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The molecular approach in malaria entomology
Symposium
88
C-11. Anopheles
s-Cll-1
(C) I Parasitology
International
47 (Suppl.)
(1998)
71-95
and Malaria One Centruy Later
BLACK SPORE FORMATION IN PLASMODIUM INFECTED MOSQUITOES: FROM ROSS TO PRESENT
S_c’I I-3
THE MOLECULARAPPROACH IN MALARIAENfOMOLQGY
Laboratoire de Biochimie et Biologie Moleculaire des Insectes, Institut Pasteur, 25 rue du Dr Roux 75724 Paris Cedex 15 Franca. On 3 January 1998 Major Ronold Ross addressed a letter to Alphonse Laveran concerning his discoveries on the various stages of the sporogonic cycle of Plasmodium. In his letter, Ross contemk mar me ‘brhct spores “are Ihubea’rde ion~rboRedrbr resista,TZ spwrc ,-f P&az5t&ar. Latera &zig,-e& r&l; Z&r interpretation and considered the “black spores” as a degenerative form of the parasite. One hundred years later we know that Laveran was correct and that black spores are not spores, bul .Wmnw~~am DDkh%5 DT Dmp2.F 2tm2 have beer2 disrurced rfte mosquiro ‘s home as@sis and have been subiecced to melanotic encapsulation. We know today that such melanotic encapsulation is regulated by the prophenoloxidase cascade, a serine proteinase cascade often considered analogous to the alternative complement pathway. Melanotic encapsulation is highly efficient for parasite sequestration and thus arrests in most cases parasite development. However, the mechanisms regulating its activation/non activation upon parasite entry remain unknown. It is thought that if we could genetically manipulate the mosquito in a way to provoke melanotic encapsulation we could @taps have a means oE cantcolling Plasmodium transmission in mosquitoes.
ANOPHELISM WITHOUT MALARIA ONE
s-Cl14 Besansky
CENTURY
LATER
NJ
A NOPHELES STEPHENSI, A VECTOR MOSQUITO OF MALARA TRANSMfSSION, TAKES THE SALWA INTO THE M tDGUT DURING BLOOD FEEDING
Thee mys"er_~'r&niab me d~sence D% ma'la+ia from regions of Europe that were densely popul&,sz& u:l'*y, ai;s_$&i'>~,+~ -'*a5s-;,.5-s& .+_.:A<;yL the dwnonstrarion I"aI "XI, macul>~e,wis" d72T>ere,qr>a> 1 9' consisf& 05 ,rr,@ic srzplri.93 From that time involved in transmission. forward, this pattern has been encountered ._^^C^_^ $xli;cl;3a'iIiIa'isrla VIzLiv172. with ~Ixwxst i;i‘i Where postmating isolating mechanisms exist, crossing experiment.9 have play& a17 important role in sibling species identtfication. Currversc1y, the pro&icZiorr of fertile f'l and hackcrass pr0gen.y in Eb.e laboraatory &es r>e< c~fi~t~t~te s'xon~ evidence of a single taxonomlc unit, because these experiments fail to account for premating isolating mechanisms operating in Thus, the problem of natural populations. sibling species identification has entaiPed the search for diagnostic differences at the The first cytological and molecular level. approaches to be developed included analyses of chromosomal banding patterns and geneMore recently, DNA-based enzyme systems. approaches have been developed that target the rDNA or other genes as well as anonymous The powers and pitfalls repeated sequences. of the practical application of these methods will be reviewed, as ~111 their overall contribution to the study of the evolutionary and population biology of slbllng species.
Before and after blood feeding, the volume of t5%r+.z%Y&~$xX!&& k%@i&s s%@rW& % extremely reduces. To observe the saliva consumption, we collected An. stephensi before feeding, during probing, on taking bbod, and after the &to& fee&g. Sampi’es of ihe sativary glands were run on the SDS-PAGE gel and stained with silver. Several proteins, whose molecular size were 33, 35,40,45 and 70kDa, depleted after the b&d feeding. Proteins in ihe salivary glands were consumed when mosquitoes were probing on mouse, and even when mosquitoes were taking blood into the midgut. Our result suggests that mosquitoes use different proteins on probing for vessels and taking blood. Moreover, in prediuresis of An. stephensi infected with Plasmodium berghei, we found sporozoites which should come from the salivary gland of the mosquito.
