Invention sharing is the mother of developmental biology.

Abstract

Here we release Part 2 of this special issue, following Part 1 in October. In the preface of Part 1, we proposed the title “Invention sharing is the mother of developmental biology” as a novel adage in place of the classic one by Jonathan Swift, "Necessity is the mother of invention", to promote the formation of research platforms for comparative evolutionary developmental biology (Ogino et al., 2021). To further convince researchers of this title, Part 2 releases two method articles and two protocols as follows. Yamanaka et al. (2022) established culture and microinjection methods for embryos of false clownfish, one of the most popular anemonefish, and demonstrated the effectiveness of RNA injection into the yolk sac as a convenient misexpression tool. These methods are expected to open the way for reverse genetics in this and related anemonefish species, and may reveal the molecular mechanisms of sex change and brilliant color pattern formation. Tagami et al. (2022) showed that RNA interference (RNAi) effectively suppresses zygotic β-catenin activity after the mid-blastula transition (MBT) in the Xenopus embryo. In contrast with other model animals, the RNAi technique had not been successfully applied in Xenopus due to the lack of an essential component of the RISC complex, Argonaute2 (Ago2), at stages earlier than the MBT. However, this study revives it as a tool for gene knock-down in later stages. Tokanai et al. (2022) provide an easy and rapid staining protocol for confocal microscopic observation and reconstruction of three-dimensional images of echinoderm (sea lily, sea urchin, and sand dollar) larvae and juveniles. This protocol uses Nile blue and benzyl alcohol/benzyl benzoate (BABB) to obtain strong and stable fluorescent staining signals and clear opaque backgrounds, which could be applicable to other organisms with untransparent tissues. Hiraga et al. (2022) provide a high-throughput screening protocol for CRISPR/Cas9-mediated genome editing in a nematode Pristionchus pacificus. The use of co-injection markers that induce a certain “roller” phenotype and fluorescent protein expression allow researchers to perform quick visual screening of desired mutants and comparative studies with Caenorhabditis elegans. We hope the above articles convince the readers that sharing methods and protocols among researchers using different organisms would move science forward by inspiring new ambitious ideas and exciting collaborations.