Diverse Genus Research Articles

Enterococcal Phages: Food and Health Applications.

Enterococcus is a diverse genus of Gram-positive bacteria belonging to the lactic acid bacteria (LAB) group. It is found in many environments, including the human gut and fermented foods. This microbial genus is at a crossroad between its beneficial effects and the concerns regarding its safety. It plays an important role in the production of fermented foods, and some strains have even been proposed as probiotics. However, they have been identified as responsible for the accumulation of toxic compounds-biogenic amines-in foods, and over the last 20 years, they have emerged as important hospital-acquired pathogens through the acquisition of antimicrobial resistance (AMR). In food, there is a need for targeted measures to prevent their growth without disturbing other LAB members that participate in the fermentation process. Furthermore, the increase in AMR has resulted in the need for the development of new therapeutic options to treat AMR enterococcal infections. Bacteriophages have re-emerged in recent years as a precision tool for the control of bacterial populations, including the treatment of AMR microorganism infections, being a promising weapon as new antimicrobials. In this review, we focus on the problems caused by Enterococcus faecium and Enterococcus faecalis in food and health and on the recent advances in the discovery and applications of enterococcus-infecting bacteriophages against these bacteria, with special attention paid to applications against AMR enterococci.

FIRST DATA ON THE DYTISCIDAE (COLEOPTERA) FROM THE COASTAL TUNDRA OF YUGORSKY PENINSULA, POLAR RUSSIA

In July 2018, diving beetles were collected in the most typical water bodies and other habitats in the vicinity of Amderma, Kara Sea coast, northern Yugorsky Peninsula. The fauna comprises 15 dytiscid species from 7 genera. The most diverse genera were Agabus and Hydroporus. The record of Dytiscus lapponicus was the northernmost for this species, while the reports of Hydroporus cf. fuscipennis and Agabus pallens were the northernmost for the Palaearctic parts of their distribution ranges. Original photographs illustrate peculiar specimens of Dytiscus lapponicus with dark head, pronotum and scutellum. Most of the species show vast Holarctic Arcto-Boreal or Arcto-Boreal-Montane distributions. The species composition of the Dytiscidae is quite similar to those of the northernmost mainland regions of the European Northeast (Pakhancheskaya Bay, Kara Tundra and Pamal), as well as the Vaigatch and Dolgyi islands, being less similar to those of the south tundra regions (Kanin Peninsula, Bolvanskaya Bay and Antipayuta village, Gydan Peninsula). Among the study habitats, the most diverse beetle assemblage inhabited thermokarst lakes (up to 14 species, the maximum density noted was 1150 ind./100 trap-days). On the contrary, on salt marshes, only 2–3 beetle species were recorded and the total abundance was significantly lower (1.8–3.6 ind./100 trap-days).

MYCOBIOTA OF THE RED ALGAE PALMARIA PALMATA IN THE KANDALAKSHA BAY OF THE WHITE SEA

This is a rst report about the diversity of micromycetes associated with living thalli of the edible red algae Palmaria palmata (dulse). We collected samples in the Kandalaksha Bay of the White Sea at upper (10 thalli in the littoral) and lower (10 thalli in the sublittoral) lines of this species distribution. The work was carried out by cultural methods, fungi were isolated from the surface of thalli. From one thallus from 0 to 55 colonies belongs to 0-24 morphotypes were isolated. The total diversity was 52 morphotypes, of which 48 were mycelia and 4 were yeast. All identi ed yeasts belong to Basidiomycota; among lamentous fungi, 2 species belongs to Zygomycota, and the rest belongs to Ascomycota, the vast majority of which are represented by anamorphic stages. The most diverse genera were Acremonium (10 morphotypes), Penicillium (9) and Cladosporium (6); the most numerous are Acremonium (158 colonies) and Cladosporium (103 colonies). Acremonium fuci is the most common species on the studied thalli (122 colonies on 15 thalli). The most important factor for the formation of the surface mycobiota of dulse is the habitat: littoral and sublittoral algal populations di er signicantly in the fungal communities number and structure. The thalli of the littoral population are much richer in fungi. The mycobiota of littoral samples in dominated by dark-colored species, as well as Acremonium fuci and Sarocladium strictum. While the mycobiota of sublittoral samples is dominated by lightcolored species, and most of the isolated yeasts were also founded here.

