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1.
Cytotherapy ; 25(12): 1349-1360, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37690020

RESUMEN

Autologous cell-based therapeutics have gained increasing attention in recent years because of their efficacy at treating diseases with limited therapeutic options. Chimeric antigen receptor (CAR) T-cell therapy has demonstrated clinical success in hematologic oncology indications, providing critically ill patients with a potentially curative therapy. Although engineered cell therapies such as CAR T cells provide new options for patients with unmet needs, the high cost and complexity of manufacturing may hinder clinical and commercial translation. The Cocoon Platform (Lonza, Basel, Switzerland) addresses many challenges, such as high labor demand, process consistency, contamination risks and scalability, by enabling efficient, functionally closed and automated production, whether at clinical or commercial scale. This platform is customizable and easy to use and requires minimal operator interaction, thereby decreasing process variability. We present two processes that demonstrate the Cocoon Platform's capabilities. We employed different T-cell activation methods-OKT3 and CD3/CD28 Dynabeads (Thermo Fisher Scientific, Waltham, MA, USA)-to generate final cellular products that meet the critical quality attributes of a clinical autologous CAR T-cell product. This study demonstrates a manufacturing solution for addressing challenges with manual methods of production and facilitating the scale-up of autologous cell therapy.


Asunto(s)
Receptores Quiméricos de Antígenos , Humanos , Receptores Quiméricos de Antígenos/genética , Receptores de Antígenos de Linfocitos T/genética , Citocinas , Linfocitos T , Inmunoterapia Adoptiva/métodos
2.
J Hum Evol ; 173: 103268, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36288639

RESUMEN

Recent studies have shown that global variation in body proportions is more complex than previously thought as some traits formerly associated with climate adaptation are better explained by geographic proximity and neutral evolutionary forces. While the recent incorporation of quantitative genetic methodologies has improved understanding of patterns related to climate in Africa, Europe, and the Americas, Asia remains underrepresented in recent and historic studies of body form. As ecogeographic studies tend to focus on male morphology, potential sex differences in features influenced by climate remain largely unexplored. Skeletal measurements encompassing the dimensions of the skull, pelvis, limbs, hands, and feet were collected from male (n = 459) and female (n = 442) remains curated in 13 collections across seven countries in East Asia (n = 901). Osteological data were analyzed with sex and minimum temperature as covariates adjusted by autosomal single-nucleotide polymorphism population genetic distance using univariate Bayesian linear mixed models, and credible intervals were calculated for each trait. Analysis supports a relationship between specific traits and climate as well as providing the magnitude of response in both sexes. After accounting for genetic distance between populations, greater association between climate and morphology was found in postcranial traits, with the relationship between climate and the skull limited primarily to breadth measurements. Larger body size is associated with colder climates with most measurements increasing with decreased temperature. The same traits were not always associated with climate for males and females nor correlated with the same intensity for both sexes. The varied directional association with climate for different regions of the skeleton and between the sexes underscores the necessity of future ecogeographic research to holistically evaluate body form and to look for sex-specific patterns to better understand population responses to environmental stresses.


Asunto(s)
Clima , Cráneo , Femenino , Masculino , Humanos , Teorema de Bayes , Cráneo/anatomía & histología , Flujo Genético , Clima Frío
3.
J Exp Biol ; 225(Suppl1)2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35119075

RESUMEN

Comparing patterns of performance and kinematics across behavior, development and phylogeny is crucial to understand the evolution of complex musculoskeletal systems such as the feeding apparatus. However, conveying 3D spatial data of muscle orientation throughout a feeding cycle, ontogenetic pathway or phylogenetic lineage is essential to understanding the function and evolution of the skull in vertebrates. Here, we detail the use of ternary plots for displaying and comparing the 3D orientation of muscle data. First, we illustrate changes in 3D jaw muscle resultants during jaw closing taxa the American alligator (Alligator mississippiensis). Second, we show changes in 3D muscle resultants of jaw muscles across an ontogenetic series of alligators. Third, we compare 3D resultants of jaw muscles of avian-line dinosaurs, including extant (Struthio camelus, Gallus gallus, Psittacus erithacus) and extinct (Tyrannosaurus rex) species to outline the reorganization of jaw muscles that occurred along the line to modern birds. Finally, we compare 3D resultants of jaw muscles of the hard-biting species in our sample (A. mississippiensis, T. rex, P. erithacus) to illustrate how disparate jaw muscle resultants are employed in convergent behaviors in archosaurs. Our findings show that these visualizations of 3D components of jaw muscles are immensely helpful towards identifying patterns of cranial performance, growth and diversity. These tools will prove useful for testing other hypotheses in functional morphology, comparative biomechanics, ecomorphology and organismal evolution.


