Separate Lineages Research Articles

Divergence of alpine plant populations of three Gentianaceae species in the Qinling sky Island

BackgroundKnown for their unique biodiversity, the Qinling Mountains are considered the only area in which alpine biomes occur in central China. Given that the alpine biomes are particularly sensitive to global warming, understanding how alpine plants respond to climatic fluctuations is essential for the evolution and conservation of biodiversity. To address this issue, three alpine species of the Gentianaceae (Gentiana crassuloides, G. hexaphylla and Swertia bifolia) that represent different life types and diverse genera were selected.ResultsGenetic clustering analysis according to around 33,317 to 185,133 SNPs showed that the Qinling population was a separate lineage within each species. A high level of genetic differentiation was observed among the Qinling populations and the other populations of each species. Divergence time estimation based on plastomes and approximate Bayesian computation based on genomic SNPs showed that Qinling populations of the three Gentianaceae species originated at different periods under various patterns including primary source and hybridization. Significant signals of isolation by distance and isolation by environment were found in all three species. The redundancy and gradient forest analyses revealed that several temperature- and precipitation-related variables mainly contributed to shaping the genetic differentiation among the Qinling populations and others, indicating that the three species exhibited a similar pattern of adaptations to local environments.ConclusionsThis study unveiled the unique genetic and evolutionary features of the Qinling populations of these three species and elucidated the contributing role of both the environmental gradient and geographical isolation in genetic differentiation, which scientifically supports future conservation efforts.

Multiple plastid losses within photosynthetic stramenopiles revealed by comprehensive phylogenomics.

Ochrophyta is a vast and morphologically diverse group of algae with complex plastids, including familiar taxa with fundamental ecological importance (diatoms or kelp) and a wealth of lesser-known and obscure organisms. The sheer diversity of ochrophytes poses a challenge for reconstructing their phylogeny, with major gaps in sampling and an unsettled placement of particular taxa yet to be tackled. We sequenced transcriptomes from 25 strategically selected representatives and used these data to build the most taxonomically comprehensive ochrophyte-centered phylogenomic supermatrix to date. We employed a combination of approaches to reconstruct and critically evaluate the relationships among ochrophytes. While generally congruent with previous analyses, the updated ochrophyte phylogenomic tree resolved the position of several taxa with previously uncertain placement and supported a redefinition of the classes Picophagea and Synchromophyceae. Our results indicated that the heterotrophic, plastid-lacking heliozoan Actinophrys sol is not a sister lineage of ochrophytes, as proposed recently, but rather phylogenetically nested among them, implying that it lacks a plastid due to loss. In addition, we found the heterotrophic ochrophyte Picophagus flagellatus to lack all hallmark plastid genes yet to exhibit mitochondrial proteins that seem to be genetic footprints of a lost plastid organelle. We thus document, for the first time, plastid loss in two separate ochrophyte lineages. Furthermore, by exploring eDNA data, we enrich the ochrophyte phylogenetic tree by identifying five novel uncultured class-level lineages. Altogether, our study provides a new framework for reconstructing trait evolution in ochrophytes and demonstrates that plastid loss is more common than previously thought.

Transcriptome analysis of novel B16 melanoma metastatic variants generated by serial intracarotid artery injection

