Expression of zebrafish anterior gradient 2 in the semicircular canals and supporting cells of otic vesicle sensory patches is regulated by Sox10.

AGR2 is a member of the protein disulfide isomerase (PDI) family, which is implicated in cancer cell growth and metastasis, asthma, and inflammatory bowel disease. Despite the contributions of this protein to several biological processes, the regulatory mechanisms controlling expression of the AGR2 gene in different organs remain unclear. Zebrafish anterior gradient 2 (agr2) is expressed in several organs, including the otic vesicles that contain mucus-secreting cells. To elucidate the regulatory mechanisms controlling agr2 expression in otic vesicles, we generated a Tg(-6.0 k agr2:EGFP) transgenic fish line that expressed EGFP in a pattern recapitulating that of agr2. Double immunofluorescence studies were used to demonstrate that Agr2 and GFP colocalize in the semicircular canals and supporting cells of all sensory patches in the otic vesicles of Tg(-6.0 k agr2:EGFP) embryos. Transient/stable transgenic analyses coupled with 5'-end deletion revealed that a 100 bp sequence within the -2.6 to -2.5 kbp region upstream of agr2 directs EGFP expression specifically in the otic vesicles. Two HMG-binding motifs were detected in this region. Mutation of these motifs prevented EGFP expression. Furthermore, EGFP expression in the otic vesicles was prevented by knockdown of the sox10 gene. This corresponded with decreased agr2 expression in the otic vesicles of sox10 morphants during different developmental stages. Electrophoretic mobility shift assays were used to show that Sox10 binds to HMG-binding motifs located within the -2.6 to -2.5 kbp region upstream of agr2. These results demonstrate that agr2 expression in the otic vesicles of zebrafish embryos is regulated by Sox10.

Phylogenetic skew: an index of community diversity.

The distribution of divergence times between member species of a community reflects the pattern of species composition. In this study, we contrast the species composition of a community against the meta-community, which we define as the species composition of a set of target communities. We regard the collection of species that comprise a community as a sample from the set of member species of the meta-community, and interpret the pattern of the community species composition in terms of the type of species sampled from the meta-community. A newly defined effective species sampling proportion explains the amount of the difference between the divergence time distributions of the community and that of the meta-community, assuming random sampling. We propose a new index of phylogenetic skew (PS), as the ratio of the maximum-likelihood estimate of the effective species sampling proportion to the observed sampling proportion. A PS value of 1 is interpreted as random sampling. If the value is >1, the sampling is suspected to be phylogenetically skewed. If it is <1, systematic thinning of species is likely. Unlike other indices, the PS does not depend on species richness as long as the community has more than a few members of a species. Because it is possible to compare partially observed communities, the index may be effectively used in exploratory analysis to detect candidate communities with unique species compositions from a large number of communities.

Temporal variation of the relationships between rice yield and climate variables since 1925.

Background: Long-term time-series datasets of crop yield and climate variables are necessary to study the temporal variation of climate effects on crops. The aim of this study was to broadly assess assessment of the effects of climate on rice, and the associated temporal variations of the effects during the long-term period. Methods: We conducted field experiments in Taiwan from 1925 to 2019 to collect and analyze rice yield data and evaluate the impacts of changes in average temperature, diurnal temperature range (DTR), rainfall, and sunshine duration on rice yield during cool and warm cropping seasons. We then estimated the relationships between annual grain yield and the climate variables using the time series of their first difference values. We also computed the total relative and annual actual yield changes using regression coefficients for each climate variable for the intervals 1925-1944, 1945-1983, and 1996-2019 to reveal the impacts of climate change on yields and the associated temporal variations during the overall experimental period. Results: The annual daily average temperature calculated from the trend of the regression lines increased by 0.94-1.03 °C during the 95-year period. The maximum temperature remained steady while the minimum temperature increased, leading to decreased DTR. The total annual rainfall decreased by 237-352 mm and the annual total sunshine duration decreased by 93.9-238.9 h during the experimental period. We observed that during the cool cropping season, yield response to temperature change decreased, while that to DTR and rainfall changes increased. During the warm cropping season, all the yield responses to temperature, DTR, and rainfall changes were negative throughout the experimental period. In recent years (1996-2019) the estimated annual actual rice yield changes during the cool cropping season were negatively affected by climate variables (except for sunshine duration), and slightly positively affected (except for temperature) during the warm cropping season. Compared to the effects of temperature and DTR, those of rainfall and sunshine duration on rice yield changes were weak. This study contributes to provide impacts of climate change on rice yield and associated long-term temporal variations over nearly a century.

