In the last year the Blair lab made several advances in understanding on the relationship between cell signaling and developmental patterning, using as a model system the wing of the fruitfly, Drosophila melanogaster. The Blair laboratory has been especially concerned with the regulation of four signaling pathways, used widely throughout the animal kingdom. The first is the Bone Morphogenetic Protein (BMP) pathway, the second is the Hedgehog pathway, the third is the Wnt-Wingless pathway, and the fourth is a quite unusual pathway that uses the protocadherin molecules Dachsous and Fat for cell-cell communication.
All of these research areas were initiated by examining the mutations that modify the pattern of veins in the fruitfly wing. The veins are ectodermal struts used for support and as conduits for nutrients, nerves and the trachea. The wing veins develop from selected regions of the wing epithelium. The molecular mechanisms that pattern and position these veins within the developing wing are understood in ever-increasing detail, and thus a careful analysis of mutations that disrupt these patterns can be used to isolate novel players in selected molecular pathways.
Intriguingly, all of the novel regulators we have discovered have vertebrate homologs that play similarly important roles in vertebrate (and presumably human) development. In the last two years, our focus has been on the role of crossveinless loci in the regulation of BMP signaling, Shifted and its vertebrate homolog Wif-1 in the regulation of Hedgehog and Wnt signaling, and the control of growth and planar cell polarity mediated by Fat and Dachsous and their regulation by Approximated. This work is supported by research grants from NIH and NSF, whose funds are used largely for graduate and postdoctoral training.
Dr. Blair is also heavily involved in undergraduate education, especially through the introductory Biology 151/152/153 sequence, the Zoology 523 Neuroscience course, and the Zoology 625 course on the development of the nervous system. Dr. Blair is also the co-chair of Biology 151/152/153, and the Letters and Sciences co-chair of the Biology Major, both of which are going through extensive reorganization.
Zoology 151 - Introductory Biology
Zoology 523 - Neurobiology
Zoology 625 - Development of the Nervous System
Zoology 965 - Seminars in Developmental Biology
Graduate students currently supervised:
Olson ( email@example.com )
Zoology Ph.D. student - The identification
and characterization of detached mutations, and their roles
in crossvein development and BMP signaling in Drosophila.
S. Avanesov ( firstname.lastname@example.org )
Genetics Ph.D. student - Hedgehog signaling and
compartmentalization during wing disc development in the
wing of Drosophila.
Chen ( email@example.com )
Genetics Ph.D. student - The role of cv-2 and cv-d mutants in
BMP signaling in the formation of the crossveins of Drosophila.
Graduate students supervised who earned graduate
Craig Micchelli (Ph.D. Neuroscience Training Program, 1999)
Mechanisms of pattern formation
in the wing imaginal disc of Drosophila : A study of
cell signaling at the dorso-ventral boundary using genetic
Catherine Conley (Ph.D. Zoology, 2000) Abstract
Molecular and genetic analysis of
cross vein patterning in the wing of Drosophila melanogaster.
Amy Ralston (Ph.D. Zoology, 2004) Abstract
The role of signaling pathways in
the specification of veins and lineage boundaries in the
wing of Drosophila .
Catherine A. Miller (Ph.D. CMB, 2004)
shifted , the Drosophila homolog of the
human Wnt inhibitory factor 1, is involved in the Hedgehog
W. Elizabeth Jones (M.S. CMB, 2004)
The cv-d and det loci: mapping and characterization
of genetic interactions with the crossveinless loci cv, cv-2
O'Connor, M.B., Umulis, D., Othmer, H. and Blair, S.S.
(2006). Shaping BMP morphogen gradients in the Drosophila
embryo and pupal wing. Development 133, 183-193
Shimmi, O.*, Ralston, A.*, Blair, S.S., and O'Connor, M.B.
(2005). The crossveinless gene encodes a new member of the
Twisted gastrulation family of BMP binding proteins which,
with Short gastrulation, promotes BMP signaling in the crossveins
of the Drosophila wing. Dev. Biol. 282, 70-83. (*co-first
Serpe, M., Ralston, A., Blair, S.S., and O'Connor, M.B.
(2005). Matching catalytic activity to developmental function:
Tolloid-related processes Sog to help specify the posterior
crossvein in the Drosophila wing. Development 132, 2645-2656.
Ralston, A., and Blair, S.S. (2005). Long-range Dpp signaling
is regulated to restrict BMP signaling to a crossvein competent
zone. Dev. Biol. 280, 187-200.
Blair, S.S. (2005). Cell Signaling: Wingless and Glypicans
together again. Curr. Biol. 15, R92-R94.
Glise, B.*, Miller, C.A.*, Crozatzier, M., Halbisen, M.A.,
Wise, S., Olson, D., Vincent, A., and Blair, S.S. (2005).
Shifted, the Drosophila orthologue of Wnt Inhibitory Factor-1,
controls the distribution and movement of Hedgehog. Dev.
Cell 8, 255-266. (*co-first authors)
Blair, S.S. (2000b). Notch signaling: Fringe really is
a glycosyltransferase (invited Dispatch). Current Biol. 10,
Conley, C.A., Silburn, R., Singer, M.A., Ralston, A., Rohwer-Nutter,
D., Olson, D.J., Gelbart, W. and Blair, S.S. (2000). Crossveinless
2 contains cysteine-rich domains and is required for high
levels of BMP-like activity during the formation of the cross
veins in Drosophila . Development 127, 3947-3959.
Micchelli, C.A. and Blair, S.S. (1999). Dorso-ventral lineage
restriction in wing imaginal discs requires Notch. Nature
Blair, S.S. (1999). Drosophila imaginal disc development:
patterning the adult fly. In Development-Genetics, Epigenetics
and Environmental Regulation , (V.E.A. Russo, D. Cove, L.
Edgar, R. Jaenisch, F. Salamini, eds), Chpt. 21, pp. 347-370.