Mitochondrial DNA Markers Research Articles

Species diversity of anchovies (Teleostei: Engraulidae) along the northwest coast of Peninsular Malaysia

Anchovies (Teleostei: Engraulidae) play an important ecological role in tropical coastal ecosystems because of their abundance. In parallel, and for the same reason, they are extensively harvested. Yet, their diversity remains insufficiently documented in many regions. In this study, we surveyed the diversity of anchovies along the northwest coast of Peninsular Malaysia based on the recently collected material with the objective to update the taxonomic list of common species and to build a database of two mitochondrial DNA markers useful for identifying species, the “barcode” fragment of the cytochrome c oxidase I gene and the whole cytochrome b gene. We first selectively collected, preserved and examined 163 specimens, comprising five genera and 16 species. All species have been described, none is endemic but one of them (Stolephorus tri) is a new record for this region. The genotyping of 74 of these specimens revealed that each species is genetically distinct to others and diagnosable. Comparisons between our list and previous inventory works based on morphology and genetics, within and nearby this region, revealed both similarities and differences. The possible causes of differences are discussed. Although certainly incomplete, our revised list of common species of anchovies along with referenced material are valuable not only to document their diversity along the northwest coast of Peninsular Malaysia but also to inform future fisheries management studies.

Assessment of Genetic Diversity and Structure of Russian and Mongolian Autochthonous Horse Breeds Using Nuclear and Mitochondrial DNA Markers

Assessment of Genetic Diversity and Structure of Russian and Mongolian Autochthonous Horse Breeds Using Nuclear and Mitochondrial DNA Markers

Genetic Structure of a Native Neotropical Fish Species: New Insights about a South American Bioindicator.

The biodiversity of Neotropical region is affected by anthropogenic disturbance. Throughout Brazil, Argentina and Uruguay, the native fish, Cnesterodon decemmaculatus, is well distributed and widely used as an excellent bioindicator of environmental quality. We investigated the diversity and genetic structure of its populations along a water pollution gradient to answer the following questions: 1- Does the genetic diversity decrease under the stressful conditions of a severe water quality gradient? and 2- Is there any relationship between the haplotypes registered along the studied basin and those recorded in other distant basins? Two mitochondrial DNA markers, Cytochrome b and D-loop, were analyzed and four haplotypes were registered for both markers along the basin. H1 was present throughout all the river sections in high frequencies leading to a low genetic diversity. We suggest that only a few haplotypes tolerate the stressful conditions of mountain rivers. On the other hand, the presence of H4 at the site located downstream suggests a history of recent colonization from the southeast to the northwest of the biome. These results, together with the abundance decrease along the pollution gradient, and the non-migratory characteristic of C. decemmaculatus suggest that its populations may be at risk of local extinction.

New Insight into Genetic Structure and Diversity of Scots Pine (Pinus sylvestris L.) Populations in Lithuania Based on Nuclear, Chloroplast and Mitochondrial DNA Markers

We studied the genetic differentiation, structure, and diversity of Scots pine populations in Lithuania based on nuclear, chloroplast microsatellite, and mitochondrial DNA markers. We focused on revealing evolutionary history, country-wide geneflow patterns, and structuring among the Scots pine populations. We genotyped 439 Scots pine individuals of mature age from 23 natural Scots pine stands in Lithuania and used the AMOVA and a set of genetic-clustering methods. The among-population differentiation was weak for nuclear microsatellite loci (nSSRs) (FST = 0.005) but much stronger for cpSSRs (PhiST = 0.240). The populations were structured into highland and lowland populations based on cpSSRs and eastern highland versus the rest for nSSRs. We detected two mtDNA mitotypes—the universal type A and northeastern type B, and the latter occurred at a markedly higher frequency in eastern Lithuania. Within-population genetic diversity was higher in large pine-dominated forest tracts in the eastern highlands than in fragmented forests in the western highlands. We concluded that phenology-based genetic networks following the temperature climate gradients have a strong effect on shaping the genetic structure of otherwise rather homogeneous gene pools of Scots pine populations in Lithuania. The possible effects of human interference with forests on genetic diversity of Scots pine populations in Lithuania are discussed.

