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1.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34373318

RESUMO

Synchronized mass coral spawning typically occurs several days after a full moon once a year. It is expected that spawning day is determined by corals sensing environmental change regulated by the lunar cycle (i.e., tide or moonlight); however, the exact regulatory mechanism remains unknown. Here, we demonstrate how moonlight influences the spawning process of coral, Dipsastraea speciosa When corals in the field were shaded 1 and 3 d before the full moon or 1 d after the full moon, spawning always occurred 5 d after shading commenced. These results suggest moonlight suppresses spawning: a hypothesis supported by laboratory experiments in which we monitored the effects of experimental moonlight (night-light) on spawning day. Different night-light treatments in the laboratory showed that the presence of a dark period between day-light and night-light conditions eliminates the suppressive effect of night-light on spawning. In nature, moonrise gets progressively later during the course of the lunar cycle, shifting to after sunset following the day of the full moon. Our results indicate that this period of darkness between sunset and moonrise triggers synchronized mass spawning of D. speciosa in nature.


Assuntos
Antozoários/fisiologia , Luz , Lua , Fotoperíodo , Reprodução , Comportamento Sexual Animal , Animais , Escuridão , Fenômenos Fisiológicos
2.
Zoolog Sci ; 40(4): 326-340, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37522604

RESUMO

The scleractinian coral genus Cyphastrea is widely distributed in the Indo-Pacific region and is common from the subtropical to the warm-temperate regions in Japan. Three new species in this genus have recently been reported from south-eastern Australia or the Red Sea. However, taxonomic and species diversity have been little studied so far in Japan. In this study, we analyzed 112 specimens of Cyphastrea collected from the subtropical to the warm-temperate regions in Japan to clarify the species diversity in the country. This analysis was based on skeletal morphological and molecular analyses using three genetic markers of the nuclear 28S rDNA, histone H3 gene, and the mitochondrial noncoding intergenic region between COI and tRNAmet. The molecular phylogenetic trees showed that our specimens are separated mainly into four clades. Considering the morphological data with the molecular phylogenetic relationships, we confirmed a total of nine species, including two species, C. magna and C. salae, recorded for the first time in Japan. Although eight out of nine species were genetically included within Cyphastrea, one species, C. agassizi, was genetically distant from all other species and was closely related to the genus Leptastrea, suggesting the return of this species to the genus to which it was originally ascribed. Two newly recorded species were reciprocally monophyletic, while the other six species (excluding C. agassizi) clustered in two clades without forming species-specific lineages, including three polyphyletic species. Thus, the species boundary between species in Cyphastrea remains unclear in most species using these three sequenced loci.


Assuntos
Antozoários , Animais , Filogenia , Antozoários/genética , Japão , DNA Ribossômico/genética , Mitocôndrias/genética , Análise de Sequência de DNA
3.
Genes Dev ; 28(22): 2547-63, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25403183

RESUMO

Control of Gli function by Suppressor of Fused (Sufu), a major negative regulator, is a key step in mammalian Hedgehog (Hh) signaling, but how this is achieved in the nucleus is unknown. We found that Hh signaling results in reduced Sufu protein levels and Sufu dissociation from Gli proteins in the nucleus, highlighting critical functions of Sufu in the nucleus. Through a proteomic approach, we identified several Sufu-interacting proteins, including p66ß (a member of the NuRD [nucleosome remodeling and histone deacetylase] repressor complex) and Mycbp (a Myc-binding protein). p66ß negatively and Mycbp positively regulate Hh signaling in cell-based assays and zebrafish. They function downstream from the membrane receptors, Patched and Smoothened, and the primary cilium. Sufu, p66ß, Mycbp, and Gli are also detected on the promoters of Hh targets in a dynamic manner. Our results support a new model of Hh signaling in the nucleus. Sufu recruits p66ß to block Gli-mediated Hh target gene expression. Meanwhile, Mycbp forms a complex with Gli and Sufu without Hh stimulation but remains inactive. Hh pathway activation leads to dissociation of Sufu/p66ß from Gli, enabling Mycbp to promote Gli protein activity and Hh target gene expression. These studies provide novel insight into how Sufu controls Hh signaling in the nucleus.


