Haplotype Network Research Articles

Genetic variation of the freshwater snail Indoplanorbis exustus (Gastropoda: Planorbidae) in Thailand, inferred from 18S and 28S rDNA sequences.

Indoplanorbis exustus, a freshwater pulmonate snail, is widely distributed in tropical and subtropical zones and plays a significant role as an intermediate host for trematode parasites. Various genetic markers have been used for species identification and phylogenetic studies of this snail. However, there are limited studies about their molecular genetics based on nuclear ribosomal DNA (rDNA) genes. A genetic analysis of I. exustus in Thailand was conducted based on the nuclear 18S rDNA (339 bp) and 28S rDNA (1036 bp) genes. Indoplanorbis snails were collected from 29 localities in 21 provinces covering six regions of Thailand. Nucleotide sequences from 44 snails together with sequences from the GenBank database were examined for phylogenetic relationships and genetic diversity. All sequences of the selected nucleotide regions exhibited a high level of similarity (99%) to the sequences of I. exustus in the GenBank database. The maximum likelihood tree based on the 18S and 28S rDNA fragment sequences of I. exustus in Thailand revealed only one group with clear separation from another genus in the family Planorbidae. The I. exustus 28S rDNA sequences showed intraspecific genetic divergence ranging from 0 to 0.78% and were classified into 8 different haplotypes. Conversely, the 18S rDNA data showed lower variation than the 28S rDNA data and revealed a single haplotype and intraspecific distances of zero among all sampled individuals. The haplotype network of 28S rDNA sequences of I. exustus in Thailand revealed six unique haplotypes and two haplotypes shared by at least two regions. Overall, both markers were successful in the identification of I. exustus. However, these markers, particularly the 18S rDNA, may not be suitable for genetic analysis within the species, particularly for population genetic studies, due to their limited variation as seen in this study. In summary, this study not only enhances understanding of genetic variation in I. exustus but is also useful for the selection of molecular markers in future genetic research.

Phylogenetic and population genetic analyses of Thrips tabaci Lindeman (Thysanoptera: Thripidae) on Allium host in India.

Onion thrips (Thrips tabaci) is a complex of cryptic species with subtle morphological differences and distinct genetic backgrounds; thus, species identification using traditional methods remains challenging. The existence of different haplotypes and genotypes within a species can significantly influence various aspects of its biology, including host preference, reproductive capacity, resistance to pesticides, and vector competence for plant viruses. Understanding the genetic diversity and population structure of cryptic species within T. tabaci will not only aid in the development of more effective control strategies tailored to specific genetic variants but also in monitoring population dynamics, tracking invasive species, and implementing quarantine measures to prevent the spread of economically damaging thrips biotypes. This study aims to explore intraspecies genetic diversity and molecular evolutionary relationships of the mitochondrial cytochrome oxidase gene subunit I (mtCOI) in T. tabaci populations from India. To capture diversity within the Indian T. tabaci populations, amplicon sequencing was performed for the thrips mtCOI gene from eight diverse localities in India. A total of 48 sequences retrieved for the mtCOI gene from the NCBI Nucleotide database were analysed. Multiple insertions and deletions were detected at various genomic positions across the populations from different localities, with the highest variation observed in the 300-400 genome position range. Molecular diversity analyses identified 30 haplotypes within the population, with certain subpopulations exhibiting higher gene flow. Analysis of single nucleotide polymorphism patterns within the mtCOI gene across diverse Indian locales revealed significant intrapopulation genetic heterogeneity and its potential repercussions on gene functionality. Elevated F statistics (Fst) values in the northern-western subpopulations suggested high genetic variability, particularly evident in haplotype networks originating mainly from the northern region, notably Delhi. While most populations displayed stable and ancient evolutionary histories, thrips populations from northern, western, and north-eastern regions indicated rapid growth.

