Mitochondrial DNA Markers Research Articles

Genetic analyses reveal a non-panmictic genetic structure in the sablefishAnoplopoma fimbriain the northern Pacific

AbstractThe sablefish Anoplopoma fimbria is distributed on the continental shelf of the North Pacific, has a high commercial value for both fisheries and aquaculture, and represents a shared resource between countries in the North Pacific basin. In the present study, we extend the geographic range surveyed in previous studies and reexamine the population’s genetic structure by integrating phylogeographic patterns of mitochondrial DNA and microsatellite DNA markers. Our results contradict the proposal that sablefish constitute a single population throughout their distributional range. We observed a signal of ancient divergence in mtDNA that differentiates the North Pacific West Coast from the rest of the sample sites, and microsatellite markers reveal a contemporary isolation of Mexican sablefish. Our findings show genetic differences between localities that should be explored in more detail to fully understand the interconnectedness that appears to exist between populations.

Different waves of postglacial recolonisation and genomic structure of bank vole populations in NE Poland.

Previous studies indicated that in some species phylogeographic patterns obtained in the analysis of nuclear and mitochondrial DNA (mtDNA) markers can be different. Such mitonuclear discordance can have important evolutionary and ecological consequences. In the present study, we aimed to check whether there was any discordance between mtDNA and nuclear DNA in the bank vole population in the contact zone of its two mtDNA lineages. We analysed the population genetic structure of bank voles using genome-wide genetic data (SNPs) and diversity of sequenced heart transcriptomes obtained from selected individuals from three populations inhabiting areas outside the contact zone. The SNP genetic structure of the populations confirmed the presence of at least two genetic clusters, and such division was concordant with the patterns obtained in the analysis of other genetic markers and functional genes. However, genome-wide SNP analyses revealed the more detailed structure of the studied population, consistent with more than two bank vole recolonisation waves, as recognised previously in the study area. We did not find any significant differences between individuals representing two separate mtDNA lineages of the species in functional genes coding for protein-forming complexes, which are involved in the process of cell respiration in mitochondria. We concluded that the contemporary genetic structure of the populations and the width of the contact zone were shaped by climatic and environmental factors rather than by genetic barriers. The studied populations were likely isolated in separate Last Glacial Maximum refugia for insufficient amount of time to develop significant genetic differentiation.

The Extracellular Matrix Vitalizer RATM Increased Skin Elasticity by Modulating Mitochondrial Function in Aged Animal Skin

Oxidative stress-induced cellular senescence and mitochondrial dysfunction result in skin aging by increasing ECM levels-degrading proteins such as MMPs, and decreasing collagen synthesis. MMPs also destroy the basement membrane, which is involved in skin elasticity. The extracellular matrix vitalizer RATM (RA) contains various antioxidants and sodium hyaluronate, which lead to skin rejuvenation. We evaluated whether RA decreases oxidative stress and mitochondrial dysfunction, eventually increasing skin elasticity in aged animals. Oxidative stress was assessed by assaying NADPH oxidase activity, which is involved in ROS generation, and the expression of SOD, which removes ROS. NADPH oxidase activity was increased in aged skin and decreased by RA injection. SOD expression was decreased in aged skin and increased by RA injection. Damage to mitochondrial DNA and mitochondrial fusion markers was increased in aged skin and decreased by RA. The levels of mitochondrial biogenesis markers and fission markers were decreased in aged skin and increased by RA. The levels of NF-κB/AP-1 and MMP1/2/3/9 were increased in aged skin and decreased by RA. The levels of TGF-β, CTGF, and collagen I/III were decreased in aged skin and increased by RA. The expression of laminin and nidogen and basement membrane density were decreased in aged skin and increased by RA. RA increased collagen fiber accumulation and elasticity in aged skin. In conclusion, RA improves skin rejuvenation by decreasing oxidative stress and mitochondrial dysfunction in aged skin.

Genetic Diversity and Population Structure of Anopheles funestus in Western Kenya Based on Mitochondrial DNA Marker COII.

