Magic embryology: master gene controls in embryo forming (Introduction)

by David Turell , Tuesday, December 22, 2020, 18:54 (1221 days ago) @ David Turell

From a study of Caenorhabditis elegans:

https://phys.org/news/2020-12-roundworms.html

"Transforming a fertilized egg into a fully functional adult is a complicated task. Cells must divide, move, and mature at specific times. Developmental genes control that process, turning on and off in a choreographed way. However, the environment influences development. A team of researchers ...reported December 22, 2020 in the journal Current Biology how gene activity matches nutrient levels. They found a master switch developing worms use to pause growth when nutrients are scarce. When the environment improves, animals continue developing. The switch adjusts gene activity to match nutrient levels.

***

"'This always happens the same way. You always get 959 cells, and the patterns of those divisions that give you those cells are always done in the same manner between one animal and the next."

"The genes that direct this flexible program switch on and off in predictable patterns as an embryo morphs through several larval stages into a fully formed worm.

"In the wild, developing worms can't always depend on comfortable temperatures and plentiful food. Sometimes, development must pause until conditions improve. Hammell's team discovered a protein called BLMP-1 that adjusts gene activity (transcription) to keep pace with development. When conditions are good, BLMP-1 levels increase and unravel stretches of DNA, so genes are more accessible. Activators then switch on the genes at the right time. "This is an anticipatory mechanism to say 'everything's okay, make development as robust as possible,'" Hammell explains. If conditions are not optimal, BLMP-1 levels go down, leaving genes packed tightly away, slowing or even stopping development.

"The team's experiments revealed BLMP-1 as a master regulator of thousands of genes that cycle on and off during development. Hammell says that was a surprise since his team initially set out to investigate this process in just a handful of developmental genes. BLMP-1 is unique in that it coordinates many different kinds of processes."

Comment: The development of any embryo is an engineering project that must follow a designed plan. The secret is in DNA with certain controlling genes. How they really work is totally unknown. How evolution developed it is also totally mysterious. Only a designer mind can do this.