Assuntos
Regulação da Expressão Gênica , Proteínas Hedgehog/fisiologia , Proteínas Repressoras/metabolismo , alfa-Amilases Salivares/metabolismo , Transdução de Sinais , Animais , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Proteínas Hedgehog/metabolismo , Humanos , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Mutação , Células NIH 3T3 , Ligação Proteica , Proteômica , Proteínas Repressoras/genética , alfa-Amilases Salivares/genética , Peixe-Zebra/genética , Proteína GLI1 em Dedos de Zinco
4.
Wilderness Environ Med ; 30(3): 268-273, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31345722

RESUMO

INTRODUCTION: In 2011, our hospital on the Izu peninsula began to hold meetings to discuss how to manage patients with decompression illness (DCI) to establish a cooperative medical system. We retrospectively investigated the influence of these meetings and the changes subsequently effected. METHODS: A medical chart review was retrospectively performed to investigate all cases between January 2005 and December 2017 in which the transport of patients with DCI via a physician-staffed helicopter emergency medical service (HEMS) was attempted. The patients were divided into 2 groups: the preprogram group and the postprogram group. RESULTS: There were 63 patients in the preprogram group and 65 in the postprogram group. There were no cases in which a patient's symptoms deteriorated during transportation by the HEMS. The frequency of dispatch to the scene for direct evacuation in the postprogram group (86%) was greater than that in the preprogram group (74%), but the difference was not statistically significant (P=0.09). In the postprogram group, the duration of activities at the scene or the first aid hospital was significantly shorter in comparison to the preprogram group (P=0.01). CONCLUSIONS: This retrospective study revealed simultaneity between the introduction of the yearly meetings and a reduced duration of the HEMS staff's activity at either the scene or the first aid hospital.


Assuntos
Doença da Descompressão/terapia , Serviços Médicos de Emergência/organização & administração , Medicina Ambiental/organização & administração , Adulto , Aeronaves/estatística & dados numéricos , Serviços Médicos de Emergência/estatística & dados numéricos , Medicina Ambiental/estatística & dados numéricos , Feminino , Primeiros Socorros/estatística & dados numéricos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
Air Med J ; 37(3): 174-177, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29735230

RESUMO

The fire department in Atami received an emergency call at 6:17 am, with notification of 4 or 5 casualties because of a fire. Because there was only 1 ambulance (O) at the station, an additional ambulance (P) was also requested. Ambulance O transported 2 patients (A and B), and ambulance P transported 2 patients (C and D). These 4 patients were judged to have severe inhalation injuries at the scene and were transported to 2 local hospitals (X and Y). After patients C and D arrived at hospital Y, the medical staff decided to transfer them to the emergency medical service center. Patient C was transported by an emergency medical helicopter (doctor helicopter), and patient D was transported to our hospital by ambulance P. After tracheal intubation, both patients (C and D) required intensive care and mechanical ventilation. Patient A at hospital X was also intubated and transported to another hospital by the doctor helicopter. Fortunately, all patients survived. After a review among the parties involved in the incident, initiating an early request for additional human resources, vehicles, and medical support was recognized as contributing a key role in achieving a successful outcome.


