E. D. McParland, J. K. Mitchell, J. Laurence-Chasen, L. C. Aspinwall, O. Afolabi, K. Takahashi, C. F. Ross, N. J. Gidmark
{"title":"The kinematics of proal chewing in rats","authors":"E. D. McParland, J. K. Mitchell, J. Laurence-Chasen, L. C. Aspinwall, O. Afolabi, K. Takahashi, C. F. Ross, N. J. Gidmark","doi":"10.1093/iob/obae023","DOIUrl":"https://doi.org/10.1093/iob/obae023","url":null,"abstract":"\u0000 Chewing kinematics are well-documented in several mammal species with fused mandibular symphyses, but relatively understudied in mammals with an unfused symphysis, despite the fact that more than half of extant Mammalia have an unfused mandibular symphysis. The Wistar brown rat (Rattus norvegicus, Berkenhout, 1769) is widely used in human health research, including studies of mastication or neurological studies where mastication is the output behavior. These animals are known to have unfused mandibular symphyses and proal jaw (rostrocaudal) motion during occlusion, but the lack of high resolution, 3-dimensional analysis of rat chewing leaves the functional significance of symphyseal mobility unknown. We used biplanar fluoroscopy and the X-ray Reconstruction Of Moving Morphology (XROMM) workflow (Brainerd et al. 2010; Gatesy et al., 2010) to quantify chewing kinematics in three brown rats, quantifying overall jaw kinematics, including motions about the temporomandibular joint (TMJ) and unfused mandibular symphysis. During occlusion, the teeth and the mandibular condyle translate almost exclusively anteriorly (proal) during occlusion, with little motion in any other degrees of freedom. At the symphysis, we observed minimal flexion throughout the chew cycle. Overall, there are fundamental differences in jaw kinematics between rats and other mammals and therefore rats are not an appropriate proxy for ancestral mammal jaw mechanics. Additionally, differences between humans and rat chewing kinematics must be considered when using rats as a clinical model for pathological feeding research.","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luis X de Pablo, Adrian Carleton, Yahya Modarres-Sadeghi, Ethan D Clotfelter
{"title":"Substrate Interactions and Free-Swimming Dynamics in the Crayfish Escape Response","authors":"Luis X de Pablo, Adrian Carleton, Yahya Modarres-Sadeghi, Ethan D Clotfelter","doi":"10.1093/iob/obae027","DOIUrl":"https://doi.org/10.1093/iob/obae027","url":null,"abstract":"\u0000 The caridoid or “tail flip” escape behavior of decapod crustaceans is a model system in neurobiology, but many aspects of its biomechanics are not well understood. To understand how the freshwater virile crayfish Faxonius virilis interacts with the substrate during the tail flip, we studied tail-flip hydrodynamics and force generation for free-moving animals standing on substrate, as well as tethered animals held at different distances from the substrate. We found no significant differences in force generation when distance from substrate was varied. Particle image velocimetry (PIV) revealed that vortex formation was similar at all distances, but there were notable differences in interactions between shed vortices and substrate at different distances. Negative vorticity (clockwise flow of water) was observed in tethered animals interacting with the substrate but was largely absent in free-swimming animals. We found no evidence of ground effects enhancing tail flip performance in either tethered or free-swimming individuals, as peak force generation occurred before vortex shedding. This study contributes to our understanding of the crayfish escape response and highlights the need for more work that incorporates free-swimming animals and complex environments in the study of crustacean biomechanics.","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A W Vogl, H Petersen, K N Gil, R Cieri, R E Shadwick
{"title":"The Soft Palate Enables Extreme Feeding and Explosive Breathing in the Fin Whale (<i>Balaenoptera physalus</i>).","authors":"A W Vogl, H Petersen, K N Gil, R Cieri, R E Shadwick","doi":"10.1093/iob/obae026","DOIUrl":"10.1093/iob/obae026","url":null,"abstract":"<p><p>The evolution of lunge feeding in rorqual whales was associated with the evolution of several unique morphological features that include non-synovial ligamentous temporomandibular joints, a tongue that can invert and extend backward to the umbilicus, walls of the oral cavity that can dramatically expand, and muscles and nerves that are stretchy. Also, among the acquired features was an enlargement of the rostral end of the soft palate into an oral plug that occludes the opening between the oral cavity and pharynx and prevents water incursion into the pharynx during the engulfment phase of a feeding lunge. During this engulfment phase of a lunge, the volume of water entering the oral cavity can exceed the volume of the whale itself. Here, using dissection of fetuses and adults and a magnetic resonance imaging dataset of a fetus, we examine the detailed anatomy of the soft palate in fin whales. We describe several innovative features relative to other mammals, including changes in the attachment and positions of the major extrinsic muscles of the palate, alterations in the morphology of the pterygoid processes related to the palate and pharynx, and the presence of distinct muscle layers in the part of the palate caudal to the oral plug. Based on the anatomy, we present a model for how the soft palate is positioned at rest, and how it functions during feeding, breathing, and swallowing.