The incidence of brain metastases (BrM) in patients with metastatic melanoma is reported to be 30–50% and constitutes the third most frequent BrM after breast and renal cancers. Treatment strategies including surgical resection, stereotactic radiation, and immunotherapy have improved clinical response rates and overall survival, but the changes that occur in circulating melanoma cells to promote invasion of the brain are not fully understood. To investigate brain tropism, we generated new variants of the B16 mouse melanoma model by serially passaging B16 cells through the brain of immune competent syngeneic C57BL/6 mice. Cells were injected into the right carotid artery and recovered from the brain after the mice had reached the study endpoint due to tumor burden, then expanded in vitro and reinjected. We compared the transcriptomes of 4th generation B16 cell populations from separate lineages with the founder B16-F0 cells. Gene set enrichment analysis (GSEA) of differentially expressed protein coding genes revealed that cells isolated from the brain as well as from the lung and meninges expressed higher levels of genes associated with an epithelial to mesenchymal transition (EMT), upregulation of the KRAS signaling pathway, and a metastasis aggressiveness gene signature associated with poor survival in melanoma patients. Principal component analysis of differentially expressed genes showed that 4th generation melanoma cells isolated from the brain, lung and meninges from one lineage were distinct from those of the other three lineages. Among the differentially expressed genes, transcript levels of several genes, including Itgb2, Rftn2, and Kcnn4, were significantly higher in all cell populations that comprised this lineage compared with all cell populations from the other three lineages. In conclusion, we have derived an aggressive, highly brain metastatic B16 variant associated with leptomeningeal disease by serially passaging cells in vivo.

Molecular Taxonomy Suggests Presence of Two Distinct Lineages of Blue Sheep (Pseudois nayaur) in Indian Himalayan Region.

Indian Himalayan Region (IHR) supports a plethora of biodiversity with a unique assemblage of many charismatic and endemic species. We assessed the genetic diversity, demographic history, and habitat suitability of blue sheep (Pseudois nayaur) in the IHR through the analysis of the mitochondrial DNA (mtDNA) control region (CR) and Cytochrome b gene, and 14 ecological predictor variables. We observed high genetic divergence and designated them into two genetic lineage groups, i.e., the Himalayan blue sheep (P. n. nayaur) in the western part, and the Chinese blue sheep (P. n. szechuanensis) in the eastern part. They exhibited poor connectivity due to landscape resistance. The genetic distance value suggested substantial genetic differentiation between them. The habitat selection by blue sheep indicated the disparity between the residence preferences in the western and eastern Himalayas. In both the regions, the habitat suitability was mostly influenced by the minimumtemperature of the coldest month. However, in the eastern Himalayas,precipitation seasonalityemerged as a significant variable influencing habitat suitability. These findings provided strong support for the presumption that the habitats preferred by blue sheep in the western Himalayas are dryer, compared with the preferred habitats in the eastern region, which were moister. The identification of two separate lineages of P. nayaur in the IHR has significant conservation implications as it underlines the necessity for a unique management approach for each lineage. In order to preserve genetic integrity, conservation efforts must make sure that each population is maintained and monitored separately, as genetic divergence across the lineages that might indicate reproductive isolation. This study has potential conservation implications as it provides insights on the crucial ecological information of a relatively lesser-known ungulates species of Himalaya essential for effective conservation planning.

A review of the Quichua Porcupine Coendou quichua complex (Rodentia: Erethizontidae) with the description of a new species from Colombia

Abstract Coendou quichua is a widely distributed trans-Andean species in Colombia, Ecuador, and Panama. However, analysis of the cytochrome b (Cytb) gene suggests the presence of cryptic diversity. Recent reviews found that morphological variation within this taxon is mainly associated with elevation. Still, mitochondrial divergence values between some populations are similar to those reported between well-diagnosable sister species in the genus. Here, we provide new Cytb sequences from Colombian and Ecuadorian specimens and morphological observations from specimens collected in different natural regions to show that C. quichua is indeed a species complex. Coendou quichua complex contains 3 separate lineages: (i) the typical C. quichua from the Andes of Ecuador; (ii) a sister lineage from the Chocó-Darién ecoregion; and (iii) an undescribed new species from wet and dry forests of the Magdalena inter-Andean valley and the Caribbean regions of Colombia. Based on morphological, ecological niche modeling, and geographical analyses, the lineage from Chocó-Darién in Colombia and Ecuador is here treated as a different species for which the name C. rothschildi is available. The lineage involving samples from the wet and dry forests of the Magdalena inter-Andean Valley and the Caribbean regions represents an unnamed taxon described herein as Coendou vossi sp. nov., endemic to Colombia.

