Interspecific Genetic Variation Research Articles

Role of Geographical Gaps in the Western Ghats in Shaping Intra- and Interspecific Genetic Diversity

Role of Geographical Gaps in the Western Ghats in Shaping Intra- and Interspecific Genetic Diversity

Comparative Analysis of Complete Chloroplast Genome Sequences in Edgeworthia (Thymelaeaceae) and New Insights Into Phylogenetic Relationships.

The complete chloroplast genomes of three species of Edgeworthia namely, Edgeworthia albiflora, Edgeworthia chrysantha, and Edgeworthia gardneri (Thymelaeaceae), are reported and characterized. The chloroplast genomes displayed a typical quadripartite structure with conserved genome arrangement and specific divergence. The genomes ranged in length from 172,708 to 173,621 bp and displayed similar GC content of 36.5–36.7%. A total of 138–139 genes were predicted, including 92–93 protein-coding, 38 tRNAs and eight rRNAs genes. Variation in the number of short simple repeats and inverted region boundaries of the three cp genomes were observed. A mutational hotspot was detected along the nucleotide sequence from the ndhF to the trnL-UAG genes. The chloroplast genome-based and internal transcribed spacer (ITS)-based phylogenetic analyses using maximum-likelihood (ML) and Bayesian inference (BI) revealed that E. albiflora diverged before E. chrysantha and E. gardneri and placed the Edgeworthia clade at the base of the Eurasian Daphne group with strong bootstrap support. With an effective taxonomic treatment of the species of Edgeworthia, further molecular analyses of their intra- and interspecific genetic variation are inclined to support the treatment of E. albiflora and E. gardneri as two natural groups. The genetic information obtained from this study will provide valuable genomic resources for the identification of additional species and for deducing the phylogenetic evolution of Edgeworthia.

Interspecific Variation and Phylogenic Architecture of Pinus densata and the Hybrid of Pinus tabuliformis×Pinus Yunnanensis in the Pinus densata Habitat: an Electrical Impedance Spectra Perspective

We evaluated a novel and non-destructive method of the electrical impedance spectroscopy (EIS) to elucidate the genetic and evolutionary relationship of homoploid hybrid conifer of Pinus densata (P.d) and its parental species Pinus tabuliformis (P.t) and Pinus yunnanensis (P.y), as well as the artificial hybrids of the P.t and P.y. Field common garden tests of96 trees sampled from 760 seedlings and 480 EIS records of 1,440 needles assessed the interspecific variation of the P.d, P.t, P.y and the artificial hybrids. We found that (1) EIS at different frequencies diverged significantly among germplasms; P.y was the highest, P.t was the lowest, and their artificial hybrids were within the range of P.t and P.y; (2) maternal species effect of EIS magnitudes in the hybrids and P.d was stronger than the paternal species characteristics; (3)EIS of the artificial hybrid confirmed the mid-parent and partial maternal species characteristics;(4) unified exponential model of EIS for the interspecific and hybrids can be constructed as |Z|=Af -B; (5) cluster analysis for species and hybrid combinations in total corroborated with the previous hybrid model of Pinus densata. Our non-destructive EIS method complemented the previous finding that Pinus densata was originated from P.t and P.y. We conclude that the impedance would be a viable indicator to investigate the interspecific genetic variations of conifers.

Development of a RAPD marker‐based classification criterion for quality semen production in Holstein crossbred bulls

In cattle production systems, an intense selection pressure for production traits has resulted in the decline of fertility traits. To optimize an efficient reproduction system, the inclusion of both male and female fertility traits in the selection process is very much essential. RAPD (Random Amplified Polymorphic DNA) was developed as a molecular biology tool and has been extensively used, to study intra- and interspecific genetic diversity. The present study was undertaken to utilize RAPD primers to investigate the association between DNA markers and semen quality traits viz. Sperm concentration, total sperm count ejaculate and initial sperm motility and thereby to identify good/poor semen producers. DNA isolated from the blood samples of healthy bulls was subjected to RAPD-PCR. The multiple regression analysis followed by independent t test was carried out to identify suitable markers. Based on the results, only 12 bands were identified as marker suitable for any of the quality trait. This includes, OPA2~760, OPA2~700, OPA6~1,200, OPA9~400, OPA9~380, OPA12~970, OPA14~715, OPA14~605, OPA16~485, OPA17~860 and OPA18~480. Multiple regression analysis selected, OPA2~760 and OPA2~1,750 for sperm concentration and OPA2~760, OPA2~700, OPA9~620, OPA4~670 and OPA18~1,015 for total sperm count/ejaculate. But the t test revealed a significant association between OPA2~760 and total sperm count. Further, discriminant function analysis also identified this marker in the first step itself. The results of the present study can be exploited as a low-cost alternative strategy for identification of good /poor semen producers in crossbred bulls at an early age.