Effect of climate change-induced water-deficit stress on long-term rice yield.

The water requirements of crops should be investigated to improve the efficiency of water use in irrigated agriculture. The main objective of the study was to assess the effects of water deficit stress on rice yields throughout the major cropping seasons. We analyzed rice yield data from field experiments in Taiwan over the period 1925-2019 to evaluate the effects of water-deficit stress on the yield of 12 rice cultivars. Weather data, including air temperatures, humidity, wind speed, sunshine duration, and rainfall were used to compute the temporal trends of reference evapotranspiration and crop water status (CWS) during rice growth stages. A negative CWS value indicates that the crop is water deficient, and a smaller value represents a lower water level (greater water-deficit stress) in crop growth. The CWS on rice growth under the initial, crop development, reproductive, and maturity stages declined by 96.9, 58.9, 24.7, and 198.6 mm in the cool cropping season and declined by 63.7, 18.1, 8.6, and 3.8 mm in the warm cropping season during the 95 years. The decreasing trends in the CWSs were used to represent the increases in water-deficit stress. The total yield change related to water-deficit stress on the cultivars from 1925-1944, 1945-1983, and 1996-2019 under the initial, crop development, reproductive, and maturity stages are -56.1 to 37.0, -77.5 to -12.3, 11.2 to 19.8, and -146.4 to 39.1 kg ha-1 in the cool cropping season and -16.5 to 8.2, -12.9 to 8.1, -2.3 to 9.0, and -9.3 to 8.0 in the warm cropping season, respectively. Our results suggest that CWS may be a determining factor for rice to thrive during the developmental stage, but not the reproductive stage. In addition, the effect of water-deficit stress has increasingly affected the growth of rice in recent years.

The behavioral signature of stepwise learning strategy in male rats and its neural correlate in the basal forebrain.

Studies of associative learning have commonly focused on how rewarding outcomes are predicted by either sensory stimuli or animals' actions. However, in many learning scenarios, reward delivery requires the occurrence of both sensory stimuli and animals' actions in a specific order, in the form of behavioral sequences. How such behavioral sequences are learned is much less understood. Here we provide behavioral and neurophysiological evidence to show that behavioral sequences are learned using a stepwise strategy. In male rats learning a new association, learning started from the behavioral event closest to the reward and sequentially incorporated earlier events. This led to the sequential refinement of reward-seeking behaviors, which was characterized by the stepwise elimination of ineffective and non-rewarded behavioral sequences. At the neuronal level, this stepwise learning process was mirrored by the sequential emergence of basal forebrain neuronal responses toward each event, which quantitatively conveyed a reward prediction error signal and promoted reward-seeking behaviors. Together, these behavioral and neural signatures revealed how behavioral sequences were learned in discrete steps and when each learning step took place.

Bullous skin signs and laboratory surgical indicators can quickly and effectively differentiate necrotizing fasciitis from cellulitis.

OBJECTIVES: The purpose of this prospective study was to investigate the different microorganisms associated with mortality, to evaluate the bullous skin sign, and to identify the positive predictive factors for differentiating necrotizing fasciitis (NF) from cellulitis on initial onset at the emergency department. METHODS: This prospective study was conducted in 145 consecutive patients with NF and 159 patients with cellulitis. Age, sex, comorbidities, infection site, microbiological results, condition of skin lesions, laboratory findings, vital signs, and clinical outcomes were compared between the two groups at the time of admission to the emergency room. RESULTS: A total of 15 patients in the NF group and two patients in the cellulitis group died, resulting in a mortality rate of 10.3% and 1.3%, respectively. The NF group had a significantly higher incidence of white blood cell counts, band form neutrophil, and C-reactive protein than the patients in the cellulitis group. Hemorrhagic bullae presentation appeared to have significantly associated with NF and death. CONCLUSION: The following diagnostic indicators can be effectively used to differentiate NF from cellulitis at the initial onset: presence of hemorrhagic bullae, white blood cell counts >11,000 cells/mm3, band forms >0%, C-reactive protein >100 mg/l, and systolic blood pressure ≤90 mm Hg at the time of consultation.

Initial skin necrosis presentation at emergency room was associated with fulminant clinical course and mortality in patients with Vibrio necrotizing fasciitis.

