Genetic Distance Analysis Research Articles

Multiple Mammarenaviruses Circulating in Angolan Rodents.

Rodents are a speciose group of mammals with strong zoonotic potential. Some parts of Africa are still underexplored for the occurrence of rodent-borne pathogens, despite this high potential. Angola is at the convergence of three major biogeographical regions of sub-Saharan Africa, each harbouring a specific rodent community. This rodent-rich area is, therefore, strategic for studying the diversity and evolution of rodent-borne viruses. In this study we examined 290 small mammals, almost all rodents, for the presence of mammarenavirus and hantavirus RNA. While no hantavirus was detected, we found three rodent species positive for distinct mammarenaviruses with a particularly high prevalence in Namaqua rock rats (Micaelamys namaquensis). We characterised four complete virus genomes, which showed typical mammarenavirus organisation. Phylogenetic and genetic distance analyses revealed: (i) the presence of a significantly divergent strain of Luna virus in Angolan representatives of the ubiquitous Natal multimammate mouse (Mastomys natalensis), (ii) a novel Okahandja-related virus associated with the Angolan lineage of Micaelamys namaquensis for which we propose the name Bitu virus (BITV) and (iii) the occurrence of a novel Mobala-like mammarenavirus in the grey-bellied pygmy mouse (Mus triton) for which we propose the name Kwanza virus (KWAV). This high virus diversity in a limited host sample size and in a relatively small geographical area supports the idea that Angola is a hotspot for mammarenavirus diversity.

Coexistence of Three Dominant Bacterial Symbionts in a Social Aphid and Implications for Ecological Adaptation.

Simple SummaryMost insects are associated with a variety of symbionts that play a crucial role in insect life history. Symbiosis of aphids and their symbionts is a good model system to study insect–symbiont interactions. Pseudoregma bambucicola is a typical social aphid that lives parthenogenetically throughout the year on bamboos in subtropical areas, and it is the only aphid that exclusively feeds on the hard stalks of bamboo. In this study, we surveyed the symbiotic bacterial community associated with P. bambucicola. Our results showed that the diversity of P. bambucicola microbiome was low, but three symbionts, namely the primary endosymbiont Buchnera and two secondary symbionts (Pectobacterium and Wolbachia), were stable coexisting with a high infection rate. Combined with the biology of P. bambucicola, we speculate that Pectobacterium may help P. bambucicola feed on the stalks of bamboo, and Wolbachia may regulate the loss of sexual reproduction or has a nutritional role in P. bambucicola. These findings will advance our knowledge of the microbiomes of social aphids and set the foundation for further studies on the functional roles of P. bambucicola symbionts.Aphids are associated with an array of symbionts that have diverse ecological and evolutionary effects on their hosts. To date, symbiont communities of most aphid species are still poorly characterized, especially for the social aphids. In this study, high-throughput 16S rDNA amplicon sequencing was used to assess the bacterial communities of the social aphid Pseudoregma bambucicola, and the differences in bacterial diversity with respect to ant attendance and time series were also assessed. We found that the diversity of symbionts in P. bambucicola was low and three dominant symbionts (Buchnera, Pectobacterium and Wolbachia) were stably coexisting. Pectobacterium may help P. bambucicola feed on the hard bamboo stems, and genetic distance analysis suggests that the Pectobacterium in P. bambucicola may be a new symbiont species. Wolbachia may be associated with the transition of reproduction mode or has a nutritional role in P. bambucicola. Statistical tests on the diversity of bacterial communities in P. bambucicola suggest that aphid populations attended by ants usually have a significantly higher evenness than populations without ant attendance but there was no significant difference among aphid populations from different seasons.

ABO Genetic Variation in Neanderthals and Denisovans.

