2018年1月8日，PNAS在线发表了题为“Detergent-extracted Volvox model exhibits an anterior–posterior gradient in flagellar Ca²⁺sensitivity ”的文章。

多细胞绿藻团藻在响应光感受过程中，通过改变其鞭毛跳动模式来显示趋光性。然而，鞭毛调控的分子机制尚不清楚。这项研究描述了一种使用非离子去污剂去除整个球体的方法，其中加入ATP重新激活鞭毛运动。这些活化的球体像活球体一样游走。鞭跳动方向以Ca2+依赖的方式改变，前半球的变化大于后半球。这些发现表明，团藻鞭毛对Ca2+的敏感性具有前后梯度，其可能在团藻趋光性中起关键作用。

团藻是一种含有约5,000个细胞的多细胞球状绿藻，每个细胞装备两个鞭毛（纤毛）。这种生物显示出惊人的光行为，没有任何已知的细胞间通讯。为了帮助理解鞭毛的行为是如何调节的，我们开发了一种用洗涤剂提取整个生物体并重新激活其鞭毛运动的方法。加入ATP后，球状体内的脱膜鞭毛活跃地跳动，并且球状体像活着一样游走。在不含Ca2+的条件下，脱膜鞭毛呈现平面和不对称的波形，并向后半球部分跳动，在没有光刺激的情况下，活球也是如此。然而，在10−6 M Ca2+的存在下，大多数脱膜鞭毛三维地向前半球跳动，类似于光刺激的活球体中的鞭毛。这种Ca2+依赖性的鞭毛方向变化在小球前极附近更明显，但在后极附近没有观察到。这种鞭毛对Ca2+敏感性的前后梯度，可以解释团藻光行为的机制。

Volvox rousseletii is a multicellular spheroidal green alga containing ～5,000 cells, each equipped with two flagella (cilia). This organism shows striking photobehavior without any known intercellular communication. To help understand how the behavior of flagella is regulated, we developed a method to extract the whole organism with detergent and reactivate its flagellar motility. Upon addition of ATP, demembranated flagella (axonemes) in the spheroids actively beat and the spheroids swam as if they were alive. Under Ca2+-free conditions, the axonemes assumed planar and asymmetrical waveforms and beat toward the posterior pole, as do live spheroids in the absence of light stimulation. In the presence of 10−6 M Ca2+, however, most axonemes beat three-dimensionally toward the anterior pole, similar to flagella in photostimulated live spheroids. This Ca2+-dependent change in flagellar beating direction was more conspicuous near the anterior pole of the spheroid, but was not observed near the posterior pole. This anterior–posterior gradient of flagellar Ca2+sensitivity may explain the mechanism of V. rousseletii photobehavior.