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11261304/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141748059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Morphological and Mechanical Tube Feet Plasticity among Populations of Sea Urchin (<i>Strongylocentrotus purpuratus</i>).","authors":"C A Narvaez, A Y Stark, M P Russell","doi":"10.1093/iob/obae022","DOIUrl":"10.1093/iob/obae022","url":null,"abstract":"<p><p>Sea urchins rely on an adhesive secreted by their tube feet to cope with the hydrodynamic forces of dislodgement common in nearshore, high wave-energy environments. Tube feet adhere strongly to the substrate and detach voluntarily for locomotion. In the purple sea urchin, <i>Strongylocentrotus purpuratus</i>, adhesive performance depends on both the type of substrate and the population of origin, where some substrates and populations are more adhesive than others. To explore the source of this variation, we evaluated tube foot morphology (disc surface area) and mechanical properties (maximum disc tenacity and stem breaking force) of populations native to substrates with different lithologies: sandstone, mudstone, and granite. We found differences among populations, where sea urchins native to mudstone substrates had higher disc surface area and maximum disc tenacity than sea urchins native to sandstone substrates. In a lab-based reciprocal transplant experiment, we attempted to induce a plastic response in tube foot morphology. We placed sea urchins on nonnative substrates (i.e., mudstone sea urchins were placed on sandstone and vice versa), while keeping a subgroup of both populations on their original substrates as a control. Instead of a reciprocal morphological response, we found that all treatments, including the control, reduced their disc area in laboratory conditions. The results of this study show differences in morphology and mechanical properties among populations, which explains population differences in adhesive performance. Additionally, this work highlights the importance of considering the impact of phenotypic plasticity in response to captivity when interpreting the results of laboratory studies.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11234643/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141579602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sharks Violate Rensch's Rule for Sexual Size Dimorphism.","authors":"J H Gayford, P C Sternes","doi":"10.1093/iob/obae025","DOIUrl":"10.1093/iob/obae025","url":null,"abstract":"<p><p>Systematic trends in body size variation exist in a multitude of vertebrate radiations, however their underlying ecological and evolutionary causes remain poorly understood. Rensch's rule describes one such trend-in which the scaling of sexual size dimorphism (SSD) depends on which sex is larger. Where SSD is male-biased, SSD should scale hyperallometrically, as opposed to hypoallometrically where SSD is female-biased. The evidence for Rensch's rule is mixed, and comes from a small subset of total vertebrate diversity. We conducted the first empirical test of Rensch's rule in sharks, seeking to confirm or refute a long-hypothesied trend. We find that sharks violate Rensch's rule, as the magnitude of SSD increases with body size despite sharks predominantly exhibiting female-biased SSD. This adds to a growing literature of vertebrate clades that appear not to follow Rensch's rule, suggesting the absence of a single, conserved scaling trend for SSD amongst vertebrates. It is likely that selection associated with fecundity results in the \"inverse Rensch's rule\" observed in sharks, although additional studies will be required to fully reveal the factors underlying SSD variation in this clade.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11247179/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141619819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zachary S Morris, Mathew W Colbert, Timothy B. Rowe