The mitochondrial marker, COII, was employed to assess the genetic structure and diversity of Anopheles funestus, a very important malaria vector in Africa that adapt and colonize different ecological niches in western Kenya. Mosquitoes were collected using mechanical aspirators in four areas (Bungoma, Port Victoria, Kombewa, and Migori) in western Kenya. Following morphological identification, PCR was used to confirm the species. The COII gene was amplified, sequenced, and analyzed to determine genetic diversity and population structure. A total of 126 (Port Victoria-38, Migori-38, Bungoma-22, and Kombewa-28) sequences of COII were used for population genetic analysis. Anopheles funestus had a high haplotype diversity (Hd = 0.97 to 0.98) but low nucleotide diversity (Π = 0.004 to 0.005). The neutrality test revealed negative Tajima's D and Fs values indicating an excess of low-frequency variation. This could be attributed to either population expansion or negative selection pressure across all the populations. No genetic or structural differentiation (Fst = -0.01) and a high level of gene flow (Gamma St, Nm = 17.99 to 35.22) were observed among the populations. Population expansion suggests the high adaptability of this species to various ecological requirements, hence sustaining its vectorial capacity and malaria transmission.

Uncovering the Male Presence in Parthenogenetic Marchalina hellenica (Hemiptera: Marchalinidae): Insights into Its mtDNA Divergence and Reproduction Strategy.

Marchalina hellenica (Hemiptera: Marchalinidae), an endemic species in Greece and Turkey, is a major contributor to the annual honey production in its native range. However, in the areas that it invades, lacking natural enemies, it has detrimental effects on pine trees and potentially contributes to tree mortality. Although it was originally reported as thelytokous, males were later reported in Turkey and on several of the islands of Greece. To further disambiguate the exact parthenogenetic reproduction strategy of M. hellenica, we studied the emergence pattern of male individuals in Greece for two consecutive years (2021 and 2022). Furthermore, we examined the genetic variation among 15 geographically distant populations of M. hellenica in Greece using a mitochondrial DNA marker and compared the results with data from Turkey. The findings of this study document the existence of an additional M. hellenica population in its native range that repeatedly produces males, apart from the areas of Greece and Turkey in which they were initially reported, suggesting that males play a major, so far unknown role in the reproduction of this species. The populations in Greece and Turkey exhibited a strong genetic affinity, while human-aided dispersal seems to have obscured the genetic pattern acquired.

United States Gulf of Mexico Waters provide important nursery habitat for Mexico’s Green turtle nesting populations

Resolving natal populations for juvenile green turtles is challenging given their potential for extensive dispersal during the oceanic stage and ontogenetic shifts among nursery habitats. Mitochondrial DNA markers have elucidated patterns of connectivity between green turtle nesting populations (rookeries) and juvenile foraging aggregations. However, missing rookery baseline data and haplotype sharing among populations have often impeded inferences, including estimating origins of Gulf of Mexico juveniles. Here, we assessed genetic structure among seven foraging aggregations spanning southern Texas (TX) to southwestern Florida (SWFL), including Port Fourchon, Louisiana (LA); a surface-pelagic aggregation (SP) offshore of Louisiana and Florida; Santa Rosa Island, Florida (SRI); St. Joseph Bay, Florida (SJB); and the Big Bend region, Florida (BB). We estimated source contributions to aggregations with novel genetic data (excluding SP and BB) using a Bayesian many-to-one mixed stock analysis (MSA) approach. Haplotype frequencies for western (TX, LA, SP, SRI) and eastern (SJB, BB, SWFL) aggregations were significantly differentiated. The largest shift in haplotype frequencies between proximal nursery sites occurred between SRI and SJB, separated by only 150 km, highlighting the lack of a geographic yardstick for predicting genetic structure. In contrast to previous MSA results, there was no signal of Florida juveniles at any foraging site. Mexican contributions dominated in all aggregations, with strong connectivity between western Bay of Campeche (Tamaulipas/Veracruz) rookeries and western foraging aggregations. MSA indicated more diverse Mexican origins for eastern aggregations, with larger inputs from the eastern Bay of Campeche (Campeche/Yucatán), Campeche Bank, and Quintana Roo rookeries. These results demonstrate the significance of the Gulf of Mexico coast and offshore waters of the United States as important nursery habitat for green turtles of Mexican origin and highlight the need for international coordination for management of these populations.