Checklist of the arbuscular mycorrhizal fungi of Oaxaca, an important hotspot of biodiversity in Mexico

Background: Oaxaca, a southern State in Mexico, belongs to the Mesoamerican hotspot of biodiversity. The taxonomic and diversity knowledge of arbuscular mycorrhizal fungi (AMF) in Oaxaca State is scattered and accessibility to it is difficult.
 Questions: Which AMF species have been identified in Oaxaca and which is their distribution?
 Studied species: Arbuscular mycorrhizal fungi.
 Study site: State of Oaxaca, Mexico.
 Methods: It was prepared an updated and annotated checklist of the AMF species with frequency of occurrence and the sampling sites where the species had been registered. All studies carried out previously (to date, 2022) were considered. Information on AMF taxa was available in scattered form in different publications in physical and electronic media, theses, projects, technical reports, and scientific papers.
 Results: The checklist includes 78 species, distributed among 23 genera, 10 families, and four orders. The most diverse families were Glomeraceae (26 species), followed by Gigasporaceae (20) and Acaulosporaceae (15), whereas the most diverse genera were Acaulospora and Glomus (15 and eight species, respectively). The most frequent species were Funneliformis geosporus, Acaulospora scrobiculata, and A. spinosa. The highest species diversity has been reported under the rhizosphere of Agave angustifolia, A. karwinskii, and Zea mays (39, 36, and 34 species, respectively). A new AMF species was recently isolated from the rhizosphere of a microendemic agave.
 Conclusions: The recorded AMF species of Oaxaca State confirms its position as one of the states with the highest AMF species diversity of Mexico.

Comparative genomics and phylogenomics of Campylobacter unveil potential novel species and provide insights into niche segregation

Campylobacter is a bacterial genus associated with community outbreaks and gastrointestinal symptoms. Studies on Campylobacter generally focus on specific pathogenic species such as C. coli and C. jejuni. Currently, there are thousands of publicly available Campylobacter genomes, allowing a more complete assessment of the genus diversity. In this work, we report a network-based analysis of all available Campylobacter genomes to explore the genus structure and diversity, revealing potentially new species and elucidating genus features. We also hypothesize that the previously established Clade III of C. coli is in fact a novel species (referred here as Campylobacter spp12). Finally, we found a negative correlation between pangenome fluidity and saturation coefficient, with potential implications to the lifestyles of distinct Campylobacter species. Since pangenome analysis depends on the number of available genomes, this correlation could help estimate pangenome metrics of Campylobacter species with less sequenced genomes, helping understand their lifestyle and niche adaptation. Together, our results indicate that the Campylobacter genus should be re-evaluated, with particular attention to the interplay between genome structure and niche segregation.

Occurrence and behavioral rhythms of the endangered Acadian redfish (Sebastes fasciatus) in the Sambro Bank (Scotian Shelf)

The genus Sebastes is a morphologically and ecologically diverse genus of rockfish characterized by high longevity, late-maturity and low natural mortality. On the northwest Atlantic continental shelf, the Acadian redfish (Sebastes fasciatus) is the most common rockfish species above 300 m depth. This species has been widely exploited resulting in the depletion or collapse of most of its stocks. Management of long-lived species with intricate life-history characteristics is challenging and requires highly integrated biological and oceanographic monitoring, which allow the identification of environmental drivers and demographic and behavioral trends. The present study uses high-temporal resolution imaging and environmental data, acquired with an autonomous lander deployed for 10-months at the Sambro Bank Sponge Conservation Area (Scotian Shelf) to elucidate S. fasciatus temporal dynamics and behavioral trends in response to near-bed environmental conditions. S. fasciatus, mostly displayed passive locomotion and static behaviors, in common with other shelf-dwelling Sebastes species. Structural complexity provided by sponges positively influenced S. fasciatus presence. Fish used sponges to avoid being dragged by bottom currents. Hydrodynamics appear to act as a synchronizing factor conditioning its swimming behavior. S. fasciatus total counts exhibited a seasonal shift in rhythm’s phase likely reflecting changes in lifestyle requirements. This study provides new insights on S. fasciatus dynamics and behavior. Nonintrusive monitoring approaches, such as the one used in this study, will be key to monitor this threatened species populations. Especially, since it is expected that S. fasciatus will experience distribution shifts to higher latitudes due to future climate stressors.

