Rhodnius prolixus Malpighian tubule's aquaporin expression is modulated by 5-hydroxytryptamine.
The purpose of the present study was to detect the presence of an aquaporin-like water channel, a member of the major intrinsic protein (MIP) family, in the Malpighian tubule (MT) of the hematophagous insect Rhodnius prolixus, which excrete a large bulk of fluid after a massive blood meal, and its possible regulation by 5-hydroxytryptamine (5-HT). Reverse transcription polymerase chain reaction (RT-PCR) and Southern blots of cDNA was obtained from adult R. prolixus MT poly (A)+ RNA. Employing degenerate primers corresponding to the NPA (amino acid sequence motifs repeats Asn-Pro-Ala) highly conserved domain of amino acids sequences of all members of the MIP gene family, we were able to identify a 365-base pair PCR product. The R. prolixus MT mRNA expression of this water transporter is increased in the animal after blood meal and in tubules treated with 5-hydroxytryptamine or cAMP. The up-regulated expression of MT MIP mRNA after a blood meal is probably due to the action of 5-hydroxytryptamine via a cyclic AMP dependent pathway.
Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Sabrina V
SV
Martini
Regina C
RC
Goldenberg
Fabio S A
FS
Fortes
Antônio C
AC
Campos-de-Carvalho
Dóris
D
Falkenstein
Marcelo M
MM
Morales
D000818:Animals; D020346:Aquaporins / Q000378:metabolism*; D015139:Blotting, Southern; D017931:DNA Primers; D003720:Densitometry; D005247:Feeding Behavior / Q000502:physiology; D019476:Insect Proteins / Q000378:metabolism*; D008297:Male; D008317:Malpighian Tubules / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012239:Rhodnius / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology
D020346:Aquaporins; D017931:DNA Primers; D019476:Insect Proteins; C437971:Rp-MIP protein, Rhodnius; D012701:Serotonin; D012260:Ribonucleases