Humphreys Tom, Sasaki Akane, Uenishi Gene, Taparra Kekoa, Arimoto Asuka, Tagawa Kuni
Pacific Biomedical Research Center, University of Hawaii at Manoa, HI 96822, USA.
Zoolog Sci. 2010 Feb;27(2):91-5. doi: 10.2108/zsj.27.91.
When the body of P. flava is severed, the animal has the ability to regenerate its missing anterior or posterior as appropriate. We have focused on anterior regeneration when the head and branchial regions are severed from the body of the worm. After transection, the body wall contracts and heals closed in 2 to 3 days. By the third day a small blastema is evident at the point of closure. The blastema grows rapidly and begins the process of differentiating into a head with a proboscis and collar. At 5 days the blastema has increased greatly in size and differentiated into a central bulb, the forming proboscis, and two lateral crescents, the forming collar. Between 5 and 7 days a mouth opens ventral to the differentiating blastema. Over the next few days the lateral crescents extend to encircle the proboscis and mouth, making a fully formed collar. By 10 to 12 days a new head, sized to fit the worm's body, has grown attached to the severed site. At about this time the animal regains apparently normal burrowing behavior. After the head is formed, a second blastema-like area appears between the new head and the old body and a new branchial region is inserted by regeneration from this blastema over the next 2 to 3 weeks. The regenerating tissues are unpigmented and whitish such that in-situ hybridization can be used to study the expression of genes during the formation of new tissues.
当黄平角涡虫的身体被切断时，该动物能够根据情况再生其缺失的前部或后部。当头部和鳃区从虫体切断后，我们重点研究前部再生。横切后，体壁收缩并在2至3天内愈合。到第三天，在愈合处可见一个小的芽基。芽基迅速生长并开始分化成带有吻部和领部的头部。在第5天，芽基大小显著增加，并分化成一个中央球、正在形成的吻部和两个侧月牙，即正在形成的领部。在5至7天之间，在分化的芽基腹侧开口形成口。在接下来的几天里，侧月牙延伸以环绕吻部和口，形成一个完整的领部。到10至12天，一个大小适合虫体的新头部生长并附着在切断部位。大约在这个时候，动物恢复明显正常的钻洞行为。头部形成后，在新头部和旧身体之间出现第二个类似芽基的区域，在接下来的2至3周内，通过这个芽基再生插入一个新的鳃区。再生组织无色素且呈白色，因此原位杂交可用于研究新组织形成过程中基因的表达。
