Spawning Induction and Embryo Micromanipulation Protocols in the Amphioxus Branchiostoma lanceolatum.

In the last decades, the cephalochordate amphioxus has reached a peculiar place in research laboratories as an excellent animal model to answer Evo/Devo questions. Nevertheless, mainly due to its restricted spawning season and to the small size of its embryos, only a few basic techniques in developmental biology could be used until recently. Fortunately, these last years, and thanks to the development of high-throughput techniques, new technical approaches have been possible, such as comparative transcriptomics and/or genomics. However, classic micromanipulation techniques are still difficult to apply. Here we present simple protocols for the manipulation of amphioxus embryos. First, we present the spawning induction method used with the European amphioxus species Branchiostoma lanceolatum. Second, we explain simple methods to manipulate the developing amphioxus embryo during the first steps of its development (before the hatching stage). These methods open many technical possibilities for future functional studies. Thus, we present here a simple technique to efficiently dechorionate a large number of embryos, we detail a protocol for the dissociation of cells during the first steps of the embryonic development and, finally, we describe micromanipulation approaches for tissue isolation during the gastrula stage.