Relationship Between Growth Hormone Gene Polymorphism with Milk Production and Its Components in Black Iraqi Goat

Local black goat are raised for the purpose of milk production. The goal of the current study was to identify the growth hormone gene's single nucleotide polymorphism (SNPS). Additionally, the effect of the GH gene SNP on the milk qualities of Iraqi black goat was evaluated. DNA was extracted from blood samples of 28 goat. A segment with a length of 330 bp in the third intron and the fourth exon of the GH gene was analyzed. Bioinformatics software was used to analyze the results. The results showed the presence of three genotypes (TT, TC, CC) at position 263 of the studied plot with a frequency of 0.36, 0.21, and 0.43, respectively. The local breed was characterized by a decrease in observed heterozygosity (21.43%). However, the expected heterozygosity was 50.65%. Low heterozygosity may indicate the presence of inbreeding within the same herd. Haplotypes network revealed a genetic relationship between the local Iraqi goat and the Egyptian goat. As well as the existence of a genetic relationship at a lower level with the Indian goats. From Tajima's D test and Fu's Fs (1.547 and 1.428), the results led to a rise in inbreeding. In milk production, energy, and the amounts of protein. The analysis of the data using bioinformatics tools predicted the effects of identified the genotypes in which the amino acid was not altered, and this is where the mutation was found. There is a relationship between the genetic polymorphism of the growth hormone gene and the production of milk and its components. The CC genotype was superior in milk production, energy, and the amounts of protein and fat over the TC and CC combinations.

Contribution to the knowledge of the distribution of <i>Parmelia</i> species (Parmeliaceae, Ascomycota) – New records confirmed by molecular data

The first records of<i> Parmelia ernstiae</i> from Madeira, as well as the new localities of <i>P. encryptata</i> from Poland and <i>P. sulcata</i> from Chile, are presented. All records are confirmed by molecular data, BLAST search, and haplotype network analysis of the nucITS rDNA sequences. The discussion on the morphology and secondary chemistry of all three species is provided with notes on their distribution and similar taxa. <i>Parmelia encryptata</i> is a rarely reported cryptic species that is morphologically indistinguishable from <i>P. sulcata</i>, and its identification requires molecular data. New localities of <i>P. encryptata</i> from northern Poland suggest that the taxon may be widespread in the country and not confined to large forests but also present in open areas on free-standing trees. Moreover, a new nucITS rDNA haplotype of the species is reported. <i>Parmelia ernstiae</i> is a near-cryptic species, morphologically and chemically very similar to <i>P. saxatilis</i> and <i>P. serrana</i>. Two specimens of the species from Madeira have sublinear lobes with marginal and laminal isidia, unlike most specimens of P. ernstiae, having short, broad lobes with laminal isidia, and thus are morphologically closer to <i>P. saxatilis</i> in lobe shape and to <i>P. serrana</i> in placement of isidia. However, the BLAST search and haplotype analysis of nucITS rDNA sequences placed these specimens in <i>P. ernstiae</i>. <i>Parmelia sulcata</i>, a common species in the Northern Hemisphere, is rare elsewhere, and only two records confirmed by molecular data were known from South America. The nucITS rDNA haplotype of two new and two previous records of the species represent the most common haplotype of the species known from the Northern Hemisphere.

Molecular and morphometric data provide evidence of intraspecific variation in shape and pigmentation pattern in Otocinclus cocama (Siluriformes: Loricariidae) across major river drainages.