Complex multiple introductions drive fall armyworm invasions into Asia and Australia

The fall armyworm (FAW) Spodoptera frugiperda is thought to have undergone a rapid ‘west-to-east’ spread since 2016 when it was first identified in western Africa. Between 2018 and 2020, it was recorded from South Asia (SA), Southeast Asia (SEA), East Asia (EA), and Pacific/Australia (PA). Population genomic analyses enabled the understanding of pathways, population sources, and gene flow in this notorious agricultural pest species. Using neutral single nucleotide polymorphic (SNP) DNA markers, we detected genome introgression that suggested most populations in this study were overwhelmingly C- and R-strain hybrids (n = 252/262). SNP and mitochondrial DNA markers identified multiple introductions that were most parsimoniously explained by anthropogenic-assisted spread, i.e., associated with international trade of live/fresh plants and plant products, and involved ‘bridgehead populations’ in countries to enable successful pest establishment in neighbouring countries. Distinct population genomic signatures between Myanmar and China do not support the ‘African origin spread’ nor the ‘Myanmar source population to China’ hypotheses. Significant genetic differentiation between populations from different Australian states supported multiple pathways involving distinct SEA populations. Our study identified Asia as a biosecurity hotspot and a FAW genetic melting pot, and demonstrated the use of genome analysis to disentangle preventable human-assisted pest introductions from unpreventable natural pest spread.

Molecular Approach for Identification of Pangasianodon Hypophthalmus based on Mitochondrial Cytochrome b Oxidase subunit i (coi) Gene from Pakistan

The aquaculture industry is dependent on rich fish resources in water bodies. Human activities have led to a rapid decline of fish species. In Asia, the Pangasiidae family is highly valued for its potential for survival and its fillet meat. DNA barcoding is a taxonomic method using genetic markers in organisms mitochondrial DNA (mt DNA) for identification. The phylogeny and identification of Pangasianodon hypophthalmus in the subcontinent is of great concern. For species identification, a precise and rapid technique is DNA barcoding. This method is strongly effective for analyzing the divergence among species. DNA barcoding is more reliable as compared to external morphology. To avoid mislabeling and conservation of species, it is equally useful in juveniles as well as adult stages of fishes. As DNA bar-coding is a taxonomic method that uses small genetic markers in organisms’ mitochondrial DNA (mt DNA) for identification of particular species. In recent study MAGA X and Kimura 2 Parameter was used to evaluate genetic distance and neighbor joining tree was constructed. BOLD and GenBank reveals the nearest identity matches. As mitochondrial cyt-b gene region was successfully used for identifying species and accepted as a standard region for DNA barcoding.

Honey bee populations of the USA display restrictions in their mtDNA haplotype diversity.

The genetic diversity of the USA honey bee (Apis mellifera L.) populations was examined through a molecular approach using two mitochondrial DNA (mtDNA) markers. A total of 1,063 samples were analyzed for the mtDNA intergenic region located between the cytochrome c oxidase I and II (COI-COII) and 401 samples were investigated for the NADH dehydrogenase 2 (ND2) coding gene. The samples represented 45 states, the District of Colombia and two territories of the USA. Nationwide, three maternal evolutionary lineages were identified: the North Mediterranean lineage C (93.79%), the West Mediterranean lineage M (3.2%) and the African lineage A (3.01%). A total of 27 haplotypes were identified, 13 of them (95.11%) were already reported and 14 others (4.87%) were found to be novel haplotypes exclusive to the USA. The number of haplotypes per state/territory ranged between two and eight and the haplotype diversity H ranged between 0.236-0.763, with a nationwide haplotype diversity of 0.597. Furthermore, the honey bee populations of the USA were shown to rely heavily (76.64%) on two single haplotypes (C1 = 38.76%, C2j = 37.62%) of the same lineage characterizing A. m. ligustica and A. m. carnica subspecies, respectively. Molecular-variance parsimony in COI-COII and ND2 confirmed this finding and underlined the central and ancestral position of C2d within the C lineage. Moreover, major haplotypes of A. m. mellifera (M3a, M7b, M7c) were recorded in six states (AL, AR, HI, MO, NM and WA). Four classic African haplotypes (A1e, A1v, A4, A4p) were also identified in nine states and Puerto Rico, with higher frequencies in southern states like LA, FL and TX. This data suggests the need to evaluate if a restricted mtDNA haplotype diversity in the US honey bee populations could have negative impacts on the beekeeping sustainability of this country.

New record of Tylodelphys metacercariae (Diplostomidae) from Perccottus glenii (Odontobutidae) and their phylogenetic assessment.