Variation at the ABO locus was one of the earliest sources of data in the study of human population identity and history, and to this day remains widely genotyped due to its importance in blood and tissue transfusions. Here, we look at ABO blood type variants in our archaic relatives: Neanderthals and Denisovans. Our goal is to understand the genetic landscape of the ABO gene in archaic humans, and how it relates to modern human ABO variation. We found two Neanderthal variants of the O allele in the Siberian Neanderthals (O1 and O2), one of these variants is shared with an European Neanderthal, who is a heterozygote for this O1 variant and a rare cis-AB variant. The Denisovan individual is heterozygous for two variants of the O1 allele, functionally similar to variants found widely in modern humans. Perhaps more surprisingly, the O2 allele variant found in Siberian Neanderthals can be found at low frequencies in modern Europeans and Southeast Asians, and the O1 allele variant found in Siberian and European Neanderthal is also found at very low frequency in modern East Asians. Our genetic distance analyses suggest both alleles survive in modern humans due to inbreeding with Neanderthals. We find that the sequence backgrounds of the surviving Neanderthal-like O alleles in modern humans retain a higher sequence divergence than other surviving Neanderthal genome fragments, supporting a view of balancing selection operating in the Neanderthal ABO alleles by retaining highly diverse haplotypes compared with portions of the genome evolving neutrally.

Monitoring genetic diversity acrossPinus tabuliformisseed orchard generations using SSR markers

The maintenance of genetic diversity across seed orchard generations is an important management objective. Here, we used Pinus tabuliformis Carrière as a model to explore the extent of genetic diversity across the species’ breeding activities through their corresponding seed orchard generations. We utilized a large number of simple sequence repeat (SSR) markers selected from P. tabuliformis transcriptomic data, and then assessed the effect of marker number on genetic diversity and genetic relationships of individuals across orchard generations. In total, we designed 125 SSR markers, of which 39 were polymorphic and used in the present study. The genetic diversity and genetic distance parameters tended to increase with an increase in loci number and a stable trend was reached at 24 SSRs. The selected optimal 24 SSR markers were further used to assess the genetic diversity across seed orchard generations, and a decreasing trend was detected with the advancement of orchard’s generations. Genetic distance analysis indicated that individuals in the 2nd generation orchard were more closely related compared with those of the 1st generation and the 1.5 generation. This study provided valuable information on the effect of selection and breeding on genetic diversity and highlighted its role for effective seed orchard management.

Forensic features and genetic legacy of the Baloch population of Pakistan and the Hazara population across Durand line revealed by Y-chromosomal STRs

The Hazara population across Durand line has experienced extensive interaction with Central Asian and East Asian populations. Hazara individuals have typical Mongolian facial appearances and they called themselves descendants of Genghis Khan's army. The people who speak the Balochi language are called Baloch. Previously, a worldwide analysis of Y-chromosomal haplotype diversity for rapidly mutating (RM) Y-STRs and with PowerPlex Y23 System (Promega Corporation Madison, USA) kit was created with collaborative efforts, but Baloch and Hazara population from Pakistan and Hazara population from Afghanistan were missing. In the current study, Yfiler Plus PCR Amplification Kit loci were examined in 260 unrelated Hazara individuals from Afghanistan, 153 Hazara individuals, and 111 Balochi individuals from Baluchistan Pakistan. For the Hazara population from Afghanistan and Pakistan overall, 380 different haplotypes were observed on these 27 Y-STR loci, gene diversities ranged from 0.51288 (DYS389I) to 0.9257 (DYF387S1), and haplotype diversity was 0.9992. For the Baloch population, every individual was unique at 27 Y-STR loci; gene diversity ranged from 0.5718 (DYS460) to 0.9371(DYF387S1). Twelve haplotypes were shared between 178 individuals, while only two haplotypes among these twelve were shared between 87 individuals in Hazara populations. Rst and Fst pairwise genetic distance analyses, multidimensional scaling plot, neighbor-joining tree, linear discriminatory analysis, and median-joining network were performed, which shed light on the history of Hazara and Baloch populations. The results of our study showed that the Yfiler Plus PCR Amplification Kit marker set provided substantially stronger discriminatory power in the Baloch population of Pakistan and the Hazara population across the Durand line.

