High Nucleotide Diversity Research Articles

Speciation driven by recombination in the evolution of tomato curly stunt virus in Mozambique

AbstractBegomoviruses constitute a group of viruses of great economic importance in agriculture, mainly in tropical and subtropical regions, including southern Africa. Tomato curly stunt virus (ToCSV) is an important begomovirus described in South Africa and later reported in Mozambique impacting tomato cultivation. In Mozambique, the severe disease caused by ToCSV limits tomato cultivation and compromises the income of small and medium farms. Due to the scarcity of information about this pathogen, in this study we explored its genetic variability to elucidate the mechanisms that drive its evolution. In 2019, 27 ToCSV full‐length sequences were obtained from tomato foliar samples with virus‐like symptoms collected in the district of Chokue in Gaza province, Mozambique. Sequence analysis showed that isolates from Mozambique have a nucleotide identity of 90.9%–96.9% with the isolate from South Africa (AF261885) and are grouped into two distinct strains that we named ToCSV‐Chok I and ToCSV‐Chok II. The ToCSV‐Chok II strain has a higher nucleotide diversity than ToCSV‐Chok I in the Rep gene. Recombination is involved in the evolutionary history of ToCSV, with both intraspecific and interspecific recombination events detected in the Rep gene. Our results indicate a prevalence of ToCSV in tomato crops in the Chokue district of Mozambique (the major tomato‐producing region of the country) and suggest that ToCSV is undergoing speciation due to the effect of recombination.

Genetic Diversity and Population Structure of Three Caranx Species from Batangas Province, Philippines

Species belonging to the genus Caranx, locally known as “talakitok,” belong to the economically important fish in the Philippines. The popularity of these species makes them prone to overexploitation, which may result to a decline in their population in the wild. Despite these circumstances, stock assessment and population genetic variation studies are scarce. In this study, three species from this genus (C. ignobilis, C. papuensis, C. ignobilis) from the Batangas region were subjected to genetic diversity and population structure analyses using the cytochrome b (cyt b) gene of the mitochondrial DNA (mtDNA) to address these information gaps. High haplotype and high nucleotide diversity were noted in C. ignobilis, which may indicate that the population is still large and stable. However, C. papuensis and C. sexfasciatus populations had a low nucleotide diversity and high haplotype diversity, which could mean a possible genetic bottleneck in the recent past. Likewise, each of these three species showed no genetic differentiation between marine and freshwater specimens, which can be attributed to their life history and biology. Analysis of molecular variance (AMOVA) revealed weak genetic structure, indicated by low percentage value between populations. Based on neutrality tests and mismatch distribution analysis, the three species may have possibly undergone demographic expansion. This study provides the genetic profile of Caranx species found in the Batangas region before the recent Taal Volcano eruption (January 2020), which can be used to investigate the effects of this eruption on the population of this species. Likewise, results obtained from this study served as preliminary data for the population genetics of Caranx spp. found in Batangas, Philippines.

Phylogeography, population connectivity and demographic history of the Stoplight parrotfish, Sparisoma viride (Teleostei: Labridae), in the Greater Caribbean

Few genetic studies that provide biological, ecological and evolutionary information have been conducted for parrotfishes, including Sparisoma viride, and none has covered the full geographic range of this species. Here, we examine the genetic patterns of the Stoplight parrotfish (S. viride) in the Greater Caribbean and its relationship with the recognized biogeographic provinces in the region. Phylogeographic, population and coalescent analyses were performed to examine the genetic structure and connectivity of S. viride populations throughout its entire range within the Greater Caribbean. Two mitochondrial (control region and coxI) and one nuclear (RHO) markers were used. The Stoplight parrotfish shows high haplotypic diversity (h) and low nucleotide diversity (π) in the control region, and low genetic diversity in coxI and RHO. No evidence of genetic structure was found, indicating a panmictic population throughout the Greater Caribbean with highly symmetrical migration rates among previously defined Caribbean biogeographic provinces. The demographic history estimates indicate events of bottlenecks followed by a population expansion dated at 80,000 years ago (kya) during the Pleistocene epoch. These results suggest that the contrasting environmental conditions that define the Greater Caribbean provinces are not barriers to gene flow for S. viride. The phylogeographic patterns of Stoplight parrotfish could be associated with the biological characteristics of the species (such as extensive pelagic larval duration and use of multiple habitats), historical demographic events and physical conditions of the Greater Caribbean, promoting the genetic homogeneity of the species in the region.