Otocinclus cocama, a uniquely colored species of the loricariid catfish genus Otocinclus described solely from the type locality in the lower Ucayali River in northern Peru, is reported occurring in the Tigre River, a tributary to the Marañón River that drains a different section of the Andean Mountain range in the western Amazon. Both populations differ in the number of dark bars spanning the flanks of the body, and we investigated whether these morphotypes constitute distinct species. The body shapes of populations from the Tigre and Ucayali rivers were compared using geometric morphometrics. Although principal component analysis detected a broad overlap between populations, multivariate analysis of variance and linear driscriminat analysis revealed a subtle differentiation between the populations of the two hydrographic basins. Average body shape of the Ucayali River population tend to be slightly higher than that of the Tigre River, with the caudal peduncle stretched vertically in the Ucayali population. Multivariate regression of shape and centroid size revealed an allometric effect of 10.7% (p < 0.001), suggesting that the variation between Tigre and Ucayali populations was purely shape variation. Molecular data of coI, cytb, nd2, and 16S mitochondrial genes indicated a nucleotide diversity range from 0.001 to 0.003, and haplotypic diversity range from 0.600 ± 0.11 to 0.79 ± 0.07. The median-joining haplotype network for the concatenated matrix exhibited two divergent haplogroups related to the geographic area and separated by <10 mutational steps. The molecular species delimitation methods based on distance (automatic barcode gap discovery and assemble species by automatic partitioning) recovered two molecular lineages evolving independently, being one of the lineages formed by individuals from both populations. Tree-based methods (generalized mixed Yule coalescent and Bayesian implementation of the Poisson tree process) recovered similar topologies and supported single lineage recognition. Methods of molecular delimitation of species disclosed the high similarity between the two populations of Otocinclus cocama, further supported by the presence of old haplotypes common to both groups which could indicate that the populations still maintain gene flow. Although the morphological data reveal a subtle variation between both river basins, the molecular data suggest a weak population structuration based on hydrographic areas, but not different species lineages, therefore Otocinclus cocama is composed of a single lineage with two distinct morphotypes.

Genetic footprints of Quaternary climatic fluctuations on the endangered Tuco-tuco-das-dunas (Ctenomys flamarioni)

Abstract The biogeographic history of a species results from responses to past and current processes, and understanding those responses at both temporal scales is essential. We explored phylogeographic and current genetic variation structure in Ctenomys flamarioni—a subterranean rodent that inhabits a small region of the coastal plain of Brazil—and contrasted the roles of “present-day niche suitability” versus “historical climate stability” to understand current and past intraspecific genetic diversity. We used both mitochondrial DNA sequences (concatenated Cytb and D-loop, n = 78) and nuclear DNA (9 microsatellites loci, n = 154) molecular markers for individuals across the entire distribution of the species. We used phylogeographic trees, Bayesian clustering, and haplotype networks to explore genetic variation and diversity. We correlated genetic diversity with measures of current niche suitability and potential areas of Late Quaternary paleostability. Phylogeographic patterns confirmed low levels of genetic diversity structured at different hierarchical levels. We also found a weak but significant pattern of isolation by distance, indicating that geographical distance partially modulates genetic differences among populations. We also observed a positive correlation between genetic diversity and climate paleostability for microsatellites at local and regional scales. However, we found no significant association between genetic diversity and niche suitability for microsatellites at local or regional scales. We observed several signatures of bottleneck and population expansion at different geographic scales. Our results suggest that Quaternary climatic fluctuations—acting together with habitat suitability and other contemporary factors—played a fundamental role in elucidating the evolutionary history of the species—including patterns of historical dispersal, and current patterns of habitat occupation and genetic structure. In addition, based on our molecular and environmental data sets from the across the range of the species and considering the restricted endemism of C. flamarioni, we emphasize the urgency of conservation actions to protect this endangered species.

Analysis of Genetic Diversity of cytb gene from Babesia gibsoni Isolates from Naturally Infected Dogs in Karnataka, India.