{"title":"Variation and variability in skeletal ossification of the gray short-tailed opossum, Monodelphis domestica","authors":"Zachary S Morris, Mathew W Colbert, Timothy B. Rowe","doi":"10.1093/iob/obae024","DOIUrl":"https://doi.org/10.1093/iob/obae024","url":null,"abstract":"\u0000 By reconstructing and comparing the sequence of ontogenetic (embryonic development and post-natal growth) events across species, developmental biologists have gained unique insights into the key processes underlying the evolution of modern lineages and their extinct relatives. However, despite the importance of intraspecific variation to evolutionary transformation and lineage divergence, variation in the sequence of developmental events is seldom acknowledged. Thus, how much variation or variability should be expected during ontogeny remains poorly understood and it is an open question to what extent it impacts interspecific comparisons of developmental patterns. To address this crucial question, we studied the skeletal development of the important biomedical and developmental model organism, Monodelphis domestica. We investigated cranial, forelimb, and hindlimb elements using Ontogenetic Sequence Analysis (OSA) to quantify and assess the full range of variation and variability in the sequence of ossification. Our study documented that previously unrecognized variation exists during M. domestica ontogeny — with over 5000 sequences for the full 92 event analysis. Further, OSA revealed unexpectedly high variability (i.e., the propensity to express variation) in the sequence of ossification for the skull and across the entire skeleton. Reconstructed modal sequences were generally in agreement with previously recognized patterns, including earlier ossification of the facial skeleton and a slight offset between forelimb and hindlimb development. However, the full range of variation shows that the majority of specimens in our analysis followed developmental trajectories distinct from those recovered by prior studies. This level of variation is quite remarkable and demonstrates the importance of assessing intraspecific ontogenetic variation. By quantifying sequence polymorphism and studying how developmental variation and variability differ among species, we can clarify more precisely how developmental patterns differ among species and gain insights into how ontogeny itself evolves.","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141683039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Morphology and Mechanics of the Fin Whale Esophagus: The Key to Fast Processing of Large Food Volumes by Rorquals.","authors":"K N Gil, A W Vogl, R E Shadwick","doi":"10.1093/iob/obae020","DOIUrl":"10.1093/iob/obae020","url":null,"abstract":"<p><p>Lunge feeding rorqual whales feed by engulfing a volume of prey laden water that can be as large as their own body. Multiple feeding lunges occur during a single foraging dive and the time between each lunge can be as short as 30 s (Goldbogen et al. 2013). During this short inter-lunge time, water is filtered out through baleen to concentrate prey in the oral cavity, and then the prey is swallowed prior to initiating the next lunge. Prey density in the ocean varies greatly, and despite the potential of swallowing a massive volume of concentrated prey as a slurry, the esophagus of rorqual whales has been anecdotally described as unexpectedly narrow with a limited capacity to expand. How rorquals swallow large quantities of food down a narrow esophagus during a limited inter-lunge time remains unknown. Here, we show that the small diameter muscular esophagus in the fin whale is optimized to transport a slurry of food to the stomach. A thick wall of striated muscle occurs at the pharyngeal end of the esophagus which, together with the muscular wall of the pharynx, may generate a pressure head for transporting the food down the esophagus to the stomach as a continuous stream rather than separating the food into individual boluses swallowed separately. This simple model is consistent with estimates of prey density and stomach capacity. Rorquals may be the only animals that capture a volume of food too large to swallow as a single intact bolus without oral processing, so the adaptations of the esophagus are imperative for transporting these large volumes of concentrated food to the stomach during a time-limited dive involving multiple lunges.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11221840/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141497949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Amphibian Segmentation Clock Models Suggest How Large Genome and Cell Sizes Slow Developmental Rate.","authors":"A Taylor, A Prasad, R Lockridge Mueller","doi":"10.1093/iob/obae021","DOIUrl":"10.1093/iob/obae021","url":null,"abstract":"<p><p>Evolutionary increases in genome size, cell volume, and nuclear volume have been observed across the tree of life, with positive correlations documented between all three traits. Developmental tempo slows as genomes, nuclei, and cells increase in size, yet the driving mechanisms are poorly understood. To bridge this gap, we use a mathematical model of the somitogenesis clock to link