Mitochondrial genome of Bulinus truncatus (Gastropoda: Lymnaeoidea): Implications for snail systematics and schistosome epidemiology

Many freshwater snails of the genus Bulinus act as intermediate hosts in the life-cycles of schistosomes in Africa and adjacent regions. Currently, 37 species of Bulinus representing four groups are recognised. The mitochondrial cytochrome c oxidase subunit 1 (cox1) gene has shown utility for identifying and differentiating Bulinus species and groups, but taxonomic relationships based on genetic data are not entirely consistent with those inferred using morphological and biological features. To underpin future systematic studies of members of the genus, we characterised here the mitochondrial genome of Bulinus truncatus (from a defined laboratory strain) using a combined second- and third-generation sequencing and informatics approach, enabling taxonomic comparisons with other planorbid snails for which mitochondrial (mt) genomes were available. Analyses showed consistency in gene order and length among mitochondrial genomes of representative planorbid snails, with the lowest and highest nucleotide diversities being in the cytochrome c oxidase and nicotinamide dehydrogenase subunit genes, respectively. This first mt genome for a representative of the genus Bulinus should provide a useful resource for future investigations of the systematics, population genetics, epidemiology and/or ecology of Bulinus and related snails. The sequencing and informatic workflow employed here should find broad applicability to a range of other snail intermediate hosts of parasitic trematodes.

New molecular data attest to the absence of cospeciation patterns between Placobdella costata (Fr. Müller, 1846) (Hirudinea) and freshwater turtles (Emys spp.) in Italy

The only Palearctic representative of the leech genus Placobdella Blanchard, 1893 is P. costata, an ectoparasite of freshwater turtles. To date, no conclusive evidence about the possible presence of coevolutionary patterns between this leech and its turtle hosts is available due to the paucity of DNA sequence data available for P. costata; moreover, comparative host data is also mostly lacking, making any inferences more difficult. The discovery of new populations of the species in northern Italy and Sicily allowed us to generate novel mitochondrial DNA sequences and to compare the topology of the resulting phylogenetic trees with the phylogeny of the turtle hosts occurring in the study area, i.e., Emys orbicularis and E. trinacris. The branching pattern of the phylogenetic tree for P. costata is not congruent with that of its turtle hosts, thus suggesting the lack of coevolutionary or cospeciation phenomena between these taxa. The lack of a coevolutionary pattern might be ascribed to the different dispersal ability of Placobdella costata and Emys spp. and to the host generality of the leech, as confirmed by the occurrence of P. costata on aquatic turtles belonging to the genus Mauremys in areas where Emys spp. are rare or absent. A single leech cytochrome c oxidase subunit 1 haplotype was found in each study region, and the overall nucleotide diversity was very low throughout the investigated distribution. This apparent lack of a clear phylogeographical pattern was unexpected in the P. costata populations occurring in the circum-Mediterranean areas, where the occurrence of high haplotype and nucleotide diversity is customary for most terrestrial and freshwater species. Based on the available data, we suggest a recent, post-glacial origin of the studied P. costata populations.

Multidisciplinary approach detects speciation within the kissing bug Panstrongylus rufotuberculatus populations (Hemiptera, Heteroptera, Reduviidae).