The study aimed to investigate genetic diversity in Babesia gibsoni, the causative agent of canine babesiosis, and to assess the presence of atovaquone-resistant isolates in naturally infected dogs. A total of 24 blood samples confirmed for B. gibsoni infection was subjected to PCR amplification and sequencing based on cytb gene. Genetic characterization of B. gibsoni as well as attempts to detect the point mutation rendering atovaquone resistance was carried out based on the analysis of nucleotide sequence of cytb gene using bioinformatics software. The findings indicated that the B. gibsoni isolates in the investigation exhibited a high nucleotide identity with the Asian genotype, ranging from 98.41 to 98.69%. Notably, none of the isolates carried cytb gene variants associated with atovaquone resistance. Phylogenetic analysis revealed clustering of most isolates with those from Japan and China, except for one isolate forming a distinct subclade. Haplotype network analysis indicated a high diversity with 22 distinct haplotypes among the B. gibsoni isolates, emphasizing the genetic variability within the studied population. In conclusion, the cytb gene exhibited remarkable conservation among the twenty-four B. gibsoni isolates studied and the study represents the first genetic diversity assessment of B. gibsoni using the cytb gene in dogs from India. These findings shed light on the genetic characteristics of B. gibsoni in the region and provide valuable insight for addressing the challenges posed by this life-threatening disease in dogs.

Redefining the phylogenetic relationships of European Angelica (Apiaceae) species

Angelica (Apiaceae) is a large complex genus with high morphological diversity. The many taxonomic treatments explain the controversy regarding the number of European species, which range from four to ten. Molecular methods have unraveled the complicated Asian and American taxonomies; however, no comprehensive molecular study has been conducted on the European taxa. We aim to determine the number of different European Angelica s.l. taxa and their relationship within the Selineae tribe by conducting Maximum Likelihood (ML) and Bayesian Inference (BI) analyses based on the nuclear Internal Transcribed Spacer (ITS) and haplotype networks by Templeton Crandall and Sing and neighbour-net analyses based on the plastid trnL. Three separate Iberian species (A. angelicastrum, A. razulii and A. pyrenaea) form the new Iberian Angelica clade, which is sister to the Archangelica clade. Although morphologically different, A. pachycarpa cannot be differentiated from A. angelicastrum by molecular methods, casting new doubts on the existing taxonomies. Molecular evidences suggest that A. heterocarpa should be considered an estuary forma of A. sylvestris. The east and west A. sylvestris subclades support the subspecies A. sylvestris subsp. elatior and A. sylvestris subsp. villosa (including A. heterocarpa). Our evidences support the classification of A. palustris as Ostericum palustre.

Population genetic characterization of Theileria annulata based on the cytochrome b gene, with genetic insights into buparvaquone susceptibility in Haryana (India)

The present investigation was aimed at population genetic characterization of Theileria annulata on the basis of the cytochrome b (cyt b) gene along with the evaluation of status of buparvaquone resistance in Haryana (India). The sequences originating from China, Egypt, India, Iran, Iraq, Tunisia, Turkey and Sudan were included in the analysis. The maximum likelihood tree based on the Tamura-Nei (TN93+G) model placed all the sequences of T. annulata into a single clade. The median-joining haplotype network exemplified geographical clustering between T. annulata haplotypes originating from each country. Only five haplotypes (7.81 %) were shared between any two countries, while the remaining 59 haplotypes (92.19 %) were singleton and unique to one country. The values of pairwise genetic distance (FST) between all the populations indicated huge genetic differentiation (> 0.25) between different T. annulata populations, barring the FST value between Iraq and Turkey (0.14454) which suggested a moderate differentiation. Contrary to the FST index, the values of gene flow (Nm) between T. annulata populations were very low. The neutrality indices and mismatch distributions indicated a population expansion in the Indian T. annulata population. Furthermore, the secondary structure and homology modeling of the partial cyt b protein is also reported. The molecular analysis of newly generated sequences for buparvaquone resistance revealed that all the isolates were susceptible to buparvaquone treatment. However, two novel mutations at positions V203I and V219I in between the Q01 and Q02 drug-binding regions of the cyt b gene were observed for the first time.