Species delimitation and taxonomic revision of Oxyopes (Araneae: Oxyopidae) of Taiwan, with description of two new species.

This study revised the spider genus Oxyopes Latreille, 1804 in Taiwan and delineated the species boundaries based on morphological and molecular characters. A total of seven Oxyopes spiders were recognized, including two newly described species, O. hasta sp. nov. and O. taiwanensis sp. nov. Oxyopes fujianicus Song Zhu 1993 from Yilan County, Nantou County, and Kaohsuing City, and O. striagatus Song 1999 from New Taipei City, Taichung City, Nantou County, and Kaohsiung City were recorded for the first time in Taiwan. An identification key and a distributional map of Taiwanese Oxyopes species were provided. Partial COI sequences were obtained for molecular phylogenetic and species delimitation analyses. Maximum likelihood and Bayesian phylogenies, and DNA barcoding gap analysis supported morphologically defined species. However, molecular species delimitation based on Automatic Barcode Gap Discovery (ABGD), PID (Liberal), and generalized mixed Yule coalescent (GMYC) were incongruent in species assignment. The results showed that the interspecific genetic divergence between O. sertatus and O. taiwanensis was relatively low (1.28 ± 0.43%), and the intraspecific genetic divergence of O. striagatus was relatively high (1.69 ± 0.35%). Ecological data, additional samples and genetic loci are required to further examine the level of reproductive isolation and patterns of population genetic structure in Taiwanese Oxyopes.

Threats Posed to the Rediscovered and Rare Salvia ceratophylloides Ard. (Lamiaceae) by Borer and Seed Feeder Insect Species

The effects of herbivorous insects on a plant population are not always well tolerated. This is especially true if the herbivorous actions are directed toward rare plant species. Salvia ceratophylloides Ard. is a rare endemism of southern Italy. Observations of the plants in situ revealed that many of them were under severe stress and did not produce seeds. Therefore, to find out which factors affect the reproductive activity as a whole, an observational study was carried out. We found bottom-up and top-down effects on plant health and reproduction associated with herbivorous action. Squamapion elongatum (Coleoptera, Curculionoidea, Apionidae), in all monitored sites, infested plants non-uniformly but was able to threaten the health condition, flowering, and seed production of sage by digging tunnels into the sage branches (bottom-up action), and then secondarily by seed feeder Systole salvia Zerova (Hymenoptera, Eurytomidae) predating sage seeds (top-down action). Mainly, chalcid parasitoid wasps such as Trichomalus spp. (Hymenoptera, Pteromalidae), as well as Eupelmus vesicularis and E. muellneri (Hymenoptera, Eupelmidae), limited the herbivorous S. elongatum population and the seed herbivore S. salviae emerged with its parasitoid Ormyrus diffinis (Hymenoptera, Ormyridae). Overall, this study showed how ecological interactions among herbivores, their host, and their natural enemies act on this sage species in all sites investigated. Among the herbivores, mainly S. elongatum affected this rare sage species, which should be taken into consideration, especially in the formulation of biological control solutions and for improving operating practice aimed at reproducing the species. This study provides the molecular characterization of the herbivorous species involved, in order to support future projects to evaluate the intra- and interspecific genetic variability of insects, their evolutionary relationships, and phylogeny studies.