When a genus must become two: resurrection of Pelagella Gray, 1850 with the description of six new species

ABSTRACT Goniodoris is the third most diverse genus of the nudibranch family Goniodorididae. The genus has undergone several taxonomic changes, with c. one-third of the recognized species of Goniodoris having been synonymized (most of these are junior synonyms of genera from other families). In addition, Goniodoris includes other synonymized genera within it, such as Pelagella, which was erected for Doris pareti. This species was synonymized with Goniodoris castanea and the genus Pelagella went almost unnoticed. In the present study, we investigate the systematics of the genus Goniodoris by examining specimens of G. castanea from England and Spain, G. joubini from Hawaii and six undescribed Goniodoris species from Australia, the Philippines and Mozambique. The morphology of the new species is studied using dissections of the internal organs and scanning electron micrographs of the radulae, labial cuticles and the penis. We also carried out phylogenetic analyses using partial DNA sequences of mitochondrial and nuclear genes. These analyses show that the type species of Goniodoris, G. nodosa, is not a member of the clade constituted by the focal species of our study; the valid name for this clade is Pelagella. Six new species of Pelagella, P. albopunctata n. sp., P. balanoyensis n. sp., P. longicornis n. sp., P. scottjohnsoni n. sp., P. rubrobranchiata n. sp. and P. vitrea n. sp., are described.

Eriocaulaceae: A new classification system based on morphological evolution and molecular evidence

AbstractPaepalanthus, in its current sense, is the most diverse genus of Eriocaulaceae in the Neotropics, comprising about 400 species. Previous studies have consistently found that the genus is not monophyletic, also being morphologically heterogeneous and diagnosable by a set of homoplasies; thus, the current circumscription needs to be revised. The new classification proposed here uses a comprehensive phylogeny of Paepalanthus and closely related genera as a framework and an evaluation of a set of morphological characters using ancestral state reconstruction, which allowed the recognition of strongly supported clades with morphological diagnosability. We propose the recognition of 12 genera in the clade encompassing Paepalanthus and allied groups, including six new genera (Coracoralina, Floralia, Giuliettia, Gnomus, Hydriade, Nisius), two new statuses (Cryptanthella, Monosperma), the reestablishment of Actinocephalus, Lachnocaulon, and Tonina, and a recircumscription of Paepalanthus. In this new circumscription, Paepalanthus comprises 257 species, most of them restricted to the Brazilian campos rupestres. Among the proposed genera, nine have potential morphological synapomorphies, one has a restricted geographical distribution, and the other two can be recognized by a combination of characters. Newly generated seed morphology data is consistent within the different genera and plays an important role in their recognition. A total of 136 new combinations are hereby proposed. We provide a genus‐level identification key, as well as generic descriptions, diagnostic features, photos illustrating their morphological diversity, maps and notes on distribution, and lists of species by genus.

New insights into the genome and transmission of the microsporidian pathogen Nosema muscidifuracis.

Nosema is a diverse genus of unicellular microsporidian parasites of insects and other arthropods. Nosema muscidifuracis infects parasitoid wasp species of Muscidifurax zaraptor and M. raptor (Hymenoptera: Pteromalidae), causing ~50% reduction in longevity and ~90% reduction in fecundity. Here, we report the first assembly of the N. muscidifuracis genome (14,397,169 bp in 28 contigs) of high continuity (contig N50 544.3 Kb) and completeness (BUSCO score 97.0%). A total of 2,782 protein-coding genes were annotated, with 66.2% of the genes having two copies and 24.0% of genes having three copies. These duplicated genes are highly similar, with a sequence identity of 99.3%. The complex pattern suggests extensive gene duplications and rearrangements across the genome. We annotated 57 rDNA loci, which are highly GC-rich (37%) in a GC-poor genome (25% genome average). Nosema-specific qPCR primer sets were designed based on 18S rDNA annotation as a diagnostic tool to determine its titer in host samples. We discovered high Nosema titers in Nosema-cured M. raptor and M. zaraptor using heat treatment in 2017 and 2019, suggesting that the remedy did not completely eliminate the Nosema infection. Cytogenetic analyses revealed heavy infections of N. muscidifuracis within the ovaries of M. raptor and M. zaraptor, consistent with the titer determined by qPCR and suggesting a heritable component of infection and per ovum vertical transmission. The parasitoids-Nosema system is laboratory tractable and, therefore, can serve as a model to inform future genome manipulations of Nosema-host system for investigations of Nosemosis.

