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At least 19 recordsLinked to original sources

[New species of tremstodes from Indian Ocean and Red Sea fishes].

On the basis of the material collected in the Red Sea and the Indian Ocean four new species of trematodes are described: Bucephalopsis pseni sp. n., Diploproctodaeum chelonodoni sp. n., Bucephalus neoscombropsi sp. n., Phyllodistomum sobolevi sp. n. Anatomical and morphological characteristics of the above species as well as original figures of the trematodes are given, their taxonomic position is discussed.

Animals

Two new species of Enenterum Linton, 1910 (Digenea) in the marine fish Neoscorpis lithophilus (Kyphosidae) from the south-western Indian Ocean.

Enenterum elsti sp. nov. and E. prudhoei sp. nov. are described from the intestine of Neoscorpis lithophilus off Mapelane, Natal, South Africa. These species differ from others of the genus Enenterum in the ratio of oral sucker to body-length and in the length of the prepharynx. E. elsti differs from E. prudhoei in size, in sucker-ratio and in the number and configuration of the oral lobes. A key to the species of Enenterum is presented and the status of the genus briefly discussed.

Animals

[Neutron activation analysis of trace elements in sea water samples (author's transl)].

Analytical values of trace elements in sea water samples have been fluctuated according to the sampling locations, the analytical procedures and so on. It is very important in marine chemistry to elucidate the cause of such concentration variations. This report is the analytical results of the samples obtained in the Pacific Ocean, the Indian Ocean and the Sea of Japan, by means of neutron activation analysis. As the preconcentration, APDC-chelate extraction and freeze-drying were adopted. The specimens obtained by this extraction from 500 or 800 ml samples were irradiated by KUR reactor for 1 min, 1 hr to 10 hrs and the gamma-ray spectrometry with a Ge(Li) detector was used for the determination of V, Mn, Cu, Zn, U, Fe, Co, Ni, Ag, Sb and Au. By about 80 hrs irradiation of the specimens obtained by freeze-drying from 20 ml samples and their gamma-ray spectrometry, Sc, Cr, Fe, Co, Zn, Rb, Sr, Ag, Sb and Cs were determined. The former procedure gives concentrations of elements in species reactable with APDC, but the latter method shows entire concentrations of the elements in the sea water samples. Some considerations on the analytical values and the comparisons of the both methods are described.

Activation Analysis

Contrasting Patterns of Connectivity Between Populations of Euphotic and Mesophotic Hydroids in Reunion Island Support the Deep Reef Refuge Hypothesis.

In the context of coral reef decline, mesophotic coral ecosystems (MCEs, 30-150 m) offer hope for the recovery of degraded euphotic reefs. The Deep Reef Refuge Hypothesis (DRRH) postulates the potential of mesophotic reefs to reseed euphotic reefs. This hypothesis needs to be further tested by estimating connectivity along the depth gradient. Mesophotic data are lacking worldwide, particularly in the southwestern Indian Ocean (SWIO). Here, using a total of 2218 samples collected at depths ranging from 10 to 103 m, we estimated the connectivity of 7 hydroid species sampled at euphotic, upper, and lower mesophotic depths around Reunion Island using a multi-species comparative framework. Population genetic analyses using 8-17 microsatellite markers per species (80 markers in total) as well as Bayesian inference were performed to estimate population structure and contemporary migration rates to highlight connectivity patterns and directionality of gene flow between depths. The results revealed three main genetic patterns depending on the species: a horizontal stepping stone pattern between areas around the island, a vertical stepping stone pattern between adjacent depths, and a quasi-panmictic pattern. Each species showed some specificity within these patterns, but overall, at least 4 of the 7 species support the assumption of vertical connectivity from the Deep Reef Refuge Hypothesis, highlighting the importance of studying multiple species. The existence of vertical connectivity between euphotic and mesophotic depths in the southwestern Indian Ocean confirms the importance of mesophotic coral ecosystems for conservation efforts and our global understanding of coral reef ecosystem dynamics.