Assuntos
Resgate Aéreo , Queimaduras por Inalação/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ambulâncias , Criança , Pré-Escolar , Feminino , Incêndios , Humanos , Japão , Masculino
6.
Dev Biol ; 388(2): 170-80, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24525297

RESUMO

During mammalian spermatogenesis, the diploid spermatogonia mature into haploid spermatozoa through a highly controlled process of mitosis, meiosis and post-meiotic morphological remodeling (spermiogenesis). Despite important progress made in this area, the molecular mechanisms underpinning this transformation are poorly understood. Our analysis of the expression and function of the putative serine-threonine kinase Fused (Fu) provides critical insight into key steps in spermatogenesis. In this report, we demonstrate that conditional inactivation of Fu in male germ cells results in infertility due to diminished sperm count, abnormal head shaping, decapitation and motility defects of the sperm. Interestingly, mutant flagellar axonemes are intact but exhibit altered periaxonemal structures that affect motility. These data suggest that Fu plays a central role in shaping the sperm head and controlling the organization of the periaxonemal structures in the flagellum. We show that Fu localizes to multiple tubulin-containing or microtubule-organizing structures, including the manchette and the acrosome-acroplaxome complex that are involved in spermatid head shaping. In addition, Fu interacts with the outer dense fiber protein Odf1, a major component of the periaxonemal structures in the sperm flagellum, and Kif27, which is detected in the manchette. We propose that disrupted Fu function in these structures underlies the head and flagellar defects in Fu-deficient sperm. Since a majority of human male infertility syndromes stem from reduced sperm motility and structural defects, uncovering Fu׳s role in spermiogenesis provides new insight into the causes of sterility and the biology of reproduction.


Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Cabeça do Espermatozoide , Espermatogênese , Animais , Masculino , Camundongos , Camundongos Transgênicos
7.
Mol Phylogenet Evol ; 77: 11-22, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24636895

RESUMO

Coral-inhabiting barnacles (Thoracica: Pyrgomatidae) are obligatory symbionts of scleractinian and fire corals. We attempted to reconstruct the phylogeny of coral-inhabiting barnacles using a multi-locus approach (mitochondrial 12S and 16S rRNA, and nuclear EF1, H3 and RP gene sequences, total 3532bp), which recovered a paraphyletic pattern. The fire-coral inhabiting barnacle Wanella milleporae occupied a basal position with respect to the other coral inhabiting barnacles. Pyrgomatids along with the coral-inhabiting archaeobalanid Armatobalanus nested within the same clade and this clade was subdivided into two major lineages: Armatobalanus+Cantellius with species proposed to be the ancestral stock of extant coral barnacles, and the other comprising the remaining genera studied. Ancestral state reconstruction (ASR) suggested multiple independent fusions and separations of shell plates and opercular valves in coral barnacle evolution, which counters the traditional hypothesis founded on a scheme of morphological similarities. Most of the coral barnacles are restricted to one or two coral host families only, suggesting a trend toward narrow host range and more specific adaptation. Furthermore, there is a close linkage between coral host usage and phylogenetic relationships with sister taxa usually being found on the same coral host family. This suggests that symbiotic relationships in coral-inhabiting barnacles are phylogenetically conserved and that host associated specialization plays an important role in their diversification.


Assuntos
Antozoários/fisiologia , Filogenia , Thoracica/genética , Animais , Loci Gênicos , Especificidade de Hospedeiro , Simbiose , Thoracica/anatomia & histologia
8.
J Anim Ecol ; 83(4): 980-90, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26050545

RESUMO

Spatial distributions of individuals are conventionally analysed by representing objects as dimensionless points, in which spatial statistics are based on centre-to-centre distances. However, if organisms expand without overlapping and show size variations, such as is the case for encrusting corals, interobject spacing is crucial for spatial associations where interactions occur. We introduced new pairwise statistics using minimum distances between objects and demonstrated their utility when examining encrusting coral community data. We also calculated the conventional point process statistics and the grid-based statistics to clarify the advantages and limitations of each spatial statistical method. For simplicity, coral colonies were approximated by disks in these demonstrations. Focusing on short-distance effects, the use of minimum distances revealed that almost all coral genera were aggregated at a scale of 1-25 cm. However, when fragmented colonies (ramets) were treated as a genet, a genet-level analysis indicated weak or no aggregation, suggesting that most corals were randomly distributed and that fragmentation was the primary cause of colony aggregations. In contrast, point process statistics showed larger aggregation scales, presumably because centre-to-centre distances included both intercolony spacing and colony sizes (radius). The grid-based statistics were able to quantify the patch (aggregation) scale of colonies, but the scale was strongly affected by the colony size. Our approach quantitatively showed repulsive effects between an aggressive genus and a competitively weak genus, while the grid-based statistics (covariance function) also showed repulsion although the spatial scale indicated from the statistics was not directly interpretable in terms of ecological meaning. The use of minimum distances together with previously proposed spatial statistics helped us to extend our understanding of the spatial patterns of nonoverlapping objects that vary in size and the associated specific scales.


