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1.
Sci Rep ; 14(1): 7957, 2024 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575626

RESUMO

DNA analysis of large herbivore feces samples collected from seagrass beds at two distant sites (Irabu Island in Miyako Islands and Kushi in Okinawa Island) in the Ryukyu Islands proved that some of these feces were from dugongs, which had been treated in recent studies as extinct in this region since the last stranding of a deceased individual in 2019. In addition, local knowledge of sightings of animals thought to be dugongs and confirmed cases of dugong feeding trails since 2010 were compiled to estimate its recent distribution. This is the first scientific report on the presence of this mammal in the Ryukyu Islands within the last four years, and particularly in the Miyako Islands within the last half-century. As the Ryukyu Islands are known to be the northern limit of the dugong's fragmented distribution in East Asia, conservation efforts are therefore needed.


Assuntos
Dugong , Animais , DNA , Ásia Oriental , Fezes , Ilhas , Japão
2.
Vet Surg ; 53(3): 415-425, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38205863

RESUMO

OBJECTIVE: To investigate the effects of mitral valve repair on the geometry of the mitral valve complex, hemodynamics, and cardiac function of dogs with myxomatous mitral valve disease (MMVD). STUDY DESIGN: Retrospective cohort study. SAMPLE POPULATION: Dogs (n = 77) with stage C MMVD undergoing mitral valve repair under cardiopulmonary bypass. METHODS: Mitral valve geometry and cardiac function were assessed using echocardiography preoperatively, 1 week postoperatively and 3 months postoperatively. RESULTS: The coaptation length (0 [0-0] vs. 7 [6-8.5] mm, p < .001) and forward stroke volume index (1.5 ± 0.4 vs. 2.3 ± 0.6 mL/kg, p < .001) were higher at 3-months postoperatively than preoperatively, whereas the vertebral heart score (12.3 ± 1.2 vs. 10.8 ± 0.8 V, p < .001), left atrial-to-aortic ratio (2.2 ± 0.7 vs. 1.2 ± 0.3, p < .001), peak velocity of early diastolic transmitral flow (144 ± 34 vs. 91 ± 18 cm/s, p < .001), and regurgitant volume index (11.3 [8.2-14.0] vs. 1.6 [0.95-2.35] mL/kg, p < .001) were lower. Postoperatively, mitral valve geometry was completely changed within 1 week, whereas changes in vertebral heart score lasted for 3 months. CONCLUSION: Mitral valve repair changed valvular geometry and improved hemodynamics as assessed by follow-up echocardiography. CLINICAL SIGNIFICANCE: This study acts as reference for surgeons and cardiologists considering or evaluating the effects of mitral valve repair in dogs and provides useful data for the enhancement of relevant surgical techniques and the selection of relevant pre- and postoperative observations.


Assuntos
Doenças do Cão , Valva Mitral , Humanos , Cães , Animais , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Estudos Retrospectivos , Ecocardiografia/veterinária , Hemodinâmica
3.
PLoS One ; 18(9): e0291224, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37756258

RESUMO

Our recent success in the long-term maintenance of lantern shark embryos in artificial uterine systems has provided a novel option for the medical treatment of premature embryos for captive viviparous elasmobranchs. The remaining issue with this system is that the embryos cannot survive the abrupt change in the chemical environment from artificial uterine fluid (AUF) to seawater during delivery. To overcome this issue, the present study developed a new protocol for seawater adaptation, which is characterized by a long-term and stepwise shift from AUF to seawater prior to delivery. This protocol was employed successfully, and the specimen survived for more than seven months after delivery, the longest captive record of the species. During the experiment, we unexpectedly detected bioluminescence of the embryonic lantern shark in the artificial uterus. This observation indicates that lantern sharks can produce luciferin, a substance for bioluminescence. This contradicts the recent hypothesis that lantern sharks lack the ability to produce luciferin and use luciferin obtained from food sources.