Genetic diversity of the endangered Mongolian saiga antelopeSaiga tatarica mongolica (Artiodactyla: Bovidae) provides insights into conservation

AbstractThe Saiga antelope (Saiga tatarica) is one of the few megafauna species from the mammoth steppe still living today. Currently, saiga are classified as critically endangered, persisting only in small areas of Central Asian steppe and desert ecosystems. The species is divided into two subspecies: Saiga tatarica mongolica and Saiga tatarica tatarica. In this study, we have for the first time characterized the genetic diversity of the Mongolian saiga (S. t. mongolica) using both mitochondrial DNA and microsatellite markers. We also analysed S. t. tatarica specimens in order to genetically compare both subspecies. The mitochondrial control region was sequenced for a total of 89 individuals: 20 skin, 53 umbilical cord, three placentae and a muscle sample from S. t. mongolica, and a total of 12 hair samples from S. t. tatarica. Additionally, 19 microsatellites developed for saiga antelope were also screened. Our results revealed that the Mongolian saiga presents very low genetic diversity at the mitochondrial level, with no shared mitochondrial haplotype between the two subspecies. Low genetic diversity is also present at the autosomal level, with most loci having low heterozygosity (Ho/He) and a low number of alleles per locus. Despite the low genetic diversity, we found no separation between the subpopulations in Mongolia, indicating that conservation corridors are actually promoting contact between different herds. Our results validate current conservation efforts and inform the implementation of new measures to increase the viability of the S. t. mongolica subspecies.

Anthropogenic influences on genetic diversity and differentiation of the clearhead icefish (Protosalanx hyalocranius), as revealed by mitochondrial and microsatellite DNA markers

The clearhead icefish, Protosalanx hyalocranius, is an economically important fishery species in China. For the past few decades, the wild resources of P. hyalocranius have markedly decreased due to human activities such as overfishing, hydro-projects and water pollution. Meanwhile, P. hyalocranius has been widely introduced into lakes and reservoirs of northern China and some have become established, invasive populations, leading to detrimental effects on ecosystems. Using mitochondrial control region sequences and nine microsatellite DNA markers, the aim of this study was to assess to what extent human activities could impact the genetic diversity and population structure of P. hyalocranius, and explore the sources of the invasive Heilong River population based on genetic characterization. Based on mitochondrial DNA, the average haplotype diversity and nucleotide diversity among six populations were 0.737 and 0.0029 respectively. Based on microsatellite markers, the observed (HO) and expected (HE) heterozygosities in each population ranged from 0.481 to 0.565 and 0.478 to 0.565, respectively. Both mitochondrial and microsatellite markers indicated the genetic diversity in Chaohu Lake was the lowest. HO and HE of the two anadromous populations (Liao River Estuary and Yalu River Estuary) were close to Chaohu Lake and relatively low among all populations. The pairwise Dest values showed high and significant genetic differentiation between Taihu Lake and other populations. There was no evidence of genetic differentiation between Chaohu Lake and the two anadromous populations. No significant reduction of genetic diversity was observed in the Heilong River population. Bottleneck analysis showed that the two anadromous populations may have experienced a recent genetic bottleneck. DIYABC analysis suggested that the sources of the invasive Heilong River population were Taihu and Hongze lakes, with a greater genetic contribution from Hongze Lake. Therefore, the anadromous populations of P. hyalocranius may have suffered more impacts from human activities than the strictly freshwater populations. Among freshwater populations, Chaohu Lake should also be paid more attention in fisheries management. In addition, our study demonstrated that multiple introductions can give rise to high genetic diversity in an invasive population.

Assessing population genetic structure of three New Zealand stream insects using mitochondrial and nuclear DNA markers.