Identification of Potential Bacteria on Several Lakes in East Java, Indonesia Based on 16S rRNA Sequence Analysis

Four bacterial isolates from Ranu Pani and Ranu Grati in east java had been revealed to be potentials to produce IAA (PIS isolate), phosphate solubilizer (GPS isolate), cellulose hydrolysis (PSS isolate) and, amylum hydrolysis (PAS), two dominant bacterial isolates from Rani Pani (PØD isolate) and Ranu Grati (GØD isolate) which were co-cultured with microalgae promoted microalgae growth, yet its taxonomical position has not been clearly known. The aim of this study was to identify those bacterial isolates using 16S rRNA barcode. This research conducted by gDNA isolation, the 16S rRNA sequence was amplified using 27F and 1492R primers. Reconstructed phylogenetic trees and genetic distance analysis showed that the isolate PIS and PSS identified as Bacillus cereus Group closely related to Bacillus paramycoides. PAS isolate identified as Bacillus subtilis Group closely related to Bacillus amyloliquefaciens, GPS isolate identified as novel species in genus Enterobacter, and two dominant isolates (PØD and GØD) identified as Enterobacter cloacae complex closely related to Enterobacter cloacae. The genomic approach and additional phenotypes-examination are required to clarify its taxonomical position.

Identification of Cannabis Sativa L. Based on rbcL Sequence.

Objective To assess the feasibility of the rbcL sequence of chloroplast DNA as a genetic marker to identify Cannabis sativa L. Methods The rbcL sequences in 62 Cannabis sativa L. samples, 10 Humulus lupulus samples and 10 Humulus scandens DNA samples were detected, and 96 rbcL sequences of the Cannabaceae family were downloaded from Genbank. Sequence alignment was performed by MEGA X software, the intraspecific and interspecific Kimura-2-Parameter （K2P） genetic distances were calculated, and the system clustering tree was constructed. Results The rbcL sequence length acquired by sequencing of Cannabis sativa L. and Humulus scandens were 617 bp and 649 bp, respectively, and two haplotypes of Cannabis sativa L. were observed in the samples. The BLAST similarity search results showed that the highest similarity between the sequences acquired by sequencing and Cannabis sativa L. rbcL sequences available from Genbank was 100%. The genetic distance analysis showed that the maximum intraspecific genetic distance （0.004 9） of Cannabis sativa L. was less than the minimum interspecific genetic distance （0.012 9）. The results of median-joining network and system clustering tree analysis showed that Cannabis sativa L. and other members of the Cannabaceae family were located in different branches. Conclusion The rbcL sequence could be used as a DNA barcode for identifying Cannabis sativa L., and combined with comparative analysis of the rbcL sequence and system cluster analysis could be a reliable and effective detection method for Cannabis sativa L. identification in forensic investigation.

Genetic structure and essential oil composition in wild populations of Salvia multicaulis Vahl.

The phytochemical study on ten populations of Salvia multicaulis Vahl. revealed that their essential oil qualitative profiles contained a significant amount of monoterpene hydrocarbons, which were the most abundant compounds. Besides, α-Pinene was the major constituent in all studied populations' essential oils. Significant correlations were observed between edaphic parameters and some major essential oil compounds. According to clustering analyses of the chemical data, the S. multicaulis populations were divided into three chemotypes: β-caryophyllene, camphene and camphor, and limonene. The population genetics study showed significant molecular differences among the populations. The Mantel test indicated a significant positive correlation between the geographical distances and genetic diversity, exhibiting a low amount of gene flow and a considerable genetic differentiation value. We also detected four genotypes based on the Nei's genetic distance and structure analysis. The identified chemical and genetic similarities/differences among these populations were correlated with edaphic parameters and geographic distances, suggesting that environmental factors are the primary drivers of the chemical polymorphism of essential oils in S. multicaulis populations.