Assuntos
Tubarões , Doenças Uterinas , Feminino , Animais , Humanos , Alimentos Marinhos , Útero , Luciferinas
4.
Data Brief ; 50: 109589, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37767132

RESUMO

We created and carried out a cross-sectional anonymous structured questionnaire on what motivates users of mobile health applications and wearables to share their collected health related data. The questionnaire was distributed online in English, French, and Norwegian. In addition, a flyer with information of where to locate the online questionnaire was distributed during a Swiss health conference. We used snowball sampling and encouraged participants to forward the questionnaires to friends, family, and others. Data were collected between October 2018 and March 2020. 58.1 % (n = 473) responded to the English survey, 34.3 % (n = 279) responded to the French survey, and 7.6 % (n = 62) responded to the Norwegian survey. The questionnaire contained 38 questions divided into seven themes: Background and health goals, Wearables and sensors, Mobile applications, Logging of health data, Data sharing- and integration, Social media and entertainment, and Demographics (age, gender, country of origin, chronic disease status, and chronic disease caretaker status). Answer options were single answer, multiple-choice, open-ended, or on a 4-point Likert scale. Questions were defined based on 16 in-person interviews with people without any chronic disorder, people with diabetes, and people with sickle cell disease. All questions were optional. Data were collected from 814 participants. All answers to the open-ended questions have been translated into English. This dataset is especially interesting for researchers interesting in what motivates people with and without chronic disease across countries to use mHealth tools and share their collected health data. Only a subset of variables has been analyzed so far and new research questions on motivation can potentially be answered using this dataset.

5.
Genome Res ; 33(9): 1527-1540, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37591668

RESUMO

Genomic studies of vertebrate chromosome evolution have long been hindered by the scarcity of chromosome-scale DNA sequences of some key taxa. One of those limiting taxa has been the elasmobranchs (sharks and rays), which harbor species often with numerous chromosomes and enlarged genomes. Here, we report the chromosome-scale genome assembly for the zebra shark Stegostoma tigrinum, an endangered species that has a relatively small genome among sharks (3.71 Gb), as well as for the whale shark Rhincodon typus Our analysis using a male-female comparison identified an X Chromosome, the first genomically characterized shark sex chromosome. The X Chromosome harbors the Hox C cluster whose intact linkage has not been shown for an elasmobranch fish. The sequenced shark genomes show a gradualism of chromosome length with remarkable length-dependent characteristics-shorter chromosomes tend to have higher GC content, gene density, synonymous substitution rate, and simple tandem repeat content as well as smaller gene length and lower interspersed repeat content. We challenge the traditional binary classification of karyotypes as with and without so-called microchromosomes. Even without microchromosomes, the length-dependent characteristics persist widely in nonmammalian vertebrates. Our investigation of elasmobranch karyotypes underpins their unique characteristics and provides clues for understanding how vertebrate karyotypes accommodate intragenomic heterogeneity to realize a complex readout. It also paves the way to dissecting more genomes with variable sizes to be sequenced at high quality.


Assuntos
Tubarões , Vertebrados , Feminino , Masculino , Animais , Sequência de Bases , Mapeamento Cromossômico , Vertebrados/genética , Tubarões/genética , Cariótipo
6.
J Am Chem Soc ; 145(28): 15049-15053, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37410114

RESUMO

We synthesized an ion pair comprising cationic and anionic Ir(III) photosensitizers ([Ir1+][Ir2-]) for photocatalytic CO2 reduction and showed that the cationic component imparts stability, while the cyclometalating ligands in the anionic component ensure effective visible-light absorption. The triplet excited state of [Ir1+] is the key photoredox species in this system and is mainly generated through the transfer of triplet excitation energy from the anionic moiety due to Coulombic interactions and appropriate triplet energy alignment between the two ionic components. The positive photosensitization effect of ion pairing was demonstrated by photocatalytic CO2 reduction in cooperation with a Re(I) molecular catalyst incorporated into a vesicle membrane.

7.
BMC Nutr ; 9(1): 73, 2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37353826

RESUMO

BACKGROUND: We have suggested "Revised Nutritional Reference Values for Feeding at Evacuation Shelters" (Revised RV) as a daily nutritional recommendation for meals served at evacuation shelters where poor diets had been reported. Since there are no meal examples to satisfy the Revised RV, our objectives were, for the future meal provision, to develop nutritionally adequate meal plans using the foods served at shelters in the past and to examine if the Revised RV could be met by changing combination of foods available. METHODS: In this case study using secondary data, we analyzed food weights of 86 meals served and recorded at 12 shelters after the heavy rains in July 2020. We obtained these data from Kumamoto Prefecture that was damaged and asked us dietary assessment for nutrition assistance. Foods were classified into 3 types according to the check mark in the record sheets: food aid (commercial packaged food), boxed meal, and hot meal service. We counted serving frequency of each food and analyzed nutritional differences by their combinations. Menus were devised by choosing foods that were served more frequently or were more nutritious among those served at shelters. The target values for one meal were set at 1/3 of the Revised RV for energy, protein, vitamins B1, B2, and C, and salt. RESULTS: None of the meals served in the shelters satisfied the target. We created 2 menus using food aid only: (#1 curry doughnut, milk with long shelf-life, and orange jelly) and (#2 salmon rice ball, ham and cheese sandwich, and vegetable juice); 1 menu by combination of boxed meal and food aid: (#3 boxed meal and vegetable juice); and 2 menus by combination of hot meal service and food aid: (#4 chicken meatball soup, packaged tofu, soy sauce, preprocessed white rice, and bottled green tea) and (#5 bamboo shoots rice, chicken and vegetable miso soup, and bottled green tea). Planned menus generally contained more energy, protein, and vitamins and less salt than the meals served. Their vitamin C contents were especially higher. CONCLUSION: Nutritionally adequate meals could be planned by changing the combination of foods available in shelters.