Complete Mitochondrial Genome of Niphon spinosus (Perciformes: Niphonidae): Genome Characterization and Phylogenetic Analysis.

The species Niphon spinosus (Cuvier, 1829) is the only representative of the family Niphonidae and the genus Niphon, and its taxonomic history is complicated; it is still unclear in a phylogenetic sense. In this study, we report the complete mitochondrial genome of N. spinosus (OP391482), which was determined to be 16,503 bp long with biased A + T contents (53.8%) using next-generation technology. The typical set of 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and one control region (D-loop) are included in the mitochondrial genome. The H-strand encoded 28 genes (14 tRNA, 2 rRNA, and 12 PCGs), and D-loop, whereas the L-strand encoded the remaining 9 genes (8 tRNA and ND6). Its nucleotide composition, gene arrangement, codon usage patterns, and tRNA secondary structures are identical with other members of the Percoidei suborder. Furthermore, we reconstructed phylogenetic trees based on the 13 PCGs. The resulting phylogenetic trees showed N. spinosus placing as a separate lineage within the family Niphonidae, its close relationship to Trachinus draco (Trachinidae), and the clustering of major subfamilies like Luciopercinae and Percinae of the Percoidei suborder. These findings will contribute to future studies on the evolutionary history, population genetics, molecular taxonomy, and phylogeny of N. spinosus and related species.

GEMLI: Gene Expression Memory-Based Lineage Inference from Single-Cell RNA-Sequencing Datasets.

Gene expression memory-based lineage inference (GEMLI) is a computational tool allowing to predict cell lineages solely from single-cell RNA-sequencing (scRNA-seq) datasets and is publicly available as an R package on GitHub. GEMLI is based on the occurrence of gene expression memory, i.e., the gene-specific maintenance of expression levels through cell divisions. This represents a shift away from experimental lineage tracing techniques based on genetic marks or physical cell lineage separation and greatly eases and expands lineage annotation. GEMLI allows to study cell lineages during differentiation in development, homeostasis, and regeneration, as well as disease onset and progression in various physiological and pathological contexts. This makes it possible to dissect cell type-specific gene expression memory, to discriminate symmetric and asymmetric cell fate decisions, and to reconstruct individual multicellular structures from pooled scRNA-seq datasets. GEMLI is particularly promising for its ability to identify small lineages in human samples, a context in which no other lineage tracing methods are applicable. In this chapter, we provide a detailed protocol of the GEMLI R package usage on gene expression matrices derived from standard scRNA-seq on various platforms. We cover the use of the main function to predict cell lineages and how to adjust its parameters to different tasks. We also show how lineage information is extracted, visualized, and fine-tuned. Finally, we describe the use of the package's functions for the detailed analysis of the predicted cell lineages. This includes the analysis of gene expression memory, cell type composition of individual large lineages, and identification of lineages at the transition point between two cell types.

Physcomitrium LATERAL SUPPRESSOR genes promote formative cell divisions to produce germ cell lineages in both male and female gametangia.

The evolution of green plants from aquatic to terrestrial environments is thought to have been facilitated by the acquisition of gametangia, specialized multicellular organs housing gametes. Antheridia and archegonia, responsible for producing and protecting sperm and egg cells, undergo formative cell divisions to produce a cell to differentiate into germ cell lineages and the other cell to give rise to surrounding structures. However, the genes governing this process remain unidentified. We isolated genes expressed during gametangia development from previously established gene-trap lines of Physcomitrium patens and characterized their function during gametangia formation. We identified P. patens LATERAL SUPPRESSOR 1 (PpLAS1) from the gene-trap library, encoding a GRAS transcription factor. The double-deletion mutant with its paralog PpLAS2 failed to form inner cells in both gametangia. PpLASs are expressed in cells undergoing formative cell division, and introducing PpLAS1 into the double-deletion mutant successfully rescued the phenotype. These findings underscore the pivotal role of PpLASs in regulating formative cell divisions, ensuring the separation of reproductive cell lineages from surrounding cells in antheridia and archegonia. Furthermore, they suggest a link between PpLASs and the evolutionary origin of male and female gametangia in the common ancestor of land plants.