Proof on the Divergence Times of Two Sympatric Species, Rhynchophorus ferrugineus and R. vulneratus (Coleoptera: Curculionidae) by Molecular Clock Analysis

Molecular clock analysis has clearly separated Rhynchophorus ferrugineus and Rhynchophorus vulneratus as two sympatric species. Calibration was performed using the fossil of R. cruentatus which evolved approximately 1 mya using sequences data of COI and Cytb combined. Divergence time indicated that R. cruentatus, the outgroup species evolved around 80.598±10 mya, followed by R. vulneratus (≈29.861±10 mya), and finally speciated to form R. ferrugineus (≈1.926±10 mya) and R. vulneratus (≈4.857±10 mya). Additionally, construction of NJ and MP trees showed distinct separation using COI, Cytb and combination of COI and Cytb. These findings were highly supported by genetic distance analysis. Although a limited number of individuals from small geographical area were used in this study, the genetic molecular clock analysis of mitochondrial data was able to effectively differentiate both species. These results reveal the first analysis to use the molecular clock to confirm separation of these two sympatric species.

Ex Situ Conservation of Large and Small Plant Populations Illustrates Limitations of Common Conservation Metrics

Premise of research. Ex situ plant conservation can be improved through genetic analysis. One area of interest is the relative value of conserving smaller or larger populations and how sampling strategies for these might differ. Current practice emphasizes collecting large sample sizes from some populations and limiting sampling from others and aims for the capture of allele diversity exceeding predetermined thresholds at the species level. Evaluating how well botanic garden collections can capture the genetic diversity of populations of different sizes can help refine guidance on conservation efforts. Methodology. A model species, Pseudophoenix sargentii (Arecaceae), was chosen for its disjunct and insular range, variation in population size, and presence in collections. We compared 123 in situ plants from three discrete island populations with 94 ex situ conservation specimens via 10 microsatellite markers. Comparison of allelic diversity among the wild populations and collections allowed for the evaluation of genetic capture. Pivotal results. Genetic distance analysis, fixation indexes, and Bayesian clustering analysis show discrete in situ geographic structure and close affinity between ex situ collections and in situ source populations. Yet collections from just the largest population met the Global Strategy for Plant Conservation Target 9 threshold for conservation success for that source population, for other smaller populations, and for all populations together. Conclusions. Percent of genetic capture thresholds may need revision, as such thresholds overlook important diversity. Efficient genetic capture is maximized by emphasizing unique maternal lineages and limiting half-siblings in a collection, but this selectivity must be balanced against the need for redundancy in living collections. Large and small populations each contribute to meeting genetic diversity goals. We recommend that botanic gardens and their networks develop conservation priorities based on genetic diversity and resources, carefully consider existing thresholds for conservation success, define metrics for ex situ conservation goals, and integrate analysis into ex situ conservation efforts.

Morphological and molecular description of a new species of Myxobolus (Myxosporea: Myxobolidae) infecting Planiliza macrolepis (Smith, 1846) from India.

The present paper describes a novel species of Myxobolus parasitizing the gill filaments of the largescale mullet, Planiliza macrolepis from Cochin backwaters, Kerala, India. The parasite develops in the gill filaments; plasmodia elongated, milky white, measured 1.37-2.18 (1.78 ± 0.35) mm × 0.07-0.12 (0.10 ± 0.02) mm in size. Mature myxospores ovoid in valvular view, biconvex in sutural view with smooth shell valves and measured 6.24-7.02 (6.63 ± 0.23) × 5.01-6.18 (5.68 ± 0.25) μm in size. Polar capsules equal, oval with pointed anterior ends, 3.07-3.58 (3.33 ± 0.12) × 1.68-2.42 (2.09 ± 0.18) μm in size. Polar filamentswith 4 coils, measured 29.61 ± 4.75μm in length when extruded. Sporoplasm binucleate with a rudimentary nucleus and a vacuole. A comparison with related Myxobolus species revealed significant morphological and morphometric differences. In BLASTN and genetic distance analysis, the present parasite showed high divergence with other myxosporean sequences, indicating its molecular uniqueness. In Maximum Likelihood and Bayesian Inference analysis, the present species stands out with M. ramadus as sister branch within the Myxobolus clade. In infected gill filaments, the plasmodia caused swelling/deformation, compression of lamellae and reduction in respiratory surface area. Three of 222 P. macrolepis screened were infected, indicating a prevalence of 1.3%. Considering the morphological, morphometric, molecular and phylogenetic differences with the previously described species of myxosporeans, along with the dissimilarities in host and geographical locations, the present parasite is treated as a new species and the name Myxobolus cochinensis n. sp. is proposed.

