Biology subjects

Fennessy, S.

Publications and source records attributed to Fennessy, S..

4 recordsLinked to original sources

bioRxiv2026

Comparative anatomy of the giraffe distal limb

Giraffe in human care are known to experience significant clinical issues related to their feet. To characterize normal foot anatomy, we analyzed six sets of front and hind feet from wild Angolan giraffe and one calf in human care. We used computed tomography, three-dimensional reconstruction, sagittal sections, and gross dissection to acquire as much gross anatomical detail as possible. Significant anatomical findings include the deep digital flexor tendon that is very gracile as it crosses the fetlock and proximal phalanges but widens significantly before inserting onto the entire palmar/plantar surface of the distal phalanx. Significant subcutaneous abaxial veins were noted at the level of the fetlock in both front and hind feet. The digital cushion was found to be a complex structure consisting of two distinct regions, one underneath the distal phalanx, characterized by multiple transversely oriented small adipose compartments separated by dense connective tissue septa, and a significantly larger portion within the heel bulb, consisting of two sagittally oriented fat bodies encased in a dense connective tissue capsule and divided by a thick septum. The proportion of adipose tissue volume in the heel bulbs compared to the distal phalanx decreases with age. The thickness of the sole was found to be much greater than that of the wall and the sole appears to be the major weight supporting structure of the foot. In particular, the heel is greatly expanded in giraffe relative to other ruminants and was found to consist of softer material than the rest of the sole. Data presented here provide an overview of normal giraffe foot anatomy, which can be compared with data from giraffe in human care to better understand, guide treatment and prevention of abnormal anatomical conditions.

zoology↗

bioRxiv2024

Random subsamples of animal populations can reveal intrinsic differences in sociality with key implications in ecology, conservation and disease transmission

Animal populations are under mounting stress from the dual threats of climate change and rapid global human population growth, raising significant concerns about declining wildlife and the rising risk of zoonotic diseases. In many species, social interactions can be a highly plastic suite of behaviours that are responsive to these disturbances and are consequential to other processes like disease transmission and population dynamics. Studying social interactions can be challenging in that researchers often rely on wildlife population subsamples due to practical constraints and costs, which can introduce biases in the reliability of social network metrics. We investigated the extent to which subsamples can depict intrinsic characteristics of wildlife populations using data from three distinct species: peri-urban fallow deer, Alpine ibex and Angolan giraffe. We showed that random subsamples of these populations could still reveal differences in their social behaviour, indicating that, as long as researchers have a reliable estimate of population size, subsampling animal populations can be an effective and precise method to infer their sociality and offer valuable empirical data for management, conservation and zoonotic disease ecology. Furthermore, we demonstrate that non-random sampling, influenced for instance by animal personality and related trappability, can introduce significant biases in social network estimates. These findings underscore the importance of accounting for sampling biases in social network analysis and offer a robust framework for using partial networks in ecological studies and conservation management.

ecology↗

bioRxiv2023

Genomic analysis reveals limited hybridization among three giraffe species in Kenya

BackgroundIn the speciation continuum the strength of reproductive isolation varies, and species boundaries are blurred by gene flow. Interbreeding among giraffe (Giraffa spp.) in captivity is known and anecdotal reports of natural hybrids exist. In Kenya, Nubian (G. camelopardalis camelopardalis), reticulated (G. reticulata), and Masai giraffe sensu stricto (G. tippelskirchi tippelskirchi) are parapatric, and thus the country might be a melting pot for these taxa. We analyzed 128 genomes of wild giraffe, 113 newly sequenced, representing these three taxa. ResultsWe found varying levels of Nubian ancestry in 13 reticulated giraffe sampled across the Laikipia Plateau most likely reflecting historical gene flow between these two lineages. Although comparatively weaker signs of ancestral gene flow and potential mitochondrial introgression from reticulated into Masai giraffe were also detected, estimated admixture levels between these two lineages are minimal. Importantly, contemporary gene flow between East African giraffe lineages was not statistically significant. Effective population sizes have declined since the Late Pleistocene, more severely for Nubian and reticulated giraffe. ConclusionsDespite historically hybridizing, these three giraffe lineages have maintained their overall genomic integrity suggesting effective reproductive isolation, consistent with the previous classification of giraffe into four species.

evolutionary biology↗

bioRxiv2021

A Scenic River in Rural Ohio Shows Elevated Antibiotic Resistance Genes, Including Acinetobacter Tetracycline and Macrolide Resistance, Downstream of Wastewater Treatment Plant Effluent

The entry of antibiotic resistance genes (ARGs) into aquatic systems has been documented for large municipal wastewater treatment plants, but there is less study of the impact of smaller plants that are situated on small rural rivers. We sampled water metagenomes for ARG and taxa composition from the Kokosing River, a small rural river in Knox County, Ohio, which has been designated an Ohio State Scenic River for retention of natural character. Samples were obtained 1.0 km upstream, 120 m downstream, and 6.4 km downstream from the effluent release of the Mount Vernon wastewater treatment plant (WWTP). ARGS were identified in metagenomes using ShortBRED markers from the CARD database screened against UniPROT. Through all seasons, the metagenome just downstream of the WWTP effluent showed a substantial elevation of at least 15 different ARGs, including 6 ARGs commonly associated with Acinetobacter baumannii such as msrE, mphE (macrolide resistance) and tet(39) (tetracycline resistance). The ARGs most prevalent near the effluent pipe persisted 6.4 km downriver. Using MetaPhlAn2 clade-specific marker genes, the taxa distribution near the effluent showed elevation of reads annotated as Acinetobacter species as well as gut-associated taxa, Bacteroides and Firmicutes. The ARG levels and taxa prevalence showed little dependence on seasonal chlorination of the effluent. Nitrogen and phosphorus were elevated near the effluent pipe but had no consistent correlation with ARG levels. We show that in a rural river microbiome, year-round wastewater effluent substantially elevates ARGs including those associated with multidrug-resistant A. baumanii. IMPORTANCEAntibiotic resistance is a growing problem worldwide, with frequent transmission between pathogens and environmental organisms. Rural rivers can support high levels of recreational use by people unaware of inputs from treated wastewater, while WWTPs can generate a small but significant portion of flow volume into a river surrounded by forest and agriculture. There is little information on the rural impacts of WWTP effluent on the delivery and transport of antibiotic resistance genes. In our study, the river water proximal to wastewater effluent shows evidence for the influx of multidrug-resistant Acinetobacter baumanii, an opportunistic pathogen of concern for hospitals but also widespread in natural environments. Our work highlights the importance of wastewater effluent in management of environmental antibiotic resistance, even in high quality, rural river systems.

microbiology↗