Exploring the significant genetic diversity of Iranian isolates of Leishmania RNA virus 2 using whole genome sequence analysis

BackgroundOur work presents the whole genome sequence and phylogenetic analysis of five Leishmania RNA virus 2 (LRV2) isolates obtained from patients with cutaneous leishmaniasis (CL) in Iran.MethodsThe whole genome sequencing of LRV2 was performed using a primer walking approach. The resulting sequences were analyzed for genetic and haplotype diversity, highlighting their independent evolution and significant genetic divergence.ResultsThe whole genome sequence of the current LRV2 showed high genetic and haplotype diversity. The study also revealed the existence of three distinct clades of LRV2, with the LRV2 sequences infecting L. major, L. aethiopica, and sauroleishmania belonging to separate lineages. These lineages have seemingly evolved independently, as the geographic distribution of their flagellate hosts does not overlap with the Leishmania species. The divergence between these three clades is attributed to considerable antiquity, leading to genetic modifications within the viruses residing in them and resulting in structural differences in their genome.ConclusionsThese findings contribute to our understanding of the genetic diversity and evolution of LRVs, providing valuable insights into their role in Leishmania infections. Further investigations are needed to understand the significance of these polymorphic sites and their potential impact on viral characteristics and disease outcomes.

Intraspecific variabilityof the norway rats (Rattus norvegicus) in Russia according to D-loop mtDNA data

For the first time in Russia, a study of the intraspecific structure of the brown rat (Rattus norvegicus) was carried out using the mitochondrial marker of the control region (D-loop) of mtDNA. MtDNA sequences of brown rats from 8 regions of the European and Asian parts of Russia were analyzed. Three clades of rats have been identified: in the European part of Russia –1, in the Asian part – 2. Synanthropic subspecies – R. n. norvegicus is represented by european and asian lineages. The european lineage included haplotypes from the regions of central and southern Russia, and the Asian lineage included haplotypes from Eastern Siberia and the Far East. The previously described free living subspecies, R. n. caraco from the Russian Far East was represented as separate genetic lineage.

Large inversions in Lake Malawi cichlids are associated with habitat preference, lineage, and sex determination.

Chromosomal inversions are an important class of genetic variation that link multiple alleles together into a single inherited block that can have important effects on fitness. To study the role of large inversions in the massive evolutionary radiation of Lake Malawi cichlids, we used long-read technologies to identify four single and two tandem inversions that span half of each respective chromosome, and which together encompass over 10% of the genome. Each inversion is fixed in one of the two states within the seven major ecogroups, suggesting they played a role in the separation of the major lake lineages into specific lake habitats. One exception is within the benthic sub-radiation, where both inverted and non-inverted alleles continue to segregate within the group. The evolutionary histories of three of the six inversions suggest they transferred from the pelagic Diplotaxodon group into benthic ancestors at the time the benthic sub-radiation was seeded. The remaining three inversions are found in a subset of benthic species living in deep waters. We show that some of these inversions are used as XY sex-determination systems but are also likely limited to a subset of total lake species. Our work suggests that inversions have been under both sexual and natural selection in Lake Malawi cichlids and that they will be important to understanding how this adaptive radiation evolved.

The mechanism underlying B-cell developmental dysfunction in Kawasaki disease based on single-cell transcriptomic sequencing.

