Scientists from the U.S. and Japan have made a breakthrough in stem cell research, finding a cheap and easy way to reprogram adult cells from mice and return them in a state resembling embryonic when cells are able to differentiate into various cell types and tissues.

In other words - the specialists were able to obtain embryonic stem cells without embryos, Reuters, ending up publication in the journal "Nature." The discovery of embryonic stem cells, scientists have high hopes for their use in the treatment of many diseases because of their pluripotency - the ability to develop into different cells and tissues.

The problem with embryonic stem cells is that retrieval means the destruction of the embryo , which raises ethical issues. With the new method, these concerns fall. In 2006, scientists offer an alternative to embryonic cells - ie. induced pluripotent cells. These are normal adult cells back into an undifferentiated pluripotent state through the introduction of foreign genetic material. The problem of induced pluripotent cells , however, is that they can be differentiated only in certain cell types, in contrast to embryonic, which are able to develop into any cell type.

Now the authors of this study - specialists from Japan Institute for physico-chemical studies and their colleagues from the hospital "Brigham end uimins" in Boston and Harvard Medical School in the U.S. have demonstrated that any mature adult cell (somatic cell) has the potential to become equivalent of embryonic stem cells.

Scientists have demonstrated in preclinical models of innovative and unique way to reprogram adult cells that does not require the introduction of foreign DNA - a process used in induced pluripotent stem cells.
In the experiments specialists left mature adult cells to multiply , then they are stressed to near the limit, exposing them to different stress factors - trauma, limited oxygen, acidic environment. Scientists have found that within days the cells survived and recovered from stressful stimuls, returning naturally to a state similar to that of embryonic stem cells.

Thus obtained cells called STAP (Stimulus-triggered acquisition of pluripotency - acquired under the influence of incentives pluripotency) cells were able to differentiate and develop into different cell types and tissues depending on the conditions in which placed.

The great age of the embryos is unusual because almost all known dinosaur embryos are from the Cretaceous Period. The Cretaceous ended some 125 million years after the bones at the Lufeng site were buried and fossilized.

Led by University of Toronto Mississauga paleontologist Robert Reisz, an international team of scientists from Canada, Taiwan, the People's Republic of China, Australia, and Germany excavated and analyzed over 200 bones from individuals at different stages of embryonic development.
"We are opening a new window into the lives of dinosaurs," says Reisz. "This is the first time we've been able to track the growth of embryonic dinosaurs as they developed. Our findings will have a major impact on our understanding of the biology of these animals."
The bones represent about 20 embryonic individuals of the long-necked sauropodomorph Lufengosaurus, the most common dinosaur in the region during the Early Jurassic period. An adult Lufengosaurus was approximately eight metres long.
The disarticulated bones probably came from several nests containing dinosaurs at various embryonic stages, giving Reisz's team the rare opportunity to study ongoing growth patterns. Dinosaur embryos are more commonly found in single nests or partial nests, which offer only a snapshot of one developmental stage.
To investigate the dinosaurs' development, the team concentrated on the largest embryonic bone, the femur. This bone showed a consistently rapid growth rate, doubling in length from 12 to 24 mm as the dinosaurs grew inside their eggs. Reisz says this very fast growth may indicate that sauropodomorphs like Lufengosaurus had a short incubation period.
Reisz's team found the femurs were being reshaped even as they were in the egg. Examination of the bones' anatomy and internal structure showed that as they contracted and pulled on the hard bone tissue, the dinosaurs' muscles played an active role in changing the shape of the developing femur. "This suggests that dinosaurs, like modern birds, moved around inside their eggs," says Reisz. "It represents the first evidence of such movement in a dinosaur."
The Taiwanese members of the team also discovered organic material inside the embryonic bones. Using precisely targeted infrared spectroscopy, they conducted chemical analyses of the dinosaur bone and found evidence of what Reisz says may be collagen fibres. Collagen is a protein characteristically found in bone.
"The bones of ancient animals are transformed to rock during the fossilization process," says Reisz. "To find remnants of proteins in the embryos is really remarkable, particularly since these specimens are over 100 million years older than other fossils containing similar organic material."
Only about one square metre of the bonebed has been excavated to date, but this small area also yielded pieces of eggshell, the oldest known for any terrestrial vertebrate. Reisz says this is the first time that even fragments of such delicate dinosaur eggshells, less than 100 microns thick, have been found in good condition.
"A find such as the Lufeng bonebed is extraordinarily rare in the fossil record, and is valuable for both its great age and the opportunity it offers to study dinosaur embryology," says Reisz. "It greatly enhances our knowledge of how these remarkable animals from the beginning of the Age of Dinosaurs grew."