Metacercariae of Tylodelphys sp. were found in the abdominal cavity of the Chinese sleeper (Perccottus glenii) collected in Liaoning Province and Inner Mongolia Autonomous Region of China. The sequences of the mitochondrial cox1 gene and ribosomal ITS1-5.8S rDNA-ITS2 region were obtained and used for molecular identification and phylogenetic assessment of this parasite species. Results of phylogenetic analyses based on ITS and cox1 markers showed that the metacercariae of Tylodelphys sp.ex P. glenii from China were conspecific with specimens of Tylodelphys sp. collected by Sokolov etal. (2013) from the same fish-host species captured earlier in West Siberia, Russia. The examined Tylodelphys sp. ex. P. glenii is the only member of the genus whose metacercariae parasitise the abdominal cavity of fish in northern Eurasia. Tylodelphys sp. ex P. glenii clustered with T. darbyi, T. immer, T.podicipina, and Tylodelphys sp. of Soldánová etal., 2017 based on mitochondrial DNA markers, and with T. darbyi, T. immer, T. kuerepus, and T. schreuringi using nuclear DNA markers.

Multiple invasions, Wolbachia and human-aided transport drive the genetic variability of Aedes albopictus in the Iberian Peninsula

The Asian tiger mosquito, Aedes albopictus, is one of the most invasive species in the world. Native to the tropical forests of Southeast Asia, over the past 30 years it has rapidly spread throughout tropical and temperate regions of the world. Its dramatic expansion has resulted in public health concerns as a consequence of its vector competence for at least 16 viruses. Previous studies showed that Ae. albopictus spread has been facilitated by human-mediated transportation, but much remains unknown about how this has affected its genetic attributes. Here we examined the factors that contributed to shaping the current genetic constitution of Ae. albopictus in the Iberian Peninsula, where the species was first found in 2004, by combining population genetics and Bayesian modelling. We found that both mitochondrial and nuclear DNA markers showed a lack of genetic structure and the presence of worldwide dominant haplotypes, suggesting regular introductions from abroad. Mitochondrial DNA showed little genetic diversity compared to nuclear DNA, likely explained by infection with maternally transmitted bacteria of the genus Wolbachia. Multilevel models revealed that greater mosquito fluxes (estimated from commuting patterns and tiger mosquito population distribution) and spatial proximity between sampling sites were associated with lower nuclear genetic distance, suggesting that rapid short- and medium-distance dispersal is facilitated by humans through vehicular traffic. This study highlights the significant role of human transportation in shaping the genetic attributes of Ae. albopictus and promoting regional gene flow, and underscores the need for a territorially integrated surveillance across scales of this disease-carrying mosquito.

Genomic resources and their applications in aquaculture of Asian seabass (Lates calcarifer)

AbstractGenomic resources, including nuclear DNA markers, mitochondrial DNA markers, high‐resolution linkage maps, transcriptomes, reference genome sequences and their annotations, are critically important in aquaculture. Their potential applications are plenty, such as enabling the analysis of genetic diversity in population structures, mating and spawning behaviour; genetic traceability; reconstructing pedigrees; mapping quantitative trait loci (QTL) for important phenotypic traits; marker‐assisted selection and genomic selection; and to understand genetic and epigenetic regulation of traits. Asian seabass (Lates calcarifer) is becoming a popular aquaculture species. In the past 30 years, many genomic resources have been developed and used to understand the genetic diversity of wild and cultured populations, setting up mating schemes, genetic traceability, mapping QTL and genome‐wide association studies for growth, omega‐3 fatty acid content, resistance to diseases and genetic improvement of important traits in breeding programmes. In this review, we systematically synthesize the status of available genomic resources and their applications in enhancing the genetic improvement and aquaculture production of Asian seabass. We also critically discuss the challenges and future research directions of developing, optimizing and applying genomic resources in Asian seabass aquaculture.