Asunto(s)
Caimanes y Cocodrilos , Dinosaurios , Sistema Musculoesquelético , Struthioniformes , Animales , Evolución Biológica , Dinosaurios/anatomía & histología , Imagenología Tridimensional , Maxilares/anatomía & histología , Músculos/anatomía & histología , Filogenia
4.
Cleft Palate Craniofac J ; 59(2): 230-238, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-33998905

RESUMEN

OBJECTIVE: To identify differences between asymptote- and rate-based methods for estimating age and size at growth cessation in linear craniofacial measurements. DESIGN: This is a retrospective, longitudinal study. Five linear measurements were collected from lateral cephalograms as part of the Craniofacial Growth Consortium Study (CGCS). Four estimates of growth cessation, including 2 asymptote- (GCasym, GCerr) and 2 rate-based (GCabs, GC10%) methods, from double logistic models of craniofacial growth were compared. PARTICIPANTS: Cephalometric data from participants in 6 historic longitudinal growth studies were included in the CGCS. At least 1749 individuals (870 females, 879 males), unaffected by craniofacial anomalies, were included in all analyses. Individuals were represented by a median of 11 images between 2.5 and 31.3 years of age. RESULTS: GCasym consistently occurred before GCerr and GCabs consistently occurred before GC10% within the rate-based approaches. The ordering of the asymptote-based methods compared to the rate-based methods was not consistent across measurements or between males and females. Across the 5 measurements, age at growth cessation ranged from 13.56 (females, nasion-basion, GCasym) to 24.39 (males, sella-gonion, GCerr). CONCLUSIONS: Adolescent growth cessation is an important milestone for treatment planning. Based on our findings, we recommend careful consideration of specific definitions of growth cessation in both clinical and research settings since the most appropriate estimation method may differ according to patients' needs. The different methods presented here provide useful estimates of growth cessation that can be applied to raw data and to a variety of statistical models of craniofacial growth.


Asunto(s)
Anomalías Craneofaciales , Adolescente , Cefalometría , Femenino , Humanos , Modelos Logísticos , Estudios Longitudinales , Masculino , Estudios Retrospectivos
5.
Can J Respir Ther ; 58: 77-83, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35800849

RESUMEN

Objective: Despite evidence-based guidelines, SpO2 maintenance-related practices of care providers remain inconsistent. Our aim was to evaluate the impact of interprofessional learning workshops, bedside coaching, and neonatal intensive care unit (NICU) level enablers on targeted behavioral change of NICU staff, focusing on SpO2 maintenance. Methods: NICU is a specialized area of the hospital with sophisticated monitors where multidisciplinary staff provide round-the-clock care for sick and preterm infants. As a subset of a quality improvement project to improve SpO2 maintenance and reduce desaturation events, three targeted evidence-based staff behaviors were deemed as important based on established capability-opportunity-motivation-behavior and theoretical domains framework models: setting SpO2 alarm limits, using SpO2 alarm management algorithms, and reporting daily summaries of SpO2 during rounds. We conducted interprofessional workshops, provided bedside coaching, and altered unit NICU processes (guidelines, automated SpO2 histogram printouts, defined staff standard work) and measured demonstrable changes in staff reaction, learning, and behaviors by direct observation of behaviors and survey questionnaires. Results: Two hundred and seventy-five (87%) and 210 (80%) of NICU staff attended workshops and received bedside coaching, respectively. The proportion of staff expressing satisfaction with workshop and bedside coaching was 85% and 82%, respectively. The proportion of staff reporting improvement in their knowledge and confidence related to SpO2 maintenance increased significantly following the workshop. Targeted behaviors related to SpO2 maintenance like setting appropriate alarm limits, adhering to SpO2 management algorithm, and reporting daily SpO2 summaries during rounds increased from 80% to 96%, 0% to 64%, and 20% to 70%, respectively. Conclusion: Focused behavioral change interventions aimed at improving staff capability, opportunity, and motivation resulted in a demonstrable change in targeted staff behaviors related to SpO2 maintenance. Further research is needed to establish ways of optimizing intended staff behaviors while implementing care bundles in a given setting.