Patterns and drivers of genetic diversity among Felidae species

Since the late Pleistocene, species in the order Carnivora have experienced a drastic reduction in their populations and distributions. However, the global genetic diversity patterns among terrestrial carnivores have not been investigated. Using felid species as model, we characterized the genetic variation within their populations among continents, between tropical and non-tropical regions, and in relation to human activities. We then evaluated how species traits influence the observed patterns of interspecific genetic diversity. Through data collected from 135 population genetic studies conducted on 28 wild felid species (70% of the described species), data analyses using GLMM modelling showed that the populations in Africa and South America have significantly higher heterozygosity and allelic richness than those in other continents. The Asiatic lions have the least genetic diversity compared to other felids in the world. Threatened species have significantly lower genetic diversity compared to low-risk species as predicted. However, genetic diversity was not related to species body mass or geographic range. We found generation length to be an important variable explaining genetic diversity variation, in which species with short generation length have reduced genetic diversity. Furthemore, the combination of generation length, habitat and home range size captures the variation in heterozygosity significantly better. Species dependent on closed-habitat and with large home range size have reduced heterozygosity compared to their counterparts. Our results allow to identify priority felid species vulnerable to loss of genetic diversity for further conservation studies, and provide an insight into the possible genetic consequences of the late Pleistocene extinctions.

Genetic variation and cryptic diversity of the

Alpheus lobidens sensu lato is one of the most common groups of snapping shrimps in the Indo-West Pacific. The objective of this study was to investigate the phylogenetic relationships among lineages of A. lobidens s.l. throughout their geographical distribution and identifying possible morphological characteristics that support the lineages from this combined dataset. Molecular data were obtained by analysing 16S rRNA from nine individuals of A. lobidens, three of A. buckupi, one of A. inopinatus and six other Alpheus species. The genetic analyses (mean p-distance and Bayesian Inference) indicate considerable genetic divergence and at least nine lineages within the A. lobidens species complex. The high morphological variability observed in Alpheus spp. and the high rates of interspecific genetic divergence agree with the Marine Ecoregions of the World and ocean currents, which suggests limited gene flow among those lineages, indicating that these could be treated as new species. However, as no informative morphological characters were identified, describing the six new taxa of the complex recognised in this study was unfeasible. Future studies using a higher number of specimens and applying more sensitive methods for detecting structural differences, might help morphologically define the new species that were uncovered herein.

A global meta-analysis of ITS rDNA sequences from material belonging to the genus Ganoderma (Basidiomycota, Polyporales) including new data from selected taxa.

Ganoderma P. Karst. is a cosmopolitan genus of white-rot fungi which comprises species with highly-prized pharmaceutical properties, valuable biotechnological applications and of significant phytopathological interest. However, the status of the taxonomy within the genus is still highly controversial and ambiguous despite the progress made through molecular approaches. A metadata analysis of 3908 nuclear ribosomal internal transcribed spacer (ITS) rDNA sequences obtained from GenBank/ENA/DDBJ and UNITE was performed by targeting sequences annotated as Ganoderma, but also sequences from environmental samples and from material examined for the first time. Ganoderma taxa segregated into five main lineages (Clades A to E). Clade A corresponds to the core of laccate species and includes G. shanxiense and three major well-supported clusters: Cluster A.1 (‘G. lucidum sensu lato’) consists of taxa from Eurasia and North America, Cluster A.2 of material with worldwide occurrence including G. resinaceum and Cluster A.3 is composed of species originating from all continents except Europe and comprises G. lingzhi. Clade B includes G. applanatum and allied species with a Holarctic distribution. Clade C comprises taxa from Asia and Africa only. Clade D consists of laccate taxa with tropical/subtropical occurrence, while clade E harbours the highest number of non-laccate species with a cosmopolitan distribution. The 92 Ganoderma-associated names, initially used for sequences labelling, correspond to at least 80 taxa. Amongst them, 21 constitute putatively new phylospecies after our application of criteria relevant to the robustness/support of the terminal clades, intra- and interspecific genetic divergence and available biogeographic data. Moreover, several other groups or individual sequences seem to represent distinct taxonomic entities and merit further investigation. A particularly large number of the public sequences was revealed to be insufficiently and/or incorrectly identified, for example, 87% and 78% of entries labelled as G. australe and G. lucidum, respectively. In general, ITS demonstrated high efficacy in resolving relationships amongst most of the Ganoderma taxa; however, it was not equally useful at elucidating species barriers across the entire genus and such cases are outlined. Furthermore, we draw conclusions on biogeography by evaluating species occurrence on a global scale in conjunction with phylogenetic structure/patterns. The sequence variability assessed in ITS spacers could be further exploited for diagnostic purposes.