A multilocus assessment reveals two new synonymies for East Asian Cyclommatus stag beetles (Coleoptera, Lucanidae).

Cyclommatus scutellaris Möllenkamp, 1912, Cyclommatus elsae Kriesche, 1921 and Cyclommatus tamdaoensis Fujita, 2010 are East Asian stag beetle species with long-debated taxonomic relationships due to high intraspecific morphological variability. In this study, we applied multilocus phylogenetic analyses to reassess their relationships. Two mitochondrial genes (16S rDNA, COI) and two nuclear genes (28S rDNA, Wingless) were used to reconstruct the phylogeny through the Bayesian inference (BI) and Maximum Likelihood (ML) methods. Both topologies supported two clades: the clade C. scutellaris was sister to the clade (C. elsae + C. tamdaoensis) with the subclade C. tamdaoensis embedded in the subclade C. elsae. The Kimura 2-parameter (K2P) genetic distance analysis yielded a low mean value (≤0.035) among the three taxa, which was well below the minimum mean value between other Cyclommatus species (≥0.122). We also compared the accuracy and efficiency of two approaches, GMYC and ABGD, in delimitating the three lineages. The result shows that ABGD is a better approach than GMYC. Our molecular data recognizes the three species as different populations of a single species, ranging from Taiwan Island to the continent. Therefore, we propose two new junior synonyms for C. scutellaris: C. tamdaoensis, syn. nov. and C. elsaesyn. nov.

Genetic Diversity and Population Structure Analysis of Triticum aestivum L. Landrace Panel from Afghanistan.

Landraces are a potential source of genetic diversity and provide useful genetic resources to cope with the current and future challenges in crop breeding. Afghanistan is located close to the centre of origin of hexaploid wheat. Therefore, understanding the population structure and genetic diversity of Afghan wheat landraces is of enormous importance in breeding programmes for the development of high-yielding cultivars as well as broadening the genetic base of bread wheat. Here, a panel of 363 bread wheat landraces collected from seven north and north-eastern provinces of Afghanistan were evaluated for population structure and genetic diversity using single nucleotide polymorphic markers (SNPs). The genotyping-by-sequencing of studied landraces after quality control provided 4897 high-quality SNPs distributed across the genomes A (33.75%), B (38.73%), and D (27.50%). The population structure analysis was carried out by two methods using model-based STRUCTURE analysis and cluster-based discriminant analysis of principal components (DAPC). The analysis of molecular variance showed a higher proportion of variation within the sub-populations compared with the variation observed as a whole between sub-populations. STRUCTURE and DAPC analysis grouped the majority of the landraces from Badakhshan and Takhar together in one cluster and the landraces from Baghlan and Kunduz in a second cluster, which is in accordance with the micro-climatic conditions prevalent within the north-eastern agro-ecological zone. Genetic distance analysis was also studied to identify differences among the Afghan regions; the strongest correlation was observed for the Badakhshan and Takhar (0.003), whereas Samangan and Konarha (0.399) showed the highest genetic distance. The population structure and genetic diversity analysis highlighted the complex genetic variation present in the landraces which were highly correlated to the geographic origin and micro-climatic conditions within the agro-climatic zones of the landraces. The higher proportions of admixture could be attributed to historical unsupervised exchanges of seeds between the farmers of the central and north-eastern provinces of Afghanistan. The results of this study will provide useful information for genetic improvement in wheat and is essential for association mapping and genomic prediction studies to identify novel sources for resistance to abiotic and biotic stresses.