Genetic population structure of the critically endangered stellate sturgeon (Acipenser stellatus) in the Black Sea basin: Implications for conservation

Abstract Stellate sturgeon (Acipenser stellatus) is a species of great conservation concern throughout its range. Over the past century, it has experienced a dramatic decline in abundance and distribution in the Black Sea basin. Information regarding the genetic structure of the species is very limited in the region, despite its crucial importance for developing adequate management plans for the species’ conservation and recovery. Samples from 163 A. stellatus were analysed using mitochondrial and microsatellite DNA markers to investigate the species’ genetic characteristics in the north‐western and southern Black Sea. Both genetic markers revealed high genetic diversity (153 haplotypes and 264 alleles) and low genetic differentiation of marine and freshwater catches. The north‐western Black Sea population is undergoing a slight demographic expansion after a bottleneck event induced by overfishing and dam constructions. The genetic population structure indicates a single genetic cluster in the north‐western Black Sea region and signs of admixture of two genetic clusters in the southern region. It also provides the first evidence for a remnant reproductive stellate sturgeon micro‐population in rivers of Turkey and Georgia. A sturgeon fishing ban and stocking activities carried out during the last decades, largely without any prior genetic assessment of the sturgeon populations, added little conservation value. Outreach initiatives and urgent actions are required to foster the recovery of this Critically Endangered species in the region. Reconstruction of the connectivity of the rivers and the enhancement of habitats and spawning grounds are beneficial to all sturgeon species. An ex‐situ conservation programme for Turkish rivers which flow into the Black Sea would be beneficial to help conserve the genetic resources until the habitats and migration routes become functional. Moreover, genetic screening and recruitment programmes must be functional for all rivers flowing into the Black Sea.

Analysis of genetic diversity among six dojo loach (Misgurnus anguillicaudatus) populations in the Pearl River Basin based on microsatellite and mitochondrial DNA markers

Due to environmental pollution and overfishing, the germplasm resources of wild loach (Misgurnus anguillicaudatus) have been degraded. To explore the genetic diversity of different geographical populations of loach in the Pearl River Basin, a total of 184 M. anguillicaudatus individuals from six dojo loach natural populations sampled from Yingde (Beijiang), Qingyuan (Beijiang), Liannan (Beijiang), Nanxiong (Dongjiang), Meizhou (Dongjiang), and Liuzhou (Liujiang) were investigated based on microsatellite DNA markers and mitochondrial DNA markers (cytb and D-loop). The results showed that a total of 71 alleles (Number of alleles, Na) were amplified in the six M. anguillicaudatus populations by 10 pairs of microsatellite primers. The average observed heterozygosity (Ho), expected heterozygosity (He), and polymorphic information content (PIC) among were 0.3892, 0.5101, and 0.4781, respectively. The average genetic differentiation coefficient (Fst) and number of migrants per generation (Nm) of the six M. anguillicaudatus populations were 0.3395 and 0.4863, respectively, indicating a low level of genetic exchange among the six populations and a high degree of genetic differentiation. Moreover, based on cytb, the number of haplotypes (h), the haplotype diversity (Hd), and nucleotide diversity (π) of the six M. anguillicaudatus populations were 34, 0.925, and 0.0539, respectively, and were 36, 0.879, and 0.0160 based on D-loop sequences. The Fst values among the six populations were 0.4963 (cytb) and 0.4833 (D-loop), and they all showed a high degree of genetic differentiation. The above results indicate that there is abundant genetic diversity of M. anguillicaudatus in the Pearl River Basin in China, and the fish could be used as excellent materials for breeding. The study provides a theoretical basis for the protection and utilization of M. anguillicaudatus natural resources in the Pearl River Basin of China.

Even short‐distance dispersal over a barrier can affect genetic differentiation in Gyraulus, an island freshwater snail