Feasibility of Cultivating Artemisia afra Jacq. ex Willd in Côte d’Ivoire (Daloa) and Evaluation of Its Genetic Diversity on the Basis of Phenotypic Variations

In the southern African regions, Artemisia afra Jacq. ex Willd is one of the most popular and commonly used herbal medicines. In recent years, A. afra has received much attention from the scientific community and its use is being investigated in the modern diseases like diabetes, cardiovascular diseases, cancer, and respiratory diseases. This growth in popularity could pose a threat to the species due to intensive harvesting. Indeed, overexploitation is a growing problem for many medicinal species in Africa. To sustain the production and availability of A. afra , cultivation seems to be a good strategy and an alternative to collecting in the wild. Unlike A. annua L. (source of artemisinin), little information is available on the cultivation of A. Afra in West African countries. In this study, feasibility of cultivating A. Afra in Côte d’Ivoire was evaluated and the extent of its genetic diversity was assessed based on morphological variations. A. annua L. was used as control. The result showed for A. afra , 30 and 28.02% nursery and field mortality respectively, and 27.77% and 0% for A. annua . A. annua showed faster growth and development kinetics during the first 90 days after field transplantation. A. annua was relatively earlier (83 days to flowering on average) than A. afra (207.20 days to flowering on average). Contrary to A. annua , A. afra was sterile and did not give viable seeds, which poses a major problem of acclimatization in the environmental conditions of Côte d’Ivoire. Assessment of morphological traits revealed significant variations within and between species. Multivariate analysis showed important intra and interspecific genetic diversity. The plants of A. afra and A. annua were grouped separately and six major clusters were found: two clusters in A. annua (cluster I and II) and four clusters in A. afra (cluster III, IV, V and VI). These results show that further studies need to be considered to make cultivation of A. afra possible in Côte d’Ivoire with superior and genetically stable genotypes. Keywords: Artemisia afra , Artemisia annua , genetic diversity, cultivation DOI: 10.7176/JBAH/10-24-04 Publication date: December 31 st 2020

OPTIMIZATION OF THE METHOD OF DNA ISOLATION FROM FOSSILS

The history of the origin and domestication of farm animals has always interested mankind. However, these issues are covered in the literature in great detail only from the time when herds of domestic animals have already formed. Most often, the genesis of individual species, the original forms that formed the basis of domestication, remain unclear. [2] An example is the history of domestication of the horse, as the horse played a central role among other domestic animals in the development of human society. In the study of mammal fauna of the Pleistocene-Holocene of Europe there is a problem of studying the origin of the domestic horse Eguus cabalus L., ie, the establishment of wild ancestors of domesticated breeds, place, time and process of their domestication. Analysis of literature data on paleontological and archaeological finds in Ukraine showed that most researchers believe that the first domesticated horses began to recognize horses, the remains of which were found during archaeological excavations of the settlement of the third millennium BC. BC in Botai (Northern Kazakhstan), but from which taxon the opinions of scientists differ. Some believe that it could be Tarpan, however, there is an opinion that a large horse could not come from a small tarpan and Przewalski's horse. Therefore, preference was given to the hypothesis of the origin of the domestic horse from the ancient Pleistocene. At present, the problem of the origin of the domestic horse does not go beyond hypotheses and assumptions, and this is primarily due to the slight difference between the bones of the domestic and wild horse. The plasticity of the skeleton of the genus Eguus is very weak and this explains the problems faced by paleontologists in trying to develop the evolutionary history of horses. Thus, to understand the processes of domestication of this animal, in addition to archaeological and paleontological research methods, it is necessary to use tools from other fields of science, such as molecular genetic analysis of DNA samples. One of the variants of test systems for studying genetic polymorphism is the use of ISSR markers, which allow to analyze DNA fragments and make certain phylogenetic connections in the studied groups.
 In the laboratory of genetics of the Institute of Breeding and Genetics of Animals named after M.V.Zubets NAAS began research in the field of paleogenetics, namely – the study of the molecular genetic component in the fossils of ancient members of the genus Eguus using ISSR-markers. Inverted repeats are of particular interest because they are unevenly distributed throughout the genome and do not require prior knowledge of the nucleotide sequence of the test DNA. A significant point in the selection of research methods for us was that intermicrosatellite polymorphism is used to study interspecific and intraspecific genetic variability. It is believed that DNA fragments obtained by ISSR analysis can be species- and breed-specific, and this method is widely used by researchers in the study of breed groups.
 The purpose of our work is to develop a new method of DNA isolation from fossil remains (bones) of ancient horses and the production of ISSR-PCR with isolated DNA samples in the laboratory of genetics IRGT. M.V.Zubets NAAS according to the available reagents and existing protocols.
 The research was carried out on samples of fossil bones of horses of the Pleistocene period (about 10 thousand years BC). One bone was found in the village. Beeches of Zhytomyr region in a career. Excavations were carried out in 1960, the metacarpal bone (os. Tarsicentral). Another bone was found in Novgorod-Siversky, Chernihiv region. in a career. Excavations were conducted by Boriskovsky PI in 1935. A tooth found in the village of Tarpan was used to study a wild tarpan horse (4.5 thousand years BC). Skibnytsia, Trostyanets district, Vinnytsia region. Excavations were conducted in 1959 by VM Danylenko. The paleontological material for the study was provided by the Kyiv National Museum of Natural History of the National Academy of Sciences of Ukraine, Department of Paleontology.
 As a result of this work for the first time in the Department of Genetics and Biotechnology IRGT. Research on paleogenetics has been started by M.V.Zubets. We optimized the method of extracting genetic material from fossils and obtained DNA from the bones of a horse of the Pleistocene period (about 10 thousand years BC) and the tooth of a wild horse tarpan (4.5 thousand years BC). Also, the optimal conditions for PCR were selected to work with DNA obtained from fossil remains, to study polymorphism with ISSR markers, and electrophoregrams of amplification products were obtained.

