Using migrating cells as probes to illuminate features in live embryonic tissues

Abstract

The biophysical and biochemical properties of live tissues are important in the context of development and disease. Methods for evaluating these properties typically involve destroying the tissue or require specialized technology and complicated analyses. Here, we present a novel, noninvasive methodology for determining the spatial distribution of tissue features within embryos, making use of nondirectionally migrating cells and software we termed “Landscape,” which performs automatized high-throughput three-dimensional image registration. Using the live migrating cells as bioprobes, we identified structures within the zebrafish embryo that affect the distribution of the cells and studied one such structure constituting a physical barrier, which, in turn, influences amoeboid cell polarity. Overall, this work provides a unique approach for detecting tissue properties without interfering with animal’s development. In addition, Landscape allows for integrating data from multiple samples, providing detailed and reliable quantitative evaluation of variable biological phenotypes in different organisms.

Primordial germ cells adjust their protrusion type while migrating in different tissue contextsin vivo

“…We have previously shown that migrating PGCs are extremely robust with respect to their ability to invade and migrate within a wide range of tissues in the developing embryo, allowing all the PGCs to arrive at their target (Gross-Thebing et al, 2020; Weidinger et al, 1999). Here, we found that when located in different environments, PGCs change the types of protrusions they produce, while maintaining their migration speed and track straightness.…”

“…Then, the RNAscope procedure was performed as in (Gross-Thebing et al, 2014). The same probes as in (Gross-Thebing et al, 2020) were used (Biotechne, Minneapolis, MN, USA): sox2 (catalog no. 494861-C3) and tp63 (catalog no.…”

“…The migration of zebrafish PGCs is guided by the chemokine Cxcl12a, which binds the receptor Cxcr4b (Doitsidou et al, 2002). Interestingly, in the absence of the guidance cue or its receptor, the PGCs remain motile and migrate non-directionally within the whole embryo (Doitsidou et al, 2002; Gross-Thebing et al, 2020).…”

Zebrafish Primordial Germ Cell Migration

“…As in several other vertebrates, such as mice ( Molyneaux, 2003 ) and chickens ( Stebler et al, 2004 ), PGC migration in zebrafish is guided by the chemokine Cxcl12a, which binds its receptor Cxcr4b on the cell surface ( Doitsidou et al, 2002 ; Knaut et al, 2003 ; Molyneaux, 2003 ). Yet, polarized bleb formation and cell motility can occur also without chemokine signaling, and thus represent a primary behavioral feature of PGCs ( Doitsidou et al, 2002 ; Gross-Thebing et al, 2020 ). Nevertheless, migrating PGCs do depend on Cxcl12a provided by cells located along the migration path to arrive at their specific intermediate and final targets ( Doitsidou et al, 2002 ; Boldajipour et al, 2008 ).…”

“…Migrating cells physically interact with a broad range of tissues, extracellular matrix and other features in their environment during normal development and homeostasis [e.g., leukocytes and neural crest cells ( Shellard and Mayor, 2019 ; Kameritsch and Renkawitz, 2020 )], as well as in pathological conditions [e.g., cancer metastasis and inflammation ( de Oliveira et al, 2016 ; Novikov et al, 2021 )]. As zebrafish PGCs can migrate practically all over the embryo, especially in the absence of the guidance cue ( Doitsidou et al, 2002 ; Gross-Thebing et al, 2020 ), they provide an excellent model for analyzing the behavior of migrating cells in different tissue contexts.…”