Necrotizing fasciitis (NF) is a life-threatening infection. Skin necrosis is an important skin sign of NF. The purposes of this study was to investigate the initial skin conditions of Vibrio NF patients between emergency room (ER) to preoperative status, to compare the clinical and laboratory risk indicators of the skin necrosis group and non-skin necrosis group when they arrived at ER, and to evaluate whether initial cutaneous necrosis related to fulminant course and higher fatalities. From 2015 to 2019, seventy-two Vibrio NF patients with surgical confirmation were enrolled. We identified 25 patients for inclusion in the skin necrosis group and 47 patients for inclusion in the non-skin necrosis group due to the appearance of skin lesion at ER. Seven patients died, resulting in a mortality rate of 9.7%. Six patients of skin necrosis group and one patient of non-skin necrosis group died, which revealed the skin necrosis group had a significantly higher mortality rate than the non-skin necrosis group. All the patients in the skin necrosis group and 30 patients of non-skin necrosis group developed serous or hemorrhagic bullous lesions before operation (p = 0.0003). The skin necrosis group had a significantly higher incidence of APACHE score, postoperative intubation, Intensive care unit stay, septic shock, leukopenia, higher counts of banded leukocytes, elevated C-reactive protein (CRP), and lower serum albumin level. Vibrio NF patients presenting skin necrosis at ER were significantly associated with fulminant clinical courses and higher mortality. Physicians should alert the appearance of skin necrosis at ER to early suspect NF and treat aggressively by those clinical and laboratory risk indicators, such as elevated APACHE score, shock, leukopenia, higher banded leukocytes, elevated CRP, and hypoalbuminia.

Exploring the Role of Intraoperative Positive Culture of Allograft Bone in Subsequent Postoperative Infections among Donors and Recipients in Bone Bank Processing.

BACKGROUND: Allografts have been frequently used in orthopedic procedures. The purposes of this study were to evaluate the discard rates and bacterial contamination of a bone bank, and to assess the clinical outcomes of recipients with bacterial culture-positive donor allografts. METHODS: We retrospectively reviewed 1764 allografts which were harvested from living donors and stored in a bone bank from 2018 to 2022. The donors whose allografts displayed bacterial contamination at retrieval of the primary hip or knee arthroplasty were followed for microbiology and subsequent prosthetic joint infection analysis. The infected pathogens, antibiotic treatment and subsequent infection were reviewed for the intraoperative positive culture group. RESULTS: The discard rate was 17%, and the bacterial contamination rate of bone retrieval was 2.15%. Thirty-eight allografts at retrieval displayed confirmed bacterial growth, and 37 patients did not reveal infective signs at 6 months follow-up. A total of 1464 allografts were stored and implanted, among which 28 allografts (1.91%) were confirmed to be positive for bacterial growth and 13 cases (0.89%) were confirmed as surgical site infections. CONCLUSIONS: Our results validate the suggestion that our bone bank system performs good quality monitoring to eliminate the risk of dissemination of viral and bacterial diseases and to decrease surgical site infection after allograft implantation. By ensuring aseptic conditions and contamination-reducing strategies during harvesting and thawing, the allografts can be safely stored and implanted while limiting bacterial contamination. Our findings confirm that the intraoperative positive cultures of allografts did not contribute to subsequent postoperative surgical site infection in donors and recipients.

Effects of plant density on the aboveground dry matter and radiation-use efficiency of field corn.

The amount of solar radiation intercepted by the plant canopy drives crop plant photosynthesis and the formation and development of plant organs. Radiation-use efficiency (RUE) is an index used to quantify the relationship between solar radiation and biomass, and crop yield can be increased by increasing RUE. The main goals of this study were to initially investigate the effects of plant densities on the aboveground dry matter of corn, and subsequently examine the effects of plant densities on RUE and leaf area index (LAI), and the effects of LAI on RUE. Finally, we provide a comparative assessment of the approaches used to determine RUE. Analyses were conducted using growth and meteorological data obtained for two field corn varieties (TNG1 and TNG7) grown under four different plant density conditions in central Taiwan in 2017. The RUE values obtained in this study were primarily estimated from the slope of the linear relationship between aboveground dry matter measured at periodic harvests and the corresponding cumulative intercepted photosynthetically active radiation up to the time of harvest. TNG1 and TNG7 with a row spacing of 37.5 cm × 20 cm had the largest amounts of aboveground dry matter and highest RUE values of 4.41 and 4.55 g MJ-1, respectively. We established that the higher the plant density, the higher were the values obtained for RUE and LAI. We also compared the different methods of estimating RUE and make recommendations in this regard. Our findings in this study will enable farmers to gain information on the dynamics of crop yield variation at an early stage of growth, and also provide reference values that can be incorporated in future crop yield models.