Assuntos
Distribuição Animal , Antozoários/fisiologia , Biodiversidade , Análise Espacial , Animais , Japão , Modelos Biológicos , Especificidade da Espécie
9.
Dev Dyn ; 242(11): 1307-19, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23907739

RESUMO

BACKGROUND: Motile cilia on the inner lining of the oviductal epithelium play a central role in ovum transport toward the uterus and subsequent fertilization by sperm. While the basic ultrastructure of 9+2 motile cilia (nine peripheral microtubule doublets surrounding a central pair) has been characterized, many important steps of ciliogenesis remain poorly understood. RESULTS: Our previous studies on mammalian Fused (Fu) (Stk36), a putative serine-threonine kinase, reveal a critical function of Fu in central pair construction and cilia orientation of motile cilia that line the tracheal and ependymal epithelia. These findings identify a novel regulatory component for these processes. In this study, we show that Fu is expressed in the multi-ciliated oviductal epithelium in several vertebrates, suggesting a conserved function of Fu in the oviduct. In support of this, analysis of Fu-deficient mouse oviducts uncovers a similar role of Fu in central pair construction and cilia orientation. We also demonstrate that Fu localizes to motile cilia and physically associates with kinesin Kif27 located at the cilium base and known central pair components Spag16 and Pcdp1. CONCLUSIONS: Our results delineate a novel pathway for central pair apparatus assembly and add important insight to the biogenesis and function of oviductal motile cilia.


Assuntos
Cílios/metabolismo , Oviductos/embriologia , Oviductos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Linhagem Celular , Cílios/ultraestrutura , Feminino , Humanos , Hibridização In Situ , Mamíferos/embriologia , Mamíferos/metabolismo , Camundongos , Camundongos Mutantes , Microscopia Eletrônica de Transmissão , Proteínas Serina-Treonina Quinases/genética
10.
Zookeys ; 1205: 205-222, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38957220

RESUMO

A new zooxanthellate scleractinian coral, Paragoniastreavariabilis Kishi, Nomura & Fukami, sp. nov. (Scleractinia, Merulinidae), is described from non-coral reef regions of Japan and northern Taiwan. This new species was previously recognized as a morphological variant of Paragoniastreadeformis (Veron, 1990) and can be morphologically distinguished from that species by lacking groove-and-tube structures on corallite wall joints, and by having larger calices, numerous septa, and up to three corallites in one valley. The new species also formed an independent clade from its congeners, P.australensis (Milne Edwards & Haime, 1857), P.deformis and P.russelli (Wells, 1954), in the molecular phylogeny based on the mitochondrial intergenic region and nuclear ribosomal internal transcribed spacers.

11.
Mar Pollut Bull ; 203: 116462, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38749153

RESUMO

Analyzing the environmental factors affecting benthic communities in coastal areas is crucial for uncovering key factors that require conservation action. Here, we collected benthic and environmental (physical-chemical-historical and land-based) data for 433 transects in Taiwan. Using a k-means approach, five communities dominated by crustose coralline algae, turfs, stony corals, digitate, or bushy octocorals were first delineated. Conditional random forest models then identified physical, chemical, and land-based factors (e.g., light intensity, nitrite, and population density) relevant to community delineation and occurrence. Historical factors, including typhoons and temperature anomalies, had only little effect. The prevalent turf community correlated positively with chemical and land-based drivers, which suggests that anthropogenic impacts are causing a benthic homogenization. This mechanism may mask the effects of climate disturbances and regional differentiation of benthic assemblages. Consequently, management of nutrient enrichment and terrestrial runoff is urgently needed to improve community resilience in Taiwan amidst increasing challenges of climate change.


