Upon their return to Earth, the space flown seedlings from the BRIC-20 experiment will undergo both RNA and proteomic analyses. The two analyses used together will pinpoint the genes involved in plant signaling in microgravity conditions.
Since the genes themselves don’t provide scientists information about the specific biochemical events driving plant signaling, the Wyatt Lab researchers analyze the downstream processes and trace them back to the genes. To understand the metaphor of downstream processes we must refer to Figure 1 which shows how DNA is transcribed into RNA and The resulting RNA is translated into proteins. One of the novel ideas of the Wyatt Lab space experiment is their use of the downstream elements (i.e., RNA and proteins) to pinpoint the DNA controlling gravitropic signaling.
Downstream analysis works by understanding the RNA present in a system, and then reverse transcribing it back to the original DNA. Next, because not all RNA that may be present may be active, the researchers analyze proteins from the same plant to identify what RNA was actually translated into proteins. By linking the proteins that are present to the RNA it was translated from, and then reverse translating RNA to the originating DNA, it is possible to identify what genes are expressed or silenced to control plant signaling responses to microgravity conditions.
Figure 1 – The normal flow of gene expression resulting in proteins.
Post Space Flight Analyses
- Proteomic analysis measures the total proteins present in a sample. Total protein analysis will yield information to help scientists understand early germination and growth events in space. When coupled with RNA transcriptome analysis, Wyatt Lab researchers intend to identify what genes are expressed or silenced when seeds germinate in space in contrast to seeds germinated on Earth under similar light and temperature conditions.
- RNA analysis identifies the RNA transcriptomes present at the time the sample was analysed. Since it is possible that RNA may be present that has not been translated into proteins, RNA analysis is not enough to pinpoint gene expression. Using proteomics and RNA analysis in concert, the researchers should have enough information to contribute a list of genes controlling gravitropic signalling to the foundational microgravity gene network revealing what genes were significantly expressed in comparison to controls.