BACKGROUND Panstrongylus rufotuberculatus (Hemiptera-Reduviidae) is a triatomine species with a wide geographic distribution and a broad phenotypic variability. In some countries, this species is found infesting and colonising domiciliary ecotopes representing an epidemiological risk factor as a vector of Trypanosoma cruzi, etiological agent of Chagas disease. In spite of this, little is known about P. rufotuberculatus genetic diversity.METHODS Cytogenetic studies and DNA sequence analyses of one nuclear (ITS-2) and two mitochondrial DNA sequences (cyt b and coI) were carried out in P. rufotuberculatus individuals collected in Bolivia, Colombia, Ecuador and Mexico. Moreover, a geometric morphometrics study was applied to Bolivian, Colombian, Ecuadorian and French Guiana samples.OBJECTIVES To explore the genetic and phenetic diversity of P. rufotuberculatus from different countries, combining chromosomal studies, DNA sequence analyses and geometric morphometric comparisons.FINDINGS We found two chromosomal groups differentiated by the number of X chromosomes and the chromosomal position of the ribosomal DNA clusters. In concordance, two main morphometric profiles were detected, clearly separating the Bolivian sample from the other ones. Phylogenetic DNA analyses showed that both chromosomal groups were closely related to each other and clearly separated from the remaining Panstrongylus species. High nucleotide divergence of cyt b and coI fragments were observed among P. rufotuberculatus samples from Bolivia, Colombia, Ecuador and Mexico (Kimura 2-parameter distances higher than 9%).MAIN CONCLUSIONS Chromosomal and molecular analyses supported that the two chromosomal groups could represent different closely related species. We propose that Bolivian individuals constitute a new Panstrongylus species, being necessary a detailed morphological study for its formal description. The clear morphometric discrimination based on the wing venation pattern suggests such morphological description might be conclusive.

Genetic analysis of Carasobarbus Karaman, 1971 (Actinopterygii Cyprinidae) in Anatolia

We sequenced the complete mitochondrial cytochrome b gene (1141 bp) of 70 individuals from ten populations of three Carasobarbus species in Anatolia. Totally eight haplotypes were identified. The intraspecies genetic distance ranged from 0.00% to 0.21%, while it varied from 2.6% to 9.0% for interspecies. Except for Gaziantep samples with low sample size, high haplotype diversity (Hd= 0,590-0,833) and low nucleotide diversity (Pi= 0,05-0,65) values can be explained by the presence of small populations sensitive to genetic drift and founder effects. Phylogenetic analyses constructed with neihgbour joining, maximum likelihood and maximum parsimony generated similar topologies supported by high bootstrap values. Phylogenetic tree topologies showed that the C. apoensis haplotype was located in the C. luteus species. Therefore, the validity of species status of C. apoensis should be checked morphologically. On the other hand, since the Kahta population in C. luteus has a remarkably high genetic diversity, it must be re-evaluated morphologically. The tectonic uplift of the Anatolian Plateau between the African and European plates during the Pliocene period may have probably prevented the presence of Carasobarbus in the west of the Anatolian diagonal.

Генотипирование черноморских трематод семейства Opecoelidae по митохондриальным маркерам

Opecoelidae Ozaki, 1925 (Trematoda: Opecoeloidea) — ведущее по числу видов и родов семейство трематод в Чёрном море. Мариты наиболее распространённых видов черноморских опецелидных трематод подробно описаны морфологически, однако сведения о структуре их геномов отрывочны, а данные о митохондриальных геномах отсутствуют полностью. Цель исследования — получить первые сведения о строении участков митохондриального генома представителей наиболее распространённых в Чёрном море в современный период родов трематод семейства Opecoelidae для последующего уточнения их таксономического статуса. Филогенетические отношения внутри анализируемой части этого семейства реконструированы на основе данных, полученных нами, и соответствующих данных из GenBank с помощью алгоритма Maximum Likelihood и модели нуклеотидных замен HKY. Для укоренения филогенетического дерева использованы соответствующие последовательности Brachycladium goliath (Brachycladioidea: Brachycladiidae). Поскольку последовательности CO1 — стандартного и наиболее популярного митохондриального маркера — для исследуемых родов опецелид до сих пор не были известны, нами на основе известных соответствующих последовательностей Xiphidiata разработаны праймеры для амплификации фрагмента CO1, чтобы впервые провести соответствующий филогенетический анализ. Впервые определены и депонированы в GenBank нуклеотидные последовательности фрагментов митохондриальных генов CO1 и 16S черноморских трематод Cainocreadium flesi Korniychuk & Gaevskaya, 2000, Gaevskajatrema perezi (Mathias, 1926) Gibson & Bray, 1982 и Helicometra fasciata (Rudolphi, 1819) Odhner, 1902 от разных видов дефинитивных хозяев — рыб. У C. flesi не выявлено специфичных к окончательным хозяевам — рыбам линий по структуре фрагмента митохондриального гена CO1, однако отмечено высокое CO1-нуклеотидное разнообразие. У марит черноморских H. fasciata определена приуроченная к зеленушкам-руленам Symphodus tinca CO1-гаплогруппа, статус которой требует дальнейшего выяснения; необходимы экологические и генетические исследования предполагаемого видового комплекса H. fasciata из разных акваторий. При анализе последовательностей фрагмента митохондриального гена 16S рРНК гостальных генетических линий у H. fasciata выделить не удалось. У черноморских G. perezi не обнаружено значительных различий по фрагменту 16S между трематодами из окончательных хозяев разных видов, однако внутривидовое 16S-нуклеотидное разнообразие оказалось высоким.

