Zebrafish Primordial Germ Cell Migration

Abstract

Similar to many other organisms, zebrafish primordial germ cells (PGCs) are specified at a location distinct from that of gonadal somatic cells. Guided by chemotactic cues, PGCs migrate through embryonic tissues toward the region where the gonad develops. In this process, PGCs employ a bleb-driven amoeboid migration mode, characterized by low adhesion and high actomyosin contractility, a strategy used by other migrating cells, such as leukocytes and certain types of cancer cells. The mechanisms underlying the motility and the directed migration of PGCs should be robust to ensure arrival at the target, thereby contributing to the fertility of the organism. These features make PGCs an excellent model for studying guided single-cell migration in vivo. In this review, we present recent findings regarding the establishment and maintenance of cell polarity that are essential for motility and discuss the mechanisms by which cell polarization and directed migration are controlled by chemical and physical cues.

Proper Balance of Small GTPase rab10 Is Critical for PGC Migration in Zebrafish

“…The transcriptome results revealed that 42 DEGs in WT and M miR-202 PGCs were significantly enriched in cell migration-associated biological processes ( Table 2 ). The motility of PGC requires a decrease of cadherin-mediated tight junction and a proper regulation of myosin-based contractility [ 3 , 23 , 26 ]. However, we found a remarkable elevation in the levels of tight junction-associated genes including cldne , itga9 and styk1b , but a reduction in the levels of myosin, polarity and bleb associated genes including myl7 , tpm4b , rab36 , cmlc1 , panx1a , cavin1a , fgf13b and rab36 in M miR-202 PGCs compared to WT PGCs.…”

“…Primordial germ cells (PGCs), the progenitors of gametes, segregate at early stages of embryonic development [ 1 , 2 ]. Shortly after specification, PGCs become motile and migrate towards the genital ridge where PGCs with somatic gonadal precursors form the gonad and enter gametogenesis to produce sperms or eggs [ 3 , 4 , 5 , 6 , 7 ]. In lower animals such as fruit fly, frog and zebrafish, the specification of PGC is determined by maternal germ plasm, a phase-separated liquid structure containing many specific factors such as coding mRNAs and their proteins ( dnd , vasa and nanos ) [ 8 , 9 , 10 ], long non-coding RNAs ( pgc and xlsirt ) [ 11 , 12 , 13 ], piRNAs [ 14 ], as well as microRNAs ( miR-9c , miR-969 and miR-202-5p ) [ 15 , 16 , 17 ].…”

Matrix topology guides collective cell migration in vivo

“…Cell migration during development occurs via distinct modes broadly classified as single or collective cell migration ( 5 ). Singly migrating cells show the intrinsic ability to move in a certain direction as shown for primordial germ cell migration ( 1 ) or neuronal migration ( 6 ). Collectively migrating cells move as a cohesive group in which they maintain contact with each other to coordinate their movements while they are additionally steered by environmental factors ( 4, 7 ).…”

“…The role of cell intrinsic factors like adherens junctions, cytoskeletal elements, and basal focal adhesions (FA) have been studied in depth and shown to be essential to facilitate cell migration in numerous contexts ( 10, 11 ). Further, cell extrinsic factors like growth factors or guiding chemokines provide directionality for long-range single and collective cell migration ( 1, 9 ).…”

“…Main Text: During organogenesis and in homeostasis, cells often actively move to the location where they later function (1,2). Further, many cancers are worsened when cell migration causes metastasis (3).…”