8.
AIMS Public Health ; 10(1): 169-182, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37063358

RESUMO

Objective: The primary goal was to evaluate the validity of food photographic estimation for nutritional assessment compared with weighed food record (WFR). Methods: We evaluated the validity and reproducibility of photographic estimation of foods provided in evacuation shelters. We analyzed 35 meals served at 12 shelters in Kumamoto Prefecture in Japan, affected by a heavy rain disaster in 2020. In this context, we compared 21 senior students' portion size estimation by food photographs to WFR. In addition, we assigned five meals for each of the 21 senior students, and the same meal photograph was estimated by three students to test reproducibility. Results: No statistically significant difference was detected between the two methods regarding energy, the total grams of meal, the protein, and vitamins B1, B2, and C, except for salt. In addition, the students who never self-cooked underestimated the total grams. Conclusion: Food photographic estimation could simplify the nutritional assessment in evacuation shelters. However, unclear photographs and food items served by weight could weaken the estimation accuracy. According to previous studies and the applied postestimation questionnaire, photographs taken from specified angles and reference food photobooks for portion size estimation may improve accuracy.

9.
Proc Natl Acad Sci U S A ; 120(13): e2220728120, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36943890

RESUMO

Spectral tuning of visual pigments often facilitates adaptation to new environments, and it is intriguing to study the visual ecology of pelagic sharks with secondarily expanded habitats. The whale shark, which dives into the deep sea of nearly 2,000 meters besides near-surface filter feeding, was previously shown to possess the 'blue-shifted' rhodopsin (RHO), which is a signature of deep-sea adaptation. In this study, our spectroscopy of recombinant whale shark RHO mutants revealed that this blue shift is caused dominantly by an unprecedented spectral tuning site 94. In humans, the mutation at the site causes congenital stationary night blindness (CSNB) by reducing the thermal stability of RHO. Similarly, the RHO of deep-diving whale shark has reduced thermal stability, which was experimentally shown to be achieved by site 178 and 94. RHOs having the natural substitution at site 94 are also found in some Antarctic fishes, suggesting that the blue shift by the substitution at the CSNB site associated with the reduction in thermal stability might be allowed in cold-water deep-sea habitats.


Assuntos
Rodopsina , Tubarões , Humanos , Animais , Rodopsina/genética , Mutação , Tubarões/genética , Regiões Antárticas
10.
J Am Nutr Assoc ; 42(5): 516-524, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-35797282

RESUMO

To maintain the health of evacuees, meals provided at emergency shelters should be monitored and improvement measures should be taken where necessary. Time and human resources are limited during devastating disasters; thus, the authors have developed the Dietary Assessment Sheets for Evacuation Shelters. This study examines whether the quality of meals can be assessed using simple check items on the Dietary Assessment Sheets.A total of 28 Dietary Assessment Sheets for 98 meals provided 16-19 days after the heavy rains in Kumamoto in July 2020 at 12 shelters were used in the analysis. Dietitians working for shelters were requested to fill the Dietary Assessment Sheets and food record sheets provided by the Prefectural Government. If any subitem was checkmarked, it was considered "checked," and if left blank, it was considered "not checked" and divided into categorical groups. Based on the food record sheets and meal photos, contents of energy, protein, and vitamins B1, B2, and C were calculated for each meal. Energy and nutrient contents were compared between the categorical groups.The study revealed that nutritionally poor meals were characterized as those comprising only "Grain dishes," those that were not "Boxed meals," and those involving "Self-Defense Forces," "Dietitians," or "Others." Their energy, protein, and vitamin B1, B2, and C content was significantly lower than that of meals with marks on other checkboxes in the same category.Shelters that provide these meals should be given priority for nutrition assistance due to their poor diets. The results imply that the Dietary Assessment Sheets could serve as a simple tool to determine the shelters that require nutritional assistance.