Long-term monitoring dataset of fish assemblages in rocky tidepools on the southern coast of Taiwan.

Long-term data of fish assemblages collected in the rocky intertidal zone provides a valuable resource for elucidating the temporal variations in species diversity and intertidal ecosystems. In this study, we describe a long-term time-series dataset of fish collected by counting the number of anesthetized fish at sampling stations in the rocky tidepools on the southern coast of Taiwan. The species assemblages were monitored seasonally at the two stations for 16 y (2000-2008 and 2012-2018). In total, 86 samples containing 5137 individuals belonging to 82 species were recorded. Our data can be used for elucidating the temporal variations in fish assemblages and intertidal ecosystems and as background information for the resilience of the fish community conservation in coastal areas. The current study presents valuable data for researchers to understand the temporal and spatial variations in species abundance, richness, diversity, and composition in relation to climate change, environmental factors, and human activities.

Rational Use of Ceftriaxone in Necrotizing Fasciitis and Mortality Associated with Bloodstream Infection and Hemorrhagic Bullous Lesions.

Necrotizing fasciitis (NF) is an uncommon life-threatening necrotizing skin and soft tissue infection. The formation of hemorrhagic bullae is a special skin sign of NF. The purposes of this study were to investigate the incidence of hemorrhagic bullae formation and bacteremia associated with different organisms, to appraise the appropriate use of ceftriaxone, and to compare the clinical and laboratory risk indicators of NF patients with Gram-positive and Gram-negative infections on the initial examination. Methods: From March 2018 to December 2020, there were seventy-four NF patients with positive monomicrobial bacterial cultures enrolled based on surgical confirmation, and were categorized into two groups: the Gram-positive group and the Gram-negative group. Ceftriaxone susceptibility tests were carried out using the standard disk diffusion technique. Data, such as demographics, clinical outcomes, microbiological results, presentations of hemorrhagic bullae, and laboratory findings, were compared among these two groups. Results: The Gram-negative group included 52 patients, of whom 6 patients died, resulting in a mortality rate of 11.5%. The Gram-positive group included 22 patients and none died. Patients with bacteremia, hemorrhagic bullae, shock, fever, higher segmented forms and banded forms, and lower platelet counts constituted higher proportions in the Gram-negative group than in the Gram-positive group. The multivariate analysis identified six variables for the differentiation of Gram-negative and Gram-positive NF: the presentation of bacteremia, hemorrhagic bullae, shock at first consultation, fever with body temperature > 38.5 °C, band forms > 0%, and segmented forms ≦ 74%. A total of 66 isolates (89.2%) was susceptible to ceftriaxone. Conclusions: Gram-negative NF patients were significantly associated with hemorrhagic bullae presentation, blood stream infection, and mortality. Physicians should be alert to NF patients with the appearance of bacteremia, shock, fever, higher WBC banded and segmented forms, and lower platelet counts at the emergency department, with patients revealed to more likely have Gram-negative infections. Ceftriaxone with/without other appropriate antibiotics under the supervision of infectious doctors appeared to be clinically effective for the treatment of NF and blood stream infections.

Preclinical Application of Reduced Manipulated Processing Strategy to Collect Transplantable Hepatocytes: A Pilot and Feasibility Study.

BACKGROUND: The complex isolation and purification process of hepatocytes for transplantation is labor intensive and with great contamination risk. Here, as a pilot and feasibility study, we examined in vitro and in vivo hepatocyte isolation feasibility and cell function of Cell Saver® Elite®, an intraoperative blood-cell-recovery system. METHODS: Rat and pig liver cells were collected using this system and then cultured in vitro, and their hepatocyte-specific enzymes were characterized. We then transplanted the hepatocytes in an established acute liver-injured (retrorsine+D-galactosamine-treated) rat model for engraftment. Recipient rats were sacrificed 1, 2, and 4 weeks after transplantation, followed by donor-cell identification and histological, serologic, and immunohistopathological examination. To demonstrate this Cell Saver® strategy is workable in the first place, traditional (classical) strategy, in our study, behaved as certainty during the cell manufacturing process for monitoring quality assurance throughout the course, from the start of cell isolation to post-transplantation. RESULTS: We noted that in situ collagenase perfusion was followed by filtration, centrifugation, and collection in the Cell Saver® until the process ended. Most (>85%) isolated cells were hepatocytes (>80% viability) freshly demonstrating hepatocyte nuclear factor 4α and carbamoyl-phosphate synthase 1 (a key enzyme in the urea cycle), and proliferating through intercellular contact in culture, with expression of albumin and CYP3A4. After hepatocyte transplantation in dipeptidyl peptidase IV (-/-) rat liver, wild-type donor hepatocytes engrafted and repopulated progressively in 4 weeks with liver functional improvement. Proliferating donor hepatocyte-native biliary ductular cell interaction was identified. Post-transplantation global liver functional recovery after Cell Saver and traditional methods was comparable. CONCLUSIONS: Cell Saver® requires reduced manual manipulation for isolating transplantable hepatocytes.