Molecular Characterization of Anguilla from Cibereum and Sapuregel Rivers Segara Anakan Watersheds Cilacap, Central Java

The taxonomic status of Anguilla species' in river watershed that empties into Segara Anakan Cilacap is uncertain, thereby making it difficult for further studies to be carried out to determine its genetic in that area. Therefore, this study evaluates Anguilla's taxonomic status and population genetic in Cibeureum and Sapuregel River watersheds. Data were obtained from molecular characterization study using cytochrome c oxidase 1, with fourteen Anguilla specimens collected from two sequenced watersheds. Taxonomic status was determined based on homology and divergence values and monophyly of the samples to the reference species. Meanwhile, genetic divergences among samples to the reference species were calculated based on the Juke-Cantor substitution model in DnaSP6. A homology test was performed using a basic local alignment search tool, with monophyly inferred from the cladogram, which was developed using neighbor-joining and maximum likelihood algorithms in MEGAX with 1000 pseudoreplicates and out-group comparison. Furthermore, population genetic was analyzed through polymorphism, haplotype, nucleotide diversity within the population, divergence, and genetic differences. All calculations conducted in Arlequin 3.5 had Anguilla samples comprising of high (99.23% to 99.84%) to low genetic divergences (0.224% to 1.127%). The result shows that cladogram with all Anguilla samples formed a monophyletic clade with A. bicolor, separated from their taxa. Furthermore, Anguilla samples from both watersheds have low genetic polymorphisms with medium to high haplotype and nucleotide diversity. The population's comparison proved that both populations have low genetic divergence, and no genetic difference based on variance analysis (p=0761). Therefore, Anguilla resources in river watersheds that empty into Segara Anakan are a single genetic conservation unit.

Comparative genomics revealed adaptive admixture in Cryptosporidium hominis in Africa.

Cryptosporidiosis is a major cause of diarrhoeal illness among African children, and is associated with childhood mortality, malnutrition, cognitive development and growth retardation. Cryptosporidium hominis is the dominant pathogen in Africa, and genotyping at the glycoprotein 60 (gp60) gene has revealed a complex distribution of different subtypes across this continent. However, a comprehensive exploration of the metapopulation structure and evolution based on whole-genome data has yet to be performed. Here, we sequenced and analysed the genomes of 26 C. hominis isolates, representing different gp60 subtypes, collected at rural sites in Gabon, Ghana, Madagascar and Tanzania. Phylogenetic and cluster analyses based on single-nucleotide polymorphisms showed that isolates predominantly clustered by their country of origin, irrespective of their gp60 subtype. We found a significant isolation-by-distance signature that shows the importance of local transmission, but we also detected evidence of hybridization between isolates of different geographical regions. We identified 37 outlier genes with exceptionally high nucleotide diversity, and this group is significantly enriched for genes encoding extracellular proteins and signal peptides. Furthermore, these genes are found more often than expected in recombinant regions, and they show a distinct signature of positive or balancing selection. We conclude that: (1) the metapopulation structure of C. hominis can only be accurately captured by whole-genome analyses; (2) local anthroponotic transmission underpins the spread of this pathogen in Africa; (3) hybridization occurs between distinct geographical lineages; and (4) genetic introgression provides novel substrate for positive or balancing selection in genes involved in host–parasite coevolution.

