000 years ago. A team of scientists led by Dr Bastien Llamas and Professor Alan Cooper from the University of Adelaide's Australian Centre for Ancient DNA (ACAD) have extracted DNA sequences from two species: a giant short-faced kangaroo (Simosthenurus occidentalis) and a giant wallaby (Protemnodon anak). These specimens died around 45,000 years ago and their remains were discovered in a cold and dry cave in Tasmania. Relatively good preservation conditions in the cave allowed enough short pieces of DNA to survive so researchers could reconstruct partial "mitochondrial genomes" - genetic material transmitted from mother to offspring and widely used to infer evolutionary relationships. "The ancient DNA reveals that extinct giant wallabies are very close relatives of large living kangaroos, such as the red and western grey kangaroos," says lead author Dr Bastien Llamas, ACAD senior research associate. "Their skeletons had suggested they were quite primitive macropods … Continue reading →

DNA molecules provide the "source code" for life in humans, plants, animals and some microbes. But now researchers report an initial study showing that the strands can also act as a glue to hold together 3-D-printed materials that could someday be used to grow tissues and organs in the lab. This first-of-its-kind demonstration of the inexpensive process is described in the brand-new journal ACS Biomaterials Science & Engineering. Andrew Ellington and colleagues explain that although researchers have used nucleic acids such as DNA to assemble objects, most of these are nano-sized -- so tiny that humans can't see them with the naked eye. Making them into larger, visible objects is cost-prohibitive. Current methods also do not allow for much control or flexibility in the types of materials that are created. Overcoming these challenges could potentially have a big payoff -- the ability to make tissues to repair injuries or even to create organs for the thousands of patients in need of organ transplants. With this in mind, Ellington's group set out to create a larger, more affordable material held together with DNA. The researchers developed DNA-coated nanoparticles made of either polystyrene or polyacrylamide. DNA binding adhered these inexpensive nanoparticles to … Continue reading →