Search bioRxiv⌕ Search

Biology subjects

Benson, A.

Publications and source records attributed to Benson, A..

6 recordsLinked to original sources

One Number to Rule Them All: The Wildlife Sperm Index for Standardized Gamete Assessment

In wildlife conservation, breeding programs focused on reintroduction are critical to recovering endangered species. Assisted reproductive technologies (ARTs) and biobanking play pivotal roles in these efforts but depend on high-quality gametes. Spermatozoa, due to their structural simplicity and well documented quality assessments are often considered the preferred cell type for cryopreservation and ARTs, especially in rare or exotic species. However, inconsistent retrieval of sperm samples with sufficient volume and concentration, especially for critically endangered species, can pose major limitations to assessing overall sperm quality. To address this information gap, we have developed the Wildlife Sperm Index (WSI), a standardized scoring system that integrates key sperm quality metrics--such as motility, viability, and DNA integrity--into a weighted composite score. While this study applies the WSI to sperm, the framework is adaptable to other cell types used in biobanking and reproductive technologies, broadening its potential utility. Unlike traditional sperm assessments that rely solely on microscopy, the WSI provides a scalable and quantitative framework for evaluating samples across species, including those that yield low-volume or concentration sperm samples. We validated the WSI against traditional means of sperm quality assessments, demonstrating its reliability as both a quality assessment and decision-making tool, enabling users to evaluate sample suitability for cryopreservation, ARTs, or downstream applications. By enabling standardized quality tracking, the WSI provides a foundation for more informed reproductive decisions to support global conservation efforts. Summary sentenceWe present the Wildlife Sperm Index (WSI), a standardized, composite scoring system that integrates key sperm quality metrics to improve gamete assessment and supports assisted reproduction and biobanking in wildlife conservation.

cell biology↗

Analyzing Biodiversity in Protected vs. Unprotected Tide Pools

This study assessed the efficacy of marine protected areas (MPAs) by comparing tide pool biodiversity in Half Moon Bay, California between a protected site (Fitzgerald Marine Reserve) and an unprotected site (Mavericks Beach). Samples were collected through random quadrat surveys. ImageJ and RStudio were used to analyze data through three methods utilizing the Simpsons Diversity Index along with three metrics. The unprotected Mavericks Beach displayed greater biodiversity through two metrics while the third did not find significant difference in biodiversity between sites. 30 unique species were present at each site with 43 species between both. These mixed findings prevent us from drawing definitive conclusions on the effectiveness of Half Moon Bays tide pool MPAs but suggest the MPA is less biodiverse. Potential explanations include the Intermediate Disturbance Hypothesis, lack of sample size, or that the MPA is not effective in maintaining biodiversity.

ecology↗

Testing a Method for Quantifying Microplastic Content in Mytilus californianus

With the proliferation of microplastics within the environment, there has been an increased need to quantify them within organic tissues of aquatic species. Several studies have examined the potential role of mussels in filtering these contaminants, prompting interest in characterizing uptake and retention of microplastics in these species. There are a variety of methods to isolate and quantify microplastics, including density separation, enzymatic digestion, and filtration. The applicability of a combined digestion and ultrasonic bath methodology in isolating microplastics from the California mussel (Mytilus californianus Conrad, 1837) was investigated. Microplastics were added to 20-gallon tanks at 0 g (control) 8 mg. Mussel tissues from each tank were digested using potassium hydroxide solutions. These digestions were subjected to vacuum filtration and a sonication bath, then treated with a mixture of sodium hypochlorite and nitric acid. It was found that this method successfully removed organic tissue from the mussels while leaving dyed microplastics intact. The latter were quantified using fluorescent microscopy. This proof-of-principle experiment indicates that this technique can be applied to further studies on environmental impact and retention of microplastics in mussels and may also have utility for other shellfish.

zoology↗

An anisotropic network model of inter-cellular coupling for robust simulation of cardiac electrical excitation in structurally complex and heterogeneous large tissue models

Remodelling of cardiac tissue structure, including intercellular electrical coupling, is a major determinant of the complex and heterogeneous excitation patterns associated with cardiac arrhythmias. Evaluation of the precise mechanisms by which local tissue structure determines global arrhythmic excitation patterns is a major challenge that may be critically important for the development of effective treatment strategies. Computational modelling is a key tool in the study of cardiac arrhythmias, yet the established approaches for organ-scale modelling are unsuitable to capture the impact of local conduction heterogeneities; a novel approach is required to provide this multi-scale mechanistic insight. We present a fundamentally simple yet powerful approach to simulate electrical excitation in highly heterogeneous whole-heart models that exploits the underlying discreteness of the myocardium. Preliminary simulations demonstrate that this approach can capture lower conduction velocities and reproduce wave breakdown and the development of re-entry in conditions where the established approaches cannot.

physiology↗

Chaperone Requirements for De Novo Folding of Saccharomyces cerevisiae Septins

Polymers of septin protein complexes play cytoskeletal roles in eukaryotic cells. The specific subunit composition within complexes controls functions and higher-order structural properties. All septins have globular GTPase domains. The other eukaryotic cytoskeletal NTPases strictly require assistance from molecular chaperones of the cytosol, particularly the cage-like chaperonins, to fold into oligomerization-competent conformations. We previously identified cytosolic chaperones that bind septins and influence the oligomerization ability of septins carrying mutations linked to human disease, but it was unknown to what extent wild-type septins require chaperone assistance for their native folding. Here we use a combination of in vivo and in vitro approaches to demonstrate chaperone requirements for de novo folding and complex assembly by budding yeast septins. Individually purified septins adopted non-native conformations and formed non-native homodimers. In chaperonin- or Hsp70-deficient cells, septins folded slower and were unable to assemble post-translationally into native complexes. One septin, Cdc12, was so dependent on co-translational chaperonin assistance that translation failed without it. Our findings point to distinct translation elongation rates for different septins as a possible mechanism to direct a stepwise, co-translational assembly pathway in which general cytosolic chaperones act as key intermediaries.

molecular biology↗

Visual attention modulates the integration of goal-relevant evidence and not value

When choosing between options, such as food items presented in plain view, people tend to choose the option they spend longer looking at. The prevailing interpretation is that visual attention increases value. However, in previous studies, value was coupled to a behavioural goal, since subjects had to choose the item they preferred. This makes it impossible to discern if visual attention has an effect on value, or, instead, if attention modulates the information most relevant for the goal of the decision-maker. Here we present the results of two independent studies--a perceptual and a value-based task--that allow us to decouple value from goal-relevant information using specific task-framing. Combining psychophysics with computational modelling, we show that, contrary to the current interpretation, attention does not boost value, but instead it modulates goal-relevant information. This work provides a novel and more general mechanism by which attention interacts with choice.

neuroscience↗