Assessing genetic differentiation among natural populations can aid understanding of dispersal patterns and connectivity among habitats. Several molecular markers have become increasingly popular in determining population genetic structure for this purpose. Here, we compared the resolution of mitochondrial cytochrome c oxidase subunit I (COI) and nuclear single nucleotide polymorphism (SNP) markers for detecting population structure among stream insects at small spatial scales. Individuals of three endemic taxa-Coloburiscus humeralis (Ephemeroptera), Zelandobius confusus (Plecoptera), and Hydropsyche fimbriata (Trichoptera)-were collected from forested streams that flow across open pasture in the North Island of New Zealand. Both COI and SNP data indicated limited population structure across the study area, and small differences observed among these species were likely related to their putative dispersal abilities. For example, fine-scale genetic differentiation between and among neighbouring stream populations for H. fimbriata suggests that gene flow, and hence dispersal, may be more limited for this species relative to the others. Based on the generally similar results provided by both types of markers, we suggest that either COI or SNP markers can provide suitable initial estimates of fine-scale population genetic differentiation in stream insects.

Record of a juvenile Omura's whale live stranded in Hainan Island: Evidence of a potential breeding ground in the South China Sea?

On January 12, 2011, a very young juvenile Bryde's-like baleen whale was found stranded alive on the east coast of Hainan Island, in the South China Sea. Unfortunately, it died the next morning. This baleen whale showed some unique external morphology and skull features of the Omura's whale (Balaenoptera omurai). Subsequently, it was genetically identified as an Omura's whale using two different mitochondrial DNA markers. This study documents the first confirmed live stranding of a juvenile Omura's whale on Hainan Island, China. Our findings expand the known distribution range of this species in Chinese waters and may indicate that waters around Hainan Island in the South China Sea could be a potential breeding ground for the Omura's whale.

Determination of the genetic structure of pro-maternal pig breeds of Irish selection using mitochondrial DNA markers

Traditionally, the mitochondrial genome is characterized as a “molecular clock” for tracking the history of phylogeny along the maternal line. Particular attention is paid to the distribution of mitochondrial DNA haplotypes among commercial pigs (Large White × Landrace) × Maxgro from RPE “Globinsky Pig Farm”, Globyno town, Poltava region, Ukraine. For the study of the genetic structure of the pigs’ hybrid markers of mitochondrial DNA — a maternal type of inheritance was used. DNA markers are a convenient tool for investigating the origin of pro-maternal pig breeds. Application of multiplex analysis PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) when examining the variable area of the D-loop between sites 15558–15917 mitochondrial genome of hybrid pigs made it possible to determine the pro-maternal haplotypes of the experimental sample (n=20). Thus, according to the multisite system developed by Pochernyaev K. F., determination of mitochondrial haplotypes of pigs, which are denoted by Latin letters from A to P allowed to determine the true pro-maternal haplotypes of the experimental sample of pigs (n=20), as evidenced by the presence of the Tas I website in the above-mentioned provisions what actually determine the haplotypes of mitochondrial DNA. According to the results of the study defined haplotypes characterize different breeds, namely 4 animals with haplotype C — Landrace (Ukraine, Poland). 6 pigs have mitochondrial haplotype N — Large White (Asian type) and 7 pigs with mitochondrial haplotype O — Landrace. 1 animal with haplotype G — wild pig and cross-border breed Wales (Italy). 2 representatives of haplotype D — not found among the breeds of domestic pigs. According to the established pro-maternal haplotypes of hybrid pigs, animals-carriers of haplotype O are representatives of Scandinavian female pigs F1 as used in uterine herds in Sweden and Ireland with the participation of the Maxgro terminal parent line in the hybridization system. Identified mitochondrial haplotypes were found to be breed-specific to hybrid pigs of Irish breeding, this is confirmed by the established polymorphism of the mitochondrial genome which is an objective marker even in complex hybridization schemes. The work was done with the support of the National Academy of Agrarian Sciences of Ukraine 31.01.00.07.F. “Investigate the pleiotropic effect gens that the SNP use in marker-associated pig breeding”. DR no. 0121U109838. Following the example of the developed systematization of the combination of restricted fragments by Pochernyaev K. F. in the future, I propose to create a database of reference haplotypes of mitochondrial DNA of pigs’ final hybrid. In the future, it will be used in further research to reconstruct the demographic history of commercial pigs of cross-border breeds.