Quantification of diversity sampling bias resulting from rice root bacterial isolation on popular and nitrogen-free culture media using 16S amplicon barcoding.

Culturing bacteria from plant material is well known to be conducive to strong bias compared to the actual diversity in the original samples. This bias is related to the bacterial cultivability, chemical composition of the media and culture conditions. Recovery bias is often observed but has never been quantified on different media using an amplicon barcoding approach whereby plant microbiota DNA extractions are compared to DNA extracted from serial dilutions of the same plant tissues grown on bacterial culture media. In this study, we: i) quantified the bacterial culturing diversity bias using 16S amplicon barcode sequencing by comparing a culture-dependent approach (CDA) focused on rice roots on four commonly used bacterial media (10% and 50% TSA, plant-based medium with rice flour, nitrogen free medium NGN and NFb) versus a culture-independent approach (CIA) assessed with DNA extracted directly from root and rhizosphere samples; ii) assessed enriched and missing taxa detected on the different media; iii) used biostatistics functional predictions to highlight metabolic profiles that could potentially be enriched in the CDA and CIA. A comparative analysis of the two approaches revealed that among the 22 phyla present in microbiota of the studied rice root samples, only five were present in the CDA (Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Verrucomicrobia). The Proteobacteria phylum was the most abundant in all CDA samples, showing high gamma-Proteobacteria enrichment. The diversity of the combined culture media represented about a third of the total microbiota diversity, and its genus diversity and frequency was documented. The functional prediction tool (PICRUSt2) detected nitrogenase enzyme enrichment in bacterial taxa sampled from nitrogen-free media, thus validating its predictive capacity. Further functional predictions also showed that the CDA mostly missed anaerobic, methylotrophic, methanotrophic and photosynthetic bacteria compared to the CIA, thereby generating valuable insight that could enable the design of ad-hoc culture media and conditions to increase the rice-associated microbiota cultivability.

Cycad phylogeny predicts host plant use of Eumaeus butterflies.

Eumaeus butterflies are obligate herbivores of Zamia, the most diverse neotropical genus of cycads. Eumaeus-Zamia interactions have been characterized mainly for species distributed in North and Central America. However, larval host plant use by the southern Eumaeus clade remains largely unknown, precluding a comprehensive study of co-evolution between the genera. Here, we combine fieldwork with museum and literature surveys to expand herbivory records for Eumaeus from 21 to 38 Zamia species. We inferred a time-calibrated phylogeny of Eumaeus to test for distinct macroevolutionary scenarios of larval host plant conservatism and co-evolution. We found a remarkable coincidence between Eumaeus and Zamia diversification, with the butterfly stem group diverging at the same time as the most recent radiation of Zamia in the Miocene. Cophylogenetic reconciliation analyses show a strong cophylogenetic signal between cycads and their butterfly herbivores. Bipartite model-based approaches indicate that this is because closely related Zamia species are used by the same Eumaeus species, suggesting larval host plant resource tracking by the butterfly herbivores. Our results highlight a case of tight evolution between Eumaeus butterflies and cycads, pointing to the generality of correlated evolution and phylogenetic tracking in plant-herbivore interactions across seed plants.

