Maternal Gene Flow Research Articles

Circum-Saharan Prehistory through the Lens of mtDNA Diversity.

African history has been significantly influenced by the Sahara, which has represented a barrier for migrations of all living beings, including humans. Major exceptions were the gene flow events that took place between North African and sub-Saharan populations during the so-called African Humid Periods, especially in the Early Holocene (11.5 to 5.5 thousand years ago), and more recently in connection with trans-Saharan commercial routes. In this study, we describe mitochondrial DNA (mtDNA) diversity of human populations from both sides of the Sahara Desert, i.e., both from North Africa and the Sahel/Savannah belt. The final dataset of 7213 mtDNA sequences from 134 African populations encompasses 470 newly collected and 6743 previously published samples, which were analyzed using descriptive methods and Bayesian statistics. We completely sequenced 26 mtDNAs from sub-Saharan samples belonging to the Eurasian haplogroup N1. Analyses of these N1 mitogenomes revealed their possible routes to the Sahel, mostly via Bab el-Mandab. Our results indicate that maternal gene flow must have been important in this circum-Saharan space, not only within North Africa and the Sahel/Savannah belt but also between these two regions.

Accurate paternal and maternal immigrant gene flow analysis over three mast years detects relative levels of gametic heterogeneity components in a natural population of Abies firma

ABSTRACT To consider and evaluate the effectiveness of strategies for genetic variation preservation of populations of targeted species, it is important to examine which components of gametic heterogeneity have a greater impact on the genetic diversity of the next generation. Here, we investigated gene dispersal patterns in dispersed seeds and the relative levels of genetic diversity and differentiation for within-population and immigrant groups of both paternal and maternal gametes in a natural population of Abies firma during three reproductive events (mast years). Accurate paternity and maternity analyses, genotyping 630 seeds (1,260 tissue samples) and 331 candidate adult trees in total, were performed by analyzing 12 nuclear microsatellite loci of both diploid biparental embryos and haploid maternal megagametophytes. We found that 53.7% of paternal gametes and 15.3% of maternal gametes were of immigrant origin, indicating substantial gene flow for both parentages. Of the three components of gametic heterogeneity (immigration, parentage, and year) of the seeds, differences in gene-flow categories (within-population vs. immigrant gametes) showed the largest variation (mean F ST = 0.030). Differences in gametes between paternal and maternal parentages had the second-largest variation (0.012), and variation among three mast years was the lowest (0.006). Diverse immigrant gametes derived from nearby populations at the landscape level and the differences in paternal and maternal reproductions of adult trees are considered to make the main contributions to the overall genetic variability of dispersed seeds of A. firma.

Regional population genetics and global phylogeography of the endangered highly migratory shark Lamna nasus: Implications for fishery management and conservation

Abstract The porbeagle shark Lamna nasus is a large highly migratory shark distributed in cold and temperate marine waters of the North Atlantic and Southern Hemisphere (SH). According to the International Union for Conservation of Nature, the porbeagle is assessed globally as Vulnerable and regionally as Critically Endangered in the North Atlantic and the Mediterranean Sea. This study explored, for the first time, the population genetics of L. nasus at a regional (south‐east Pacific Ocean) and global scale. In this study, the null hypotheses of no genetic discontinuities among populations (i) within the SH, and (ii) between the SH and Northern Hemisphere (NH) were tested. Also, the demographic history of L. nasus in different ocean basins was assessed. Two mitochondrial markers (Control Region [CR] and cox1) well suited for population genetics inferences in sharks were used. Spatial–genetic analyses suggested two genetic clusters co‐occurring in the south‐eastern Pacific Ocean. A two‐way ANOVA using the cox1 but not the CR mtDNA fragment detected an effect of genetic identity on shark body size. Phylogeographic analyses, haplotype networks, and analyses of molecular variance demonstrated genetic differences between populations from the NH and SH but not among populations in the SH. Migration estimates indicated limited current maternal gene flow between the two hemispheres but high gene flow within hemispheres. Two well‐defined haplotype groups with star‐like shapes inhabited all ocean basins in the SH. These results could reflect a historical scenario of reproductive isolation and more recent mixture among previously isolated populations in the SH. A Bayesian skyline plot analysis indicated sudden population expansion in the SH occurring ~100–125 kya. This study highlights the need for additional studies focusing on the population genomics (using nuclear markers, i.e. single nucleotide polymorphisms) and the general biology of L. nasus to explore the existence of genetically dissimilar populations in the SH. Such studies will help implementing efficient genetic monitoring programmes.