The habitat use and trophic niche comparisons among closely related land snails in Northeast Asia

AbstractThe diversification of phenotypes and species has been a major concern in evolutionary biology. Both resource competition and predator–prey interactions have been suggested as mechanisms that drive phenotypic divergence and speciation, but the latter has attracted much less attention than the former. TheKaraftohelixland snails in Northeast Asia provide an excellent model to investigate the effects of competition and predation on the divergence process. This is because (1) all species—especiallyKaraftohelix edithaandKaraftohelix gainesiin northern Japan—are closely related and sometimes indistinguishable by genital morphologies and neutral nuclear and mitochondrial DNA markers, despite the distinct phenotypes among species; (2) two different anti‐predatory strategies (i.e., passive and active defenses) are observed for each species in this group; and (3) multiple species have generally overlapping distributions and were often observed at exactly the same time and place. In this study, we conducted quantitative quadrat surveys and carbon/nitrogen stable isotope analyses to compare the microhabitat and trophic niches amongKaraftohelixland snails and estimated the cause of adaptive radiation in this taxon. All the results indicated that the differences in microhabitats and trophic niches amongKaraftohelixland snails—especially between the most closely related sister species,K. edithaandK. gainesiin northern Japan—were too small to promote the adaptive radiation in this group. Therefore, it is difficult to explain the extreme divergence of phenotypes and species amongKaraftohelixland snails in Northeast Asia based on environmental adaptation through resource competition and/or reproductive interference.

Genetic Structure and Demographic History of Yellow Grouper (Epinephelus awoara) from the Coast of Southeastern Mainland China, Inferred by Mitochondrial, Nuclear and Microsatellite DNA Markers

The yellow grouper (Epinephelus awoara) is distributed in the West Pacific Ocean. Its genetic structure and demography were investigated using mitochondrial COI, Cyt b, the ND2 gene, the nuclear RyR3 gene, and 10 microsatellite DNA markers. A total of 120 individuals were collected from four locations along the coast of southeastern mainland China. High levels of haplotype diversity (0.968) were observed in mitochondrial DNA, and the average number of alleles ranged from 13.4 to 20.3 in microsatellite DNA data, which showed that all populations exhibited a high level of genetic diversity. Deficiency of heterozygosity was observed in all populations with positive FIS, showing that the characteristics of hermaphroditism might also be an underlying cause. The results of PCA, UPGMA clustering analysis and the significant genetic differentiation found in the Beibu Gulf population revealed the prevention of gene flow caused by the Qiongzhou Strait. The population of E. awoara also presented two major lineages, resulting in the appearance of the land bridge of the Taiwan Strait as a possible factor during the Pleistocene glaciation. Analysis of demographic history revealed that E. awoara underwent a reduction in effective population size in the past, followed by a single instantaneous increase in population size.

Siphoderina hustoni n. sp. (Platyhelminthes: Trematoda: Cryptogonimidae) from the Maori snapper Lutjanus rivulatus (Cuvier) on the Great Barrier Reef

A new cryptogonimid trematode, Siphoderina hustonin. sp., is reported, collected off Lizard Island, Queensland, Australia, from the Maori snapper Lutjanus rivulatus (Cuvier). The new species is moderately distinctive within the genus. It is larger and more elongate than most other species of Siphoderina Manter, 1934, has the shortest forebody of any, a relatively large ventral sucker, a long post-testicular zone, and is perhaps most recognisable for the substantial space in the midbody between the ventral sucker and ovary devoid of uterine coils and vitelline follicles, the former being restricted to largely posterior to the ovary and the latter distributed from the level of the anterior testis to the level of the ovary. In phylogenetic analyses of 28S ribosomal DNA, the new species resolved with the other nine species of Siphoderina for which sequence data are available, all of which are from Queensland waters and from lutjanid and haemulid fishes. Molecular barcode data were also generated, for the ITS2 ribosomal DNA and cox1 mitochondrial DNA markers. The new species is the first cryptogonimid known from L. rivulatus and the first metazoan parasite reported from that fish in Australian waters.

