Transcription factors with fractional g responses. Each dot on the graph shows the normalized gene expression level for the transcription factor in the sixteen microgravity replicates (µg), and the four replicates at 0.53 g, 0.65 g, and 0.88 g. The red line indicates the mean expression level in that gravity level. Shown are three transcription factors with a gravity-level responsive increase in transcription (a) NFYA1, (b) SPL6, and (c) TCP7. (d) HM2 shows a dose-dependent decrease in transcript levels in response to increasing gravity levels. (e) GATA9 and (f) ANAC009 both show a threshold response, where the transcription level is reduced in response to 0.53 g, and reaches a plateau at 0.65 g and 0.88 g.