Congenital tremor in piglets: Is bovine viral diarrhea virus an etiological cause?

Congenital tremor in pigs involves several etiologies, including pestivirus, which may cause neurological injuries in different animal species. To evaluate whether bovine viral diarrhea virus (BVDV), an important pestivirus, is one of the etiological agents of congenital tremor in swine, gilts and the fetuses were challenged at 45 days of gestation with BVDV-2. Four pregnant gilts were inoculated oronasally, four gilts underwent fetal intrauterine inoculation, and two gilts constituted the control group. Antibody titers were determined by virus neutralization (VN), and viral RNA was detected by RT-PCR. Blood samples were collected from all gilts and piglets born to obtain whole blood and serum for analysis. One third of the neonates were euthanized at three days old, and samples of the encephalon, brain stem and spinal cord were collected for anatomopathological evaluation and viral RNA detection. The piglets that remained alive were clinically evaluated every day, and blood sampling was performed regularly for 35 days. The piglets from gilts in both inoculation treatment groups showed no clinical neurological signs and were born with no viral RNA in their blood and organs. Piglets born from oronasally inoculated gilts did not present antibodies against BVDV-2 at birth, although they were acquired by passive maternal transfer. In contrast, intrauterine-inoculated piglets were born with high antibody titers (80 to 640) against the agent, which remained high until the end of the experimental period. Microscopically, no noticeable changes were observed. Macroscopically, 29.5% of the total piglets euthanized, from both inoculation groups, were born with a low cerebellar:brain ratio. Nevertheless, some piglets had a high cerebellar:brain ratio, indicating the need for standardizing this value. Thus, it was concluded that BVDV is not an etiological agent for congenital swine tremor.

The sugarcane signal transduction (SUCAST) catalogue: prospecting signal transduction in sugarcane

O sequenciamento de ESTs (etiquetas de seqüências transcritas) tem possibilitado a descoberta de muitos novos genes em uma ampla variedade de organismos. Um aumento do aproveitamento desta informaçäo pela comunidade científica tem sido possível graças ao desenvolvimento de base de dados contendo seqüências completamente anotadas. O trabalho aqui relatado teve como objetivo a identiflcaçäo de ESTs de cana de açúcar seqüenciadas através do projeto SUCEST (http://sucest.lad.ic.unicamp.br) que codificam para proteínas envolvidas em mecanismos de transduçäo de sinal. Nós também preparamos um catálogo dos componentes de transduçäo de sinal da cana de açúcar (SUCAST) englobando as principais categorias e vias conhecidas (http://sucest.lad.ic.unicamp.br/private/mining-reports/QG/QG-mining.htm). ESTs codificadoras de enzimas envolvidas nas rotas de biossíntese de hormônios (giberelinas, etileno, auxinas, ácido abscíssico, ácido jasmônico) foram encontradas e sua expressäo específica nos tecidos foi inferida a partir de seu enriquecimento nas diferentes bibliotecas. Quando possível, transmissores do sinal hormonal e da resposta a peptídeos produzidos pela planta foram associados a suas respectivas vias. Mais de 100 receptores foram encontrados na cana de açúcar, entre os quais uma grande família de receptores Ser/Thr quinase e também de fotoreceptores, receptores do tipo histidina quinase e seus respectivos reguladores da resposta. Proteínas G e GTPases pequenas foram também analisadas e comparadas com membros destas famílias já conhecidos em mamíferos e plantas. As vias principais que envolvem a participaçäo de proteínas quinases e fosfatases foram mapeadas, em especial as vias da quinase MAP quinase e do inositol que säo bem estudadas em plantas.