Assuntos
Antozoários , Mudança Climática , Monitoramento Ambiental , Taiwan , Animais , Ecossistema , Biodiversidade
12.
J Biol Rhythms ; 38(2): 148-158, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36461677

RESUMO

Many marine organisms synchronously spawn at specific times to ensure the success of external fertilization in the ocean. Corals are famous examples of synchronized spawning at specific lunar phases, and two distinct spawning patterns have been observed in two dominant taxa: merulinid corals spawn at regular lunar phases, several days after the full moon, whereas Acropora corals spawn at more irregular lunar phases around the full moon. Although it has been suggested that the two coral taxa have different responses to moonlight and seawater temperature, their spawning times have never been analyzed by integrating the two environmental factors, resulting in an incomplete understanding of the regulatory mechanisms of spawning. In this study, we developed a new predictive model of coral spawning days by integrating moonlight and temperature effects based on the external coincidence model for the lunar cycle. We performed model fitting using a 10-year monitoring record of coral spawning time in Taiwan. Our model successfully demonstrated the synergistic effects of moonlight and temperature on coral spawning time (days) and provided two testable hypotheses to explain the different spawning patterns regarding the preparation (maturation) process for spawning and the sensitivity to moonlight at different circadian phases: (1) Acropora corals may have an earlier onset and longer period of preparation for spawning than merulinid corals; and (2) merulinid corals may use moonlight signals near sunset, while Acropora corals may have a similar onset at approximately midnight. This is the first study to indicate the difference in circadian phase-dependent moonlight sensitivities between coral taxa, providing a basis for underlying coral spawning mechanisms for rhythmic studies.


Assuntos
Antozoários , Animais , Antozoários/fisiologia , Lua , Ritmo Circadiano , Luz , Reprodução
13.
Juntendo Iji Zasshi ; 69(3): 216-221, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38855437

RESUMO

Objectives: We retrospectively investigated the degree of completion of the checklist during or immediately after diving accident, who were transported by a physician-staffed helicopter emergency medical service (HEMS). Methods: From May 2016 to December 2020, we conducted a retrospective the diving accident checklist review of all patients with diving accident, who were transported by HEMS. If all questions of the diving accident checklist were answered, full marks were 40 points. Subjects were divided into two groups: the Arrest group, which included subjects who became cardiac arrest in prehospital setting, and the Control group. Results: A total of 86 patients with diving accident were transported by the HEMS. Among these patients, there were 16 subjects in the Arrest group and 70 in the Control group. Average total score in the Arrest group were significantly smaller than those in the Control group. Conclusions: Degree of completion of the diving accident checklist in cases with cardiac arrest was low in comparison with cases without cardiac arrest. To improve this, further approach based on several remedies will be required in the future.

14.
Disaster Med Public Health Prep ; 16(1): 147-152, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32959747

RESUMO

OBJECTIVE: This research was carried out to report the activity of the headquarters for disaster control at our hospital, and investigate the usefulness of obtaining information from Twitter when Typhoon Hagibis hit Izu Peninsula. METHODS: First, we recounted the activity of the headquarters for disaster control. We then collected information from Twitter from October 12-14, 2019, using the keyword Izunokuni.' We took into consideration the contents of Twitter user posts as well as the number of reactions ('retweets' and 'likes'). Twitter information was classified into photo (+) and (-) groups, depending on whether or not the post had a photo or video included. The number of reactions between the two groups was then analyzed. RESULTS: We counted 122 Twitter posts containing Hagibis-related information for Izunokuni City. The average number of both 'retweets' and 'likes' in the photo (+) group were significantly greater than those in the photo (-) group. All photos and videos depicted specific places in Izunokuni City and included actual footage of disaster scenes or local warning signs. CONCLUSION: Based on our experience at the headquarters for disaster control during Typhoon Hagibis, Twitter was considered to be a useful tool for obtaining local disaster information based on its timeliness, reality and specificity.