Variations in the soil micro-food web structure and its relationship with soil C and N mineralization during secondary succession of subalpine forests

The soil micro-food web is an important network of belowground trophic relationships and it participates directly and indirectly in soil ecological processes. In recent decades, the roles of the soil micro-food web in regulating ecosystem functions in grasslands and agroecosystems have received much attention. However, the variations in the soil micro-food web structure and its relationship with ecosystem functions during forest secondary succession remain unclear. In this study, we investigated how forest secondary succession affected the soil micro-food web (including soil microbes and nematodes) and soil carbon and nitrogen mineralization across a successional sequence of “grasslands – shrublands – broadleaf forests – coniferous forests” in a subalpine region of southwestern China. With forest successional development, the total soil microbial biomass and the biomass of each microbial group generally increased. The significant influences of forest succession on soil nematodes were mainly reflected in several trophic groups with high colonizer-persister values (particularly bacterivore3, herbivore5 and omnivore-predator5) that are sensitive to environmental disturbance. The increases in the connectance and nematode genus richness, diversity, and maturity index indicated an increasingly stable and complex soil micro-food web with forest succession, which was closely related to soil nutrients, particularly the soil carbon contents. Additionally, we found that the soil carbon and nitrogen mineralization rates also exhibited generally increasing trends during forest succession, which had significant positive correlations with the soil micro-food web composition and structure. The path analysis results indicated that the variances in ecosystem functions induced by forest succession were significantly determined by soil nutrients and soil microbial and nematode communities. Overall, these results suggested that forest succession enriched and stabilized the soil micro-food web and promoted ecosystem functions via the increase in soil nutrients, and the soil micro-food web played an important role in regulating ecosystem functions during forest succession.

A reassessment of the distinctiveness of dryopithecine genera from the Iberian Miocene based on enamel-dentine junction geometric morphometric analyses.

A vast diversity of catarrhines primates has been uncovered in the Middle to Late Miocene (12.5-9.6Ma) of the Vallès-Penedès Basin (northeastern Spain), including several hominid species (Pierolapithecus catalaunicus, Anoiapithecus brevirostris, Dryopithecus fontani, Hispanopithecus laietanus, and Hispanopithecus crusafonti) plus some remains attributed to 'Sivapithecus' occidentalis (of uncertain taxonomic validity). However, Pierolapithecus and Anoiapithecus have also been considered junior synonyms of Dryopithecus by some authors, which entail a lower generic diversity and an inflated intrageneric variation of the latter genus. Since the distinction of these taxa partly relies on dental features, the detailed and quantitative analysis of tooth shape might help disentangling the taxonomic diversity of these Miocene hominids. Using diffeomorphic surface matching and three-dimensional geometric morphometrics, we investigate the enamel-dentine junction shape (which is a reliable taxonomic proxy) of these Miocene hominids, with the aim of investigating their degree of intra- and intergeneric variation compared with that of extant great ape genera. We conducted statistical analyses, including between-group principal component analyses, canonical variate analyses, and permutation tests, to investigate whether the individual and combined (i.e., Dryopithecus s.l.) variation of the extinct genera exceeds that of the extant great apes. Our results indicate that Pierolapithecus, Anoiapithecus, Dryopithecus, and Hispanopithecus show morphological differences of enamel-dentine junction shape relative to the extant great apes that are consistent with their attribution to different genera. Specifically, the variation displayed by the Middle Miocene taxa combined exceeds that of extant great ape genera, thus undermining the single-genus hypothesis. 'Sivapithecus' occidentalis specimens fall close to Dryopithecus but in the absence of well-preserved comparable teeth for Pierolapithecus and Anoiapithecus, their taxonomic attribution remains uncertain. Among the Hispanopithecus sample, IPS1802 from Can Llobateres stands out and might either be an outlier in terms of morphology, or represent another dryopithecine taxon.

Speleomycology of Air in Stopića Cave (Serbia).

Fungi can colonize organic matter present in subterranean sites and have a significant role as dwellers in different microniches of cave habitats. In order to analyze the content of airborne fungal propagules in different parts of "Stopića Cave," a touristic site in Serbia, air sampling was carried out in three seasons during 2020, prior to and during the onset of COVID-19 pandemic. Culturable mycobiota was identified using both microscopic techniques and ITS region/BenA gene barcoding, while multivariate analyses were employed to establish the link between fungal taxa and different environmental factors. The maximal measured fungal propagule concentrations were recorded during spring sampling which were based on fungal propagule concentration categories; the cave environment matches the category V. A total of 29 fungal isolates were identified, while Aspergillus, Cladosporium, Fusarium, Lecanicillium, Mucor, and Penicillium were the most diverse genera. According to the trophic mode, most of the isolated fungal species were pathotrophs (75.86%), but when regarding ecological guilds, the most dominant were undefined saprobes and animal pathogens (41.38% for each). Show caves are especially vulnerable to human impacts, and the fungal propagules' concentration within the caves could be good indices for the level of ecological disturbance.