Complete mitochondrial genome of the hemp borer, Grapholita delineana (Lepidoptera: Tortricidae): Gene variability and phylogeny among Grapholita

The mitochondrial genome (mitogenome) has been extensively used in phylogenetics and species-level evolutionary investigations. The lepidopteran family Tortricidae (leaf-roller moths), including the genus Grapholita, contains numerous species of economic importance, but for the majority of Grapholita species, their mitogenomes remain poorly studied. Here, we sequence and annotate the full mitogenome of Grapholita delineana, an important pest of hemp worldwide and compare it with the mitogenomes of two congeneric species available from GenBank. The G. delineana mitogenome is 15,599 bp long, including 37 typical mitochondrial genes and an A + T-rich region. Gene content, order and orientation are identical to other reported tortricid mitogenomes. Analyses of nucleotide diversity, Ka/Ks, genetic distance and number of variable sites together suggest that nad6 is the fastest-evolving gene among the mitochondrial PCGs of Grapholita. Our analyses indicate that Grapholita, as presently defined, is not monophyletic, confirming previous morphological and multiple-gene studies, using mitogenomic evidence. Our study provides information on comparative mitogenomics of Tortricidae especially Grapholita.

Combined Low-/High-Density Modern and Ancient Genome-Wide Data Document Genomic Admixture History of High-Altitude East Asians.

The Tibetan Plateau (TP) is considered to be one of the last terrestrial environments conquered by the anatomically modern human. Understanding of the genetic background of highland Tibetans plays a pivotal role in archeology, anthropology, genetics, and forensic investigations. Here, we genotyped 22 forensic genetic markers in 1,089 Tibetans residing in Nagqu Prefecture and collected 1,233,013 single nucleotide polymorphisms (SNPs) in the highland East Asians (Sherpa and Tibetan) from the Simons Genome Diversity Project and ancient Tibetans from Nepal and Neolithic farmers from northeastern Qinghai-Tibetan Plateau from public databases. We subsequently merged our two datasets with other worldwide reference populations or eastern ancient Eurasians to gain new insights into the genetic diversity, population movements, and admixtures of high-altitude East Asians via comprehensive population genetic statistical tools [principal component analysis (PCA), multidimensional scaling plot (MDS), STRUCTURE/ADMIXTURE, f3, f4, qpWave/qpAdm, and qpGraph]. Besides, we also explored their forensic characteristics and extended the Chinese National Database based on STR data. We identified 231 alleles with the corresponding allele frequencies spanning from 0.0005 to 0.5624 in the forensic low-density dataset, in which the combined powers of discrimination and the probability of exclusion were 1–1.22E-24 and 0.999999998, respectively. Additionally, comprehensive population comparisons in our low-density data among 57 worldwide populations via the Nei’s genetic distance, PCA, MDS, NJ tree, and STRUCTURE analysis indicated that the highland Tibeto-Burman speakers kept the close genetic relationship with ethnically close populations. Findings from the 1240K high-density dataset not only confirmed the close genetic connection between modern Highlanders, Nepal ancients (Samdzong, Mebrak, and Chokhopani), and the upper Yellow River Qijia people, suggesting the northeastern edge of the TP served as a geographical corridor for ancient population migrations and interactions between highland and lowland regions, but also evidenced that late Neolithic farmers permanently colonized into the TP by adopting cold-tolerant barley agriculture that was mediated via the acculturation of idea via the millet farmer and not via the movement of barley agriculturalist as no obvious western Eurasian admixture signals were identified in our analyzed modern and ancient populations. Besides, results from the qpAdm-based admixture proportion estimation and qpGraph-based phylogenetic relationship reconstruction consistently demonstrated that all ancient and modern highland East Asians harbored and shared the deeply diverged Onge/Hoabinhian-related eastern Eurasian lineage, suggesting a common Paleolithic genetic legacy existed in high-altitude East Asians as the first layer of their gene pool.