Assuntos
Meios de Comunicação , Tempestades Ciclônicas , Desastres , Mídias Sociais , Hospitais , Humanos
15.
Zoolog Sci ; 27(12): 959-64, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21110723

RESUMO

Didemnum molle, a colonial ascidian that harbors the symbiotic cyanophyte Prochloron spp., is distributed throughout the coral reefs of the Indo-West Pacific Ocean. Several morphotypes of D. molle are characterized by the color and size of their colonies. Previous molecular phylogeny inferred from gene sequences for the cytochrome oxidase subunit I (COI) identified four morphotypes (i.e., gray, brown, white, and large) from several sites in the Ryukyu Islands, Japan. With the addition of 17 specimens, including another morphotype (small), from several collection sites (Taiwan and the Ryukyus), the present report demonstrates genetic separation among the five morphotypes based on COI sequences. A number of sexually mature specimens of the different morphotypes were collected at the same times and sites, indicating reproductive isolation among morphotypes.


Assuntos
Variação Genética , Urocordados/classificação , Urocordados/genética , Animais , Demografia , Japão , Taiwan
16.
Zool Stud ; 59: e19, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33262843

RESUMO

Some didemnid ascidians harbor cyanobacterial symbionts, and this is the only obligate photosymbiosis system known in chordates. These photosymbiotic ascidians are found only in tropical and subtropical waters, probably because the photosymbionts are vulnerable to low temperatures. We surveyed the photosymbiotic ascidian fauna along the east coast of Taiwan. The present and previous reports recorded 13 species in Taiwan, and the species richness and composition is different in five areas along the east coast. Along the middle-east, southeast, and south coasts, five or more species have been recorded, whereas only one species has been found along the northeast coast, and no species have been recorded on the north coast. This gap in the species richness is probably related to the Kuroshio Current, which travels from south to north along the east coast of Taiwan but changes to an easterly direction off the northeast coast. Increases in water temperature due to global warming could cause northward expansion of the distribution ranges of these ascidians in the future. Hence, the photosymbiotic ascidian fauna could be an environmental indicator in subtropical, shallow water, and the present study provides a basic dataset that illustrates the current status of photosymbiotic ascidians in Taiwan.

17.
Acute Med Surg ; 7(1): e544, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32695428

RESUMO

AIM: To investigate the prospective frequency of post-traumatic stress disorder (PTSD) among relatives of sudden death patients following provision of a pamphlet explaining the stages of the complicated grief process and self-regulating techniques. METHODS: From May 2017 to February 2018, we prospectively and consecutively provided a pamphlet to relatives of out-of-hospital sudden cardiac arrest victims who failed to obtain spontaneous circulation. We investigated the psychiatric status of the bereaved relatives using the Impact of Event Scale - Revised (IES-R). An IES-R score over 24 was defined as PTSD. RESULTS: Fifty-four relatives of the 54 dead patients (victims) provided permission of entry to this research. All subjects and victims were Japanese. Among them, 24 subjects had an IES-R score of 0 and 5 (9.3%) had PTSD approximately 1 month after their bereavement. There were no relatives who received spontaneous psychiatric treatment. The IES-R scores for non-medical cardiac arrest, death inquests, and parent variables were significantly higher compared with medical cardiac arrest, no inquest, and no parent, respectively. The IES-R scores in those who were a child of the victim were significantly lower than in those who were not. CONCLUSION: The present study showed that the frequency of PTSD was 9.3% at 1 month following bereavement among Japanese relatives of sudden death victims after an intervention. This frequency was minimal compared with previous reports.