Chloroplast genomes elucidate diversity, phylogeny, and taxonomy of Pulsatilla (Ranunculaceae)

Pulsatilla (Ranunculaceae) consists of about 40 species, and many of them have horticultural and/or medicinal value. However, it is difficult to recognize and identify wild Pulsatilla species. Universal molecular markers have been used to identify these species, but insufficient phylogenetic signal was available. Here, we compared the complete chloroplast genomes of seven Pulsatilla species. The chloroplast genomes of Pulsatilla were very similar and their length ranges from 161,501 to 162,669 bp. Eight highly variable regions and potential sources of molecular markers such as simple sequence repeats, large repeat sequences, and single nucleotide polymorphisms were identified, which are valuable for studies of infra- and inter-specific genetic diversity. The SNP number differentiating any two Pulsatilla chloroplast genomes ranged from 112 to 1214, and provided sufficient data for species delimitation. Phylogenetic trees based on different data sets were consistent with one another, with the IR, SSC regions and the barcode combination rbcL + matK + trnH-psbA produced slightly different results. Phylogenetic relationships within Pulsatilla were certainly resolved using the complete cp genome sequences. Overall, this study provides plentiful chloroplast genomic resources, which will be helpful to identify members of this taxonomically challenging group in further investigation.

Detecting no natural hybridization and predicting range overlap in Saccharina angustata and Saccharina japonica

Natural hybridization can play a significant role in evolutionary processes and influence the adaptive diversification and speciation of brown seaweeds. However, this phenomenon is as yet unknown in Saccharina kelps. Saccharina angustata and two varieties of Saccharina japonica (S. japonica var. japonica and S. japonica var. diabolica) partly overlap in distribution along the Pacific coast of Hokkaido, which makes them a good model system to study hybridization and introgression among species of the genus Saccharina. Based on 13 highly variable nuclear microsatellites and a mitochondrial marker, we assessed the genetic diversity levels of S. angustata for the first time and populations from Muroran to Shiranuka (western part of the Pacific coast in Hokkaido) exhibited highest genetic diversity. Genetic diversity of S. japonica was higher in S. japonica var. japonica as compared with S. japonica var. diabolica. There was significant genetic differentiation (FST > 0.25, p < 0.05) between S. japonica and S. angustata based on both markers. Moreover, there was poor genetic connectivity and limited interspecific hybridization among these closely related Saccharina species. Ecological niche models projected a northward expansion of both S. japonica and S. angustata under future climate scenarios and a range overlap between two species along the coast of Okhotsk Sea in Kamchatka Peninsula. The interspecific hybridization and genetic diversity among these kelps provide insights for kelp selection and cultivation as well as future conservation strategies of wild stocks.

