Cassidy Justin J, Straughan Alexander J, Carthew Richard W
Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208.
Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
Genetics. 2016 Feb;202(2):675-87. doi: 10.1534/genetics.115.183822. Epub 2015 Nov 27.
Genetic variation is prevalent among individuals of the same species and yet the potential effects of genetic variation on developmental outcomes are frequently suppressed. Understanding the mechanisms that are responsible for this suppression is an important goal. Previously, we found that the microRNA miR-9a mitigates the impact of natural genetic variants that promote the development of scutellar bristles in adult Drosophila. Here we find that miR-9a does not affect the impact of genetic variants that inhibit the development of scutellar bristles. We show this using both directional and stabilizing selection in the laboratory. This specificity of action suggests that miR-9a does not interact with all functional classes of developmental genetic variants affecting sensory organ development. We also investigate the impact of miR-9a on a fitness trait, which is adult viability. At elevated physiological temperatures, miR-9a contributes to viability through masking genetic variants that hinder adult viability. We conclude that miR-9a activity in different developmental networks contributes to suppression of natural variants from perturbing development.
遗传变异在同一物种的个体中普遍存在，然而遗传变异对发育结果的潜在影响常常受到抑制。了解造成这种抑制的机制是一个重要目标。此前，我们发现微小RNA miR-9a可减轻促进成年果蝇小盾刚毛发育的自然遗传变异的影响。在此我们发现，miR-9a并不影响抑制小盾刚毛发育的遗传变异的影响。我们通过在实验室中进行定向选择和稳定选择来证明这一点。这种作用的特异性表明，miR-9a并非与影响感觉器官发育的所有功能类别的发育遗传变异相互作用。我们还研究了miR-9a对一种适应性性状（即成年果蝇的生存能力）的影响。在较高的生理温度下，miR-9a通过掩盖阻碍成年果蝇生存能力的遗传变异来促进其生存能力。我们得出结论，miR-9a在不同发育网络中的活性有助于抑制自然变异对发育的干扰。
