Characterization of two novel lipocalins expressed in the Drosophila embryonic nervous system

Citation
D. Sanchez et al., Characterization of two novel lipocalins expressed in the Drosophila embryonic nervous system, INT J DEV B, 44(4), 2000, pp. 349-359
Citations number
41
Categorie Soggetti
Cell & Developmental Biology
Journal title
INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY
ISSN journal
02146282 → ACNP
Volume
44
Issue
4
Year of publication
2000
Pages
349 - 359
Database
ISI
SICI code
0214-6282(200006)44:4<349:COTNLE>2.0.ZU;2-O
Abstract
We have found two novel lipocalins in the fruit fly Drosophila melanogaster that are homologous to the grasshopper Lazarillo, a singular lipocalin wit hin this protein family which functions in axon guidance during nervous sys tem development. Sequence analysis suggests that the two Drosophila protein s are secreted and possess peptide regions unique in the lipocalin family. The mRNAs of DNLaz (for Drosophila neural Lazarillo) and DGLaz (for Drosoph ila glial Lazarillo) are expressed with different temporal patterns during embryogenesis. They show low levels of larval expression and are highly exp ressed in pupa and adult flies. DNLaz mRNA is transcribed in a subset of ne urons and neuronal precursors in the embryonic CNS. DGLaz mRNA is found in a subset of glial cells of the CNS: the longitudinal glia and the medial ce ll body glia. Both lipocalins are also expressed outside the nervous system in the developing gut, fat body and amnioserosa. The DNLaz protein is dete cted in a subset of axons in the developing CNS. Treatment with a secretion blocker enhances the antibody labeling, indicating the DNLaz secreted natu re. These findings make the embryonic nervous system expression of lipocali ns a feature more widespread than previously thought. We propose that DNLaz and DGLaz may have a role in axonal outgrowth and pathfinding, although ot her putative functions are also discussed.