6.
Ann Hum Biol ; 47(5): 434-445, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32543236

RESUMEN

BACKGROUND: Estimates pertaining to the timing of the adolescent growth spurt (e.g. peak height velocity; PHV), including age at peak height velocity (aPHV), play a critical role in the diagnosis, treatment, and management of skeletal growth and/or developmental disorders. Yet, distinct statistical methodologies often result in large estimate discrepancies. AIM: The aim of the present study was to assess the advantages and disadvantages of three modelling methodologies for height as well as to determine how estimates derived from these methodologies may differ, particularly those that may be useful in paediatric clinical practice. SUBJECTS AND METHODS: Height data from 686 individuals of the Fels Longitudinal Study were modelled using 5th order polynomials, natural cubic splines, and SuperImposition by Translation and Rotation (SITAR) to determine aPHV and PHV for all individuals together (i.e. population average) by sex and separately for each individual. Estimates within and between methodologies were calculated and compared. RESULTS: In general, mean aPHV was earlier, and PHV was greater for individuals when compared to estimates from population average models. Significant differences between mean aPHV and PHV for individuals were observed in all three methodologies, with SITAR exhibiting the latest aPHV and largest PHV estimates. CONCLUSION: Each statistical methodology has a number of advantages when used for specific purposes. For modelling growth in individuals, as one would in paediatric clinical practice, we recommend the use of the 5th order polynomial methodology due to its parameter flexibility.


Asunto(s)
Antropometría/métodos , Estatura , Adolescente , Factores de Edad , Niño , Femenino , Humanos , Estudios Longitudinales , Masculino , Missouri , Adulto Joven
7.
J Cell Biochem ; 120(5): 7590-7601, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30417549

RESUMEN

Bone metastases occur in 65% to 75% of patients with advanced breast cancer and significantly worsen their survival and quality of life. We previously showed that conditioned medium (CM) from osteocytes stimulated with oscillatory fluid flow, mimicking bone mechanical loading during routine physical activities, reduced the transendothelial migration of breast cancer cells. Endothelial cells are situated at an ideal location to mediate signals between osteocytes in the bone matrix and metastasizing cancer cells in the blood vessels. In this study, we investigated the specific effects of flow-stimulated osteocytes on the interaction between endothelial cells and breast cancer cells in vitro. We observed that CM from flow-stimulated osteocytes reduced endothelial permeability by 15% and breast cancer cell adhesion onto endothelial monolayers by 18%. The difference in adhesion was abolished with anti-intercellular adhesion molecule 1 (ICAM-1) neutralizing antibodies. Furthermore, CM from endothelial cells conditioned in CM from flow-stimulated osteocytes significantly altered the gene expression in bone-metastatic breast cancer cells, as shown by RNA sequencing. Specifically, breast cancer cell expression of matrix metallopeptidase 9 (MMP-9) was downregulated by 62%, and frizzled-4 (FZD4) by 61%, when the osteocytes were stimulated with flow. The invasion of these breast cancer cells across Matrigel was also reduced by 47%, and this difference was abolished by MMP-9 inhibitors. In conclusion, we demonstrated that flow-stimulated osteocytes downregulate the bone-metastatic potential of breast cancer cells by signaling through endothelial cells. This provides insights into the capability of bone mechanical regulation in preventing bone metastases; and may assist in prescribing exercise or bone-loading regimens to patients with breast cancers.