Kawasaki disease (KD) is an acute systemic vasculitis that can lead to acquired heart disease in children mostly from in developed countries. The previous research showed that B cells in KD patients underwent a profound change in both the cell numbers and types after intravenous immunoglobulin (IVIG) therapy. We performed the single-cell RNA-sequencing for the peripheral blood mononuclear cells (PBMCs) from three febrile patients and three KD patients to investigate the possible mechanism underlying B cell developmental dysfunction in KD. The pseudo-time analysis was employed to study the developmental trajectories of the PBMCs in febrile control and KD patients. Overall single-cell expression profiles show that the biological processes of immunity, B cell activation pathway and their related biological entities are repressed in KD patients before IVIG treatment compared to febrile patient and KD patients after IVIG treatment. The differentially expressed gene analyses further demonstrate that B cell signaling pathway is downregulated in B cells and plasma blast cells of KD patients before treatment while cell cycle genes and MYC gene are upregulated in dendritic cells (DCs) and hematopoietic stem and progenitor cells (HSPCs) of KD patients before treatment. The biological process of immune response is upregulated in the HSPCs of KD patients before treatment in our dataset while the biological process of inflammatory response is upregulated in the HSPCs of KD patients before treatment in GSE168732 dataset. Single-cell trajectory analyses demonstrate that KD patients before treatment have a shortened developmental path in which B cells and T cells are failed to differentiate into separate lineages. HSPD1 and HSPE1 genes show an elevated expression level in the early cell development stage of KD patients before treatment accompanied with the repression of MYC, SPI1, MT2A and UBE2C genes. Our analyses of all B cells from KD patients before treatment show most of B cells are arrested in a transitional state with an ill developmental path compared with febrile patients and KD patients after treatment. Our results indicate that the immune premature HSPCs accompanied with the abnormal expression dynamics of cell cycle and SPI1 genes are the mechanism underlying B cell developmental dysfunction in KD patients.

Lineage diversity in a Melanesian lizard radiation (Gekkonidae: Nactus) further highlights exceptional diversity and endemism in eastern Papua New Guinea

New Guinea and surrounding islands are home to some of the richest assemblages of insular biodiversity in the world. The key geological drivers of species richness in this region are largely considered to be mountain uplift and development of offshore archipelagos—some of which have accreted onto New Guinea—with the role of mountain uplift and elevational gradients receiving more attention than the role of isolation on islands. Here, we examine the distribution of lineage richness and body-size diversity in a radiation of Melanesian lizards that is almost entirely absent from montane habitats but closely associated with islands—the geckos of the genus Nactus. Our data indicate that eastern New Guinea—centred on the East Papuan Composite Terrane (EPCT)—shows particularly high levels of endemism and body-size diversity and is also inferred to be a source area for multiple independent colonisations elsewhere in New Guinea, the Pacific and Australia. Two Nactus lineages in Australia have closest relatives occurring to the north of New Guinea’s Central Cordillera, suggesting dispersal through this area in the mid-Miocene, possibly via seaways that would have isolated the islands to the east and west of the proto-Papuan region. Syntopic species tend to differ in body length; however, at a phylogenetic scale, this trait appears to be conservative, with small-sized and large-sized species clustered into separate lineages. These data suggest that species richness in Melanesian Nactus is in part explained by morphological diversification enabling the presence of sympatric communities to exist, but to a greater extent by multiple instances of dispersal and extensive allopatric and parapatric speciation, especially in and around the islands of the EPCT.

Description of immature stages of Hybosa acutangula Spaeth, 1913 (Coleoptera, Chrysomelidae, Cassidinae).

The immature stages of Hybosa acutangula Spaeth, 1913, member of the tribe Cassidini Gyllenhal, 1813, are described in detail and compared with other members of Cassidini and Ischyrosonychini Chapuis, 1875 species. The eggs, oothecae and first instar larvae are described for the first time. The morphology of the immatures of H. acutangula, unusual for the species of the Cassidini tribe, was the impulse that initiated the research. The result of the comparative analysis is the conclusion that the morphological features of the immature stages of H. acutangula are a mixture of characters observed in representatives of the Cassidini and Ischyrosonychini tribes. The similarity to Ischyrosonychini may only be convergence, but it cannot be ruled out that there is a separate phylogenetic lineage within Cassidini, represented by H. acutangula. Verification of this hypothesis requires further research.