Recovery and variation of the coastal fish community following a cold intrusion event in the Penghu Islands, Taiwan.

Knowledge of community resilience aids the development of strategies to mitigate the impacts of a disturbance. An extreme low-seawater temperature event in late January and February 2008 resulted in high fish mortality in the coastal waters of the Penghu Islands, Taiwan. In this study, we used underwater diving visual censuses to analyze fish communities at eight sampling stations along the coast of the Penghu Islands for seven years after the 2008 event. We evaluated community metrics, including species richness, abundance-weighted diversity, average thermal affinity, and average trophic level, and described the temporal variation in select dominant species abundances. Species richness and diversity of the communities required 53 months to reach a steady-state at the sampling stations following the cold water intrusion. The cold event initially reduced community thermal affinity, which then increased throughout the study period, reflecting the recovery of the community to baseline thermal conditions. The increased average trophic level after the cold event implied that the temperature shock decreased the proportion of lower trophic-level fishes. Average trophic level declined as the communities recovered from the disturbance, reflecting the recovery of the community to baseline species composition in terms of feeding habit. Our results suggest that functional diversity may require longer to recover than taxonomic diversity for communities in the Penghu Islands.

A long-term monitoring dataset of fish assemblages in rocky tidepools on the northern coast of Taiwan.

The assemblage of fish species in the rocky intertidal zone is highly affected by the destructive impact of human activities and has an extended impact on land-sea interactions. There are a few long-term research projects that have focused on rocky intertidal ecosystems, especially on the resident fish community. Here, we describe a long-term time series dataset of fish collected by counting the number of anesthetized fishes at sampling stations in rocky tidepools in the intertidal zones on the northern coast of Taiwan. The species assemblages were monitored seasonally at three stations from 1999 to 2018. In total, 144 samples containing 1,577 individuals belonging to 106 species were recorded in the surveys. The resulting data can be used as background information for conservation and resilience studies of the fish community in coastal areas and to establish reasonable conservation strategies. This study presents valuable data to ecologists and fisheries biologists interested in understanding the temporal patterns of species abundance, richness, and composition in relation to environmental factors, climate change, and anthropogenic pressures.

Bayesian inference of environmental effects on seaweed production in Japan via a production-environmental suitability model.

BACKGROUND: Both natural and human-induced disturbances are commonly responsible for an overall decrease of the world's seaweed. Along Japan's coastal areas, edible seaweed production has been decreasing for decades. In this study, a production-environmental suitability model to estimate the impacts of environmental factors on seaweed production was developed. The developed model not only estimates human-induced disturbances but also quantifies the impacts of environmental factors responsible for the decline of annual seaweed production. The model estimated the temporal variation in human-induced disturbances and the effects of environmental factors (i.e., rainfall, CO2 concentrations, temperature, typhoons, solar radiation, water nutrient levels, and water quality) on edible seaweeds in Japan from 1985 to 2012. RESULTS: The environmental suitability for seaweed production in Japan was about 4.6 times greater in 1992 than in 2011, meanwhile as a result of human activities, human-induced disturbances of seaweed increased at a rate of 4.9 times faster during the period of 1998-2012 than the period of 1985-1997. The ratio of decreased production to decreased environmental suitability for seaweed production in Japan increased by 15.2% during the study years, which means that seaweed production has become more sensitive to environmental disturbances, including climatic factors and human activities in 1998-2012. CONCLUSIONS: The results are novel in demonstrating temporal variations in the level of environmental suitability to seaweed production by using a simple mathematical model. The production-environmental suitability model successfully predicted seaweed production by reflecting the 28-year temporal variation of the observed seaweed production in Japan.