8.
Heredity (Edinb) ; 122(5): 582-594, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30356225

RESUMEN

The nutritional conditions experienced by a population have a major role in shaping trait evolution in many taxa. Constraints exerted by nutrient limitation or nutrient imbalance can influence the maximal value that fitness components such as reproduction and lifespan attains, and organisms may shift how resources are allocated to different structures and functions in response to changes in nutrition. Whether the phenotypic changes associated with changes in nutrition represent an adaptive response is largely unknown. Further, it is unclear whether the response of fitness components to diet even has the potential to evolve in most systems. In this study, we use an admixed multi-parental population of Drosophila melanogaster reared in three different diet conditions to estimate quantitative genetic parameters for lifespan and fecundity. We find significant genetic variation for both traits in our population and show that lifespan has moderate to high heritabilities within diets. Genetic correlations for lifespan between diets were significantly less than one, demonstrating a strong genotype by diet interaction. These findings demonstrate substantial standing genetic variation in our population that is comparable to natural populations and highlights the potential for adaptation to changing nutritional environments.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales/genética , Evolución Biológica , Drosophila melanogaster/genética , Animales , Dieta , Drosophila melanogaster/fisiología , Fertilidad/genética , Variación Genética , Genética de Población , Herencia , Longevidad/genética , Fenotipo , Sitios de Carácter Cuantitativo/genética
9.
J Exp Biol ; 222(Pt 18)2019 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-31481636

RESUMEN

Numerous vertebrates exhibit cranial kinesis, or movement between bones of the skull and mandible other than at the jaw joint. Many kinetic species possess a particular suite of features to accomplish this movement, including flexible cranial joints and protractor musculature. Whereas the musculoskeletal anatomy of these kinetic systems is well understood, how these joints are biomechanically loaded, how different soft tissues affect joint loading and kinetic capacity, and how the protractor musculature loads the skull remain poorly understood. Here, we present a finite element model of the savannah monitor, Varanus exanthematicus, a modestly kinetic lizard, to better elucidate the roles of soft tissue in mobile joints and protractor musculature in cranial loading. We describe the 3D resultants of jaw muscles and the histology of palatobasal, otic and jaw joints. We tested the effects of joint tissue type, bite point and muscle load to evaluate the biomechanical role of muscles on the palate and braincase. We found that the jaw muscles have significant mediolateral components that can impart stability across palatocranial joints. Articular tissues affect the magnitude of strains experienced around the palatobasal and otic joints. Without protractor muscle loading, the palate, quadrate and braincase experience higher strains, suggesting this muscle helps insulate the braincase and palatoquadrate from high loads. We found that the cross-sectional properties of the bones of V. exanthematicus are well suited for performing under torsional loads. These findings suggest that torsional loading regimes may have played a more important role in the evolution of cranial kinesis in lepidosaurs than previously appreciated.


Asunto(s)
Articulaciones/anatomía & histología , Lagartos/anatomía & histología , Cráneo/anatomía & histología , Animales , Fenómenos Biomecánicos , Simulación por Computador , Maxilares/anatomía & histología , Cinesis , Hueso Paladar/anatomía & histología , Tomografía Computarizada por Rayos X
10.
J Cell Biochem ; 119(7): 5665-5675, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29384215

RESUMEN

Bone metastases, the migration of cancers to bone, occur in 65-80% of patients with advanced breast cancer. Metastasized cancer cells interact with cells such as the bone-resorbing osteoclasts to alter bone remodeling. Exercise, often suggested as an intervention for cancer patients, regulates bone remodeling via osteocytes. Osteocytes also signal to endothelial cells, which may affect cancer cell extravasation. Therefore, we hypothesize that mechanically stimulated osteocytes can regulate processes in breast cancer bone metastasis. To test this, we exposed osteocytes to oscillatory fluid flow in vitro using parallel-plate flow chambers. We observed that conditioned medium from flow-stimulated osteocytes increased migration (by 45%) and reduced apoptosis (by 12%) of breast cancer cells. Conditioned medium from osteoclasts conditioned in flowed osteocytes' conditioned medium reduced migration (by 47%) and increased apoptosis (by 55%) of cancer cells. Cancer cell trans-endothelial migration was reduced by 34% toward flowed osteocytes' conditioned medium. This difference was abolished with ICAM-1 or IL-6 neutralizing antibodies. Conditioned medium from endothelial cells conditioned in flowed osteocytes' conditioned medium increased cancer cell apoptosis by 29%. To summarize, this study demonstrated mechanically stimulated osteocytes' potential to affect breast cancer cells not only through direct signaling, but also through osteoclasts and endothelial cells. The anti-metastatic potential of the indirect signalings is particularly exciting since osteocytes are further away from metastasizing cancer cells than osteoclasts and endothelial cells. Future studies into the effect of bone mechanical loading on metastases and its mechanism will assist in designing cancer intervention programs that lowers the risk for bone metastases.


