The active migration of Drosophila primordial germ cells

Abstract

We describe our analysis of primordial germ cell migration in Drosophila wild-type and mutant embryos using high resolution microscopy and primary culture in vitro. During migratory events the germ cells form transient interactions with each other and surrounding somatic cells. Both in vivo and in vitro they extend pseudopodia and the accompanying changes in the cytoskeleton suggest that actin polymerization drives these movements. These cellular events occur from the end of the blastoderm stage and are regulated by environmental cues. We show that the vital transepithelial migration allowing exit from the gut primordium and passage into the interior of the embryo is facilitated by changes in the structure of this epithelium. Migrating germ cells extend processes in different directions. This phenomenon also occurs in primary culture where the cells move in an unoriented fashion at substratum concentration-dependent rates. In vivo this migration is oriented leading germ cells to the gonadal mesoderm. We suggest that this guidance involves stabilization of states of an intrinsic cellular oscillator resulting in cell polarization and oriented movement.

A Clockwork Bleb: cytoskeleton, calcium, and cytoplasmic fluidity

“…Amoeboid migration is observed not only in pathological condition but also in normal development. For example, primordial germ cells (PGCs) of drosophila [22] and zebrafish [23] utilize bleb for cell migration. In addition, slime mold (Dictyostelium) also uses bleb during chemotaxis [24,25].…”

DLC3/Cv-c function in testis development in humans and Drosophila: implication for variants of sex development

“…Analysis of fixed mutant testes shows that the extruded germ cells extend blebs that are more characteristic of the earlier migratory phase (Fig. 3 I to J arrowheads) (Jaglarz & Howard, 1995). These blebs are not observed in the ovaries of cv-c mutant females (Supplementary Fig.…”

“…However, when subjected to ectopic signals, germ cells continue to show protrusions and migrating behavior without a clear polarization (Kardash et al ., 2010; Richardson & Lehmann, 2010). The PGCs’ close association with the SGPs end the migratory phase, the last PGCs divisions are detected prior to compaction completion and the germ cells stop extending protrusions entering an “inactive” phase (Jaglarz & Howard, 1995).…”

A conserved function of Human DLC3 and Drosophila Cv-c in testis development

“…However, after this stage the germ cells become extruded from the testis ( Videos 2 and 3 ). Analysis of fixed mutant testes shows that the extruded germ cells extend blebs that are more characteristic of the earlier migratory phase ( Figure 3I , arrowheads and J; Figure 3—source data 1 ; Jaglarz and Howard, 1995 ). These blebs are not observed in the ovaries of cv-c mutant females ( Figure 3—figure supplement 1B ) nor in the wild-type testis after gonad compaction ( Figure 3H, J ).…”

“…However, when subjected to ectopic signals, germ cells continue to show protrusions and migrating behaviour without a clear polarization ( Kardash et al, 2010 ; Richardson and Lehmann, 2010 ). The PGCs’ close association with the SGPs end the migratory phase, the last PGCs divisions are detected prior to compaction completion and the germ cells stop extending protrusions entering an ‘inactive’ phase ( Jaglarz and Howard, 1995 ).…”