Search

Ten types of bovine papillomavirus (BPV) have been described and there are reports of viral transmission via blood. The presence of viral DNA in lymphocytes was described to be associated with chromosome instability in these cells. This study presents an evaluation of chromosome instability in short-term peripheral lymphocyte cultures from cows presenting skin papillomatosis, compared with asymptomatic infected animals and non-infected healthy bovines. In a total of 2203 cells, 918 (42%) showed at least one chromosome aberration: 42.7 (± 7.8) in animals with papillomatosis (BPV + W), 40.2 (± 11) in asymptomatic animals (BPV-W) and 4 (± 2) in control animals. Significant differences were found between the infected group (with or without symptoms) and the control group (P < 0.0001). The increased frequencies of chromosome aberrations suggest an interaction between the virus and host cell chromatin., (© 2011 Blackwell Publishing Ltd.)

Papillomaviruses have been reported to be very difficult to grow in cell culture. Also, there are no descriptions of cell cultures from lesions of bovine cutaneous papillomatosis, with identification of different bovine papilloma virus (BPV) DNA sequences. In the present report, we describe primary cell cultures from samples of cutaneous lesions (warts). We investigated the simultaneous presence of different BPV DNA sequences, comparing the original lesion to different passages of the cell cultures and to peripheral blood. BPV 1, 2 and 4 DNA sequences were found in lesion samples, and respective cell cultures and peripheral blood, supporting our previous hypothesis of the possible activity of these sequences in different samples and now also showing how they can be maintained in different passages of cell cultures.

Bovine papillomavirus (BPV) DNA sequences were detected in different tissues, in addition to epithelium. Cytogenetic abnormalities were observed in blood lymphocytes. The presence of more than one virus in a single tissue is a difficult aspect to evaluate, especially when the DNA sequences are detected in tissues that are not specifically targeted by the virus. BPV and bovine leukemia virus (BLV) are clastogenic, causing chromosome aberrations in peripheral blood lymphocytes. In the present study, we investigated the simultaneous presence of DNA sequences of both viruses and the possibility of vertical transmission and compared the types of chromosome aberrations related to viral action. BPV 1, 2, and 4 DNA sequences were found in three females of the herd and in their offspring. BLV DNA sequences were not detected in their progeny. A newborn calf that was negative for BLV infection showed specific chromosome rearrangements possibly related to the effect of infection with BPV.

The development of a bovine papillomavirus (BPV) vaccine is an outstanding challenge. BPV protein L1 gene transfection in the Drosophila melanogaster S2 cell expression system failed to produce L1 protein notwithstanding correct L1 gene insertion. Severe genetic inbalance in the host cell line, including cytogenetic alterations, may account for the lack of protein expression.

Bovine papillomavirus type 4 (BPV-4) and bracken fern are cofactors in the carcinogenesis of the upper gastrointestinal (GI) tract of cattle. An experimental in vitro model system has been developed to analyse the co-operation between the viral transforming protein E7, the cellular ras oncogene and quercetin, one of the mutagens of bracken fern, during neoplastic progression of primary bovine cells. We now report cytogenetic studies of these cells at different stages of malignant transformation: parental primary non-transformed PalF cells; E7R cells transformed by BPV-4 E7 and activated ras but not tumorigenic, and tumorigenic E7Q cells derived from E7R cells after treatment with quercetin. All cell lines presented increased numbers of aneuploid cells. The rate of structural chromosomal aberrations observed was increased in transformed cells. In addition, E7Q cells showed chromosomes with peculiar rearrangements, which resulted in metacentric and submetacentric marker chromosomes, with an increase in the mean chromosome arm number. These markers were the products of possible centric fusions. These aberrations and rearrangements were distributed throughout the karyotype, no specific chromosome was involved and the heterochromatic centromeric regions appeared to be preserved.

Enzootic haematuria and urinary bladder cancer in cattle are associated with feeding on bracken fern and bovine papillomavirus (BPV) infection. An increased rate of chromosomal aberrations in peripheral blood lymphocytes from chronically affected haematuric cows raised in bracken fern pastures has been reported, suggesting the presence of BPV in the peripheral blood of afflicted animals. The purpose of the present investigation was to examine the role of peripheral blood as a potential BPV-transmitting agent and search for clastogenic effects in experimentally infected animals kept on a bracken fern-free diet. Healthy cows were inoculated with blood samples of haematuric animals every two weeks for 18 months. Recipient cows, their offspring, donor animals and a control group were kept on a bracken fern-free diet throughout the experiment. Clinical and molecular analyses for detection of BPV infection were carried out periodically in all groups. Short-term lymphocyte cultures were performed to assess chromosomal aberration levels. The donor cows, the recipient cows and their offspring presented increased levels of chromosomal aberrations. BPV-2 DNA was identified by Southern blotting, PCR and cycle-sequencing of PCR products in peripheral blood of donor and recipient animals and in the progeny of recipient animals. Data support both the concept that BPV can be transmitted through blood and the hypothesis that infection with the virus causes the clastogenic alterations observed in the present experimental model. The presence of BPV-2 DNA and chromosomal alterations in peripheral blood of offspring at the moment of birth is evidence for vertical transmission of BPV.

We report on a sibship from a consanguineous couple consisting of one boy with anophthalmia, one boy with buphthalmos and multiple congenital skeletal, muscle, and cardiac abnormalities, and a stillborn girl with anophthalmia and cardiac and skeletal abnormalities. A possible new syndrome of autosomal recessive inheritance and variable expressivity is discussed, comparing this report with others.

A prospective study of the fragile X syndrome [fra(X)] was initiated one year ago to refine the estimates of recurrence risks based on the phenotype of the mother and the family history of the syndrome. The basic unit of data consists of the description of the conceptus of women known to carry the fra(X) gene or of mothers of an isolated case. To date, information on 261 women and their conceptuses was ascertained primarily through prenatal diagnosis; these data are summarized here. Although tests of significance were limited due to small sample sizes in subgroups, the following trends were observed: 1) the penetrance of fra(X) site expression was 80% in both male and female conceptuses suggesting that fra(X) site expression is equally penetrant early in development; 2) the sex ratio at the time of prenatal diagnosis did not differ from one, indicating that selection against fra(X) fetuses, if any, does not differ among sexes; 3) the recurrence risk among offspring of borderline/mildly retarded mothers was higher than that among offspring of intellectually normal mothers; 4) the recurrence risk in offspring did not differ based on the mother's fra(X) site expression; and 5) the recurrence risk in offspring of mothers with isolated cases was slightly less (34%) than that of obligate carrier mothers (41%) although this was not significant. The potential use of these prospective data on the fra(X) syndrome is emphasized.

An apparently new X-linked syndrome is presented. It occurred in four male first cousins. The main manifestations of this syndrome are severe mental retardation, bilateral congenital hip luxation, and short stature. Three of the affected males showed a new glucose-6-phosphate dehydrogenase variant.