Applicability of RAPD markers on silver-stained polyacrylamide gels to ascertain genetic diversity in Peripatus acacioi (Peripatidae; Onychophora)

RAPD (random amplification of polymorphic DNA) molecular markers can be utilized for analyzing genetic variability in populations for which only a few or no molecular markers are available. They were used in a study of an endangered species, Peripatus acacioi, found in the Tripuí Ecological Station, in Ouro Preto, MG, Brazil. The ecological station was specifically created to protect this velvet worm species, the first of this group found in Brazil. For an initial evaluation of the genetic diversity of this species, DNA samples from the lobopods of four individuals, collected at random, were analyzed using RAPD. Each reaction was run with a different primer (Operon RAPD 10-mer Kits), totaling 13 primers (OPC2, OPC3, OPC4, OPC6, OPC8, OPC10, OPC11, OPL2, OPL7, OPL11, OPL13, OPL18, and OPL19). Due to the low amplification yield, RAPD fragments were separated in polyacrylamide gels and stained with silver nitrate. Numerous bands were observed. Fifty-five of the amplified bands proved to be reproducible, both in terms of presence and intensity. Among these, 27 were variable and 28 were constant. The average number of bands per gel was 4.2. Nine of the 13 primers tested allowed the identification of constant and variable bands among these four individuals. RAPD analysis of genetic variation using silver-stained polyacrylamide gel electrophoresis provided measures of band sharing among the individuals, and therefore could be used in population genetics studies of P. acacioi.

Estudo do comportamento dos linfocitos derivados do timo em pacientes com penfigo foliaceo na presenca de levamisol. / Behaviour of T - lymphocytes in patients with foliaceus pemphigus at the presence of levamisole

Foram estudados linfocitos T de pacientes portadores de penfigo foliaceo em relacao a sua capacidade de formar rosaceas "E", diante de concentracoes do imunopotenciador levamisol. O levamisol e uma substancia que estimula formacao de rosaceas de linfocitos T ativos em individuos normais: Os linfocitos de pacientes antes da corticoterapia sistemica nao responderam ao levamisol ja os linfocitos de pacientes em tratamento com corticoides tiveram inibida sua capacidade de formar rosaceas. Esses achados sugerem altecao no metabolismo celular dos linfocitos de pacientes penfigosos devido provavelmente a alguma falha no sistema enzimatico dessas celulas envolvendo a fosfodiesterase do AMPc