Assuntos
Desastres , Abrigo de Emergência , Humanos , Avaliação Nutricional , Refeições , Nutrientes
11.
Org Biomol Chem ; 20(46): 9142-9147, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36331031

RESUMO

Trihalo-substituted vinylsilane was readily synthesized in 77% yield and in an excellent regio- and stereoselective manner from in situ-generated fluorosilylacetylene, followed by the addition of I2 and NCS. The silane was committed to sequential Sonogashira coupling with various terminal acetylenes under mild conditions, affording desilylated chlorofluoro-enyne adducts in moderate to good yields.


Assuntos
Alcinos , Estereoisomerismo
12.
F1000Res ; 11: 1077, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36262334

RESUMO

The taxon Elasmobranchii (sharks and rays) contains one of the long-established evolutionary lineages of vertebrates with a tantalizing collection of species occupying critical aquatic habitats. To overcome the current limitation in molecular resources, we launched the Squalomix Consortium in 2020 to promote a genome-wide array of molecular approaches, specifically targeting shark and ray species. Among the various bottlenecks in working with elasmobranchs are their elusiveness and low fecundity as well as the large and highly repetitive genomes. Their peculiar body fluid composition has also hindered the establishment of methods to perform routine cell culturing required for their karyotyping. In the Squalomix consortium, these obstacles are expected to be solved through a combination of in-house cytological techniques including karyotyping of cultured cells, chromatin preparation for Hi-C data acquisition, and high fidelity long-read sequencing. The resources and products obtained in this consortium, including genome and transcriptome sequences, a genome browser powered by JBrowse2 to visualize sequence alignments, and comprehensive matrices of gene expression profiles for selected species are accessible through https://github.com/Squalomix/info.


Assuntos
Tubarões , Animais , Tubarões/genética , Genoma , Vertebrados , Cromatina , Disseminação de Informação
13.
Gen Comp Endocrinol ; 327: 114076, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35710034

RESUMO

The many diverse reproductive strategies of elasmobranchs (sharks, skates and rays) from lecithotrophic oviparity to matrotrophic viviparity have attracted significant research attention. However, the endocrine control of elasmobranch reproduction is less well-documented largely due to their reproductive characteristics, such as a long reproductive cycle, and/or repeated internal fertilization using stored sperm in oviparous species. In the present study, for the first time, we succeeded in non-invasive monitoring of the continuing egg-laying cycle of the cloudy catshark Scyliorhinus torazame using portable ultrasound devices. Furthermore, long-term simultaneous monitoring of the egg-laying cycle and measurement of plasma sex steroids revealed cycling patterns of estradiol-17ß (E2), testosterone (T) and progesterone (P4). In particular, a decline in T followed by a reciprocal surge in plasma P4 were consistently observed prior to the appearance of the capsulated eggs, implying that P4 is likely associated with the ovulation and/or egg-case formation. While the cycling pattern of E2 was not as apparent as those of T and P4, threshold levels of E2 (>5 ng/mL) and T (>1 ng/mL) appeared to be crucial in the continuation of egg-laying cycle. The possibility to trace the dynamics of plasma sex steroids in a single individual throughout the reproductive cycles makes the catshark a useful model for regulatory and mechanistic studies of elasmobranch reproduction.


Assuntos
Oviparidade , Tubarões , Animais , Estradiol , Feminino , Hormônios Esteroides Gonadais , Masculino , Progesterona , Reprodução , Sêmen , Ultrassonografia
14.
J Anat ; 241(2): 372-392, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35428996

RESUMO

The lifelong tooth replacement in elasmobranch fishes (sharks, rays and skates) has led to the assemblage of a great number of teeth from fossil and extant species, rendering tooth morphology an important character for taxonomic descriptions, analysing phylogenetic interrelationships and deciphering their evolutionary history (e.g. origination, divergence, extinction). Heterodonty (exhibition of different tooth morphologies) occurs in most elasmobranch species and has proven to be one of the main challenges for these analyses. Although numerous shark species are discovered and described every year, detailed descriptions of tooth morphologies and heterodonty patterns are lacking or are only insufficiently known for most species. Here, we use landmark-based 2D geometric morphometrics on teeth of the tiger shark Galeocerdo cuvier to analyse and describe dental heterodonties among four different ontogenetic stages ranging from embryo to adult. Our results reveal rather gradual and subtle ontogenetic shape changes, mostly characterized by increasing size and complexity of the teeth. We furthermore provide the first comprehensive description of embryonic dental morphologies in tiger sharks. Also, tooth shapes of tiger sharks in different ontogenetic stages are re-assessed and depicted in detail. Finally, multiple cases of tooth file reversal are described. This study, therefore, contributes to our knowledge of dental traits across ontogeny in the extant tiger shark G. cuvier and provides a baseline for further morphological and genetic studies on the dental variation in sharks. Therefore, it has the potential to assist elucidating the underlying developmental and evolutionary processes behind the vast dental diversity observed in elasmobranch fishes today and in deep time.