Asunto(s)
Apoptosis/efectos de los fármacos , Neoplasias de la Mama/patología , Movimiento Celular/efectos de los fármacos , Medios de Cultivo Condicionados/farmacología , Endotelio Vascular/fisiología , Osteoclastos/patología , Osteocitos/patología , Animales , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Células Cultivadas , Endotelio Vascular/citología , Femenino , Humanos , Ratones , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismo , Osteocitos/efectos de los fármacos , Osteocitos/metabolismo , Osteogénesis , Estrés Mecánico
11.
Am J Phys Anthropol ; 165(3): 457-470, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29154456

RESUMEN

OBJECTIVES: Analyses of bone cross-sectional geometry are frequently used by anthropologists and paleontologists to infer the loading histories of past populations. To address some underlying assumptions, we investigated the relative roles of genetics and exercise on bone cross-sectional geometry and bending mechanics in three mouse strains: high bone density (C3H/He), low bone density (C57BL/6), and a high-runner strain homozygous for the Myh4Minimsc allele (MM). METHODS AND MATERIALS: Weanlings of each strain were divided into exercise (wheel) or control (sedentary) treatment groups for a 7-week experimental period. Morphometrics of the femoral mid-diaphysis and mechanical testing were used to assess both theoretical and ex vivo bending mechanics. RESULTS: Across all measured morphological and bending traits, we found relatively small effects of exercise treatment compared to larger and more frequent interstrain differences. In the exercised group, total distance run over the experimental period was not a predictor of any morphological or bending traits. Cross-sectional geometry did not accurately predict bone response to loading. DISCUSSION: Results from this experimental model do not support hypothesized associations among extreme exercise, cross-sectional geometry, and bending mechanics. Our results suggest that analysis of cross-sectional geometry alone is insufficient to predict loading response, and questions the common assumption that cross-sectional geometry differences are indicative of differential loading history.


Asunto(s)
Fémur/anatomía & histología , Fémur/fisiología , Condicionamiento Físico Animal/fisiología , Anatomía Transversal , Animales , Antropología Física , Fenómenos Biomecánicos/fisiología , Diáfisis/anatomía & histología , Diáfisis/fisiología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Soporte de Peso/fisiología
12.
J Exp Biol ; 220(Pt 11): 2036-2046, 2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28363902

RESUMEN

Three-dimensional computational modeling offers tools with which to investigate forces experienced by the skull during feeding and other behaviors. American alligators (Alligator mississippiensis) generate some of the highest measured bite forces among extant tetrapods. A concomitant increase in bite force accompanies ontogenetic increases in body mass, which has been linked with dietary changes as animals increase in size. Because the flattened skull of crocodylians has substantial mediolaterally oriented muscles, crocodylians are an excellent model taxon in which to explore the role of mediolateral force components experienced by the feeding apparatus. Many previous modeling studies of archosaur cranial function focused on planar analysis, ignoring the mediolateral aspects of cranial forces. Here, we used three-dimensionally accurate anatomical data to resolve 3D muscle forces. Using dissection, imaging and computational techniques, we developed lever and finite element models of an ontogenetic series of alligators to test the effects of size and shape on cranial loading and compared estimated bite forces with those previously measured in vivo in A. mississippiensis We found that modeled forces matched in vivo data well for intermediately sized individuals, and somewhat overestimated force in smaller specimens and underestimated force in larger specimens, suggesting that ontogenetically static muscular parameters and bony attachment sites alone cannot account for all the variation in bite force. Adding aponeurotic muscle attachments would likely improve force predictions, but such data are challenging to model and integrate into analyses of extant taxa and are generally unpreserved in fossils. We conclude that anatomically accurate modeling of muscles can be coupled with finite element and lever analyses to produce reliable, reasonably accurate estimate bite forces and thus both skeletal and joint loading, with known sources of error, which can be applied to extinct taxa.