Mitochondrial phylogeography reveals high haplotype diversity and unique genetic lineage in Indian dugongs (Dugong dugon)

Abstract India plays a significant role in dugong conservation by having the largest population within South Asia. The status of dugongs in India is largely unknown due to a paucity of reliable ecological data. This study generated mitochondrial control region sequences from ~10% of dugong individuals from existing populations within India. Furthermore, data generated in this study were compared with the global data to assess genetic lineages, population structure, and genetic diversity of Indian populations. Multiple analyses suggest that the Indian dugong populations are part of a single genetic cluster, comprising South Asia, North‐west Indian Ocean, and South‐west Indian Ocean populations. Despite small population size, they retain high genetic diversity with unique mitochondrial DNA haplotypes within South Asia. Within India, novel haplotypes are observed from all dugong habitats sampled, with overall high haplotype diversity (0.85 ± 0.04) but low nucleotide diversity (0.005 ± 0.001). Indian populations exhibit genetic differentiation with higher within‐population variance (63.41%) than among populations (36.59%). Two of the haplotypes observed in India are shared with Sri Lanka, implying genetic connectivity between these populations. The genetic data from Indian dugong populations provide critical insights into the identification of dugong corridors and important dugong conservation zones in India. We suggest site‐specific interventions, including the creation of new marine protected areas and boundary reorganization and expansion of other existing protected areas, to ensure population connectivity. In addition, simultaneous efforts towards seagrass meadow restoration, reduction of dugong mortalities, and community participation in dugong conservation are recommended for population recovery of this threatened marine herbivore.

Characterization of genetic diversity of an invasive Lessepsian Migrant, Nemipterus randalli Russell, 1986 from its native and non-native regions using mitochondrial DNA marker

This study assessed and compared the genetic diversity of Nemipterus randalli across its native and non-native regions analysing the mitochondrial DNA D-loop region. Including all the geographical population samples, 68 haplotypes were observed with an average haplotype diversity value of 0.92±0.04. Relatively, a smaller number of haplotypes was observed in the invasive range of the Mediterranean Sea. All other native geographical samples showed high haplotype and nucleotide diversity values. A significant high genetic differentiation value was observed between the native population samples of India and the invasive samples of the Mediterranean Sea. In the median-joining network tree, N. randalli from the Mediterranean Sea and the Red Sea formed a single haplogroup while other samples from India are clustered into two haplogroups.

Genetic diversity, haplotype analysis, and risk factor assessment of hepatitis A virus isolates from the West Bank, Palestine during the period between 2014 and 2016.

BackgroundHepatitis A virus (HAV) infection is one of the major causes of acute viral hepatitis. HAV genotypes and its genetic diversity is rarely investigated in our region as well as worldwide.AimsThe aims of the present study were to determine the HAV genotypes and its risk factors and to investigate the genetic diversity of the HAV isolates in the West Bank, Palestine.Study designA cohort of 161 clinically and laboratory-confirmed HAV (IgM-positive) cases and 170 apparently healthy controls from all the districts of the West Bank, Palestine during the period of 2014 to 2016 were tested for HAV infection using IgM antibodies, RT-PCR and sequence analysis of the VP3/VP1 junction region of the HAV genome. Phylogenetic analysis, genetic diversity and haplotypes analysis were used to characterize the VP3/VP1 sequences.ResultsAll the 34 sequences of the HAV were found to be of HAV-IB sub-genotype. The phylogenetic analysis showed four main clusters with cluster III exclusively consisting of 18 Palestinian isolates (18/23-78%), but with weak bootstrap values. A high haplotype diversity (Hd) and low nucleotide diversity (π) were observed. Cluster III showed high number of haplotypes (h = 8), but low haplotype (gene) diversity (Hd = 0.69). A total of 28 active haplotypes with some consisting of more than one sequence were observed using haplotype network analysis. The Palestinian haplotypes are characterized by closely related viral haplotypes with one SNV away from each other which ran parallel to cluster III in the phylogenetic tree. A smaller Palestinian haplotype (4 isolates) was three SNVs away from the major haplotype cluster (n = 10) and closer to others haplotypes from Iran, Spain, and South Africa. Young age, low level of parent’s education, infrequent hand washing before meals, and drinking of un-treated water were considered the major HAV risk factors in the present study.ConclusionHaplotype network analysis revealed haplotype variation among the HAV Palestinian sequences despite low genetic variation and nucleotide diversity. In addition, this study reconfirmed that age and parent’s level of education as HAV risk factors, while hand washing and treating drinking water as protective factors.