Evidence for spatial niche partitioning in the ectocommensal Symbion americanus (Cycliophora) on its lobster host, Homarus americanus (Arthropoda, Malacostraca)

AbstractSymbion americanus is a microscopic marine invertebrate in the phylum Cycliophora that lives as an ectocommensal on the mouthparts of the American lobster, Homarus americanus. Previous phylogeographic work on S. americanus identified three lineages corresponding to one described and two potential new species, along with evidence of sympatry. But these studies did not explore whether individuals of S. americanus from different genetic lineages segregate onto different host mouthparts. The present study examines the population structure and microhabitat of 196 individuals of S. americanus from lobsters from five North American localities (from Newfoundland, Canada, to Boston, MA) collected between June and September 2019. Specimens were sequenced at two mitochondrial DNA (mtDNA) markers, a 487 bp fragment of cytochrome c oxidase subunit I (COI) and a 481 bp fragment of 16S rRNA. Phylogenetic analyses recover three distinct lineages of Symbion americanus, corroborating previous studies. Population genetic analyses of individuals belonging to the C and G lineages show clear population structure at the level of host mouthparts. Microhabitat data suggest the segregation of different genetic lineages in S. americanus onto different host mouthparts, perhaps indicating the role of spatial niche partitioning in the incipient speciation of S. americanus.

Nuclear copies of mitochondrial DNA as a potential problem for phylogenetic and population genetic studies of Odonata

AbstractThe use of mitochondrial markers for taxonomic identification and biodiversity monitoring is not without risks or limitations. Most importantly, the natural transfer of DNA from the mitochondria to the nucleus generates nonfunctional nuclear copies of mitochondrial DNA (NUMTs). Their abundance and size vary significantly among taxa, and NUMTs have been reported to complicate molecular studies based on mitochondrial markers in several insect orders, most prominently in Orthoptera. The significance of this phenomenon in Odonata has not yet been properly addressed. Here, we present a complete mitochondrial genome and a draft nuclear genome of Leucorrhinia albifrons (Odonata: Libellulidae), as well as NUMT and cox1 sequences from the related species Leucorrhinia dubia. We document the presence of NUMTs in the L. albifrons nuclear genome and in nuclear genomes of two other Odonata species available in public databases. Our results show that NUMTs can have a serious impact on barcoding, phylogenetic, population and phylogeographic studies of Odonata, especially when the barcode is located in the cox1 gene, the most frequently used molecular marker for Odonata. We suggest that nad1 should be used alone or in combination with cox1 to minimize unintended confusion with NUMTs. Finally, we present a mitophylogenomic analysis of Odonata and document several cases of misidentified mitochondrial genomes belonging to species different from those indicated in public databases. In conclusion, our findings represent an important step for future metabarcoding studies of Odonata based on mitochondrial DNA markers.