Assuntos
Tubarões , Rajidae , Animais , Dentição , Fósseis , Filogenia , Tubarões/anatomia & histologia
15.
Ambio ; 51(8): 1800-1818, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35119616

RESUMO

Scientific and public interest in acid deposition and its ecological impacts have increased throughout 1990s in East Asia (Northeast and Southeast Asia). After being established in 2001, the Acid Deposition Monitoring Network in East Asia (EANET) celebrates the 20th anniversary in 2021, and is now being expanded in scope reflecting the shifting social concern from acid deposition to broader air quality and climate change in recent years. This paper reviews the past 30 years of development of scientific research and policy related to acid deposition in East Asia. Since the onset of the twenty-first century, East Asia has had the highest SO2 and NOx emissions in the world by continents, with substantial economic developmental inequality among countries. An overview of studies on sulfur and nitrogen deposition, the acidification of inland water and forest soil, and forest decline reveal that although limited acidification of inland water and forest soils have been documented, no decline in the populations of fish and other aquatic biota has been reported in East Asia. After a review of policy-oriented modeling studies on source receptor relationships and the critical loads of sulfur and nitrogen in East Asia, the history of EANET and its success and challenges are discussed. Finally, the importance of epistemic communities as the interface between science and policy in the region is discussed. Regional governance and cooperation are essential for reducing the emission of greenhouse gases, especially short-lived climate pollutants and atmospheric pollutants to realize the co-benefits of global climate change mitigation and improved air quality.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Ásia Oriental , Nitrogênio/análise , Políticas , Solo , Enxofre/análise , Água
16.
Anat Rec (Hoboken) ; 305(7): 1724-1731, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34981899

RESUMO

Examination of the uterus of a dead female white shark (Carcharodon carcharias), which contained the earliest known white shark embryos, revealed that the uterine wall produces lipid-rich secretion (histotroph or "uterine milk") for embryonic nutrition. Uterine tissue was processed for light and electron microscopy, and immunohistochemical techniques to identify its secretory mechanism. Our results indicate that the white shark uterus secretes lipids via holocrine secretion. This type of secretion is characterized by the release of large lipid droplets accumulated in the epithelial cells into the uterine lumen through cell disintegration. The secretory epithelium of the uterus is stratified, and new surface epithelial cells are continuously supplied from deeper epithelial layers to replace the dead secretory cells at the surface. This vertical replacement possibly facilitates the active renewal of the surface epithelium, which is necessary for maintaining holocrine secretory mechanisms. These secretory mechanisms are different from those of myliobatiform stingrays, another elasmobranch taxon that exhibits lipid histotrophy. This may reflect the different origins of lipid histotrophy between these taxa.


Assuntos
Tubarões , Rajidae , Animais , Feminino , Lactação , Lipídeos , Útero/metabolismo
17.
AIMS Public Health ; 9(4): 734-757, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36636146

RESUMO

The Japanese Ministry of Health, Labour and Welfare compiled an Excel sheet - "Simple simulator for calculating nutritional food stocks in preparation for large-scale disasters" (Simulator). We examined the level of recognition and use of the Simulator by local governments and identified the points for its improvement. In stage 1, we surveyed local government personnel who participated in the "Workshop for nutrition assistance during large-scale disasters" held in November 2020 (n = 458; 313 responded) with an online questionnaire on the use of the Simulator and associated issues. Stage 2 involved group interviews with 15 public health dietitians who had been involved in food assistance during past natural disasters to identify points for improving the Simulator and the problems with food assistance during natural disasters. In stage 1, 233 responders (74.4%) confirmed their awareness of the existence of the Simulator. While 85 individuals (36.6%) used the Simulator, 63 individuals (74.1%) confirmed that they would use it in the future to plan and evaluate local government stocks. In stage 2, multiple comments regarding the Simulator's applicability and improvement in a realistic situation were collected. In order for the administrative staff in charge of disaster management to understand the nutritional importance of stockpiling main/side dishes, it was suggested that specific combinations of foods that meet the required amounts should be shown and that visualization using food products and the number of people covered by stockpiled foods may be easier to understand than pure nutritional values.

