New study reveals how frog heads are formed

MOSCOW, June 20 (UPI) -- A new study by researchers at the Institute of Bioorganic Chemistry, part of the Russian Academy of Sciences, has revealed the genetic mechanism underlying frog head formation.

Scientists have previously identified the "Noggin" family of cell-secreted proteins as key in signaling tissue formation. New analysis has identified a member protein singularly responsible for the formation of frog embryos and frog heads.

Previous research has revealed Wnt-cascade proteins are central to embryogenesis and cell differentiation, as well as the growth and development of malignant tumors. Computer models showed that the Noggin4 signaling protein binds exclusively to Wnt-cascade proteins.

"In the course of the study, we discovered that the Noggin4 signaling protein is not like its relatives," researcher Fedor Eroshkin said in a news release. "Unlike Noggin1 and Noggin2, it is not able to bind to proteins that organize the construction of tissues in the body, but instead binds only to those proteins that are responsible for the development of the embryo."

"Noggin4 therefore plays a key role in the formation of the head, and in particular, in the formation of the forebrain during embryogenesis," Eroshkin concluded.

When scientists artificially suppressed Noggin4 expression, live frog embryos suffered significant head formation defects.

"For Wnt-signal suppressers, we first found a partner which really diffuses much faster than other protein sensors, morphogens, by which cells communicate, 'feel' their spatial position within the embryo and instruct each other for further differentiation," explained Eroshkin.

The researchers hope their findings -- published recently in the journal Scientific Reports -- could improve human stem cell research and therapies.