Solari Cristian A, Drescher Knut, Goldstein Raymond E
CONICET, Departamento de Biodiversidad y Biología Experimental (FCEyN), Laboratorio de Biología Comparada de Protistas, Universidad de Buenos Aires, Buenos Aires C1428EHA, ArgentinaDepartment of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, UK.
J Phycol. 2011 Jun;47(3):580-583. doi: 10.1111/j.1529-8817.2011.00983.x. Epub 2011 Apr 25.
Steering their swimming direction toward the light is crucial for the viability of Volvox colonies, the larger members of the volvocine algae. While it is known that this phototactic steering is achieved by a difference in behavior of the flagella on the illuminated and shaded sides, conflicting reports suggest that this asymmetry arises either from a change in beating direction or a change in beating frequency. Here, we report direct observations of the flagellar behavior of various Volvox species with different phyletic origin in response to light intensity changes and thereby resolve this controversy: Volvox barberi W. Shaw from the section Volvox sensu Nozaki (2003) changes the direction of the flagellar beating plane, while species encompassed in the group Eudorina (Volvox carteri F. Stein, Volvox aureus Ehrenb., and Volvox tertius Art. Mey.) decrease the flagellar beating frequency, sometimes down to flagellar arrest.
将游动方向转向光源对于团藻群落（团藻目藻类中较大的成员）的生存能力至关重要。虽然已知这种趋光转向是通过光照面和阴影面鞭毛行为的差异实现的，但相互矛盾的报告表明，这种不对称性要么源于摆动方向的变化，要么源于摆动频率的变化。在这里，我们报告了对不同系统发育起源的各种团藻物种鞭毛行为对光强变化的直接观察结果，从而解决了这一争议：来自团藻属（按照野崎2003年的分类）的巴氏团藻改变了鞭毛摆动平面的方向，而包含在真多藻属（卡特团藻、金藻团藻和第三团藻）中的物种则降低了鞭毛摆动频率，有时甚至导致鞭毛停止摆动。
