Transport of Germ Plasm on Astral Microtubules Directs Germ Cell Development in Drosophila

• Published in: Current biology Vol. 21; no. 6; pp. 439 - 448
• Main Authors: Lerit, Dorothy A., Gavis, Elizabeth R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 22.03.2011; Elsevier Inc
• Subjects: active transport; Animals; Biological Transport; Biological Transport - physiology; Centrosome; Centrosome - metabolism; centrosomes; cortex; DEAD-box RNA Helicases; DEAD-box RNA Helicases - metabolism; Drosophila; Drosophila - embryology; Drosophila Proteins; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Dyneins; Dyneins - metabolism; embryology; genetics; germ cells; Germ Cells - growth & development; germplasm; growth & development; image analysis; Kinesins; Kinesins - metabolism; metabolism; Microscopy, Fluorescence, Multiphoton; microtubules; Microtubules - metabolism; Models, Biological; physiology; proteins; Ribonucleoproteins; Ribonucleoproteins - metabolism; RNA, Messenger; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA-Binding Proteins; RNA-Binding Proteins - genetics
• ISSN: 0960-9822; 1879-0445; 1879-0445
• DOI: 10.1016/j.cub.2011.01.073

In many organisms, germ cells are segregated from the soma through the inheritance of the specialized germ plasm, which contains mRNAs and proteins that specify germ cell fate and promote germline development. Whereas germ plasm assembly has been well characterized, mechanisms mediating germ plasm inheritance are poorly understood. In the Drosophila embryo, germ plasm is anchored to the posterior cortex, and nuclei that migrate into this region give rise to the germ cell progenitors, or pole cells. How the germ plasm interacts with these nuclei for pole cell induction and is selectively incorporated into the forming pole cells is not known. Live imaging of two conserved germ plasm components, nanos mRNA and Vasa protein, revealed that germ plasm segregation is a dynamic process involving active transport of germ plasm RNA-protein complexes coordinated with nuclear migration. We show that centrosomes accompanying posterior nuclei induce release of germ plasm from the cortex and recruit these components by dynein-dependent transport on centrosome-nucleated microtubules. As nuclei divide, continued transport on astral microtubules partitions germ plasm to daughter nuclei, leading to its segregation into pole cells. Disruption of these transport events prevents incorporation of germ plasm into pole cells and impairs germ cell development. Our results indicate that active transport of germ plasm is essential for its inheritance and ensures the production of a discrete population of germ cell progenitors endowed with requisite factors for germline development. Transport on astral microtubules may provide a general mechanism for the segregation of cell fate determinants. [Display omitted] ▸ Centrosomes induce release of germ plasm from the cortex of the Drosophila embryo ▸ Dynein transports germ plasm ribonucleoprotein complexes on astral microtubules ▸ Active transport is essential for germ plasm segregation and germ cell specification