Palaeognaths Reveal Evolutionary Ancestry of the Avian Major Histocompatibility Complex Class II.

The multigene family of the major histocompatibility complex (MHC) codes for the key antigen-presenting molecules of the vertebrate immune system. In birds, duplicated MHC class II (MHC-II) genes are highly homogenized by concerted evolution, and thus, identification of their orthologous relationships across long evolutionary timescales remains challenging. Relatively low evolutionary rate of avian MHC class IIA genes has been expected to provide a promising avenue to allow such inferences, but availability of MHC-IIA sequences in nonmodel bird species has been limited until recently. Here, taking advantage from accumulating genomic resources, we identified and analyzed MHC-IIA sequences from the most basal lineage of extant birds (Palaeognathae). Conserved region of the MHC-IIA membrane-proximal domain was used to search for orthologous relationships between palaeognath birds and nonavian reptiles. First, analyses of palaeognath sequences revealed the presence of a separate MHC-IIA gene lineage (DAA3) in kiwis, which did not cluster with previously described avian MHC-IIA lineages (DAA1 and DAA2). Next, phylogenetic reconstruction showed that kiwi DAA3 sequences form a single well-supported cluster with turtle MHC-IIA. High similarity of these sequences most likely reflects their remarkable evolutionary conservation and retention of ancient orthologous relationships, which can be traced back to basal archosauromorphs ca. 250 million years ago. Our analyses offer novel insights into macroevolutionary history of the MHC and reinforce the view that rapid accumulation of high-quality genome assemblies across divergent nonmodel species can substantially advance our understanding of gene evolution.

Description of a new endemic Enteromius (Teleostei: Cyprinidae) from the upper Malagarazi in Burundi: Lessons for a protected area under implementation.

Recent collecting efforts in the upper Malagarazi basin (2013-2022) allowed for an integrative study based on qualitative (colour), quantitative (meristic and metric), and barcoding gene [mtDNA, cytochrome c oxidase (COI)] data of specimens similar to Enteromius sp. 'ascutelatus', being a previously identified, potentially, new species. Based on these data, the present study confirms its identification as a new species for science, which is here formally described as Enteromius nzigidaherai sp. nov. This new species belongs to the group of Enteromius species for which the last unbranched ray of the dorsal fin is flexible and devoid of serrations along its posterior edge. This species has a horizontal series of black spots at the midlateral level of the sides. Three congeneric species, known from the Congo basin sensu lato, with two of them also found in the upper Malagarazi basin, are most similar to it. However, E. nzigidaherai sp. nov. is distinguished from the two sympatric upper Malagarazi species, that is, E. quadrilineatus and E. lineomaculatus, at least by two meristics and two morphometrics. It is also distinguished from E. urostigma, known from the upper Congo basin, by two meristics and one, apparently related, morphometric. In addition, a barcoding (mtDNA, COI) study revealed that the specimens of E. nzigidaherai sp. nov. form a well-supported, separate lineage, with a K2P genetic distance of more than 10% with specimens identified as E. quadrilineatus and E. lineomaculatus, both originating from the upper Malagarazi basin and for which tissue samples were available. Finally, the new species was found to be endemic to the upper reaches of two left bank affluents of the upper Malagarazi basin: the Muyovozi and the Kinwa. However, both affluents are threatened by human activities, which seem to have resulted in its local disappearance as recent intensive collecting efforts in the latter affluent have remained unsuccessful. The species should thus be considered Critically Endangered (CR) according to IUCN criteria B1ab(ii,iv)c(i,iii). Therefore, it is hoped that the present description draws renewed attention to the importance of aquatic protection in the region by highlighting the need for the effective establishment of the Malagarazi Nature Reserve and concern for its optimal delimitation to efficiently protect the entire ichthyofauna of the upper Malagarazi, without excluding the fish species confined to its affluent rivers.

Intraspecific Variation of Brown Rat Rattus norvegicus in Russia by D-Loop mtDNA Data.