New color patterns and new synonym of Odontolabis sinensis (Westwood, 1848) (Coleoptera: Lucanidae): insights from a multilocus phylogeny and species delimitation.

Taxonomy of Odontolabis sinensis (Westwood, 1848) and Odontolabis fallaciosa Boileau, 1901 has long been a controversial issue due to their highly morphological similarity except for elytral color patterns. In the present work, we assessed their taxonomic status by combining molecular phylogeny and species delimitation based on multilocus datasets (COI, 16S rDNA, Cytb, CAD, Wingless). Phylogenetic analyses under both Maximum Likelihood inference and Bayesian inference recovered identical topologies. All the examined individuals in the clade of O. sinensis and O. fallaciosa formed into five subclades belonging to four color patterns, respectively. The Kimura-2-Parameter (K2P) genetic distance analysis yielded a low mean value (0.0108-0.0295). The multiple species delimitations (ABGD, PTP and GMYC) reinforced them to be one MOTU. Our results suggest that these clades belong to the same species, and thus we propose O. fallaciosa to be a junior subjective synonym of O. sinensis. We also found two new color patterns corresponding to two clades from Southwestern China (north of 20°N and east of 105°E), respectively displaying the reddish-orange, slenderly rimmed patch and brownish-orange broad patches along the elytral edge, which was probably attributable to both historical and ecological factors in this particular region.

Mitochondrial genomes of eight Scelimeninae species (Orthoptera) and their phylogenetic implications within Tetrigoidea.

Scelimeninae is a key member of the pygmy grasshopper community, and an important ecological indicator. No mitochondrial genomes of Scelimeninae have been reported to date, and the monophyly of Scelimeninae and its phylogenetic relationship within Tetrigidae is still unclear. We sequenced and analyzed eight nearly complete mitochondrial genomes representing eight genera of Scelimeninae. These mitogenomes ranged in size from 13,112 to 16,380 bp and the order of tRNA genes between COII and ATP8 was reversed compared with the ancestral order of insects. The protein-coding genes (PCGs) of tetrigid species mainly with the typical ATN codons and most terminated with complete (TAA or TAG) stop codons. Analyses of pairwise genetic distances showed that ATP8 was the least conserved gene within Tetrigidae, while COI was the most conserved. The longest intergenic spacer (IGS) region in the mitogenomes was always found between tRNASer(UCN) and ND1. Additionally, tandem repeat units were identified in the longest IGS of three mitogenomes. Maximum likelihood (ML) and Bayesian Inference (BI) analyses based on the two datasets supported the monophyly of Tetriginae. Scelimeninae was classified as a non-monophyletic subfamily.

Short Communication: Molecular study on mt-DNA COX2 gene of Sumatran elephant (Elephas maximus sumatranus)