The first two mitochondrial genomes from Apiotrichum reveal mitochondrial evolution and different taxonomic assignment of Trichosporonales

Apiotrichum is a diverse anamorphic basidiomycetous yeast genus, and its mitogenome characterization has not been revealed. In this study, we assembled two Apiotrichum mitogenomes and compared them with mitogenomes from Agaricomycotina, Pucciniomycotina and Ustilaginomycotina. The mitogenomes of Apiotrichum gracile and A. gamsii comprised circular DNA molecules, with sizes of 34,648 bp and 38,096 bp, respectively. Intronic regions were found contributed the most to the size expansion of A. gamsii mitogenome. Comparative mitogenomic analysis revealed that 6.85–38.89% of nucleotides varied between tRNAs shared by the two Apiotrichum mitogenomes. The GC content of all core PCGs in A. gamsii was lower than that of A. gracile, with an average low value of 4.97%. The rps3 gene differentiated the most among Agaricomycotina, Pucciniomycotina and Ustilaginomycotina species, while nad4L gene was the most conserved in evolution. The Ka/Ks values for cob and rps3 genes were > 1, indicating the two genes may be subjected to positive selection in Agaricomycotina, Pucciniomycotina and Ustilaginomycotina. Frequent intron loss/gain events and potential intron transfer events have been detected in evolution of Agaricomycotina, Pucciniomycotina and Ustilaginomycotina. We further detected large-scale gene rearrangements between the 19 mitogenomes from Agaricomycotina, Pucciniomycotina and Ustilaginomycotina, and fifteen of the 17 mitochondrial genes shared by Apiotrichum varied in gene arrangements. Phylogenetic analyses based on maximum likelihood and Bayesian inference methods using a combined mitochondrial gene dataset revealed different taxonomic assignment of two Apiotrichum species, wherein A. gamsii had a more closely relationship with Trichosporon asahii. This study served as the first report on mitogenomes from the genus Apiotrichum, which promotes the understanding of evolution, genomics, and phylogeny of Apiotrichum.

Species of Ergasilus von Nordmann, 1832 (Copepoda: Ergasilidae) from cichlid fishes in Lake Tanganyika.

Ergasilus (von Nordmann, 1832) (Ergasilidae) is a species-rich group of parasitic copepods with a wide distribution in freshwater, marine and brackish environments. Up to now, 9 species of Ergasilus are known from cichlid fishes in Africa. In this study, 5 species, including 3 new, were collected from the gills of 12 cichlid species (11 genera: Bathybates, Ctenochromis, Eretmodus, Gnathochromis, Lamprologus, Neolamprologus, Ophthalmotilapia, Perissodus, Simochromis, Spathodus and Tanganicodus) of the northeastern shore of Lake Tanganyika in Burundi, namely E. macrodactylus (Sars, 1909), E. megacheir (Sars, 1909), E. caparti n. sp., E. parasarsi n. sp. and E. parvus n. sp. All species found were identified and described on the basis of adult female specimens using an integrative taxonomy approach mixing morphological characterization and molecular analyses of 2 ribosomal DNA markers (partial 18S and 28S rDNA sequences). An identification key for Ergasilus species from Lake Tanganyika is included. This study provides the first molecular data for Ergasilus species in Africa. The phylogenetic analyses suggest that the Ergasilus species parasitizing Lake Tanganyikan cichlids form a well-supported clade within the Ergasilidae. However, their phylogenetic relationships with other congeners still remain unclear due to a lack of molecular data for this diverse genus.