Animals

Microbial membrane transporters reveal trace metal niche adaptation in distinct water masses of the Southern Ocean.

BACKGROUND: Trace metals are co-factors for enzymes that are essential for microbial metabolism and the cycling of major elements. Membrane transporters allow microbes to sense and react to trace elements in the environment and to balance their uptake and export for the regulation of intracellular metal homeostasis. The acquisition and efflux of trace metals could lead to reciprocal feedbacks between microbes and the surrounding environment. Whether these processes vary among trace metals and across habitats is presently not known. We used membrane transporters into and out of the cell as indicators for the uptake and efflux of trace metals and provide a detailed picture of the distribution of the respective genes in distinct provinces in surface waters and in subsurface water masses across a transect in the Southern Indian Ocean. RESULTS: We observed marked spatial and vertical patterns in normalized gene abundances of transporters of iron (Fe), manganese (Mn), nickel (Ni) and copper (Cu). Changes in gene abundances were specific to the type of transporter and trace metal, and pronounced differences between surface and specific water masses emerged. We found an enrichment in genes related to efflux and homeostasis of Fe, Ni and Cu in two water masses of the deep ocean that are North Atlantic Deep Water (NADW) and Lower Circumpolar Deep Water (LCDW). This pattern was observed on the community level and for metagenome-assembled genomes (MAGs) affiliated with Alteromonadaceae and Burkholderiaceae that were abundant in these two water masses. CONCLUSIONS: The enrichment in trace metal efflux and resistance genes points to microbially mediated processes, exerted by homeostasis, with potential influence on the trace metal speciation and distribution in specific water masses in the deep ocean. The gene repertoire and distinct distribution pattern of the taxa identified as potential key players could reflect an adaptation to these old water masses with trace metals acting as selective driver. Video Abstract.

Membrane Transport Proteins

[Criteria of identification of schistosomiasis caused by Schistosoma hamatobium and S. mansoni (486 patients: 275 case of schistosomiasis)].

Out of a total of 486 patients who originated from French Equatorial Africa, from the West Indies or from the Indian Ocean, the authors identified 275 cases of schistosomiasis of which 230 were due to S. Hematobium and 45 to S. Mansoni. The diagnostic methods were biopsy of the rectal mucosa, immunofluorescence, in the West Indians, examination of the stools, in the Africans examination of the urine, intravenous urography and less often cystoscopy. The value of these investigations was studied in each case, then by comparison with one another and with data in the literature. The most valuable investigation was biopsy of the rectum, better in Africans than examination of the urine, immunofluorescence and better than cystoscopy when this was possible.

Adolescent

Chikungunya virus in Thailand (2020-2023): Epidemiology, clinical features, and genomic insights.

Chikungunya virus (CHIKV) caused significant outbreaks in Thailand during 2008-2009 and 2018-2020. Despite the COVID-19 pandemic, CHIKV continued to circulate; however, data on its epidemiological, clinical, and genetic characteristics during and after this period remains limited. This study investigated CHIKV infections in Thailand from March 2020 to December 2023. Serum samples (n = 1,264) were collected from patients with suspected CHIKV infection at 14 hospitals across five provinces in central, eastern, and northeastern Thailand. Samples were tested by RT-qPCR and IgM fluorescence immunoassay. CHIKV infection was confirmed in 50.5% (638/1,264) of cases. Infections occurred across all age groups, with the highest prevalence among individuals aged ≥56 years. Clinical symptoms significantly associated with infection included myalgia, arthralgia, rash, and conjunctivitis. Rash was more frequently in individuals aged ≤15 years and was significantly associated with lower viral loads. Arthralgia was more common among older adults and was linked to later illness onset. Myalgia was least frequently reported in younger patients. Thirty-eight complete coding sequences of our Thai CHIKV strains were analyzed in phylogenetic and time-scaled trees alongside 186 global strains and 109 ECSA-IOL strains from GenBank, respectively. Genome analysis revealed that CHIKV strains circulating in Thailand during 2020-2023 belonged to the East/Central/South African-Indian Ocean lineage (ECSA-IOL). These strains did not evolve from earlier ECSA-IOL variants that carried the E1-A226V mutation, which was previously detected in Thailand. Instead, all isolates carried E1-K211E and E2-V264A, along with E1-226A, likely introduced from the Indian subcontinent around 2016-2017. This introduction triggered a major outbreak between late 2018 and 2020, followed by sustained transmission. The 2020-2023 Thai strains exhibited high genetic similarity to those from neighboring countries, with multiple nonsynonymous mutations suggesting ongoing viral adaptation. Understanding CHIKV epidemiology, clinical features, and evolution supports improved surveillance, diagnostics, and public health interventions.