Pleistocene climate-driven diversification of plateau zokor (Eospalax baileyi) in the eastern Qinghai-Tibet Plateau

Glacial oscillations and associated tectonic processes during the middle-late Pleistocene are thought to have created a unique pattern of species distribution diversity in the Qinghai-Tibet Plateau (QTP). As a subterranean rodent endemic to the QTP, the impact of these geological events on the genetic diversity and demographic history of plateau zokors (Eospalax baileyi) is worth exploring. In this study, genetic diversity analyses were performed based on two mitochondrial DNA regions and microsatellite markers, representing 370 individuals from five populations on a large scale and six populations on two small scales in the eastern QTP. On a large scale, both mitochondrial DNA and microsatellite markers implied substantial genetic diversity and strong differentiation of the five populations. All sampled populations showed only unique haplotypes and lacked shared haplotypes, revealing the isolated nature of most populations. The genetic differentiation of the plateau zokor was in line with that of the isolate by distance (IBD) model. Mismatch distribution and Bayesian skyline analysis suggested recent demographic expansions highly consistent with glaciation events, and BEAST divergence analysis unveiled southward divergence events originating from the northern populations of the eastern QTP. The genetic structure of the five populations was almost singular. On a small scale, all the populations showed high genetic diversity. However, the analysis of molecular variation (AMOVA) showed less variation among populations; the genetic differentiation of the populations no longer conformed to IBD model, and the genetic information among populations was more heterogenous and similar to those of each other. Overall, our research revealed the genetic differentiation of plateau zokor driven by quaternary climatic oscillation and the variations in the genetic diversity of the plateau zokor at different geographical scales.

Mangrove macroalgae increase their growth under ocean acidification: A study with Bostrychia (Rhodophyta) haplotypes from different biogeographic provinces

Increasing oceanic CO2 has caused a decrease in oceanic pH, a process termed ocean acidification (OA). OA may benefit fleshy macroalgae due to the increased availability of inorganic carbon sources for photosynthesis since they are tolerant of decreases in pH. In this study, we analyzed multiple physiological responses of Bostrychia montagnei and Bostrychia calliptera from two biogeographic provinces of Brazil (Tropical Southwestern Atlantic [TSA] and Warm Temperate Southwestern Atlantic [WTSA]) after culturing them at a set of bioreactors in three pH levels (7.2, 7.6, and 8.0). Two pH were decreased by CO2 enrichment into the culture medium. Molecular analyses using plastidial (rbcL-3P) and mitochondrial (COI-5P) DNA markers were also performed to identify genetic divergences between macroalgae from TSA and WTSA. Molecular evidence of COI-5P marker demonstrated that the specimens of both B. montagnei and B. calliptera from TSA and WTSA constitute different haplotypes, with a strong segregation between them. Macroalgae from both localities increased their growth in treatments of decreased pH with increased CO2 availability. Overall, physiological responses of the algae were not negatively affected by decreased pH. B. montagnei from TSA increased its polysaccharide and allophycocyanin content at pH 7.2, and B. montagnei from WTSA increased its low molecular weight carbohydrate content at pH 7.2 as well. Antioxidant activity — a proxy for physiological stress — was not affected by decreased pH. Our study indicates that haplotypes of B. montagnei and B. calliptera from TSA and WTSA can be relevant to CO2 sequestration in mangroves once they are tolerant of decreased pH and increase their growth under increased CO2 availability.

Admixture and selection patterns across the European distribution of Scots pine, Pinus sylvestris (Pinaceae)

Abstract We analysed data on nucleotide polymorphism at 78 nuclear genes to search for signatures of divergence and selection in populations from across the distribution of Pinus sylvestris in Europe. Data on variation at a large set of maternally inherited mitochondrial DNA markers were also analysed. Most nuclear loci showed homogeneous patterns of variation across populations from Spain, Central Europe, Nordic countries and Scotland. Mitochondrial markers did not reveal strong population structure but suggested admixture of samples carrying different mitochondrial lineages in certain parts of the distribution. At nuclear DNA loci, we found high nucleotide polymorphism, generally low population differentiation and weak signals of isolation by distance. Together with the mitochondrial DNA results, these patterns seem most likely to be associated with a process of colonization from multiple sources and efficient gene flow. The results are in line with demographic inference indicating establishment of Central European and Nordic populations before the Last Glacial Maximum and admixture of colonization fronts from mainland Europe in Scottish populations. Coalescent and outlier detection methods identified several genes showing molecular signatures of selection especially in response to temperature variation in ecologically and phenotypically divergent populations. The study provides a large set of markers for analysis of genetic diversity in populations of P. sylvestris, including candidate genes that are implicated in local adaptation and population divergence.