Deterministic versus stochastic control in β-diversity, abundance and co-occurrence patterns of a soil nematode assemblage living in a Mediterranean soil

In this paper we studied the determinism-stochasticity trade-off affecting the structure of a soil nematode assemblage. Specifically, in a field experiment that lasted six months, the soil temperature and moisture conditions were manipulated in 14 plots. The generic composition of the soil nematode assemblage was explored by estimations of β-diversity, its turnover and nestedness components and by fitting rank abundance models. Further the associative aspects between the assemblage members and between them and habitat attributes were accounted for by analyzing the niche overlap based on Pearson correlation coefficients. Using variation partitioning and null models, we found that the generic diversity of the assemblage was more strongly determined by non-registered lateral experimental factors (stochastic control). By contrast, the deterministic control—less strong than the stochastic counterpart—was exerted both in synchronization with the changes in habitat characteristics and/or with a time delay. The network analysis showed that, under favorable habitat conditions in July, September and October, reduced network modularity and enhanced connectivity were favored, which probably led to a niche-based deterministic selection that outperformed stochasticity. Conversely, under changing experimental conditions in August and lower temperature in November and December, stochasticity would be superior to niche identity, leading to enhanced modularity and relatively loose networks.

Identification of Neotropical Culex Mosquitoes by MALDI-TOF MS Profiling.

The mosquito (Diptera: Culicidae) fauna of French Guiana encompasses 242 species, of which nearly half of them belong to the genus Culex. Whereas several species of Culex are important vectors of arboviruses, only a limited number of studies focus on them due to the difficulties to morphologically identify field-caught females. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a promising method for the identification of mosquitoes. Culex females collected in French Guiana were morphologically identified and dissected. Abdomens were used for molecular identification using the COI (cytochrome oxidase 1) gene. Legs and thorax of 169 specimens belonging to 13 Culex species, (i.e., Cx. declarator, Cx. nigripalpus, Cx. quinquefasciatus, Cx. usquatus, Cx. adamesi, Cx. dunni, Cx. eastor, Cx. idottus, Cx. pedroi, Cx. phlogistus, Cx. portesi, Cx. rabanicolus and Cx. spissipes) were then submitted to MALDI-TOF MS analysis. A high intra-species reproducibility and inter-species specificity of MS spectra for each mosquito body part tested were obtained. A corroboration of the specimen identification was revealed between MALDI-TOF MS, morphological and molecular results. MALDI-TOF MS protein profiling proves to be a suitable tool for identification of neotropical Culex species and will permit the enhancement of knowledge on this highly diverse genus.

Complete Chloroplast Genome of Four Thai Native Dioscorea Species: Structural, Comparative and Phylogenetic Analyses.

The chloroplast genomes of Dioscorea brevipetiolata, D. depauperata, D. glabra, and D. pyrifolia are 153,370-153,503 bp in size. A total of 113 genes were predicted, including 79 protein-coding sequences (CDS), 30 tRNA, and four rRNA genes. The overall GC content for all four species was 37%. Only mono-, di-, and trinucleotides were present in the genome. Genes adjacent to the junction borders were similar in all species analyzed. Eight distinct indel variations were detected in the chloroplast genome alignment of 24 Dioscorea species. At a cut-off point of Pi = 0.03, a sliding window analysis based on 25 chloroplast genome sequences of Dioscorea species revealed three highly variable regions, which included three CDS (trnC, ycf1, and rpl32), as well as an intergenic spacer region, ndhF-rpl32. A phylogenetic tree based on the complete chloroplast genome sequence displayed an almost fully resolved relationship in Dioscorea. However, D. brevipetiolata, D. depauperata, and D. glabra were clustered together with D. alata, while D. pyrifolia was closely related to D. aspersa. As Dioscorea is a diverse genus, genome data generated in this study may contribute to a better understanding of the genetic identity of these species, which would be useful for future taxonomic work of Dioscorea.

Applications of Antioxidant Secondary Metabolites of Sargassum spp.

Sargassum is one of the largest and most diverse genus of brown seaweeds, comprising of around 400 taxonomically accepted species. Many species of this genus have long been a part of human culture with applications as food, feed, and remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of natural antioxidant compounds of great interest, including polyphenols, carotenoids, meroterpenoids, phytosterols, and several others. Such compounds provide a valuable contribution to innovation that can translate, for instance, into the development of new ingredients for preventing product deterioration, particularly in food products, cosmetics or biostimulants to boost crops production and tolerance to abiotic stress. This manuscript revises the chemical composition of Sargassum seaweeds, highlighting their antioxidant secondary metabolites, their mechanism of action, and multiple applications in fields, including agriculture, food, and health.