Humans

Genomic and transcriptomic characterization of genes expressed at 20 MPa by the marine actinobacterium Kocuria flava.

A marine hydrocarbonoclastic actinobacterium Kocuria flava IOS11 was isolated from 3500 m deep-sea water of the Indian Ocean. The isolate efficiently degraded phenanthrene (250 mg/L) achieving 82 and 98% of degradation at 0.1 MPa and 20 MPa, respectively within a period of 5 days. Whole genome, transcriptomee and metabolomic analysis elucidated its phenanthrene biodegradation efficiency under in situ deep-sea conditions. The genome sequence comprises 3.47 Mb distributed across 88 scaffolds with a high GC content of 74.30%. The genome analysis encoded 3126 genes including 3052 protein coding sequences with functional annotation identifying a broad array of genes associated with PAHs degradation, environmental stress adaptation, biosurfactant and siderophore synthesis. Transcriptome profiling under 0.1 and 20 MPa conditions with phenanthrene as a sole carbon source revealed enhanced expression of hydrocarbon degrading genes, transporters, biosurfactant associated enzymes and stress responsive genes including integrases, DNA repair protein Rad, alanine ligase, heat and cold shock proteins under high pressure conditions underscoring the deep-sea adaptation capabilities of the strain. The degradation pathway of phenanthrene was proposed through integrated genome, transcriptome and metabolomic analysis. These studies provided K. flava IOS11 as a metabolically versatile and pressure adapted bacterium with promising potential for bioremediation application in extreme marine environment.

Transcriptome

Chromosome-level genome assembly and annotation of the porcupine fish (Diodon hystrix).

The porcupinefish (Diodon hystrix), a coral reef teleost, is widely distributed in tropical/subtropical waters of the Pacific, Atlantic, Indian Oceans, and Mediterranean Sea. It shares easily recognizable features with pufferfish, such as body inflation and spines. Additionally, its culinary value makes D. hystrix a highly desirable species in many tropical coastal regions, with considerable market potential. However, lack of a high-quality genome hindered further studies on its reproduction, molecular biology, and genomic improvement. Here, we assembled the chromosome-scale genome using PacBio HiFi, ultra-long reads, and Hi-C. Of the 713.62 Mb genome, 98.63% anchored to 23 chromosomes (scaffold N50: 31.52 Mb) with 39.82% repetitive sequences. The assembled genome achieved a BUSCO completeness score of 97.7%, with 23,171 protein-coding genes predicted, 22,221 of which were functionally annotated. Phylogenetic analysis identified D. hystrix's evolutionary relationships with other species in the Tetraodontiformes. In summary, the high-quality genome of D. hystrix sheds light on valuable insights into genome size evolution, and provides a valuable resource for exploiting genomic study and breeding applications in this species.

Animals

Accounting for recombination rate variation improves inference of barrier loci and reveals the role of both natural and sexual selection in an incipient bird radiation.

