Center for Integrated Medical Research, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan.
Department of Business Communication, Shiga Junior College, Otsu, Shiga 520-0803, Japan.
Zoolog Sci. 2021 Dec;38(6):544-557. doi: 10.2108/zs210029.
Sexually mature planarians produce sex-inducing substances that induce postembryonic development of hermaphroditic reproductive organs in asexual freshwater planarians. Although the sex-inducing substances may be useful for elucidating the mechanism underlying this reproductive switch, the available information is limited. The potency of sex-inducing activity is conserved, at least at the order level. Recently, we showed that the sex-inducing activity in the land planarian was much higher than that in freshwater planarians. In the present study, we performed bioassay-guided fractionation of the sex-inducing substances produced by and propose that crucial sex-inducing activity that triggers complete sexualization for asexual worms of the freshwater planarian is produced by additive and/or synergetic effects of various sex-inducing substances involved in ovarian development. The current study provided an isolation scheme for the minimum-required combination of sex-inducing substances for producing crucial sex-inducing activity.
性成熟涡虫产生诱导物质，诱导无性淡水涡虫的胚胎后发育为两性生殖器官。虽然这些诱导物质可能有助于阐明这种生殖转变的机制，但目前的信息有限。诱导活性的效力至少在目级是保守的。最近，我们表明，陆地涡虫的诱导活性远远高于淡水涡虫。在本研究中，我们对产生的诱导物质进行了基于生物测定的分级分离，并提出触发无性淡水涡虫完全性化的关键诱导活性是由参与卵巢发育的各种诱导物质的累加和/或协同作用产生的。本研究为产生关键诱导活性所需的诱导物质的最小组合提供了一种分离方案。