For the first time in Russia, the intraspecific structure of the brown rat Rattus norvegicus was studied using the mitochondrial control region (D-loop) as a molecular marker. The mtDNA sequence was determined in brown rats from eight regions of European and Asian Russia. Three rat clades were identified, including one in European Russia and two in Asian Russia. The synanthropic subspecies R. n. norvegicus was found to have two, European and Asian, lineages. The European lineage included haplotypes from central and southern regions of Russia, and the Asian lineage included haplotypes from Eastern Siberia and the Russian Far East. The exoanthropic subspecies R. n. caraco from the Russian Far East formed a separate genetic lineage.

Exploring the mitochondrial genomes and phylogenetic relationships of trans-Andean Bryconidae species (Actinopterygii: Ostariophysi: Characiformes).

Comparative mitogenomics and its evolutionary relationships within Bryconidae remains largely unexplored. To bridge this gap, this study assembled 15 mitogenomes from 11 Bryconidae species, including five newly sequenced. Salminus mitogenomes, exceeding 17,700 bp, exhibited the largest size, contrasting with a median size of 16,848 bp in the remaining species (Brycon and Chilobrycon). These mitogenomes encode 37 typical mitochondrial genes, including 13 protein-coding, 2 ribosomal RNA, and 22 transfer RNA genes, and exhibit the conserved gene arrangement found in most fish species. Phylogenetic relationships, based on the maximum-likelihood method, revealed that the trans-Andean species (found in northwestern South America) clustered into two main sister clades. One clade comprised the trans-Andean species from the Pacific slope, Brycon chagrensis and Chilobrycon deuterodon. The other clade grouped the trans-Andean species from the Magdalena-Cauca Basin Brycon moorei and Salminus affinis, with their respective cis-Andean congeners (found in eastern South America), with Brycon rubricauda as its sister clade. Since the current members of Brycon are split in three separated lineages, the systematic classification of Bryconidae requires further examination. This study provides novel insights into mitogenome characteristics and evolutionary pathways within Bryconidae, standing as crucial information for prospective phylogenetic and taxonomic studies, molecular ecology, and provides a valuable resource for environmental DNA applications.

Neolithic Yersinia pestis infections in humans and a dog

Yersinia pestis has been infecting humans since the Late Neolithic (LN). Whether those early infections were isolated zoonoses or initiators of a pandemic remains unclear. We report Y. pestis infections in two individuals (of 133) from the LN necropolis at Warburg (Germany, 5300–4900 cal BP). Our analyses show that the two genomes belong to distinct strains and reflect independent infection events. All LN genomes known today (n = 4) are basal in the phylogeny and represent separate lineages that probably originated in different animal hosts. In the LN, an opening of the landscape resulted in the introduction of new rodent species, which may have acted as Y. pestis reservoirs. Coincidentally, the number of dogs increased, possibly leading to Y. pestis infections in canines. Indeed, we detect Y. pestis in an LN dog. Collectively, our data suggest that Y. pestis frequently entered human settlements at the time without causing significant outbreaks.

Amazon deep South: Schubarthelphusa, a new genus to accommodate two freshwater crab species from the State of Rondônia, Brazil (Brachyura, Pseudothelphusidae)

Abstract A new genus of pseudothelphusid crab is proposed to accommodate two species from the state of Rondônia in the southern Amazon region of Brazil. The new taxon was retrieved as a separate lineage from the genus Fredius Pretzmann, 1967, based on an integrative approach using molecular phylogenetic analysis and morphological characters of the male first gonopod, as well as taking into account its geographic distribution. In terms of gonopod morphology, the new genus resembles Fredius but it is characterized by an enlarged and distinctly inflated proximal portion of the cephalic lobe, a well-developed patch of strong, corneous spines along the mesial and abdominal surfaces of the cephalic lobe, and a mesial lobe that is extremely developed on a long, narrow, sinuous or convoluted projection. The new genus has the southernmost distribution of the Pseudothelphusidae within the Amazon Basin.