Examining genomic patterns of differentiation across lineage pairs at different stages of the speciation continuum, in combination with recombination maps, can help disentangle the effects of linked and divergent selection and identify lineage-specific targets of selection that may act as barrier loci during speciation. Here, we apply this framework to genomic data from African and Indian Ocean bird species of the genus Zosterops (Zosteropidae) to identify candidate barrier loci between ecologically, phenotypically, and genetically distinct Reunion gray white-eye (Zosterops borbonicus) parapatric geographic forms. Using analyses that account for recombination rate variation, we show that putative targets of divergent selection are primarily located on the Z chromosome, except in comparisons between geographic forms that differ in their ecologies. Functional annotation revealed that candidate barrier loci between forms with similar environmental niches are associated with genes involved in song formation and immune function, whereas those between forms with different environmental niches are associated with adaptation to altitude, morphology, and song behavior. Our results highlight the combined roles of natural and sexual selection in the evolution of reproductive barriers in this incipient species radiation.

Animals

Absence of triradius d on the palms of normal people.

Absence of the digital triradius d is a very rare phenomenon, previously only reported in abnormal XXXXY males. During the past few years the anomaly has been found on the palms of three normal females, namely a young English woman and two sisters in the Nicobar Islands in the Indian Ocean. These cases are described and illustrations of the palmar dermatoglyphics presented. The occurrence of such a rare phenomenon in two sisters suggests that it is genetically determined.

Adolescent

Recovering the precolonial population structure of Khoe-San descendant populations.

San populations from Botswana and Namibia retain exceptional linguistic, cultural, and genetic diversity, but few Khoisan-speaking groups remain south of the Kalahari Desert. However, historically, far southern Africa was home to many San and Khoekhoe groups. Popular opinion often implies that such populations do not contribute to the ancestry of contemporary South Africans. Here, we characterize the genetic ancestry of self-identified South African Coloured groups and reconstruct precolonial and colonial population structures from 620 newly sampled individuals. These groups retain the majority of Khoe-San genetic ancestry (>48%), suggesting the persistence of Khoe-San ancestry to the present day. By isolating the Khoe-San ancestry component, we show that it is intermediate between the ≠Khomani San and Nama and distinct from Kalahari Khoe-San populations. We also find that signatures of the Indian Ocean slave trade can be traced to Indonesian islands such as Sulawesi, Java, and Flores, while the South Asian ancestry is regionally nonspecific.

Humans

Grains, trade and war in the multimodal transmission of Rice yellow mottle virus: An historical and phylogeographical retrospective.

Rice yellow mottle virus (RYMV) is a major pathogen of rice in Africa. RYMV has a narrow host range limited to rice and a few related poaceae species. We explore the links between the spread of RYMV in East Africa and rice history since the second half of the 19th century. The phylogeography of RYMV in East Africa was reconstructed from coat protein gene sequences (ORF4) of 335 isolates sampled over two million square kilometers between 1966 and 2020. Dispersal patterns obtained from ORF2a and ORF2b, and full-length sequences converged to the same scenario. The following imprints of rice cultivation on RYMV epidemiology were unveiled. RYMV emerged in the middle of the 19th century in the Eastern Arc Mountains where slash-and-burn rice cultivation was practiced. Several spillovers from wild hosts to cultivated rice occurred. RYMV was then rapidly introduced into the nearby large rice growing Kilombero valley and Morogoro region. Harvested seeds are contaminated by debris of virus infected plants that subsist after threshing and winnowing. Long-distance dispersal of RYMV is consistent (i) with rice introduction along the caravan routes from the Indian Ocean Coast to Lake Victoria in the second half of the 19th century, (ii) seed movement from East Africa to West Africa at the end of the 19th century, from Lake Victoria to the north of Ethiopia in the second half of the 20th century and to Madagascar at the end of the 20th century, (iii) and, unexpectedly, with rice transport at the end of the First World War as a troop staple food from the Kilombero valley towards the South of Lake Malawi. Overall, RYMV dispersal was associated to a broad range of human activities, some unsuspected. Consequently, RYMV has a wide dispersal capacity. Its dispersal metrics estimated from phylogeographic reconstructions are similar to those of highly mobile zoonotic viruses.

Oryza