Vernós I, Carratalá M, González-Jurado J, Valverde J R, Calleja M, Domingo A, Vinós J, Cervera M, Marco R
Departamento de Bioquímica de la UAM, Madrid, Spain.
Adv Space Res. 1989;9(11):137-46. doi: 10.1016/0273-1177(89)90068-9.
Gravity and radiation are undoubtedly the two major environmental factors altered in space. Gravity is a weak force, which creates a permanent potential field acting on the mass of biological systems and their cellular components, strongly reduced in space flights. Developmental systems, particularly at very early stages, provide the larger cellular compartments known, where the effects of alterations in the size of the gravity vector on living organisms can be more effectively tested. The insects, one of the more highly evolved classes of animals in which early development occurs in a syncytial embryo, are systems particularly well suited to test these effects and the specific developmental mechanisms affected. Furthermore, they share some basic features such as small size, short life cycles, relatively high radio-resistance, etc. and show a diversity of developmental strategies and tempos advantageous in experiments of this type in space. Drosophila melanogaster, the current biological paradigm to study development, with so much genetic and evolutionary background available, is clearly the reference organism for these studies. The current evidence on the effects of the physical parameters altered in space flights on insect development indicate a surprising correlation between effects seen on the fast developing and relatively small Drosophila embryo and the more slowly developing and large Carausius morosus system. In relation to the issue of the importance of developmental and environmental constraints in biological evolution, still the missing link in current evolutionary thinking, insects and space facilities for long-term experiments could provide useful experimental settings where to critically assess how development and evolution may be interconnected. Finally, it has to be pointed out that since there are experimental data indicating a possible synergism between microgravity and space radiation, possible effects of space radiation should be taken into account in the planning and evaluation of experiments designed to test the potential role of microgravity on biological developmental and evolution.
重力和辐射无疑是太空环境中发生改变的两个主要因素。重力是一种微弱的力，它产生一个作用于生物系统及其细胞成分质量的永久势场，在太空飞行中会大幅减弱。发育系统，尤其是在非常早期的阶段，提供了已知的更大的细胞区室，在其中可以更有效地测试重力矢量大小变化对生物体的影响。昆虫是动物中进化程度较高的类别之一，其早期发育发生在合胞体胚胎中，是特别适合测试这些影响以及受影响的特定发育机制的系统。此外，它们具有一些基本特征，如体型小、生命周期短、相对较高的抗辐射能力等，并且在这种太空实验中展现出多种有利于实验的发育策略和节奏。黑腹果蝇是目前用于研究发育的生物学范例，有大量可用的遗传和进化背景信息，显然是这些研究的参考生物体。目前关于太空飞行中改变的物理参数对昆虫发育影响的证据表明，在快速发育且相对较小的黑腹果蝇胚胎和发育较慢且体型较大的桑蚕系统上观察到的影响之间存在惊人的相关性。关于发育和环境限制在生物进化中的重要性这一问题，仍是当前进化思维中缺失的环节，昆虫和用于长期实验的太空设施可以提供有用的实验环境，用于批判性地评估发育和进化可能如何相互关联。最后，必须指出的是，由于有实验数据表明微重力和太空辐射之间可能存在协同作用，在设计用于测试微重力对生物发育和进化潜在作用的实验的规划和评估中，应考虑太空辐射的可能影响。
