Molecular Mechanisms Controlling Guided Germ Cell Migration in Zebrafish

摘要: During zebrafish embryonic development, primordial germ cells (PGCs) migrate through the developing embryo towards gonad, where they will differentiate into sperm and egg. their migration, these are guided by chemokine CXCL12a its receptor CXCR4b. Dynamic cxcl12a expression lays out a chemotactic path, remain in immediate proximity to secreting chemokine. This implies that protein level is highest at site of mRNA expression, yet little known about molecular mechanisms controlling distribution this chemoattractant vivo. work demonstrates activity second receptor, CXCR7, crucial for proper migration PGCs toward targets. It shown CXCR7 expressed somatic environment rather than within migrating PGCs. Upon loss function, exhibit phenotype signifies defects gradient formation, as fail polarize effectively Indeed, expressing show enhanced internalization suggesting acts decoy CXCL12a; thus, allowing dynamic changes transcription be mirrored similar dynamics level. In addition guidance CXCL12a, paralog CXCL12 termed CXCL12b during development. not required cell gonads, but capable attracting Although being time ignored long present. sets identify mechanism employ between very ligands identified an amino acid 30 s loop chemokines responsible differential activity. To end, recombinant production established structure, binding vivo, glycosaminoglycan vitro investigated. experiments still progress, it appears single controls activation, whereas glycosaminoglycans affected.