Expanding the phylogeography and connectivity of Perkinsus species across North and Central America

AbstractAimParasites in the genus Perkinsus infect marine molluscs globally, with novel detections expanding and reshaping our knowledge of their biogeographic patterns and the factors influencing those patterns. Here, we aimed to characterize the phylogeography and genetic connectivity of Perkinsus spp. in bivalves across North and Central America, which included infection hot spots (e.g., the Gulf of Mexico, Chesapeake Bay) and areas where these parasites had not been previously reported (e.g., along the California coast).LocationAll coasts of North America and both coasts of Panama.MethodsUtilizing standard PCR and DNA sequencing, we genetically screened 933 bivalves from across North America for parasites in the genus Perkinsus, then combined this with 752 bivalves previously screened from Panama, which included 16 species from three different countries. Phylogenetic methods were used to confirm the identifications of all the bivalves collected and the Perkinsus spp. detected. We combined our data with publicly available sequence data for these parasites to create global haplotype networks to assess regional and continental genetic diversity and phylogeographic patterns.ResultsWe detected three species across North and Central America, including Perkinsus beihaiensis, P. chesapeaki, P. marinus, while P. olseni was only detected in Panama. We report for the first time P. chesapeaki was detected in Isognomon sp. from Mexico and P. beihaiensis detections in Ostrea lurida from California, USA. Additionally, our results indicate extremely low‐genetic diversity of P. beihaiensis, P. chesapeaki and P. marinus across continental and global spatial scales.Main conclusionsOur results add further evidence of recent or continuous long‐range dispersal and global connectivity for many haplotypes, suggesting that parasite dispersal through anthropogenic activities, such as maritime trade, likely contributes to these phylogeographic patterns.

Environmental selection and gene flow jointly determine the population genetic diversity and structure of Diaphanosoma dubium along a watershed elevation

Biodiversity of local communities has been found to generally decrease with elevation. However, the elevational patterns of intraspecific genetic diversity remain unclear, especially in passive dispersers and species with short life histories. In this study, we investigated the populations of a tropical dominant Cladoceran, Diaphanosoma dubium, along elevation in the largest watershed of South China. The studied populations were grouped into four regional groups based on elevation and habitat connectivity. No significant elevation pattern was observed for mitochondrial genetic diversity, but nuclear diversity was influenced by habitat type. The haplotype network showed a radial pattern with a common haplotype at the centre, and many private haplotypes existed in each regional group. Four clusters of D. dubium populations were identified and exactly corresponding to the four investigated regions, indicating a strong spatial genetic structure. Weak but significant isolation by distance (IBD) supported the critical role of environmental selection with elevation. Precipitation significantly explained population genetic variation at the watershed scale. Bidirectional gene flow was a common pattern that occurred among the four regional groups. Our results highlight that habitat selection with gene flow plays an important role in shaping the genetic pattern of tropical freshwater Cladocera along an elevational gradient.

The Grasshopper Paradigm in damselflies: evidence for phalanx-like postglacial recolonization of Europe from a Balkan refugium in Platycnemis pennipes Pallas (Odonata: Zygoptera: Platycnemidae)

We explore haplotype diversity, phylogeography and phylogenetic relationships of the damselfly Platycnemis pennipes in Europe based on 618 bp DNA from the mitochondrial gene COI. A haplotype network analysis shows that the species is divided into two haplotype groups. One is restricted to the Italian Peninsula, while the other is found from the Black Sea region across eastern and central Europe to Scandinavia, England, and southwestern France. This pattern is recovered in a Bayesian phylogenetic analysis. Genetic distance (K2P) between the two groups is approximately 1.5%, while within-group variation is an order of magnitude lower. An analysis of the molecular variance (AMOVA) shows that variation between the two groups account for more than 96% of the total variation within the dataset, adding to the evidence that they have been isolated for a considerable amount of time. The pattern we find is similar to the so-called Grasshopper Paradigm in European phylogeography, where a species has recolonized Europe after the last glaciation from a glacial refugium in the southeast, while other refugial populations in the Iberian and Italian peninsulas have remained isolated to this day. In P. pennipes there is only an isolated refugial population in Italy as the species does not have current populations in the Iberian Peninsula. By comparing the genetic distance between the two groups to a previously published divergence time analysis of European Odonata we estimate that they have likely been isolated since the onset of the Saale Glaciation ca 400 ky ago.