Asunto(s)
Caimanes y Cocodrilos/crecimiento & desarrollo , Fuerza de la Mordida , Cráneo/anatomía & histología , Caimanes y Cocodrilos/anatomía & histología , Caimanes y Cocodrilos/fisiología , Animales , Fenómenos Biomecánicos , Simulación por Computador , Análisis de Elementos Finitos , Músculo Esquelético/anatomía & histología , Músculo Esquelético/crecimiento & desarrollo , Cráneo/crecimiento & desarrollo , Tomografía Computarizada por Rayos X
14.
Genetics ; 227(1)2024 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-38506092

RESUMEN

Thermal tolerance is a fundamental physiological complex trait for survival in many species. For example, everyday tasks such as foraging, finding a mate, and avoiding predation are highly dependent on how well an organism can tolerate extreme temperatures. Understanding the general architecture of the natural variants within the genes that control this trait is of high importance if we want to better comprehend thermal physiology. Here, we take a multipronged approach to further dissect the genetic architecture that controls thermal tolerance in natural populations using the Drosophila Synthetic Population Resource as a model system. First, we used quantitative genetics and Quantitative Trait Loci mapping to identify major effect regions within the genome that influences thermal tolerance, then integrated RNA-sequencing to identify differences in gene expression, and lastly, we used the RNAi system to (1) alter tissue-specific gene expression and (2) functionally validate our findings. This powerful integration of approaches not only allows for the identification of the genetic basis of thermal tolerance but also the physiology of thermal tolerance in a natural population, which ultimately elucidates thermal tolerance through a fitness-associated lens.


Asunto(s)
Drosophila melanogaster , Sitios de Carácter Cuantitativo , Termotolerancia , Animales , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Termotolerancia/genética , Variación Genética
15.
Am J Phys Anthropol ; 167(1): 190-193, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29900531
16.
Sci Rep ; 13(1): 19294, 2023 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-37935807

RESUMEN

Dense, longitudinal sampling represents the ideal for studying biological growth. However, longitudinal samples are not typically possible, due to limits of time, prohibitive cost, or health concerns of repeat radiologic imaging. In contrast, cross-sectional samples have few such drawbacks, but it is not known how well estimates of growth milestones can be obtained from cross-sectional samples. The Craniofacial Growth Consortium Study (CGCS) contains longitudinal growth data for approximately 2000 individuals. Single samples from the CGCS for individuals representing cross-sectional data were used to test the ability to predict growth parameters in linear trait measurements separately by sex. Testing across a range of cross-sectional sample sizes from 5 to the full sample, we found that means from repeated samples were able to approximate growth rates determined from the full longitudinal CGCS sample, with mean absolute differences below 1 mm at cross-sectional sample sizes greater than ~ 200 individuals. Our results show that growth parameters and milestones can be accurately estimated from cross-sectional data compared to population-level estimates from complete longitudinal data, underscoring the utility of such datasets in growth modeling. This method can be applied to other forms of growth (e.g., stature) and to cases in which repeated radiographs are not feasible (e.g., cone-beam CT).


Asunto(s)
Sistema Musculoesquelético , Humanos , Estudios Transversales , Radiografía , Tomografía Computarizada de Haz Cónico , Esqueleto , Estudios Longitudinales
17.
bioRxiv ; 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37461510

RESUMEN

Thermal tolerance is a fundamental physiological complex trait for survival in many species. For example, everyday tasks such as foraging, finding a mate, and avoiding predation, are highly dependent on how well an organism can tolerate extreme temperatures. Understanding the general architecture of the natural variants of the genes that control this trait is of high importance if we want to better comprehend how this trait evolves in natural populations. Here, we take a multipronged approach to further dissect the genetic architecture that controls thermal tolerance in natural populations using the Drosophila Synthetic Population Resource (DSPR) as a model system. First, we used quantitative genetics and Quantitative Trait Loci (QTL) mapping to identify major effect regions within the genome that influences thermal tolerance, then integrated RNA-sequencing to identify differences in gene expression, and lastly, we used the RNAi system to 1) alter tissue-specific gene expression and 2) functionally validate our findings. This powerful integration of approaches not only allows for the identification of the genetic basis of thermal tolerance but also the physiology of thermal tolerance in a natural population, which ultimately elucidates thermal tolerance through a fitness-associated lens.

