Biology subjects

Roberts, L. E.

Publications and source records attributed to Roberts, L. E..

4 recordsLinked to original sources

bioRxiv2026

Extreme disparity in the appendicular skeleton of domestic dogs (Canis familiaris)

Domestic dogs (Canis familiaris) display more morphological variation than any other mammal. Cranial morphology has been extensively studied, as have the relationships with function, development, genetics, veterinary medicine, and breed welfare. Postcrania remain comparatively understudied, despite well-documented breed-specific predispositions to musculoskeletal disease. Here, we apply three-dimensional landmark-free morphometrics to quantify the shape of 743 elements from 213 dogs, including the scapula, humerus, radius, ulna, pelvic girdle, femur, tibia, and fibula. We assess integration among limb elements and investigate drivers of shape variation within and between breeds. Across most breeds, limb bone shape is strikingly similar. Dachshunds, however, exhibit distinct morphology across all elements and one to two orders of magnitude greater variation than any other breed. Despite this disparity, integration remains high between all element pairs. Remarkably, we find no significant relationship between bone shape and body mass, age, or pathology, but comparison with historic specimens reveals marked changes in dachshund long bone shape over the past [~]150 years. These extreme differences are not shared by other sampled chondrodysplastic breeds, underscoring the need to understand morphological diversity beyond simple categorisation. These findings provide a quantitative framework for linking postcranial morphology with function, disease risk, and evidence-based improvements to canine welfare.

zoology↗

bioRxiv2024

Introducing SPROUT (Semi-automated Parcellation of Region Outputs Using Thresholding): an adaptable computer vision tool to generate 3D segmentations

The segmentation of fine-grained and complex structures from volumetric data, such as 3D biomedical images, is a manually intensive process, with performance hindered by limited training data and the difficulty of adapting AI models for specialised datasets. Here, we introduce SPROUT, a user-friendly and interpretable segmentation framework that leverages domain-specific priors, enabling experts to translate their knowledge into reproducible, high-quality segmentations across diverse imaging modalities without the need for training data. Its adaptive design facilitates parameter transferability and improves generalisation across similar datasets. Implemented as scripts and a napari plugin, it supports interactive editing and scalable batch processing, lowering the technical barrier for domain experts. We applied SPROUT to datasets spanning different imaging modalities, anatomical complexities, postures, and target structures, producing high-quality segmentations across 2D and 3D tasks. Quantitative comparisons with other methods on a representative dataset showed SPROUT achieved results comparable to expert-corrected interpolation while requiring substantially less manual input. In scenarios where SPROUT achieved high-quality results, supervised models often struggled to reach similar accuracy, highlighting the challenge of deep learning methods in complex domains. We also explored integration with foundation models to accelerate segmentation in high-contrast datasets, illustrating potential for hybrid workflows.

evolutionary biology↗

bioRxiv2022

Duplicated zebrafish (Danio rerio) inositol phosphatases inpp5ka and inpp5kb diverged in expression pattern and function

One hurdle in the development of zebrafish models of human disease is the presence of multiple zebrafish orthologs resulting from whole genome duplication in teleosts. Mutations in Inositol polyphosphate 5-phosphatase K (INPP5K) lead to a syndrome characterized by variable presentation of intellectual disability, brain abnormalities, cataracts, muscle disease, and short stature. INPP5K is a phosphatase acting at position 5 of phosphoinositides to control their homeostasis and is involved in insulin signaling, cytoskeletal regulation, and protein trafficking. Previously, our group and others have replicated the human phenotypes in zebrafish knockdown models by targeting both INPP5K orthologs inpp5ka and inpp5kb. Here, we show that inpp5ka is the more closely related orthologue to human INPP5K. While both inpp5ka and inpp5kb mRNA expression levels follow a similar trend in the developing head, eyes, and tail, inpp5ka is much more abundantly expressed in these tissues than inpp5kb. In situ hybridization revealed a similar trend, also showing unique localization of inpp5kb in the pineal gland indicating different transcriptional regulation. We also found that inpp5kb has lost its catalytic activity against its preferred substrate, PtdIns(4,5)P2. Since most human mutations are missense changes disrupting phosphatase activity, we propose that loss of inpp5ka alone can be targeted to recapitulate the human presentation. In addition, we show that the function of inpp5kb has diverged from inpp5ka and may play a novel role in the zebrafish.

developmental biology↗

bioRxiv2021

Plasmodium falciparum GBP2 is a telomere-associated protein that binds to G-quadruplex DNA and RNA

In the early-diverging protozoan parasite Plasmodium, few telomere-binding proteins have been identified and several are unique. Plasmodium telomeres, like those of most eukaryotes, contain guanine-rich repeats that can form G-quadruplex structures. In model systems, quadruplex-binding drugs can disrupt telomere maintenance and some quadruplex-binding drugs are potent anti-plasmodial agents. Therefore, telomere-interacting and quadruplex-interacting proteins may offer new targets for anti-malarial therapy. Here, we report that P. falciparum GBP2 is such a protein. It was identified via Proteomics of Isolated Chromatin fragments, applied here for the first time in Plasmodium. In vitro, PfGBP2 binds specifically to G-rich telomere repeats in quadruplex form and it can also bind to G-rich RNA. In vivo, PfGBP2 partially colocalises with the known telomeric protein HP1 but is also found in the cytoplasm, probably due to its affinity for RNA. Consistently, its interactome includes numerous RNA-associated proteins. PfGBP2 is evidently a multifunctional DNA/RNA-binding factor in Plasmodium.

microbiology↗