A new species of Scapholeberis Schoedler, 1858 (Anomopoda: Daphniidae: Scapholeberinae) from the Colombian Amazon basin highlighted by DNA barcodes and morphology.

BackgroundThe Amazon basin is recognized as one of the most complex and species-rich freshwater environments globally. The diversity of zooplankton here remains unknown, with many species undescribed.MethodsHere, we describe a new species of Scapholeberis Schoedler, 1858 (Cladocera: Anomopoda: Daphniidae: Scapholeberinae) from the Colombian Amazon Basin, collected with recently designed light traps. The description is based on detailed morphology (based on SEM and light microscopy) of parthenogenetic females, ephippial females, males, and molecular data based on the COI gene.ResultsScapholeberis yahuarcaquensis n. sp. has a combination of characters present in Scapholeberis kingi Sars, 1888 and Scapholeberis armata freyi Dumont & Pensaert, 1983. These are a trilobate rostrum, with the middle lobe well developed with sides straight to relatively rounded, the presence of an elongated slit frontal head pore, a dorsal pore in the juncture of the cephalic shield and the valves, and a single denticulate membrane at the posterior rim of the valves, with stronger setae in the last third. The unique characters of the parthenogenetic females are ventral sucker with delicate triangles. Each has a filament-like projection in the lamellae’s inner side and an external section forming convex folds with denticle-like projections in the middle zone of the sucker-plate. There is a peculiar pitted sculpture in the ephippial females and a strong projection in the front of it. The male hook on the limb I with a blunt tip, a quirky lamella-like outgrow in the proximal side, and a paddle with well-developed spines scattered on its surface. The ventral sucker-lamellae in the male is much more developed than the female. The COI gene sequences showed an interspecific mean genetic divergence of 16.4% between S. yahuarcaquensis n. sp. and the closest species S. freyi from Mexico, supporting our results. A coalescence analysis and Barcode Index Number also support the new species based on the DNA sequences. New methods of collecting and integrative biology will give important support to recognize the fauna from the Amazon Basin, one of the most important sources of fresh water in the world that remains unknown in many respects.

DNA barcoding and molecular phylogeny of Dumasia (Fabaceae: Phaseoleae) reveals a cryptic lineage

Dumasia taxonomy and classification have long been problematic. Species within this genus have few morphological differences and plants without flowers or fruits are difficult to accurately identify. In this study, we evaluated the ability of six DNA barcoding sequences, one nuclear (ITS) and five chloroplast regions (trnH-psbA, matK, rbcL, trnL-trnF, psbB-psbF), to efficiently identify Dumasia species. Most single markers or their combinations identify obvious barcoding gaps between intraspecific and interspecific genetic variation. Most combined analyses including ITS showed good species resolution and identification efficiency. We therefore suggest that ITS alone or a combination of ITS with any cpDNA marker are most suitable for DNA barcoding of Dumasia. The phylogenetic analyses clearly indicated that Dumasia yunnanensis is not monophyletic and is separated as two independent branches, which may result from cryptic differentiation. Our results demonstrate that molecular data can deepen the comprehension of taxonomy of Dumasia and provide an efficient approach for identification of the species.

Mitochondrial ribosomal genes as novel genetic markers for discrimination of closely related species in the Angiostrongylus cantonensis lineage

