First published online June 16, 2005
Journal of Experimental Biology 208, 2497-2502 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01664
Laminin and the malaria parasite's journey through the mosquito midgut
Romanico B. G. Arrighi1,*,
Gareth Lycett1,2,*,
Vassiliki Mahairaki1,3,
Inga Siden-Kiamos1 and
Christos Louis1,3,
1 Institute of Molecular Biology and Biotechnology, Foundation for Research
and Technology Hellas, Vassilika Vouton, PO Box 1527, 71110 Heraklion,
Crete, Greece
2 European Molecular Biology Laboratory, Meyerhofstr. 1, 69000 Heidelberg,
Germany
3 Department of Biology, University of Crete, 71110 Heraklion, Crete,
Greece

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Fig. 1. Association of laminin and developing Plasmodium berghei in the
mosquito midgut. Mosquitoes were given a blood meal containing P.
berghei parasites. At different time points, the midguts were dissected
and immunostained using the antibodies described in detail in Materials and
methods. (A,B) A parasite is seen reaching the basal lamina 2024 h
after blood feeding. Green, SOAP protein; red, laminin; insets in B show
details of the parasite staining showing only the red or green colour channel.
Scale bars: 2 mm in A, 1 mm in B. (C) A young oocyst localized close to the
muscle layer surrounding the midgut 3 days after the blood meal; green, P28
protein; red, laminin. Insets in C: details of the parasite staining showing
only the red or green colour channel. Scale bar: 10 mm. (D) 10 days after the
blood meal laminin (green) is seen concentrated around the larger oocyst. Bar:
10 mm. (E) 15 days after blood feeding, a thin coat of laminin (green) is seen
on a mature oocyst protruding through the muscle layer shortly before
rupturing. Scale bar: 10 mm. (F) A midgut 15 days after the blood meal.
Individual sporozoites can be seen (green: CSP) along the muscles (red:
laminin) while an almost mature oocyst is seen on the right; blue T-PRO
stained nuclei of immature oocysts or epithelial cells. Scale bar: 100 mm. (G)
Higher magnification of the midgut shown in F. Individual sporozoites can be
seen (green: CSP) along the muscles (red: laminin). Scale bar: 10 mm.
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Fig. 2. (A) Schematic representation of the Anopheles gambiae LANB2 gene.
The coding area is represented by boxes corresponding to the domains of the
protein (grey: domain V, containing EGF repeats and shown previously to
interact with P25 and P28). The black line indicates non-coding segments,
while the small map below shows the extent of the segment used to obtain the
dsRNA used in the experiments spanning the nucleotides indicated. (B) Effects
of dsRNA injections. The bars indicate the mean number of oocysts found in the
midguts of mosquitoes that had previously been injected with dsRNA directed
against the GFP gene as a control (a) or the LANB2 gene (b).
Error bars represent standard error of the mean (N=85 and
N=79, respectively). The asterisk indicates a significant difference
in oocyst burden (P<0.0001). See Results for details. (C)
Estimates of the LANB2 gene mRNA copy number expressed in percent of
the S7 gene mRNA copies after injection of dsRNA determined by
quantitative real-time PCR. a, sugar-fed mosquitoes injected with dsRNA
against GFP; b, sugar-fed mosquitoes injected with dsRNA against
LANB2; c, blood-fed mosquitoes injected with dsRNA against
GFP; d, bloodfed mosquitoes injected with dsRNA against
LANB2. Error bars represent the standard error of the mean
(N=3). See Materials and methods for experimental details.
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Fig. 3. LANB2 mRNA accumulation in the midgut. Semi-quantitative PCR was
performed to determine LANB2 mRNA accumulation in isolated midguts
(Lam) using S7 mRNA as a standard (S7). 1, sugarfed
mosquitoes injected with dsRNA against GFP; 2, sugar-fed mosquitoes injected
with dsRNA against LANB2; 3, blood-fed mosquitoes injected with dsRNA
against GFP; 4, blood-fed mosquitoes injected with dsRNA against
LANB2. See Materials and methods for experimental details.
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© The Company of Biologists Ltd 2005