slowed developmental tempo with changes in intra-cellular gene expression kinetics induced by increasing genome size and nuclear volume. We adapt a well-known somitogenesis clock model to two model amphibian species that vary 10-fold in genome size: <i>Xenopus laevis</i> (3.1 Gb) and <i>Ambystoma mexicanum</i> (32 Gb). Based on simulations and backed by analytical derivations, we identify parameter changes originating from increased genome and nuclear size that slow gene expression kinetics. We simulate biological scenarios for which these parameter changes mathematically recapitulate slowed gene expression in <i>A. mexicanum</i> relative to <i>X. laevis</i>, and we consider scenarios for which additional alterations in gene product stability and chromatin packing are necessary. Results suggest that slowed degradation rates as well as changes induced by increasing nuclear volume and intron length, which remain relatively unexplored, are significant drivers of slowed developmental tempo.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11245677/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141616317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Buffered Lugol's Iodine Preserves DNA Fragment Lengths.","authors":"P M Gignac, D Valdez, A C Morhardt, L M Lynch","doi":"10.1093/iob/obae017","DOIUrl":"10.1093/iob/obae017","url":null,"abstract":"<p><p>Museum collections play a pivotal role in the advancement of biological science by preserving phenotypic and genotypic history and variation. Recently, contrast-enhanced X-ray computed tomography (CT) has aided these advances by allowing improved visualization of internal soft tissues. However, vouchered specimens could be at risk if staining techniques are destructive. For instance, the pH of unbuffered Lugol's iodine (I<sub>2</sub>KI) may be low enough to damage deoxyribonucleic acid (DNA). The extent of this risk is unknown due to a lack of rigorous evaluation of DNA quality between control and experimental samples. Here, we used formalin-fixed mice to document DNA concentrations and fragment lengths in nonstained, ethanol-preserved controls and 3 iodine-based staining preparations: (1) 1.25% weight-by-volume (wt/vol.) alcoholic iodine (I<sub>2</sub>E); (2) 3.75% wt/vol. I<sub>2</sub>KI; and (3) 3.75% wt/vol. buffered I<sub>2</sub>KI. We tested a null hypothesis of no significant difference in DNA concentrations and fragment lengths between control and treatment samples. We found that DNA concentration decreases because of staining-potentially an effect of measuring intact double-stranded DNA only. Fragment lengths, however, were significantly higher for buffered I<sub>2</sub>KI and control samples, which were not, themselves, significantly different. Our results implicate buffered I<sub>2</sub>KI as the appropriate choice for contrast-enhanced CT imaging of museum wet collections to safely maximize their potential for understanding genetic and phenotypic diversity.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11182668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141418837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Four-bar geometry is shared among ecologically divergent fish species","authors":"H Camarillo, E D Burress, M M Muñoz","doi":"10.1093/iob/obae019","DOIUrl":"https://doi.org/10.1093/iob/obae019","url":null,"abstract":"\u0000 Understanding the factors that influence morphological evolution is a major goal in biology. One such factor is the ability to acquire and process prey. Prey hardness and evasiveness are important properties that can impact evolution of the jaws. Similar diets and biomechanical systems have repeatedly evolved among fish lineages, providing an opportunity to test for shared patterns of evolution across distantly related organisms. Four-bar linkages are structures often used by animals to transmit force and motion during feeding, and which provide an excellent system to understand the impact of diet on morphological and biomechanical evolution. Here, we tested how diet influences the evolutionary dynamics of the oral four-bar linkage system in wrasses (Family: Labridae) and cichlids (Family: Cichlidae). We found that shifts in prey hardness/evasiveness are associated with limited modifications in four-bar geometry across these two distantly related fish lineages. Wrasse and cichlid four-bar systems largely exhibit many-to-one mapping in response to dietary shifts. Across two iconic adaptive radiations of fishes an optimal four-bar geometry has largely been co-opted for different dietary functions during their extensive ecological diversification. Given the exceptional jaw diversity of both lineages, many-to-one mapping of morphology to mechanical properties may be a core feature of fish adaptive radiation.","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141342825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}