Abstract. Wibowo DS, Widiyanti R, Asvan M, Restanti PD, Wijayanto H. 2021. Short Communication: Molecular study on mt-DNA COX2 gene of Sumatran elephant (Elephas maximus sumatranus). Biodiversitas 22: 1063-1068. Sumatran elephant is the only subspecies of Asian elephants that receives a critically endangered status from the International Union for Conservation and Nature Resources (IUCN). Identifying the genetic marker of Sumatran elephants is, therefore, important for their conservation. This study aimed to identify the Sumatran elephant based on specific mitochondrial DNA markers of the Cytochrome c oxidase subunit II (COX2) gene. It is an exploratory research considering the limited data and research about the genetic, especially the COX2 of Sumatran elephant (Elephas maximus sumatranus). Forward and reverse sequencing of PCR products was conducted using the primary COX2 from Sumatran elephant samples. The results of the subsequent gene sequencing were aligned with the sequences of other Asian elephants from Genbank using Clustal W software and analyzed using the MEGA program version 6.06. The analysis of genetic distance based on COX2 constituent nucleotides calculated with Kimura’s two-parameter method showed that the genetic distance between Elephas maximus sumatranus and Elephas maximus outside of Sumatra was 0.25%. The phylogenetic trees analyzed using the maximum-likelihood based on nucleotide sequences showed a high homogeneity. The ratio of Elephas maximus sumatranus with Elephas maximus shows levels of nucleotide mutations which are nine nucleotides and four nucleotides. These results indicated that the COX2 gene could not identify the individual species of Sumatran elephant because of the high intraspecies homogeneity, but it detected the interspecies divergence clustered in Asian elephant clade.

Phylogenetic Analysis of Rasbora spp. Based on the Mitochondrial DNA COI gene in Harapan Forest

Harapan forest is the remaining lowland tropical forest in Sumatra which represents about 20 percent of the biodiversity on the island of Sumatra. There are several Rasbora species found in the Sungai Kapas Tengah River Refuge in the Harapan Jambi Forest that the relationship is not yet known.This research aims to know kinship and genetic distance several species of Rasbora from Sungai Kapas Tengah, Hutan Harapan Jambi. The method in this research using secondary data from the NCBI website ((National Center for Biotechnology Information). The data taken, namelynucleotide sequence from the Cytochrome Oxidase I (COI) gene in mitochondrial DNA. The Rasbora species analyzed were Rasbora from identification results in the Sungai Kapas Tengah River Refuge, Harapan Jambi Forest, consisting of, Rasbora bankanensis, R. caudimaculata, R. cf. sumatrana, R. dusonensis, R. elegans, R. sumatrana, and R. trilineata. Based on phylogenetic analysis, the location of the branch length in each Rasbora species, the closest kinship is owned byR. sumatrana and R. elegans species. Based on the results of genetic distance analysis, the closest genetic distance was the species R. elegans and R. sumatrana, with a distance value of 0.023 (2.3%). While the farthest genetic distance between R. bankanensis and R. caudimaculata, with a distance value of 0.172 (17.2%).Based on research results It can be concluded that R. bankanensis has a greater kinship and genetic distance value than other Rasbora species, so that this species forms a separate group. Meanwhile, 5 other species have kinship and the value of close genetic distance so that these species are united in the same group. For future researchers, it is hoped that some additional families of fish species will be analyzed for phylogenetic analysis in Sungai Kapas, Hutan Harapan Jambi, so that they can find out the relationship of several other species.

Genetic structure analysis of cultivated and wild chestnut populations reveals gene flow from cultivars to natural stands

Japanese chestnut (Castanea crenata Sieb. et Zucc.), the only fruit tree species domesticated in Japan, has been cultivated alongside natural stands since prehistorical times. Understanding the genetic diversity of this species and the relationships between cultivated and wild chestnut is important for clarifying its breeding history and determining conservation strategies. We assessed 3 chestnut cultivar populations and 29 wild chestnut populations (618 accessions). Genetic distance analysis revealed that wild populations in the Kyushu region are genetically distant from other populations, whereas other wild and cultivar populations are comparatively similar. Assignment tests suggested that cultivars were relatively similar to populations from central to western Honshu. Bayesian structure analyses showed that wild individuals were roughly classified according to geographical distribution along the Japanese archipelago, except that some wild individuals carried the genetic cluster prevalent in cultivars. Parentage analyses between cultivars and wild individuals identified 26 wild individuals presumed to have a parent–offspring relationship with a cultivar. These results suggested that the genetic structure of some wild individuals in natural stands was influenced by gene flow from cultivars. To conserve wild individuals carrying true “wild” genetic clusters, these individuals should be collected and preserved by ex situ conservation programs.