18.
J Exp Biol ; 215(Pt 23): 4070-84, 2012 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-22933610

RESUMEN

The biomechanical and neuromuscular mechanisms used by different animals to generate turns in flight are highly variable. Body size and body plan exert some influence, e.g. birds typically roll their body to orient forces generated by the wings whereas insects are capable of turning via left-right wingbeat asymmetries. Turns are also relatively brief and have low repeatability, with almost every wingbeat serving a different function throughout the change in heading. Here we present an analysis of Anna's hummingbirds (Calypte anna) as they fed continuously from an artificial feeder revolving around the outside of the animal. This setup allowed for examination of sustained changes in yaw without requiring any corresponding changes in pitch, roll or body position. Hummingbirds sustained yaw turns by expanding the wing stroke amplitude of the outer wing during the downstroke and by altering the deviation of the wingtip path during both downstroke and upstroke. The latter led to a shift in the inner-outer stroke plane angle during the upstroke and shifts in the elevation of the stroke plane and in the deviation of the wingtip path during both strokes. These features are generally more similar to how insects, as opposed to birds, turn. However, time series analysis also revealed considerable stroke-to-stroke variation. Changes in the stroke amplitude and the wingtip velocity were highly cross-correlated, as were changes in the stroke deviation and the elevation of the stroke plane. As was the case for wingbeat kinematics, electromyogram recordings from pectoral and wing muscles were highly variable, but no correlations were found between these two features of motor control. The high variability of both kinematic and muscle activation features indicates a high level of wingbeat-to-wingbeat adjustments during sustained yaw. The activation timing of the muscles was more repeatable than the activation intensity, which suggests that the former may be constrained by harmonic motion and that the latter may play a large role in kinematic adjustments. Comparing the revolution frequency of the feeder with measurements of free flight yaws reveals that feeder tracking, even at one revolution every 2 s, is well below the maximum yaw capacity of the hummingbirds.


Asunto(s)
Aves/fisiología , Vuelo Animal , Actividad Motora , Músculo Esquelético/fisiología , Alas de Animales/fisiología , Análisis de Varianza , Animales , Fenómenos Biomecánicos , California , Electromiografía , Masculino , Músculos Pectorales/fisiología , Análisis de Componente Principal , Factores de Tiempo , Grabación en Video
19.
Can J Respir Ther ; 53(4): 66-68, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-30996637
20.
Anat Rec (Hoboken) ; 305(10): 2791-2822, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35661427

RESUMEN

Jaw muscles are key features of the vertebrate feeding apparatus. The jaw musculature is housed in the skull whose morphology reflects a compromise between multiple functions, including feeding, housing sensory structures, and defense, and the skull constrains jaw muscle geometry. Thus, jaw muscle anatomy may be suboptimally oriented for the production of bite force. Crocodylians are a group of vertebrates that generate the highest bite forces ever measured with a flat skull suited to their aquatic ambush predatory style. However, basal members of the crocodylian line (e.g., Prestosuchus) were terrestrial predators with plesiomorphically tall skulls, and thus the origin of modern crocodylians involved a substantial reorganization of the feeding apparatus and its jaw muscles. Here, we reconstruct jaw muscles across a phylogenetic range of crocodylians and fossil suchians to investigate the impact of skull flattening on muscle anatomy. We used imaging data to create 3D models of extant and fossil suchians that demonstrate the evolution of the crocodylian skull, using osteological correlates to reconstruct muscle attachment sites. We found that jaw muscle anatomy in early fossil suchians reflected the ancestral archosaur condition but experienced progressive shifts in the lineage leading to Metasuchia. In early fossil suchians, musculus adductor mandibulae posterior and musculus pterygoideus (mPT) were of comparable size, but by Metasuchia, the jaw musculature is dominated by mPT. As predicted, we found that taxa with flatter skulls have less efficient muscle orientations for the production of high bite force. This study highlights the diversity and evolution of jaw muscles in one of the great transformations in vertebrate evolution.


Asunto(s)
Evolución Biológica , Maxilares , Animales , Fuerza de la Mordida , Maxilares/anatomía & histología , Músculos , Filogenia , Cráneo/anatomía & histología
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