It's another source of variation for scientists to consider. "Researchers have been exploring whether organisms evolve different ways to cope with genetic and environmental variation," said author Scott Rifkin, an assistant professor of biology at UC San Diego. "This study adds random variation to that mix."
Rifkin, who joined the UCSD faculty this fall, completed the study while working at MIT. The paper, co-authored by Arjun Raj, who contributed equally to the work, Erik Andersen and Alexander van Oudenaarden of MIT, is published in the February 18 issue of Nature.
Rifkin and his colleagues looked at the development of the gut in C. elegans. In many, but not all worms with mutations in a gene called skn-1, the gut failed to develop, even when the embryos were genetically identical and incubated together.
"Often when people look at variation in a trait among organisms they try to trace it back to genetic differences or differences in environmental conditions or some combination of the two. In our study there were no such differences, and so we hypothesized that the only other source for the variation could be differences that arose at random during the process of development," Rifkin said.
The mutated gene is the first in a series of several genes that control each other in sequence to determine whether the gut precursors begin to develop into intestinal cells.
In mutant worms, the final gene was either on or off, and that determined whether an embryo developed gut cells or not. But the activity of an intermediate gene varied widely. That's where chance seems to play a role.
Some mutant cells transcribed the gene many times, ultimately creating enough of the protein to activate the final gene. Others made too few transcripts and the final gene stayed off.
DNA winds tightly around proteins, like thread around a spool, and must uncoil for the transcriptional machinery to access a gene.
Some proteins unwind the DNA; others wind it up again. In the mutant worms, the balance shifted to favor the proteins that keep DNA wound. But in some of the worms, the DNA stayed uncoiled long enough to generate sufficient numbers of transcripts to activate the final gene. And so, by chance, those worms developed a gut.
The National Institutes of Health funded this work.
Scott Rifkin | EurekAlert!
Studying mitosis' structure to understand the inside of cancer cells
19.02.2018 | Biophysical Society
Calcium may play a role in the development of Parkinson's disease
19.02.2018 | University of Cambridge
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
19.02.2018 | Information Technology
19.02.2018 | Ecology, The Environment and Conservation
19.02.2018 | Life Sciences