Abstract Dispersal is a fundamental mechanism for maintaining biodiversity, and long‐distance dispersal (LDD) has attracted the interest of many researchers owing to its unusual characteristics. Conventionally, LDD has been defined based on absolute and proportional distances; however, it has recently been redefined based on geographic and genetic limits. Based on this redefinition, short‐distance dispersal can have the same characteristics as LDD, depending upon the dispersal dynamics of an organism. However, the effects of LDD at a local scale on the genetic structure and diversification of organisms are poorly understood, since many studies have focused on definitive LDD, such as oversea dispersal. We focused on the freshwater snail Gyraulus sp. on an oceanic island, Chichijima Island, attempting to clarify the dynamics and effects of LDD on its genetic structure. We conducted molecular phylogenetic analyses, including divergence‐time estimation, using mitochondrial DNA and nuclear DNA markers to reveal the origin of the snail. In addition, we clarified the genetic structure, gene flow, and evolutionary history of snails on the island using mitochondrial DNA and genome‐wide single‐nucleotide polymorphisms. Finally, we followed a landscape ecology approach to identify barriers to dispersal. Our phylogenies suggested that the snail has a single origin. Based on our divergence–time estimation, colonisation was estimated to have occurred around the late Pliocene to early Pleistocene. Our population genetic analyses documented genetic differentiation even within this small oceanic island. Based on the divergence time estimation and approximate Bayesian computation using single‐nucleotide polymorphisms, the differentiation was estimated to have begun around the late Pleistocene. Little gene flow occurred between the geographically structured snail genetic groups. Landscape analysis suggested that catchment boundaries were a major barrier to dispersal. Considering the geography of the island, these results suggested that low‐frequency dispersal over barriers is an important factor in genetic differentiation within the island. Furthermore, dispersal over barrier may be considered LDD, even though the dispersal distance is only several kilometres. Genetic evidence also suggested that resistance to gene flow over the barrier, rather than distance, is more important in determining whether dispersal should be considered LDD. This suggests that a definition of LDD that depends only on the distance may mislead an understanding of dispersal mode.

Microsatellite and mitochondrial DNA markers unveil the genetic structure of Nellore Palla sheep of India

The present study is carried out to genetically characterise the Nellore Palla sheep and document the genetic divergence among the three varieties of the Nellore sheep breed. Thirty two unrelated individuals from the hometract of Palla, nine each of Brown and Jodipi were sampled for the molecular studies. Fluorscent microsatellite markers were employed to genetically characterise Palla population.The analysis revealed a total of 201 alleles across the 26 loci studied. The mean observed and effective number of alleles per locus was 7.73 and 5.82 respectively. The overall observed and expected heterozygosity across 26 loci was 0.52 and 0.69 respectively. The mean FIS value in the sampled population was 0.24 with a range varying between − 0.24 (MAF209) to 0.77 (INRA063). The mean PIC value and the Shannon’s index value across the 26 loci was 0.643 and 1.49 respectively. The study concluded a considerable amount of genetic diversity with in the Nellore Palla population. The genetic divergence among the three varieties was analysed using 728 bp mitochondrial control region. The analysis for polymorphism and divergence was done with DnaSP software and the results concluded a high polymorphism within the genetic groups. The genetic differentiation estimates revealed no genetic differentiation among the three varieties of Nellore sheep breed. The phylogenetic analysis indicated that all the haplotypes of the three varieties of Nellore were clustering with lineage A except for one haplotype of Palla variety which was clustering with lineage B.

Paleobiogeographical origins of Fasciola hepatica and F. gigantica in light of new DNA sequence characteristics of F. nyanzae from hippopotamus.

Fascioliasis is a highly pathogenic disease affecting humans and livestock worldwide. It is caused by the liver flukes Fasciola hepatica transmitted by Galba/Fossaria lymnaeid snails in Europe, Asia, Africa, the Americas and Oceania, and F. gigantica transmitted by Radix lymnaeids in Africa and Asia. An evident founder effect appears in genetic studies as the consequence of their spread by human-guided movements of domestic ruminants, equines and Old World camelids in the post-domestication period from the beginning of the Neolithic. Establishing the geographical origins of fasciolid expansion is multidisciplinary crucial for disease assessment. Sequencing of selected nuclear ribosomal and mitochondrial DNA markers of F. nyanzae infecting hippopotamuses (Hippopotamus amphibius) in South Africa and their comparative analyses with F. hepatica and F. gigantica, and the two Fascioloides species, Fs. jacksoni from Asian elephants and Fs. magna from Holarctic cervids, allow to draw a tuned-up evolutionary scenario during the pre-domestication period. Close sequence similarities indicate a direct derivation of F. hepatica and F. gigantica from F. nyanzae by speciation after host capture phenomena. Phylogenetic reconstruction, genetic distances and divergence estimates fully fit fossil knowledge, past interconnecting bridges between continents, present fasciolid infection in the wild fauna, and lymnaeid distribution. The paleobiogeographical analyses suggest an origin for F. gigantica by transfer from primitive hippopotamuses to grazing bovid ancestors of Reduncinae, Bovinae and Alcelaphinae, by keeping the same vector Radix natalensis in warm lowlands of southeastern Africa in the mid-Miocene, around 13.5 mya. The origin of F. hepatica should have occurred after capture from primitive, less amphibious Hexaprotodon hippopotamuses to mid-sized ovicaprines as the wild bezoar Capra aegagrus and the wild mouflon Ovis gmelini, and from R. natalensis to Galba truncatula in cooler areas and mountainous foothills of Asian Near East in the latest Miocene to Early Pliocene, around 6.0 to 4.0 mya and perhaps shortly afterwards.