Co-occurrence of dual lineages within Simulium (Gomphostilbia) atratum De Meijere in the Indonesian Archipelago along Wallace's Line

Mitochondrial cytochrome c oxidase subunit I (COI) sequences were utilized to infer the population genetic structure of Simulium (Gomphostilbia) atratum De Meijere, an endemic simulid species to Indonesia. Both median-joining haplotype network and maximum-likelihood tree revealed two genetic lineages (A and B) within the species, with an overlap distribution in Lombok, which is situated along Wallace's line. Genetic differentiation and gene flow with varying frequencies (FST = 0.02–0.967; Nm = 0.01–10.58) were observed between populations of S. (G.) atratum, of which population pairs of different lineages showed high genetic differentiation. Notably, the high genetic distance of up to 5.92 % observed within S. (G.) atratum in Lombok was attributed to the existence of two genetically distinct lineages. The co-occurrence of distinct lineages in Lombok indicated that Wallace's line did not act as faunistic border for S. (G.) atratum in the present study. Moreover, both lineages also exhibited unimodal distributions and negative values of neutrality tests, suggesting a pattern of population expansion. The expansion and divergence time estimation suggested that the two lineages of S. (G.) atratum diverged and expanded during the Pleistocene era in Indonesia.

Genetic variation of European mouflon depends on admixture of introduced individuals

In the early twentieth century, European mouflon was introduced in Croatia, while all introductions in Slovenia occurred in the 1950s and 1960s. Although majority of the introductions were historically documented, occasional cases involving individuals of unknown origin have likely contributed to a mixed genetic pool in established colonies. To understand the impact of past management and the potential founder effects on contemporary mouflon populations, we performed the first genetic study of the species in these two countries. Utilising next-generation sequencing of both mitochondrial control region (mtDNA CR) and major histocompatibility complex (MHC DRB exon 2), our study scrutinises the genetic diversity and structure of these populations. Additionally, the origins and genetic variability of mouflon in Croatia and Slovenia were compared with reference samples from Czech Republic, Sardinia (Italy), and Corsica (France). The mtDNA haplotype network showed that the majority of mouflon from Slovenia are closely related to mouflon from Sardinia, and only few shared the same haplotypes with mouflon from Croatia. Some mouflon from mainland Croatia share identical or closely related haplotypes with individuals from the initially established population in this country (on the Brijuni Archipelago), while others belong to a distinctly different cluster. We found five MHC alleles previously reported for mouflon in Europe, and genetic diversity was similar in both studied countries. We observed an excess of the Ovar-DRB1*07012/*07012 genotype, and only a few individuals exhibited the advantageous genotypes for parasite infection (Ovar-DRB1*0114 allele and Ovar-DRB1*0324/*0114 genotype). Genetic data showed that the population origins are generally in agreement with the written historical records, although we found signals of release of extra individuals into certain colonies.

Assessment of genetic diversity of Trypanosoma evansi in the domestic animal populations through ITS-1 gene sequence analysis.

Trypanosoma evansi infects domestic animals, causing a debilitating and occasionally fatal disease. The disease leads to significant economic losses to farmers and poses a substantial impediment to the growth of livestock production in developing nations, including India. Considering the challenges associated with managing this infection, there is an urgent need to enhance our understanding of the molecular and genetic diversity of T. evansi. Therefore, this study was planned to analyze the genetic diversity of T. evansi using available internal transcribed spacer-1 (ITS-1) gene sequences from India and compare them with sequences from around the globe. Blood samples used in this study were collected from naturally infected animals including dogs, cattle, and buffaloes in the Indian state of Madhya Pradesh. Using the ITS-1 gene, we amplified a 540 base pairs (bp) segment using polymerase chain reaction (PCR), sequenced it, and identified intra-specific variations. Phylogenetic analysis of 90 sequences, including 27 from India, revealed three distinct clusters with high bootstrap support values. A haplotype network analysis identified 34 haplotypes, with H7 being the most prevalent, indicating a complex evolutionary history involving multiple countries. The genetic analysis of the Indian population revealed distinct characteristics. Despite low nucleotide diversity, there was high haplotype diversity in comparison to other populations. Tajima's D, Fu and Li's D, and Fu and Li's F exhibited non-significant negative values, indicating potential stability. Additionally, the slightly positive values in Fu's Fs, Raggedness (r), and Ramos-Onsins and Rozas (R2) statistics suggested a lack of recent significant selective pressures or population expansions. Furthermore, the presence of genetic differentiation and gene flow among T. evansi populations highlighted ongoing evolutionary processes. These findings collectively depicted a complex genetic landscape, suggesting both stability and ongoing evolutionary dynamics within the Indian population of T. evansi. The findings of this study are important for understanding the evolutionary history and population dynamics of T. evansi, and they may help us develop effective control strategies.

