toutvelu, a regulator of heparan sulfate proteoglycan biosynthesis, controls guidance cues for germ-cell migration.
The primitive embryonic gonad in Drosophila melanogaster is composed of germ cells and somatic gonadal precursor cells (SGPs). The assembly of a functional gonad involves a complex series of germ-cell migration events, which are thought to be guided by attractive and repulsive cues. Here, we demonstrate a novel role for toutvelu (ttv), a regulator of heparan sulfate proteoglycan biosynthesis during this process. Germline clonal analysis suggests that maternal deposition of ttv is required for proper germ-cell migration. Conversely, ectopic expression of ttv in early embryos results in severe germ-cell migration defects and inappropriate spreading of Hh protein. Moreover, overexpression of ttv in only the receiving cells, rather than in the sending cells, leads to phenotypic consequences. Finally, supporting the claim that the signaling molecule Hedgehog (Hh) may function as a chemoattractant to guide germ cells, errant germ cells are found localized near pockets containing high concentrations of Hh protein.
Deshpande
Girish
G
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08540, USA.
Sethi
Nilay
N
Schedl
Paul
P
D000818:Animals; D002465:Cell Movement; D003463:Cues; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D005854:Germ Cells / Q000166:cytology / Q000502:physiology*; D019812:Heparan Sulfate Proteoglycans / Q000096:biosynthesis*; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D010058:Oviposition
D029721:Drosophila Proteins; D019812:Heparan Sulfate Proteoglycans; D008565:Membrane Proteins; C113073:TTV protein, Drosophila