New York: Biologists have identified what they claim is a key mechanism controlling early embryonic development that is critical in determining how structures such as appendages -- arms and legs in humans -- grow in the right place and at the right time.
A team from New York University and University of Iowa says that much research has focused on the spatial regulatory networks that control early developmental processes. However, they note, less attention has been paid to how such networks can be precisely coordinated over time.
The biologists have found that a protein called Zelda is responsible for turning on groups of genes essential to development in an exquisitely coordinated fashion, the `PLoS Genetics` journal reported.
"Zelda does more than initiate gene networks – it orchestrates their activities so that the embryo undergoes developmental processes in a robust manner at the proper time and in the correct order," team leader Chris Rushlow from New York University said.
Added team member John Manak from the University of Iowa: "Our results demonstrate the significance of a timing mechanism in coordinating regulatory gene networks during early development, and bring a new perspective to classical concepts of how spatial regulation can be achieved."
The biologists say their findings break new ground.
"We discovered a key transcriptional regulator, Zelda, which is the long-sought-after factor that activates the early zygotic genome. Initially, the embryo relies on maternally deposited gene products to begin developing, and the transition to dependence on its own zygotic genome is called the maternal-to-zygotic transition.
"Two hallmark events that occur during this transition are zygotic gene transcription and maternal RNA degradation, and interestingly, Zelda appears to be involved in both processes," Rushlow said.