Genetic structure of Ilyoplax delsmani (Crustacea: Decapoda: Brachyura: Dotillidae) on the western Indonesian waters

Estuarine crab disperses passively to different areas during their larval stage through sea currents. Ilyoplax delsmani, one of the estuarine crabs, is widely distributed in the Indo-Malaysia Archipelago. The present study aims to discern the genetic structure of Ilyoplax delsmani in the western part of Indonesia. Specimens were collected from three sites, i.e. one site in Kalimantan and two sites in Java Island. We analyzed the genetic structure of I. delsmani with COI gene using MEGA-X, DNASP v6.12.03, Arlequin v3.5.2.2., and Network v10.2. The constructed phylogenetic tree with MEGA-X with maximum likelihood (ML) using Kimura 2 parameter based on the COI gene revealed two distinct clades, i.e., Kalimantan_5133-Java_5135 as Clade 1 and Java_5136 as Clade 2. The genetic distance within the clade range from 0.2% to 2.2%, meanwhile the distance between the clades is approximately 19.3%–20.7%. Moreover, the haplotype network and FST values calculated between pairs of localities generate a congruent result with the phylogenetic tree. Through calculation using MEGA-X, we estimate that the divergence time between both clades is approximately 42.49 mya, aligning with the middle Eocene period. Hence, we deduce that both clades represent distinct species.

A new species of alkali-sink Paruroctonus Werner, 1934 (Scorpiones, Vaejovidae) from California’s San Joaquin Valley

Herein a new species of Paruroctonus Werner, 1934 is described from alkali-sink habitats in the San Joaquin Desert of central California, Paruroctonus tularesp. nov. It can be differentiated from other Paruroctonus by a combination of morphological features including scalloped pedipalp fingers in males, specific setal counts and morphometric ratios, and specific patterns of fuscous pigmentation. It also inhabits a unique distribution allopatric with all other Paruroctonus species except P. variabilis Hjelle, 1982. Photographs of a large series of live P. tularesp. nov. from across their range and detailed images of several morphological features are provided, their distribution is modeled, a haplotype network is presented, and details about their habitat, ecology, and conservation are discussed.

Anopheles gambiae on remote islands in the Indian Ocean: origins and prospects for malaria elimination by genetic modification of extant populations

The mosquito Anopheles gambiae s.s. is a primary malaria vector throughout sub-Saharan Africa including the islands of the Comoros archipelago (Anjouan, Grande Comore, Mayotte and Mohéli). These islands are located at the northern end of the Mozambique Channel in eastern Africa. Previous studies have shown a relatively high degree of genetic isolation between the Comoros islands and mainland populations of A. gambiae, but the origin of the island populations remains unclear. Here, we analyzed phylogenetic relationships among island and mainland populations using complete mitochondrial genome sequences of individual A. gambiae specimens. This work augments earlier studies based on analysis of the nuclear genome. We investigated the source population of A. gambiae for each island, estimated the number of introductions, when they occurred and explored evidence for contemporary gene flow between island and mainland populations. These studies are relevant to understanding historical patterns in the dispersal of this important malaria vector and provide information critical to assessing their potential for the exploration of genetic-based vector control methods to eliminate this disease. Phylogenetic analysis and haplotype networks were constructed from mitogenome sequences of 258 A. gambiae from the four islands. In addition, 112 individuals from seven countries across sub-Saharan Africa and Madagascar were included to identify potential source populations. Our results suggest that introduction events of A. gambiae into the Comoros archipelago were rare and recent events and support earlier claims that gene flow between the mainland and these islands is limited. This study is concordant with earlier work suggesting the suitability of these oceanic islands as appropriate sites for conducting field trial releases of genetically engineered mosquitoes (GEMs).