18.
Artigo em Inglês | MEDLINE | ID: mdl-34639364

RESUMO

It is important to provide nutritionally adequate food in shelters to maintain the health of evacuees. Since the Great East Japan Earthquake in 2011, Japan's Ministry of Health, Labour and Welfare has released the "Nutritional Reference Values for Evacuation Shelters" (Reference Values) after every major natural disaster. There is clear evidence, however, that the Reference Values have only been used infrequently. This study aims to revise these guidelines to include the actual situation in the affected areas and the feasibility of the endeavor. This qualitative study uses group interviews with local government dietitians to propose revisions to Japan's Reference Values. These revisions include the following: issuing Reference Values within 1 week of a disaster, showing one type of values for meal planning for each age group, showing the minimum values of vitamins, upgrading salt to basic components, creating three phases of nutrition (Day 1, Days 1-3, and After Day 4), stipulating food amounts rather than nutrient values, and creating a manual. Local government officials could use the Reference Values as guidelines for choosing food reserves, and dietitians could use them while formulating supplementary nutrition strategies for a model menu in preparation for disasters.


Assuntos
Planejamento em Desastres , Terremotos , Nutricionistas , Abrigo de Emergência , Humanos , Japão , Saúde Pública , Valores de Referência
19.
Elife ; 102021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34409936

RESUMO

Chondrichthyes (cartilaginous fishes) are fundamental for understanding vertebrate evolution, yet their genomes are understudied. We report long-read sequencing of the whale shark genome to generate the best gapless chondrichthyan genome assembly yet with higher contig contiguity than all other cartilaginous fish genomes, and studied vertebrate genomic evolution of ancestral gene families, immunity, and gigantism. We found a major increase in gene families at the origin of gnathostomes (jawed vertebrates) independent of their genome duplication. We studied vertebrate pathogen recognition receptors (PRRs), which are key in initiating innate immune defense, and found diverse patterns of gene family evolution, demonstrating that adaptive immunity in gnathostomes did not fully displace germline-encoded PRR innovation. We also discovered a new toll-like receptor (TLR29) and three NOD1 copies in the whale shark. We found chondrichthyan and giant vertebrate genomes had decreased substitution rates compared to other vertebrates, but gene family expansion rates varied among vertebrate giants, suggesting substitution and expansion rates of gene families are decoupled in vertebrate genomes. Finally, we found gene families that shifted in expansion rate in vertebrate giants were enriched for human cancer-related genes, consistent with gigantism requiring adaptations to suppress cancer.


Assuntos
Evolução Molecular , Proteínas de Peixes/genética , Genoma , Tubarões/genética , Transcriptoma , Animais , Biomarcadores Tumorais/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Duplicação Gênica , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imunidade Inata/genética , Neoplasias/genética , Neoplasias/patologia , Filogenia , Receptores Imunológicos/genética , Tubarões/imunologia , Sequenciamento Completo do Genoma
20.
Zoology (Jena) ; 147: 125932, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34130224

RESUMO

The present study provides a noninvasive method to estimate the body volume of sharks (Elasmobranchii, Selachii) using a computational geometric model. This method allows the volume of sharks to be estimated from lateral and ventral photographs assuming an elliptical body cross-sectional geometry. A comparison of the estimated and actual body volumes of several shark species showed that the estimation error was < 0.5%. The accuracy of the model decreased if photographs that were inclined to the orthogonal plane were used, although this error was on average < 2.3% if the inclination angle was 10° or less. Applying this model to captive whale sharks (Rhincodon typus) that were 8.0 and 8.8 m in total length revealed that their body volumes were 3.5 and 4.5 m3, respectively. These estimates allowed for the quantitative evaluation of our hypothesis, that the whale shark uses suctioned air for buoyancy control during vertical feeding-a behavior unique to this species among elasmobranchs. The volume estimates of the captive whale sharks, together with the density estimates from their liver proportions, revealed that the air occupying a part of oro-pharyngeal and branchial cavities can help the whale sharks to keep their body floating. This hypothesis may explain how the whale shark sometimes stays at the water surface without fin motion during vertical feeding, even though their body density is greater than that of seawater.


Assuntos
Tamanho Corporal , Comportamento Alimentar/fisiologia , Modelos Biológicos , Tubarões/fisiologia , Animais
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