Phylogeographic and molecular characterization of Pronghorn spiny lobster (Panulirus penicillatus Olivier, 1791) in the Southern Coast of Java and Lombok, Indonesia

Abstract. Irwani, Wijayanti DP, Satria AW, Sabdono A. 2020. Phylogeographic and molecular characterization of Pronghorn spiny lobster (Panulirus penicillatus Olivier, 1791) in the Southern Coast of Java and Lombok, Indonesia. Biodiversitas 21: 5691-5697. Panulirus penicillatus is one of the most important lobster species in Central Java. It is one of the most populous species in the southern part of Java and Lombok. However, uncontrolled catching causes a decrease in the population of P. penicillatus. Despite such human threats, information about the taxonomic status of this species is limited. Several previous reports on the taxonomy of this species have always been based on the morphological features that cause ambiguous identification. Therefore, this study aimed to establish the relationships of P. penicillatus in southern parts of the southern part of Java and Lombok by using the molecular technique. Twelve samples were collected from four study areas of the southern coast of the southern part of Java and Lombok and identified using DNA barcoding technique. DNA barcoding technique was used for the first time to identify P. penicillatus in this region. This study demonstrated that all specimens belonged to P. penicillatus. However, one specimen (PPK-06) showed high intraspecies nucleotide divergence that formed a distinct subclade. Therefore, the specimen (PPK-06) could represent a cryptic species within P. penicillatus that needs to be studied further.

Molecular identification and population differentiation of Aurelia spp. ephyrae in sea cucumber aquaculture ponds of northern China

Aurelia spp. ephyrae have been reported to form blooms in sea cucumber aquaculture ponds in the Bohai and Yellow Seas. To identify the species, we carried out a genetic analysis of Aurelia spp. ephyrae and medusae based on mitochondrial 16S rRNA gene. Samples of four Aurelia sp. ephyrae populations were collected in sea cucumber aquaculture ponds and samples of four Aurelia sp. medusae populations were collected in coastal waters. Using a BLASTn search, we found that both the ephyrae collected in the aquaculture ponds and medusae collected in coastal waters belong to Aurelia coerulea. Seventeen haplotypes were recovered from the 16S rRNA gene. The overall haplotype diversity and nucleotide diversity of the 166 A. coerulea individuals were 0.686 and 0.329%, respectively, indicating high haplotype diversity and low nucleotide diversity. Moreover, the haplotype diversity of ephyrae populations were generally lower than that of medusae populations with close sampling points. The genetic differentiation between ephyrae populations collected in the sea cucumber aquaculture ponds and A. coerulea medusae collected in coastal waters was not significant, suggesting the ephyrae populations in the sea cucumber culture ponds were part of the same genetic group as the medusae populations in the coastal waters. Phylogeographic analysis of the 16S rRNA region revealed that there was no significant correlation between the haplotypes and the geographic distribution of populations. Pairwise fixation index values showed significant genetic differentiation and limited gene flow between A. coerulea population of Weifang and other locations.

Population Structure of Double-Stranded RNA Mycoviruses That Infect the Rice Blast Fungus Magnaporthe oryzae in Japan.