Extensive gene flow in a threatened bat (Rhinonicteris aurantia) in an arid landscape

The bat fauna of Australia comprises some 25% of all terrestrial species, yet we know very little of the demography, dispersal, and movement dynamics of most bat species. The Pilbara leaf-nosed bat ( Rhinonicteris aurantia Pilbara form) is a threatened microbat that roosts exclusively in caves that occur in mineral rich deposits in the Pilbara region. Due to their specific roost microclimate requirements these bats cannot survive for long without a suitable roost and are sensitive to roost disturbance. Understanding the connectivity of roosts throughout the Pilbara is crucial for informed decisions to mitigate potential impacts to persistence of this species in areas under economic development. Along with mitochondrial DNA (mtDNA) markers, we used reduced representation genomic sequencing of over 150 individuals from eight roost sites throughout the Pilbara and tested for landscape-scale population differentiation associated with the two major subregions — the Hamersley and Chichester, as well as finer-scale among roost variation. We found evidence of high rates of dispersal and low population structure within the Pilbara, indicating one panmictic population, with mtDNA results suggesting evidence of some female philopatry. Our results highlight the ongoing need for detailed genetic studies to provide critical insight to species dispersal, particularly in multi-use landscapes. We discuss the importance of identifying and retaining connectivity of key habitat to maintain genetic diversity and gene flow throughout panmictic populations.

Contemporary genetic structure of Xantus's Hummingbird (Basilinna xantusii) in the Baja California peninsula

Genetic structure and phylogeographic patterns of natural populations are of great importance in assessing the conservation status of species. These population properties can be estimated using molecular markers of either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) to understand the historical, ecological and dispersal patterns that influence genetic exchange within and between populations. Basilinna xantusii is a sexually dimorphic hummingbird endemic to the Baja California Peninsula (BCP). It comprises three ancestral mitochondrial lineages linked to vicariant events, late Pleistocene climate changes and the geographical distribution of oases. This study aimed to determine and understand the current population genetic structure of this hummingbird. The genotypes of 16 microsatellite loci from 100 individuals collected across the geographical range of this species were compared with mtDNA sequences previously published. Cluster analyses identified five populations, two with almost no genetic admixture in the northern part of the BCP and three others with varying levels of admixed ancestry across the BCP. In San José de Magdalena, at the northernmost end of the range of Xantus's Hummingbird, 40% of individuals collected belong to one genetic cluster and the remaining 60% to another, both genetic clusters showing very little admixed ancestry. We hypothesize that, despite being in sympatry, these individuals do not interbreed, unlike the other populations where individuals showed ancestry coefficients of the other genetic groups. The philopatric behaviour of males and the long‐range dispersal capacity of females probably determine the observed genetic differentiation pattern. The mito‐nuclear discordance detected could be due to the molecular markers used and to female‐biased dispersal. Gene flow is asymmetric in this species, being greater from north to south than vice versa, which is probably related to differences in the seasonality of precipitation across the BCP and to urbanization of the oases.

Population genetic structure of Neoschongastia gallinarum in South China based on mitochondrial DNA markers.

The genetic diversity and differentiation of four geographic populations of Neoschongastia gallinarum were evaluated using concatenated mitochondrial gene sequences (pCOI, pCOII, and pND5). Based on the results, the N. gallinarum populations had high genetic diversity and strong ecological adaptability. Genetic differentiation among paired populations calculated using concatenated mitochondrial gene sequences revealed that geographic isolation resulted in genetic differentiation among the populations of N. gallinarum, and gene flow between populations associated with human trade activities. Systematic development and molecular variance based on haplotypes revealed that genetic variation existed in different haplotypes; however, no clear rule related to geographic region was found. Further, genetic variation was mainly derived from individuals within the population. A neutral test based on concatenated mitochondrial gene sequences and nucleotide pair differences revealed that N. gallinarum did not experience an obvious population expansion in recent historical periods. Accordingly, the population size was relatively stable.