The Angiostrongylus cantonensis lineage (Nematoda: Metastrongyloidea) consists of the closely related species A. cantonensis, Angiostrongylus malaysiensis, and Angiostrongylus mackerrasae. Various genetic markers have been used for species discrimination in molecular phylogenetic studies of this lineage. However, despite showing potential in other organisms, mitochondrial 12S and 16S ribosomal RNA (rRNA) genes have not been used for Angiostrongylus species discrimination. Therefore, this study assessed these genes’ suitability for inter- and intraspecies discrimination in the A. cantonensis lineage. The ultimate aim was to provide a novel genetic marker to support existing phylogenies. Sixty adult Angiostrongylus spp. worms from four geographic locations in Thailand were identified morphologically before molecular identification with 12S and 16S rRNA genes. Neighbor-joining and maximum likelihood algorithms were used for phylogenetic analyzes, and sequence variation was calculated to determine whether the genes could be used to discriminate among species. Furthermore, sequence variation was compared among previously used genetic markers to evaluate the robustness of the 12S and 16S rRNA genes as markers. Using both markers, the A. cantonensis lineage formed a monophyletic clade with a clear separation between A. cantonensis, A. malaysiensis, and A. mackerrasae. From our representative A. cantonensis and A. malaysiensis specimens, the genetic distance between the two clades was 6.8% –7.9% and 7.9% –10.0% for 12S and 16S rRNA genes, respectively, which is sufficient interspecific genetic variation for species discrimination. Higher levels of genetic variation were observed for the 16S rRNA gene, with 12 haplotypes and an intraspecific variation ≤2.2%. Thus, as a genetic marker, the 16S rRNA gene is comparable to mitochondrial protein-coding genes, which are commonly used in intra-level Angiostrongylus spp. studies. In conclusion, mitochondrial 12S and 16S rRNA genes can discriminate among closely related species in the A. cantonensis lineage, and they represent novel genetic markers for supporting existing phylogenies and verifying the phylogenetic position of A. mackerrasae.

Integrated Approaches in Support of Taxonomic Identification of Mosquitoes (Diptera: Culicidae) in Vector Surveillance in Spain.

The pandemic of Zika virus in 2016 and other arboviruses prompted La Rioja Government in Spain to implement an entomological surveillance program of mosquitoes (Diptera; Culicidae) in the region of La Rioja. The morphological identification was supported by genetic analysis using the COI (cytochrome c oxidase subunit I) and the ITS2 (internal transcribed spacer 2) genes. In total, we identified 24 species arranged in 6 genera: Aedes (7 species), Anopheles (4 species), Coquillettidia (1 species), Culex (7 species), Culiseta (4 species), and Uranotaenia (1 species). Aedes sticticus and Aedes geniculatus are newly reported for La Rioja region. In total, 465 COI sequences were analyzed for Culicinae and Anophelinae and 54 ITS2 sequences for Anophelinae; all individuals identified as the same species clustered together in the Neighbor Joining trees. The levels of sequence divergence based on COI ranged between 0% and 2.62%, while the interspecific genetic divergence ranged from 3.05% to 20.07%. Within the genus Culiseta, certain specimens of Culiseta annulata, Culiseta litorea, and Culiseta subochrea were morphologically misidentified due to variation in the main diagnostic characters. The interspecific genetic divergence based on the ITS2 ranged from 0% to 2.98%. An accurate identification of mosquito vectors is the first step to establish a vector surveillance program for preventing pathogen transmission.

Genome-wide identification and integrated analysis of lncRNAs in rice backcross introgression lines (BC2F12)

BackgroundDistant hybridization is an important way to create interspecific genetic variation and breed new varieties in rice. A lot of backcross introgression lines (BILs) had been constructed for the scientific issues in rice. However, studies on the critical regulatory factor lncRNA in cultivated rice, wild rice and their BIL progenies were poorly reported.ResultsHere, high-throughput RNA sequencing technology was used to explore the functional characteristics and differences of lncRNAs in O. sativa, O. longistaminata and their three BC2F12 progenies. A total of 1254 lncRNAs were screened out, and the number of differentially expressed lncRNAs between progenies and O. sativa were significantly less than that between progenies and O. longistaminata. Some lncRNAs regulated more than one mRNA, and 89.5% of lncRNAs regulated the expression of target genes through cis-acting. A total of 78 lncRNAs and 271 mRNAs were targeted by 280 miRNAs, and 22 lncRNAs were predicted to be the precursor of 20 microRNAs. Some miRNAs were found to target their own potential precursor lncRNAs. Over 50% of lncRNAs showed parental expression level dominance (ELD) in all three progenies, and most lncRNAs showed ELD-O. sativa rather than ELD-O. longistaminata. Further analysis showed that lncRNAs might regulate the expression of plant hormone-related genes and the adaptability of O. sativa, O. longistaminata and their progenies.ConclusionsTaken together, the above results provided valuable clues for elucidating the functional features and expression differences of lncRNAs between O. sativa, O. longistaminata and their BIL progenies, and expanded our understanding about the biological functions of lncRNAs in rice.