Various viruses infect Magnaporthe oryzae (syn. Pyricularia oryzae), which is a well-studied fungus that causes rice blast disease. Most research has focused on the discovery of new viruses and the hypovirulence-associated traits conferred by them. Therefore, the diversity and prevalence of viruses in wild fungal populations have not been explored. We conducted a comprehensive screening of M. oryzae mycoviruses from various regions in Japan using double-stranded RNA (dsRNA) electrophoresis and RT-PCR assays. We detected three mycoviruses, Magnaporthe oryzae virus 2 (MoV2), Magnaporthe oryzae chrysovirus 1 (MoCV1), and Magnaporthe oryzae partitivirus 1 (MoPV1), among 127 of the 194 M. oryzae strains screened. The most prevalent virus was MoPV1 (58.8%), which often co-infected in a single fungal strain together with MoV2 or MoCV1. MoV2 and MoCV1 were found in 22.7 and 10.8% of strains, respectively, and they were usually distributed in different regions so that mixed-infection with these two mycoviruses was extremely rare. The predominance of MoPV1 in M. oryzae is supported by significant negative values from neutrality tests, which indicate that the population size of MoPV1 tends to increase. Population genetic analyses revealed high nucleotide diversity and the presence of phylogenetically diverse subpopulations among the MoV2 isolates. This was not the case for MoPV1. Furthermore, studies of a virus-cured M. oryzae strain revealed that MoV2 does not cause any abnormalities or symptoms in its host. However, a leaf sheath inoculation assay showed that its presence slightly increased the speed of mycelial growth, compared with virus-free mycelia. These results demonstrate that M. oryzae in Japan harbors diverse dsRNA mycovirus communities with wide variations in their population structures among different viruses.

Population diversity and virulence characteristics of Cryptococcus neoformans/C. gattii species complexes isolated during the pre-HIV-pandemic era.

Cryptococcosis has become a major global health problem since the advent of the HIV pandemic in 1980s. Although its molecular epidemiology is well-defined, using isolates recovered since then, no pre-HIV-pandemic era epidemiological data exist. We conducted a molecular epidemiological study using 228 isolates of the C. neoformans/C. gattii species complexes isolated before 1975. Genotypes were determined by URA5 restriction fragment length polymorphism analysis and multi-locus sequence typing. Population genetics were defined by nucleotide diversity measurements, neutrality tests, and recombination analysis. Growth at 37°C, melanin synthesis, capsule production, and urease activity as virulence factors were quantified. The pre-HIV-pandemic isolates consisted of 186 (81.5%) clinical, 35 (15.4%) environmental, and 7 (3.1%) veterinary isolates. Of those, 204 (89.5%) belonged to C. neoformans VNI (64.0%), VNII (14.9%) and VNIV (10.5%) while 24 (10.5%) belonged to C. gattii VGIII (7.5%), VGI (2.6%) and VGII (0.5%). Among the 47 sequence types (STs) identified, one of VNII and 8 of VNIV were novel. ST5/VNI (23.0%) in C. neoformans and ST75/VGIII (25.0%) in C. gattii were the most common STs in both species complexes. Among C. neoformans, VNIV had the highest genetic diversity (Hd = 0.926) and the minimum recombination events (Rm = 10), and clinical isolates had less genetic diversity (Hd = 0.866) than environmental (Hd = 0.889) and veterinary isolates (Hd = 0.900). Among C. gattii, VGI had a higher nucleotide diversity (π = 0.01436) than in VGIII (π = 0.00328). The high-virulence genotypes (ST5/VNI and VGIIIa/serotype B) did not produce higher virulence factors levels than other genotypes. Overall, high genetic variability and recombination rates were found for the pre-HIV-pandemic era among strains of the C. neoformans/C. gattii species complexes. Whole genome analysis and in vivo virulence studies would clarify the evolution of the genetic diversity and/or virulence of isolates of the C. neoformans/C. gattii species complexes during the pre- and post-HIV-pandemic eras.

Chromoblastomycosis in an Endemic Area of Brazil: A Clinical-Epidemiological Analysis and a Worldwide Haplotype Network.

Chromoblastomycosis (CBM) is a neglected implantation mycosis prevalent in tropical climate zones, considered an occupational disease that affects impoverished rural populations. This retrospective study described clinical aspects of CBM in a hyperendemic area in Brazil and constructed a worldwide haplotype network of Fonsecaea spp. strains. The variables were collected from medical records using a standard report form, reporting 191 patients with CBM from Maranhão, Brazil. The mean age was 56.1 years, 168 (88%) patients were male and predominantly farmers (85.8%). The mean time of evolution of the disease until diagnosis was 9.4 years. Lower limbs (81.2%) and upper limbs (14.2%) were the main sites affected. Most patients exhibited verrucous (55%) and infiltrative plaque (48.2%). Fonsecaea spp. were identified in 136 cases and a haplotype network constructed with ITS sequences of 185 global strains revealed a total of 59 haplotypes exhibiting high haplotypic and low nucleotide diversities. No correlation was observed between the different haplotypes of Fonsecaea species and dermatological patterns, severity of disease or geographic distribution inside Maranhão. Data from this area contributed to better understanding the epidemiology of CBM. For the first time, a robust haplotype network with Fonsecaea strains reveals an evolutionary history with a recent population expansion.