Monitoring of the toxic dinoflagellate Alexandrium catenella in Osaka Bay, Japan using a massively parallel sequencing (MPS)-based technique.

Since 2002, blooms of Alexandrium catenella sensu Fraga et al. (2015) and paralytic shellfish toxicity events have occurred almost yearly in Osaka Bay, Japan. To better understand the triggers for reoccurring A. catenella blooms in Osaka Bay, phytoplankton community was monitored during the spring seasons of 2012-2015. Monitoring was performed using massively parallel sequencing (MPS)-based technique on amplicon sequences of the 18S rRNA gene. Dense blooms of A. catenella occurred every year except in 2012, however, there was no significant correlation with the environmental parameters investigated. Plankton community diversity decreased before and middle of the A. catenella blooms, suggesting that the decline in diversity could be an indicator for the bloom occurrence. The yearly abundance pattern of A. catenella cells obtained by morphology-based counting coincided with the relative sequence abundances, which supports the effectiveness of MPS-based phytoplankton monitoring.

Time series dataset of fish assemblages near thermal discharges at nuclear power plants in northern Taiwan.

Long-term time series datasets with consistent sampling methods are rather rare, especially the ones of non-target coastal fishes. Here we described a long-term time series dataset of fish collected by trammel net fish sampling and observed by an underwater diving visual census near the thermal discharges at two nuclear power plants on the northern coast of Taiwan. Both experimental and control stations of these two investigations were monitored four times per year in the surrounding seas at both plants from 2000 to 2017. The underwater visual census mainly monitored reef fish assemblages and trammel net samples monitored pelagic or demersal fishes above the muddy/sandy bottom. In total, 508 samples containing 203,863 individuals from 347 taxa were recorded in both investigations at both plants. These data can be used by ecologists and fishery biologists interested in the elucidation of the temporal patterns of species abundance and composition.

Hypothesis Testing of Inclusion of the Tolerance Interval for the Assessment of Food Safety.

In the testing of food quality and safety, we contrast the contents of the newly proposed food (genetically modified food) against those of conventional foods. Because the contents vary largely between crop varieties and production environments, we propose a two-sample test of substantial equivalence that examines the inclusion of the tolerance intervals of the two populations, the population of the contents of the proposed food, which we call the target population, and the population of the contents of the conventional food, which we call the reference population. Rejection of the test hypothesis guarantees that the contents of the proposed foods essentially do not include outliers in the population of the contents of the conventional food. The existing tolerance interval (TI0) is constructed to have at least a pre-specified level of the coverage probability. Here, we newly introduce the complementary tolerance interval (TI1) that is guaranteed to have at most a pre-specified level of the coverage probability. By applying TI0 and TI1 to the samples from the target population and the reference population respectively, we construct a test statistic for testing inclusion of the two tolerance intervals. To examine the performance of the testing procedure, we conducted a simulation that reflects the effects of gene and environment, and residual from a crop experiment. As a case study, we applied the hypothesis testing to test if the distribution of the protein content of rice in Kyushu area is included in the distribution of the protein content in the other areas in Japan.

Global pattern of phylogenetic species composition of shark and its conservation priority.

The diversity of marine communities is in striking contrast with the diversity of terrestrial communities. In all oceans, species richness is low in tropical areas and high at latitudes between 20 and 40°. While species richness is a primary metric used in conservation and management strategies, it is important to take into account the complex phylogenetic patterns of species compositions within communities. We measured the phylogenetic skew and diversity of shark communities throughout the world. We found that shark communities in tropical seas were highly phylogenetically skewed, whereas temperate sea communities had phylogenetically diversified species compositions. Interestingly, although geographically distant from one another, tropical sea communities were all highly skewed toward requiem sharks (Carcharhinidae), hammerhead sharks (Sphyrnidae), and whale sharks (Rhincodon typus). Worldwide, the greatest phylogenetic evenness in terms of clades was found in the North Sea and coastal regions of countries in temperate zones, such as the United Kingdom, Ireland, southern Australia, and Chile. This study is the first to examine patterns of phylogenetic diversity of shark communities on a global scale. Our findings suggest that when establishing conservation activities, it is important to take full account of phylogenetic patterns of species composition and not solely use species richness as a target. Protecting areas of high phylogenetic diversity in sharks, which were identified in this study, could form a broader strategy for protecting other threatened marine species.