We present the application of a real-time quantitative PCR assay, previously developed to measure relative telomere length in humans and mice, to two bird species, the zebra finch Taeniopygia guttata and the Alpine swift Apus melba. This technique is based on the PCR amplification of telomeric (TTAGGG) n sequences using specific oligonucleotide primers. Relative telomere length is expressed as the ratio (T/S) of telomere repeat copy number (T) to control single gene copy number (S). This method is particularly useful for comparisons of individuals within species, or where the same individuals are followed longitudinally. We used glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a single control gene. In both species, we validated our PCR measurements of relative telomere length against absolute measurements of telomere length determined by the conventional method of quantifying telomere terminal restriction fragment (TRF) lengths using both the traditional Southern blot analysis (Alpine swifts) and in gel hybridization (zebra finches). As found in humans and mice, telomere lengths in the same sample measured by TRF and PCR were well correlated in both the Alpine swift and the zebra finch.. Hence, this PCR assay for measurement of bird telomeres, which is fast and requires only small amounts of genomic DNA, should open new avenues in the study of environmental factors influencing variation in telomere length, and how this variation translates into variation in cellular and whole organism senescence.

Shortening of telomeres, specific nucleotide repeats that cap eukaryotic chromosomes, is thought to play an important role in cellular and organismal senescence. We examined telomere dynamics in two longlived seabirds, the European shag and the wandering albatross. Telomere length in blood cells declines between the chick stage and adulthood in both species. However, among adults, telomere length is not related to age. This is consistent with reports of most telomere loss occurring early in life in other vertebrates. Thus, caution must be used in estimating annual rates of telomere loss, as these are probably not constant with age. We also measured changes within individuals in the wild, using repeat samples taken from individual shags as chicks and adults. We found high inter-individual variation in the magnitude of telomere loss, much of which was explained by circumstances during growth. Individuals laying down high tissue mass for their size showed greater telomere shortening. Independently of this, individuals born late in the season showed more telomere loss. Early conditions, possibly through their effects on oxidative stress, appear to play an important role in telomere attrition and thus potentially in the longevity of individuals.

It is now widely recognized that BPV-1 and less commonly BPV-2 are the causative agents of equine sarcoids. Here we present the generation of equine cell lines harboring BPV-1 genomes and expressing viral genes. These lines have been either explanted from sarcoid biopsies or generated in vitro by transfection of primary fibroblasts with BPV-1 DNA. Previously detected BPV-1 genome variations in equine sarcoids are also found in sarcoid cell lines, and only variant BPV-1 genomes can transform equine cells. These equine cell lines are morphologically transformed, proliferate faster than parental cells, have an extended life span and can grow independently of substrate. These characteristics are more marked the higher the level of viral E5, E6 and E7 gene expression. These findings confirm that the virus has an active role in the induction of sarcoids and the lines will be invaluable for further studies on the role of BPV-1 in sarcoid pathology.

Abstract. Papillomas and fibropapillomas may occur in the skin and in different organs in animals. Ten different genotypes of bovine papillomavirus (BPV) have been identified. BPV-1 through BPV-10 are all strictly species-specific, but BPV-1/2 may also infect other species such as equids, inducing fibroblastic tumors. BPV-1 and BPV-2 are associated with fibropapillomas in cattle; these tumors are formed by excessive proliferation of virus-infected dermal fibroblasts and epidermal keratinocytes. Nine water buffalo (Bubalus bubalis) were examined for the presence of multiple cutaneous and perivulvar tumors. Cutaneous and perivulvar fibropapillomatosis were confirmed histologically. Negative-stain transmission electron microscopic examination revealed papillomavirus-like particles in the fibropapillomas, and papillomaviral DNA was also detected by the polymerase chain reaction. The amplified long control region (LCR) DNA sequence was identical to that of BPV-1. The BPV-1 E5 oncoprotein was strongly expressed in the tumor cells thus confirming a causal role of the virus. This article represents the first report of cutaneous, perivulvar, and vulvar fibropapilloma associated with BPV-1 infection in the water buffalo and describes another example of cross-species infection by BPV-1.