18.
Sci Rep ; 10(1): 20346, 2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-33230223

RESUMO

Herbivores control algae and promote coral dominance along coral reefs. However, the majority of previous studies have focused on herbivorous fish. Here we investigated grazing effects of the sea urchin Diadema savignyi on algal abundance and coral recruitment processes. We conducted an in situ cage experiment with three density conditions of D. savignyi (0, 8, 16 indiv. m-2) for three months during the main coral recruitment season in Taiwan. Results demonstrated a strong algal control by D. savignyi. At the end of the experiment, average algal cover was 95% for 0 indiv. m-2, compared to 47% for 8 indiv. m-2 and 16% for 16 indiv. m-2. Average algal biomass at 8 indiv. m-2 declined by one third compared to 0 indiv. m-2 and almost zero at 16 indiv. m-2. On the other hand, a negative grazing effect of D. savignyi was observed on coral recruitment processes. Notably, at 16 indiv. m-2, the density of coral recruits declined and mortality of small coral fragments (proxy of coral juveniles) increased. Our results confirm findings of previous studies and indicate the need to balance both positive (strong algal control) and negative (physical damage) influences of Diadema grazing to facilitate the coral recruitment process.


Assuntos
Antozoários/fisiologia , Clorófitas/fisiologia , Herbivoria/fisiologia , Ouriços-do-Mar/fisiologia , Animais , Recifes de Corais , Ecossistema , Cadeia Alimentar , Oceano Pacífico , Dinâmica Populacional/tendências , Taiwan
19.
Sci Rep ; 9(1): 2936, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30814532

RESUMO

Sex change has been widely studied in animals and plants. However, the conditions favoring sex change, its mode and timing remain poorly known. Here, for the first time in stony corals, we report on a protandrous (youngest individuals are males) repetitive sex change exhibited by the fungiid coral Herpolitha limax across large spatial scales (the coral reefs of Japan, Jordan and Israel) and temporal scales (2004-2017). In contrast to most corals, this species is a daytime spawner (08:00-10:00 AM) that spawned at the same time/same date across all the study sites. The sporadically scattered populations of H. limax among the coral reefs of Eilat (Israel) and Aqaba (Jordan) exhibited significantly slower growth, earlier sex change, and lower percentages of reproduction and sex change in comparison to the densely aggregated populations in Okinawa (Japan). At all sites, sex ratio varied among years, but was almost always biased towards maleness. Growth rate decreased with size. We conclude that comparable to dioecious plants that display labile sexuality in response to energetic and/or environmental constraints, the repetitive sex change displayed by H. limax increases its overall fitness reinforcing the important role of reproductive plasticity in the Phylum Cnidaria in determining their evolutionary success.


Assuntos
Antozoários/crescimento & desenvolvimento , Antozoários/fisiologia , Recifes de Corais , Reprodução/fisiologia , Razão de Masculinidade , Animais , Ecossistema , Monitoramento Ambiental , Feminino , Aptidão Genética , Israel , Japão , Jordânia , Masculino , Densidade Demográfica , Caracteres Sexuais
20.
Curr Opin Genet Dev ; 23(4): 429-37, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23725801

RESUMO

The unexpected connection between cilia and signaling is one of the most exciting developments in cell biology in the past decade. In particular, the Hedgehog (Hh) signaling pathway relies on the primary cilium to regulate tissue patterning and homeostasis in vertebrates. A central question is how ciliary localization and trafficking of Hh pathway components lead to pathway activation and regulation. In this review, we discuss recent studies that reveal the roles of ciliary regulators, components and structures in controlling the movement and signaling of Hh players. These findings significantly increase our mechanistic understanding of how the primary cilium facilitates Hh signal transduction and form the basis for further investigations to define the function of cilia in other signaling processes.


Assuntos
Cílios/genética , Proteínas Hedgehog/genética , Transdução de Sinais/genética , Vertebrados/genética , Animais , Movimento Celular/genética , Núcleo Celular , Proteínas Hedgehog/metabolismo , Humanos , Transporte Proteico , Vertebrados/crescimento & desenvolvimento
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