Chromosomal distribution of the retroelements Rex 1, Rex 3 and Rex 6 in species of the genus Harttia and Hypostomus (Siluriformes: Loricariidae)

The transposable elements (TE) have been widely applied as physical chromosome markers. However, in Loricariidae there are few physical mapping analyses of these elements. Considering the importance of transposable elements for chromosomal evolution and genome organization, this study conducted the physical chromosome mapping of retroelements (RTEs) Rex1, Rex3 and Rex6 in seven species of the genus Harttia and four species of the genus Hypostomus, aiming to better understand the organization and dynamics of genomes of Loricariidae species. The results showed an intense accumulation of RTEs Rex1, Rex3 and Rex6 and dispersed distribution in heterochromatic and euchromatic regions in the genomes of the species studied here. The presence of retroelements in some chromosomal regions suggests their participation in various chromosomal rearrangements. In addition, the intense accumulation of three retroelements in all species of Harttia and Hypostomus, especially in euchromatic regions, can indicate the participation of these elements in the diversification and evolution of these species through the molecular domestication by genomes of hosts, with these sequences being a co-option for new functions.(AU)

Os elementos transponíveis (TE) têm sido amplamente aplicados como marcadores cromossômicos. Contudo, em Loricariidae, há poucas análises de mapeamento físico destes elementos. Considerando a importância de elementos transponíveis para a evolução cromossômica e organização genômica, este trabalho realizou o mapeamento físico cromossômico dos retroelementos (RTEs) Rex1, Rex3 e Rex6 em sete espécies do gênero Harttia e em quatro espécies do gênero Hypostomus, com o intuito de melhor compreender a organização e dinâmica dos genomas das espécies de Loricariidae. Os resultados evidenciaram um intenso acúmulo dos RTEs Rex1, Rex3 e Rex6 e distribuição dispersa em regiões heterocromáticas e eucromáticas no genoma das espécies estudadas. A presença de retroelementos em algumas regiões cromossômicas sugere sua participação em vários rearranjos cromossômicos. Além disso, o intenso acúmulo dos três retroelementos em todas as espécies de Harttia e Hypostomus, especialmente em regiões eucromáticas, pode indicar a participação destes elementos na diversificação e evolução destas espécies através da domesticação molecular pelo genoma dos hospedeiros, com estas sequências sendo co-optadas paras novas funções.(AU)

HER-2 gene expression in atypical ductal hyperplasia associated with canine mammary carcinomas / Expressão gênica de HER2 em hiperplasias ductais atípicas associadas a carcinomas mamários caninos

O presente estudo apresenta o comportamento do gene HER2, a partir do uso da técnica de hibridização cromogênica in situ, em hiperplasias ductais atípicas associadas a carcinomas mamários caninos positivos para HER2. Aparentemente, uma fraca expressão da proteína HER2 foi observada nas hiperplasias ductais atípicas, bem como uma ausência de amplificação do seu gene codificador nessas hiperplasias e nos carcinomas mamários associados. O comportamento da proteína HER2 e do seu gene em carcinomas mamários caninos é similar ao observado em alguns subtipos histológicos de tumores mamários humanos, e a ausência dessas alterações sugerem que esse gene poderia aparentemente não estar envolvido com os estágios iniciais de proliferação celular atípica...

Detection of porcine reproductive and respiratory syndrome virus in oral fluid from naturally infected pigs in a breeding herd

The objectives of the present study were to evaluate the anatomic localization of porcine reproductive and respiratory syndrome virus (PRRSV) in naturally infected pigs and to determine whether oral fluid could be used to detect the virus in infected animals. Two sows, seven 2-month-old grower pigs, and 70 6-month-old gilts were included in this study. PRRSV in sera and oral fluid were identified by nested reverse transcription PCR (nRT-PCR) while lung, tonsil, and tissue associated with oral cavity were subjected to nRT-PCR, immunohistochemistry, and in situ hybridization. In sows, PRRSV was identified in oral fluid and tonsils. PRRSV was also detected in oral fluid, tonsils, salivary glands, oral mucosa, and lungs of all seven grower pigs. However, viremia was observed in only two grower pigs. Double staining revealed that PRRSV was distributed in macrophages within and adjacent to the tonsillar crypt epithelium. In gilts, the North American type PRRSV field strain was detected 3 to 8 weeks after introducing these animals onto the farm. These results confirm previous findings that PRRSV primarily replicates in tonsils and is then shed into oral fluid. Therefore, oral fluid sampling may be effective for the surveillance of PRRSV in breeding herds.

PapillomatosIs in cattle: in situ detection of bovine papillomavirus DNA sequences in reproductive tissues

Bovine papillomatosis is a common viral infection in Brazil that is caused by a bovine papillomavirus(BPV). Dissemination is by direct contact between infected animals, although the investigation of othermodes of transmission is a very important aspect in the management of this condition. BPV DNA sequenceshave been detected in many tissues by using the polymerase chain reaction. In this work, we used in situhybridization to detect BPV DNA sequences in bovine reproductive tissues and cells. The detection ofBPV in these tissues strongly suggests that these sequences could be an important alternative of viraltransmission that could contribute to the widespread incidence of bovine papillomatosis and its complexpathology. Alternatively, the viral sequences could result from cell apoptosis and may therefore not bedirectly involved in the infection.