88
C-11. Anopheles
s-Cll-1
(C) I Parasitology
International
47 (Suppl.)
(1998)
71-95
and Malaria One Centruy Later
BLACK SPORE FORMATION IN PLASMODIUM INFECTED MOSQUITOES: FROM ROSS TO PRESENT
S_c’I I-3
THE MOLECULARAPPROACH IN MALARIAENfOMOLQGY
Laboratoire de Biochimie et Biologie Moleculaire des Insectes, Institut Pasteur, 25 rue du Dr Roux 75724 Paris Cedex 15 Franca. On 3 January 1998 Major Ronold Ross addressed a letter to Alphonse Laveran concerning his discoveries on the various stages of the sporogonic cycle of Plasmodium. In his letter, Ross contemk mar me ‘brhct spores “are Ihubea’rde ion~rboRedrbr resista,TZ spwrc ,-f P&az5t&ar. Latera &zig,-e& r&l; Z&r interpretation and considered the “black spores” as a degenerative form of the parasite. One hundred years later we know that Laveran was correct and that black spores are not spores, bul .Wmnw~~am DDkh%5 DT Dmp2.F 2tm2 have beer2 disrurced rfte mosquiro ‘s home as@sis and have been subiecced to melanotic encapsulation. We know today that such melanotic encapsulation is regulated by the prophenoloxidase cascade, a serine proteinase cascade often considered analogous to the alternative complement pathway. Melanotic encapsulation is highly efficient for parasite sequestration and thus arrests in most cases parasite development. However, the mechanisms regulating its activation/non activation upon parasite entry remain unknown. It is thought that if we could genetically manipulate the mosquito in a way to provoke melanotic encapsulation we could @taps have a means oE cantcolling Plasmodium transmission in mosquitoes.
ANOPHELISM WITHOUT MALARIA ONE
s-Cl14 Besansky
CENTURY
LATER
NJ
A NOPHELES STEPHENSI, A VECTOR MOSQUITO OF MALARA TRANSMfSSION, TAKES THE SALWA INTO THE M tDGUT DURING BLOOD FEEDING
Thee mys"er_~'r&niab me d~sence D% ma'la+ia from regions of Europe that were densely popul&,sz& u:l'*y, ai;s_$&i'>~,+~ -'*a5s-;,.5-s& .+_.:A<;yL the dwnonstrarion I"aI "XI, macul>~e,wis" d72T>ere,qr>a> 1 9' consisf& 05 ,rr,@ic srzplri.93 From that time involved in transmission. forward, this pattern has been encountered ._^^C^_^ $xli;cl;3a'iIiIa'isrla VIzLiv172. with ~Ixwxst i;i‘i Where postmating isolating mechanisms exist, crossing experiment.9 have play& a17 important role in sibling species identtfication. Currversc1y, the pro&icZiorr of fertile f'l and hackcrass pr0gen.y in Eb.e laboraatory &es r>e< c~fi~t~t~te s'xon~ evidence of a single taxonomlc unit, because these experiments fail to account for premating isolating mechanisms operating in Thus, the problem of natural populations. sibling species identification has entaiPed the search for diagnostic differences at the The first cytological and molecular level. approaches to be developed included analyses of chromosomal banding patterns and geneMore recently, DNA-based enzyme systems. approaches have been developed that target the rDNA or other genes as well as anonymous The powers and pitfalls repeated sequences. of the practical application of these methods will be reviewed, as ~111 their overall contribution to the study of the evolutionary and population biology of slbllng species.
Before and after blood feeding, the volume of t5%r+.z%Y&~$xX!&& k%@i&s s%@rW& % extremely reduces. To observe the saliva consumption, we collected An. stephensi before feeding, during probing, on taking bbod, and after the &to& fee&g. Sampi’es of ihe sativary glands were run on the SDS-PAGE gel and stained with silver. Several proteins, whose molecular size were 33, 35,40,45 and 70kDa, depleted after the b&d feeding. Proteins in ihe salivary glands were consumed when mosquitoes were probing on mouse, and even when mosquitoes were taking blood into the midgut. Our result suggests that mosquitoes use different proteins on probing for vessels and taking blood. Moreover, in prediuresis of An. stephensi infected with Plasmodium berghei, we found sporozoites which should come from the salivary gland of the mosquito.