Phylogenetic, population structure, and population demographic analyses reveal that Vicia sepium in Japan is native and not introduced

Vicia sepium (bush vetch) is a perennial legume widely distributed throughout the Eurasian continent. However, its distribution in Japan is limited to Mt. Ibuki and small parts of central and southern Hokkaido. Therefore, each Japanese V. sepium lineage has been considered to have been introduced separately from Europe. Here, we examined whether the species was introduced or not on the basis of cpDNA sequences and genome-wide SNPs from Japanese and overseas samples. Both the cpDNA haplotype network and the nuclear DNA phylogenetic tree showed that Japanese V. sepium is monophyletic. Furthermore, although the nuclear DNA phylogenetic tree also showed that each lineage is clearly monophyletic, genetic admixture of the genetic cluster dominated in the Hokkaido lineage was also detected in the Mt. Ibuki lineage. Population divergence analysis showed that the two lineages diverged during the last glacial period. The Mt. Ibuki lineage showed a sudden population decline 300–400 years ago, indicating that some anthropogenic activity might be involved, while the Hokkaido lineage showed a gradual population decline from 5000 years ago. Consequently, these two lineages show low current genetic diversity compared with overseas lineages. These results show that the Japanese V. sepium is not introduced but is native.

Evolutionary history of a cold-adapted limnephilid caddisfly: Effects of climate change and topography on genetic structure

The distribution of organisms is influenced by complex factors such as the phylogenetic evolutionary histories of species, the physiological and ecological characteristics of organisms, climate, and geographical and geohistorical features. In this study, we focused on a caddisfly, Asynarchus sachalinensis (Trichoptera: Limnephilidae), which has adapted to cold habitats. From phylogeographic analyses based on the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) and 16S rRNA regions and the nuclear DNA (nDNA) 18S rRNA, 28S rRNA, carbamoyl-phosphate synthetase (CAD), elongation factor-1 alpha (EF1-α), and RNA polymerase II (POLII) regions, two distinct genetic clades were detected. Clade I was shown to be widely distributed from Sakhalin to Honshu, whereas Clade II was only distributed within Honshu. The distributions of these clades overlapped in Honshu. The habitats were located at relatively lower altitudes for Clade I and higher altitudes for Clade II. The divergence time of these clades was estimated to be during the Pleistocene, indicating that repeated climatic changes facilitated distributional shifts. Haplotype network and demographic analyses based on the mtDNA COI region showed contrasting genetic structures in the two clades. It was indicated that the population sizes of Clade I had expanded rapidly in a recent period, whereas Clade II had maintained stable population sizes. The habitats of Clade II were typically isolated and scattered at high altitudes, resulting in restricted migration and dispersal because of their discontinuous “Sky Island” habitats. The habitats of Clade I were located at relatively low altitudes, and it was assumed that the populations were continuous, which resulted in a higher frequency of migration and dispersal between populations. Thus, differences in the spatial scale of the adapted habitats of each clade may have resulted in different patterns of population connectivity and fragmentation associated with repeated climatic changes during the Pleistocene. Our study provided new insight into the distributional patterns of cold-adapted aquatic insects in the Japanese Archipelago. Furthermore, the distributional shifts predicted by ecological niche modeling under future climatic change conditions were different for each clade. Therefore, different principles are required in the assessment of each clade to predict temporal changes in their distributions.