Nhu Tran
Genetic variation in a phenotype can be due to a single gene or a combination of genes. It is the single alleles, not the genetic interactions per se, that are heritable from parents to offspring. The latter can result in a fraction that does not either fuel the natural selection or enable artifical selection. In broad term, my project questions (1) the heritable and non-heritable components of varation in phenotype, transcriptome, and methylome in Arabidopsis lyrata model; and (2) how the genetic variation in transcription and methylation are linked to that in phenotype. To this end, we hope this knowledge can contribute to leveraging future conservation efforts and breeding strategies.
Simplistic example of the causes behind heritable and non-heritable fractions of genetic variation. A “good“ phenotype can be because the individual has a “good“ gene (blue gene; Panel A), or a “good“ combination of genes (blue, orange, black genes; Panel B).
A: Offspring that receive this good gene will be able to express the same “good“ phenotype (big leaf size). Dark blue allele results in a higher copy number of transcript compared to light blue allele. The variation in transcript copy number of this gene can result in changes in the phenotype of interest (smaller leaf size).
B: Assuming that the presented combination is required for the expression of this “good“ phenotype. As alleles are reshuffled during the transmission from parents to offspring, the combination at each loci (light blue and dark blue; light orange and dark orange) may be different. The “good“ phenotype cannot be inherited if the exact combination is not passed on.
C: The same idea is applied for transcriptional variation. For example, the transcript copy number (wiggly lines) can be due to a single regulator, so that changes in that single regulator (blue circle to blue triangle) would result in a different transcript level. In the last scenario, transcription are controlled by a combination of regulators. The two regulators (yellow diamond and blue circle) must appear with each other to have that exact copy number of transcript.
Schematic representation of the main project aim. We use systems biology approach to link variation in phenotype, transcriptome, and methylome. There can be many intricate ways that changes in phenotype (plant figure), transcription (wiggly lines) and methylation (DNA symbol) can be related to each other.