Mitochondrial DNA analysis reveals spatial genetic structure and high genetic diversity of Massicus raddei (Blessig) (Coleoptera: Cerambycidae) in China.

The oak longhorned beetle (OLB), Massicus raddei (Blessig, 1872) (Coleoptera: Cerambycidae), is widely distributed in Asia (China, the Korean Peninsula, Japan, Vietnam and the Russian Far‐East), but pest outbreaks have occurred only in Liaoning Province and Jilin Province of China. In order to explore possible mechanisms of local population outbreaks and characterize the genetic diversity and genetic structure of M. raddei across its range in China, three mitochondrial genes (COI, Cytb, and COII) were sequenced and analyzed for seven M. raddei populations collected from six provinces in China. From these different populations, we found a high haplotype and nucleotide diversity. Haplotype networks and phylogenetic analyses both demonstrate apparent genetic diversification between SC (southern China) and NC (northern China) population groups. A set of 21 pairwise comparisons for Fst (pairwise fixation indices) and Nm (genetic flow index) showed significant genetic differentiation and limited gene flow except for two pairs, Shandong (SD) and Liaoning (LN), and Anhui (AH) and Henan (HN). This pattern suggested that the periodic outbreak of the LN population could not be attributed to the absence of genetic flow with other spatial populations and that regional environmental factors might be responsible. AMOVA (Analysis of molecular variance) showed that the greater molecular genetic variation was among populations. Based on Tajima's D statistic, Fu's Fs, and the mismatch distribution test, we determined that the seven populations sampled were stable and had not experienced any recent population expansion. The fact that all the sampled populations showed only unique haplotypes and lacked shared or ancestral haplotypes, as well as the nonstar‐like distribution of haplotype network for concatenated genes, collectively provided powerful evidence of the stable and isolated nature of most populations. The high genetic differentiation and spatial genetic structuring among populations are both likely related to the beetle's moderate flight capacity, regional variation in host tree species and microclimate, as well as the geographic distance between sampling sites.

Maternal Origins and Haplotype Diversity of Seven Russian Goat Populations Based on the D-loop Sequence Variability.

Simple SummaryRussia has diverse specifically selected and multipurpose goat resources. However, the origin of the local goats is still enigmatic. In this study, we sequenced and analyzed mitochondrial DNA (mtDNA) fragments of seven Russian local goat populations to provide the first insight into their maternal lineage.The territory of modern Russia lies on the crossroads of East and West and covers various geographical environments where diverse groups of local goats originated. In this work, we present the first study on the maternal origin of Russian local goats, including Altai Mountain (n = 9), Dagestan Downy (n = 18), Dagestan Local (n = 12), Dagestan Milk (n = 15), Karachaev (n = 21), Orenburg (n = 10), and Soviet Mohair (n = 7) breeds, based on 715 bp D-loop mitochondrial DNA (mtDNA) sequences. Saanen goats (n = 5) were used for comparison. Our findings reveal a high haplotype (HD = 0.843–1.000) and nucleotide diversity (π = 0.0112–0.0261). A total of 59 haplotypes were determined in the Russian goat breeds, in which all differed from the haplotypes of the Saanen goats. The haplotypes identified in Altai Mountain, Orenburg, Soviet Mohair, and Saanen goats were breed specific. Most haplotypes (56 of 59) were clustered together with samples belonging to haplogroup A, which was in accordance with the global genetic pattern of maternal origin seen in most goats worldwide. The haplotypes that were grouped together with rare haplogroups D and G were found in the Altai Mountain breed and haplogroup C was detected in the Soviet Mohair breed. Thus, our findings revealed that local goats might have been brought to Russia via various migration routes. In addition, haplotype sharing was found in aboriginal goat populations from overlapping regions, which might be useful information for their official recognition status.