Cells in simulated microgravity undergo a reversible morphology switch, causing the appearance of two distinct phenotypes. Despite the dramatic splitting into an adherent-fusiform and a floating-spherical population, when looking at the gene-expression phase space, cell transition ends up in a largely invariant gene transcription profile characterized by only mild modifications in the respective Pearson’s correlation coefficients. Functional changes among the different phenotypes emerging in simulated microgravity using random positioning machine are adaptive modifications—as cells promptly recover their native phenotype when placed again into normal gravity—and do not alter the internal gene coherence. However, biophysical constraints are required to drive phenotypic commitment in an appropriate way, compatible with physiological requirements, given that absence of gravity foster cells to oscillate between different attractor states, thus preventing them to acquire a exclusive phenotype. This is a proof-of-concept of the adaptive properties of gene-expression networks supporting very different phenotypes by coordinated ‘profile preserving’ modifications.

模拟微重力中的细胞经历可逆的形态转换，导致出现两种不同的表型。尽管细胞分裂成粘附梭形和浮动球形群体，但当观察基因表达相空间时，细胞转变最终导致基本不变的基因转录谱，其特征在于各自的皮尔逊相关系数仅发生轻微修改。使用随机定位机模拟微重力中出现的不同表型之间的功能变化是适应性修改——因为细胞在再次置于正常重力中时会迅速恢复其天然表型——并且不会改变内部基因的一致性。然而，考虑到重力的缺乏会促进细胞在不同吸引子状态之间振荡，从而阻止它们获得独特的表型，因此需要生物物理限制以适当的方式驱动表型承诺，并与生理要求兼容。这是基因表达网络的适应性特性的概念验证，通过协调的“轮廓保留”修改来支持非常不同的表型。