Computer-aided pattern recognition of large reptiles as a noninvasive application to identify individuals.

For large species, the capture and handling of individuals in capture-mark-recapture studies introduces nonhuman animal welfare issues associated with handling, physical marking, and possible wounding due to tag loss. The use of photographic identification for these species offers an alternative and less invasive marking technique. This study investigated the opportunity offered by photo identification to individually mark individuals of a large reptile, the perentie (Varanus giganteus), in Australia and therefore avoid the stress of physically capturing and handling. Photographs submitted by a remotely located community were first validated to confirm whether perenties could be individually identified from their spots electronically using a computer program. Computer-aided selection of unique patterns was found to be appropriate for the identification of individuals and confirmed 38 individuals during the sampling period. The value of this approach is 2-fold: There is a benefit to animal welfare in that handling an animal is not required to capture him or her, thus reducing capture-related stress; and confirmation that photo identification of distinctive patterns of the perentie is valid and offers a useful option to identify individuals of this large species.

Extensive sequence variation exists among isolates of murine cytomegalovirus within members of the m02 family of genes.

Murine cytomegalovirus (MCMV) is a widely used model for human cytomegalovirus (HCMV) and has facilitated many important discoveries about the biology of CMVs. Most of these studies are conducted using the laboratory MCMV strains Smith and K181. However, wild-derived isolates of MCMV, like HCMV clinical isolates, exhibit genetic variation from laboratory strains, particularly at the ends of their genomes in areas containing known or putative immune-evasion and tropism genes. This study analysed the nucleotide sequence of the m02-m05 region, within the m02 gene family, of a number of laboratory and wild-derived MCMV isolates, and found a large degree of variation in both the sequence and arrangement of genes. A new open reading frame (ORF), designated m03.5, was found to be present in a number of wild isolates of MCMV in place of m03. Two distinct isolates, W8 and W8211, were found to possess both m03 and m03.5. Both m03 and m03.5 had early transcription kinetics and the encoded proteins could be detected on the cell surface, consistent with a possible role in immune evasion through binding to host-cell proteins. These data show that gene duplication and sequence variation occur within different isolates of MCMV found in the wild. As this variation among strains may alter the function of genes, these findings should be considered when analysing gene function or host-virus interactions in laboratory models.

Mixed infection with multiple strains of murine cytomegalovirus occurs following simultaneous or sequential infection of immunocompetent mice.

As with human cytomegalovirus (HCMV) infection of humans, murine CMV (MCMV) infection is widespread in its natural host, the house mouse Mus domesticus, and may consist of mixed infection with different CMV isolates. The incidence and mechanisms by which mixed infection occurs in free-living mice are unknown. This study used two approaches to determine whether mixed infection with MCMV could be established in laboratory mice. The first utilized two naturally occurring MCMV strains, N1 and G4, into which the lacZ gene was inserted by homologous recombination. The lacZ gene was used to track recombinant and parental viruses in simultaneously coinfected mice. In the second approach, a real-time quantitative PCR (qPCR) assay was used to detect viral immediate-early 1 (ie1) gene sequences in mice successively coinfected with G4 and then with the K181 MCMV strain. In both systems, mixed infection was detected in the salivary glands and lungs of experimentally infected mice. MCMV-specific antibody in sera and G4 IE1-specific cytotoxic lymphocyte responses in the spleens of twice-infected mice did not prevent reinfection. Finally, the prevalence of mixed infection in free-living mice trapped in four Australian locations was investigated using real-time qPCR to detect ie1 DNA sequences of N1, G4 and K181. Mixed infection with MCMVs containing the G4 and K181 ie1 sequences was detected in the salivary glands of 34.2 % of trapped mice. The observations that mixed infections are common in free-living M. domesticus and are acquired by immunocompetent mice through simultaneous or successive infections are important for vaccine development.