Evolutionary Developmental Biology
Ph.D. 1997 Edinburgh University
Post doctoral work (1997-98) Harvard University
Post doctoral work (1999-2001) Leiden University
Assistant Professor (2001) University at Buffalo
Antónia Monteiro
Department of Biological Sciences
107 Dorsheimer
State University of New York at Buffalo
Buffalo, NY 14260
(716) 645-2363 ext: 135
To send e-mail: monteiro@acsu.buffalo.edu
I seek to understand the evolution and development of butterfly wing patterns. My research combines population genetics, phylogenetics, and developmental biology so as to understand the nature of the variation underlying developmental mechanisms and how this variation is distributed among groups of closely related species. My model organisms are African satyrid butterflies in the genus Bicyclus.
Work in my lab will address the general question of how variation at the DNA level in developmental genes determines wing pattern variation. We will be testing the causal involvement of transcription factors that are expressed in the wing discs at critical stages of development, in areas that correlate with the adult color pattern. We will also try to generate transgenic Bicyclus with GFP and PiggyBac transposable elements. Subsequently, we will seek to detect the regulatory regions of the candidate transcription factors that drive their expression in the wing using transgenic Lac-Z constructs. These regulatory regions will then be sequenced across selection lines and closely related species with a known phylogenetic history in order to understand how the evolution of wing pattern development has occurred.
A hypothetical developmental model of patterning butterflies wings
The coloured symmetry systems of
the Nymphalid Ground Plan1 may be set up by the
redeployment of regulatory genes involved in vein patterning and
overall wing growth, now hardwired through cis-regulatory
evolution to pigment production pathways. My hypothesis
incorporates recent work on Drosophila vein patterning 2;
homologues of Drosophila genes already identified in
butterflies are indicated in the figure. A) The
anterior-posterior (AP) boundary (set up very early in
embryogenesis) is thought to be the initial source of patterning
signals that through several steps subdivide the butterfly wing
at the wing disc stage into separate genetic compartments along
the AP axis (B). At the same time (C) long range patterning
morphogens such as wingless may be important in
subdividing the wing into separate genetic compartments along the
proximal-distal (PD) axis (D). Together, these two types of
regional regulatory genes may be involved in positioning the
longitudinal and cross veins in the butterfly wing (as they do in
Drosophila 2), which differentiate at
boundaries of gene expression. E) Vein markers, such as the
putative butterfly homologue to the Drosophila gene, rhomboid
(in red), may become expressed at such boundaries and define the
future position of the veins. F) In turn, several other genes may
be turned on in and around the ‘future’ vein tissue.
These regulatory cascades, which may involve signaling from the
presumptive veins and wing margin, and lateral inhibition
processes, are repeated in each wing cell. G) In eyespot bearing
species, a central group of cells differentiates in the late
larval wing disc, that during the pupal stage will be involved in
eyespot signaling. H) Complex gene regulatory cascades are
probably involved in patterning each wing cell and in specifying
eyespot foci. Evidence for this complexity is seen in the great
diversity of regulatory gene expression patterns in late larval
wing disc of P. coenia and B. anynana 3,
4, 5. I propose that this patterning mechanism is modified
in each wing cell by the different genetic backgrounds that were
important in setting up the position of the veins (represented by
the different shades of red and green in E). The interaction
between the genes in (H) and the genes in (E) allows the
evolution and "uncoupling" of pattern within a row of
serially homologous elements such as the eyespots. The bands of
the central and basal symmetry systems may be determined by : I)
Pre-pattern genes responding in a threshold-like fashion to
gradients established from the wing margin; J) Boundaries of gene
expression established by genes patterning the PD axis (D) and
defining a row of cells that later become signalling centres for
the bands or; K) genes patterning the AP axis (B) that interact
with the PD axis patterning genes (in C or D), and make pieces of
the band "foci" dislocate when crossing a longitudinal
vein boundary. The genes/gene products are abbreviated as
follows: Ci, cubitus interruptus; Ci, distal-less;
Dll, decapentaplegic; Dpp, engrailed or invected;
En, hedgehog, Hh, patched; Ptc, spalt;
Sal, and wingless, Wg.
1 Nijhout, H.F. (1991) The Development and Evolution of
Butterfly Wing Patterns, Smithsonian Institution Press
2 Biehs, B., Sturtevant, M.A. and Bier, E. (1998) Development
125, 4245-4257
3 Carroll, S.B. et al. (1994) Science 265, 109-114
4 Brakefield, P.M. et al. (1996) Nature 384, 236-242
5 Keys, D.N. et al. (1999) Science 283, 532-534
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