Distribution of alfalfa weevil (Coleoptera: Curculionidae) and its parasitoids on the Canadian Prairies, with a key to described species of NearcticBathyplectes(Hymenoptera: Ichneumonidae)

AbstractThis study recorded distribution and size of alfalfa weevil (Hypera postica(Gyllenhal); Coleoptera: Curculionidae) populations in Saskatchewan, Canada, from 2001 to 2014. The spread of alfalfa weevil across the province, originally southwest to southeast, was northward and westward during this time. By 2014, only northwestern and west central areas remained relatively alfalfa weevil free. From a minor pest in 2001, the alfalfa weevil increased to be the principal insect pest of alfalfa (Medicago sativaLinnaeus; Fabaceae) in 2014. The parasitoidBathyplectes curculionis(Thomson) (Hymenoptera: Ichneumonidae) had a similar distribution. Other parasitoids collected includedOomyzus incertus(Ratzeburg) (Hymenoptera: Eulophidae) andMicroctonus colesiDrea (Hymenoptera: Braconidae). Conservation of these parasitoids is an important step in maximising their effectiveness as alfalfa weevil biocontrol agents. Molecular sequencing of the DNA barcoding region of specimens identified morphologically asB. curculionisindicated moderately high levels of sequence divergence among specimens (up to 5.8%); however, interspecific genetic variation between other species ofBathyplectesFörster was also high. Therefore, we conclude thatB. curculioniswas the onlyBathyplectesspecies collected in our study. An illustrated key to the described species ofBathyplectesin North America is provided, as well as DNA barcodes of most species, including five distinct barcodes in theBathyplectes curculionis–B. exiguus(Gravenhorst) species complex.

Analysis of Structural Genomic Diversity in Aegilops umbellulata, Ae. markgrafii, Ae. comosa, and Ae. uniaristata by Fluorescence In Situ Hybridization Karyotyping.

Fluorescence in situ hybridization karyotypes have been widely used for evolutionary analysis on chromosome organization and genetic/genomic diversity in the wheat alliance (tribe Triticeae of Poaceae). The karyotpic diversity of Aegilops umbellulata, Ae. markgrafii, Ae. comosa subsp. comosa and subsp. subventricosa, and Ae. uniaristata was evaluated by the fluorescence in situ hybridization (FISH) probes oligo-pSc119.2 and pTa71 in combination with (AAC)5, (ACT)7, and (CTT)12, respectively. Abundant intra- and interspecific genetic variation was discovered in Ae. umbellulata, Ae. markgrafii, and Ae. comosa, but not Ae. uniaristata. Chromosome 7 of Ae. umbellulata had more variants (six variants) than the other six U chromosomes (2–3 variants) as revealed by probes oligo-pSc119.2 and (AAC)5. Intraspecific variation in Ae. markgrafii and Ae. comosa was revealed by oligo-pSc119.2 in combination with (ACT)7 and (CTT)12, respectively. At least five variants were found in every chromosome of Ae. markgrafii and Ae. comosa, and up to 18, 10, and 15 variants were identified for chromosomes 2 of Ae. markgrafii, 4 of Ae. comosa subsp. comosa, and 6 of Ae. comosa subsp. subventricosa. The six Ae. uniaristata accessions showed identical FISH signal patterns. A large number of intra-specific polymorphic FISH signals were observed between the homologous chromosomes of Ae. markgrafii and Ae. comosa, especially chromosomes 1, 2, 4, and 7 of Ae. markgrafii, chromosome 4 of Ae. comosa subsp. comosa, and chromosome 6 of Ae. comosa subsp. subventricosa. Twelve Ae. comosa and 24 Ae. markgrafii accessions showed heteromorphism between homologous chromosomes. Additionally, a translocation between the short arms of chromosomes 1 and 7 of Ae. comosa PI 551038 was identified. The FISH karyotypes can be used to clearly identify the chromosome variations of each chromosome in these Aegilops species and also provide valuable information for understanding the evolutionary relationships and structural genomic variation among Aegilops species.