A chromosome-level genome of the human blood fluke Schistosoma japonicum identifies the genomic basis of host-switching.

The evolution and adaptation of S.japonicum, a zoonotic parasite that causes human schistosomiasis, remain unclear because of the lack of whole-genome data. We construct a chromosome-level S.japonicum genome and analyze it together with 72 samples representing six populations of the entire endemic region. We observe a Taiwan zoophilic lineage splitting from zoonotic populations ∼45,000 years ago, consistent with the divergent history of their intermediate hosts. Interestingly, we detect a severe population bottleneck in S.japonicum, largely coinciding with human history in Asia during the last glacial maximum. We identify several genomic regions underlying natural selection, including GATAD2A and Lmln, both showing remarkable differentiation among different areas. RNAi knockdown suggests association of GATAD2A with parasite development and infection in definitive hosts, while Lmln relates to the specificity of the intermediate hosts. Our study provides insights into the evolution of S.japonicum and serves as a resource for further studies.

DNA barcoding based on 16S mitochondrial DNA (mtDNA) Molecular Marker of Mangrove Clams from the Selected Sites of Davao Region, Philippines

Aims: The taxonomic identification of mangrove clams was confirmed using DNA barcoding based on 16S mitochondrial DNA (mtDNA) genome.
 Study design: DNA was extracted from adductor muscle of mangrove clams sample. Purified DNA were sequenced and barcode was generated.
 Place and duration of the study: The mangrove clams samples used in the study were collected from Malita, Davao Occidental; Santa Cruz, Davao Del Sur; Mati, Davao Oriental, Philippines from January 2021 to June 2021.
 Methodology: DNA was extracted from adductor muscle of mangrove clams using the Promega GoTaq PCR kit. The extracted DNA were then purified and viewed using the Gel Electrophoresis. The Purified DNA samples were then sequenced and various softwares were then utilized namely sequenced assembly and alignment namely Basic Local Search Tool (BLAST) and Barcode Of Life Database(BOLD) and phylogenetic tree was generated.
 Results: There are two species morphologically identified as Anodontia philippiana (Reeve, 1850) and Austriella corrugata (Deshayes, 1843) from Davao region. BLAST search established the two species to be closely related to Anodontia (Cavatidens) omissa (Iredale, 1930) and Phacoides pectinatus (Gmelin, 1791), also a member of the Lucinidae family.
 Conclusion: In this study, the taxonomic identification of the two mangrove clams were further elucidated using the 16S mitochondrial DNA marker.

Genome-wide SNPs detect fine-scale genetic structure in threatened populations of squirrel glider Petaurus norfolcensis

Australian arboreal mammals are experiencing significant population declines, particularly due to land clearing and resulting habitat fragmentation. The squirrel glider, Petaurus norfolcensis, is a threatened species in New South Wales, with a stronghold population in the Lake Macquarie Local Government Area (LGA) where fragmentation due to urbanization is an ongoing problem for the species conservation. Here we report on the use of squirrel glider mitochondrial (385 bp cytochrome b gene, 70 individuals) and nuclear DNA (6,834 SNPs, 87 individuals) markers to assess their population genetic structure and connectivity across 14 locations sampled in the Lake Macquarie LGA. The mitochondrial DNA sequences detected evidence of a historical genetic bottleneck, while the genome-wide SNPs detected significant population structure in the Lake Macquarie squirrel glider populations at scales as fine as one kilometer. There was no evidence of inbreeding within patches, however there were clear effects of habitat fragmentation and biogeographical barriers on gene flow. A least cost path analysis identified thin linear corridors that have high priority for conservation. These areas should be protected to avoid further isolation of squirrel glider populations and the loss of genetic diversity through genetic drift.