Biology subjects

Lynton-Jenkins, J. G.

Publications and source records attributed to Lynton-Jenkins, J. G..

4 recordsLinked to original sources

bioRxiv2025

Investigating high pathogenicity avian influenza virus incursions to remote islands: Detection of H5N1 on Gough Island in the South Atlantic Ocean

Understanding the mechanisms underlying the emergence and spread of high pathogenicity avian influenza virus (HPAIV) is critical for tracking its global dissemination, particularly via migratory seabirds, given their role in transmission over long distances. Scavenging seabirds, such as skuas, may act as both reservoirs and vectors, and have been linked to multiple outbreaks since 2021. Here, we report the detection of HPAIV H5N1 clade 2.3.4.4b in three Tristan skua (Stercorarius antarcticus hamiltoni) carcasses on Gough Island in the central South Atlantic Ocean. To investigate potential incursion routes, we combined genomic analyses with year-round tracking data from global location sensors. Although migratory movement patterns suggested southern Africa as the most obvious pathway, the strain detected on Gough Island was more closely related to that identified in South Georgia, indicating that infection may have occurred during the pre-laying exodus, when skuas disperse into frontal waters south of the island. No further cases have been confirmed for Gough, but more systematic monitoring is needed to understand the dynamics of virus infection. The detection of HPAIV H5N1 in skuas on Gough Island highlights the importance of continued vigilance, proactive and geographically inclusive surveillance strategies, and biosecurity measures globally, alongside efforts to reduce other pressures on globally important seabird populations to help strengthen their resilience.

pathology↗

bioRxiv2023

Detection and spread of high pathogenicity avian influenza virus H5N1 in the Antarctic Region

Until recent events, the Antarctic was the only major geographical region in which high pathogenicity avian influenza virus (HPAIV) had never previously been detected. The current panzootic of H5N1 HPAIV has decimated wild bird populations across Europe, North America, and South America. Here we report on the detection of clade 2.3.4.4b H5N1 HPAIV in the Antarctic and sub-Antarctic regions of South Georgia and the Falkland Islands, respectively. We initially detected H5N1 HPAIV in samples collected from brown skuas at Bird Island, South Georgia on 8th October 2023. Since this detection, mortalities were observed in brown skuas, kelp gulls, South Georgia shag, Antarctic tern, elephant seals and fur seals at multiple sites across South Georgia. Subsequent testing confirmed H5N1 HPAIV across several sampling locations in multiple avian species and two seal species. Simultaneously, we also confirmed H5N1 HPAIV in southern fulmar and black-browed albatross in the Falkland Islands. Genetic assessment of the virus indicates spread from South America, likely through movement of migratory birds. Critically, genetic assessment of sequences from mammalian species demonstrates no increased risk to human populations. Here we describe the detection, species impact and genetic composition of the virus and propose both introductory routes and potential long-term impact on avian and mammalian species across the Antarctic region. We also speculate on the threat to specific populations following recent reports in the area.

microbiology↗

bioRxiv2020

Leprosy in wild chimpanzees

Humans are considered the main host for Mycobacterium leprae, the aetiologic agent of leprosy, but spill-over to other mammals such as nine-banded armadillos and red squirrels occurs. Although naturally acquired leprosy has also been described in captive nonhuman primates, the exact origins of infection remain unclear. Here, we report on leprosy-like lesions in two wild populations of western chimpanzees (Pan troglodytes verus) in the Cantanhez National Park, Guinea-Bissau, and the Tai National Park, Cote dIvoire, West Africa. Longitudinal monitoring of both populations revealed the progression of disease symptoms compatible with advanced leprosy. Screening of faecal and necropsy samples confirmed the presence of M. leprae as the causative agent at each site and phylogenomic comparisons with other strains from humans and other animals show that the chimpanzee strains belong to different and rare genotypes (4N/O and 2F). The independent evolutionary origin of M. leprae in two geographically distant populations of wild chimpanzees, with no prolonged direct contact with humans, suggests multiple introductions of M. leprae from an unknown animal or environmental source.

evolutionary biology↗

bioRxiv2020

Sex identification in embryos and adults of Darwins finches

Darwins finches, endemic to the Galapagos and Cocos islands, are an iconic example of adaptive radiation and evolution under natural selection. Comparative genetic studies using embryos of Darwins finches have shed light on the possible evolutionary processes underlying the speciation of this clade. Molecular identification of the sex of embryonic samples is important for such studies, where this information often cannot be inferred otherwise. We tested a fast and simple chicken embryo protocol for extraction of genomic DNA on Darwins finch embryos. In addition, we suggest modifications to two of the previously reported PCR primer sets for CHD1, a gene used for sexing in adult passerine birds. The sex of all 29 tested embryos of six species of Darwins finches was determined successfully by PCR, using both primer sets. Hatchlings/nestlings and fledglings are also impossible to distinguish visually. This includes juveniles of sexually dimorphic species which are yet to moult in adult-like plumage and beak colouration. Furthermore, four species of Darwins finches are monomorphic, males and females looking alike. Therefore, sex assessment in the field can be a source of error, especially with respect to juveniles and mature monomorphic birds outside of the mating season. We caught 567 juveniles and adults belonging to six species of Darwins finches and only 44% had unambiguous sex-specific morphology. We sexed 363 birds by PCR, including individuals sexed based on marginal sex specific morphological traits (N=278) and birds which were impossible to classify in the field (N=39). For birds with marginal sex specific traits, PCR results revealed a 13% sexing error rate. This demonstrates that PCR based sexing can improve field studies on Darwins finches, especially when individuals with unclear sex-related morphology are involved. The protocols used here provide an easy and reliable way to sex Darwins finches throughout ontogeny, from embryos to adults.

molecular biology↗