Comparison of the mitochondrial phylogeographical structure of a generalist and two specialist frog species reveals contrasting patterns in the Eastern and Western Cape provinces of South Africa

AbstractIn this study, we examined the phylogeographical structure of three frog species (Anhydrophryne rattrayi, Arthroleptis wageri and Cacosternum nanum) in the Eastern and Western Cape provinces of South Africa. The first two species are forest dwelling and exhibit direct development, whereas the last species is a habitat generalist, breeding in open freshwater bodies and exhibiting rapid metamorphosis. Evolutionary relationships were inferred using combined mitochondrial DNA (mtDNA) sequence data [16S rRNA and cytochrome b (Cytb)]. Divergence times were estimated for each species using the combined mtDNA dataset, and population genetic structuring was inferred using haplotype networks and analysis of molecular variance using the rapidly evolving Cytb locus. The two forest-dwelling species (Anhydrophryne rattrayi and Arthroleptis wageri) each revealed two statistically well-supported clades and were characterized by marked genetic differentiation and the general absence of shared maternal haplotypes, indicating no maternal gene flow between conspecific populations; a result corroborated by moderate values of pairwise genetic distance. In contrast, for the generalist species C. nanum, two shallow clades were observed and several haplotypes were shared between localities, indicating moderate maternal gene flow. Diversification in the two forest-dwelling species occurred during the Plio-Pleistocene climatic oscillations and was associated with increased xeric conditions, whereas in C. nanum a recent, Holocene divergence was inferred. Ancient climatic factors thought to be causal in the divergences within each of the three species are discussed. The marked mtDNA differentiation in the two forest specialist species suggests the presence of distinct management units that should be considered in future conservation management decisions.

Massively parallel sequencing of mitogenome sequences reveals the forensic features and maternal diversity of tai-kadai-speaking hlai islanders

As a single maternally inherited locus, human mitochondrial DNA (mtDNA) is geographically arranged and plays a key role in forensic applications. Hlai population has been evidenced as the most typical and unmixed representative of the Tai-Kadai-speaking populations via genome-wide analyses. However, forensic features and maternal diversity of the complete mitogenomes in this Tai-Kadai ancestrally related population are scarce. Thus, we sequenced the complete mitogenomes in 127 Hainan Hlais and found 109 distinct haplotypes belonging to 43 terminal haplogroups resulting in the haplotype diversity of 0.9970. Our results of comprehensive population comparisons showed that Hlai islanders had a close genetic affinity with Tai-Kadai-speaking populations from Southeast Asia, which is consistent with the back-migration of Chinese Neolithic farmers into this region via the inland route. Besides, maternally genetic evidence further revealed a close genetic relationship between Tai-Kadai-speaking and Austronesian-speaking populations when only East Asian dataset was considered, which is consistent with the common origin from Yangtze rice farmers and then spread southward along the inland and coastal routes, respectively. In the reconstructed phylogenetic tree and median-joining networks, the vast majority of Hlais were clustered in exclusive clades, which demonstrated that Hlai people probably had undergone founder effect or genetic bottleneck in their history, and remained genetically isolated for a long time. Collectively, Hainan Hlai did not exhibit detectable maternal gene flow from surrounding or incoming populations. Mitogenome information generated in this study is a contribution in mitigating the underrepresentation of Chinese data in forensic mitogenetics and will assist geography-, metapopulation-, as well as phylogeny-based queries.

Evidence of restricted maternal gene flow of Purana (old) Population in the suburbs of Sigiriya, Sri Lanka

IntroductionBased on historical records suggesting that the ancestry of the Purana (old) population living in the suburbs of Sigiriya in Sri Lanka can be traced back to the times of the Sinhalese Kings of the 5th century A.D. (1,450 YBP) and studies reporting that the Purana are biometrically different from the rest of present Sri Lankans and other populations in the world, we investigate the maternally inherited Mitochondrial DNA (mtDNA) of Purana population in the suburbs of Sigiriya to better understand genetic affinities of them to present day Sri Lankans. Materials and MethodsForty six Purana inhabitants belonging to Purana pedigrees were recruited in the study. Mitochondrial DNA was extracted, amplified and sequenced. Polymorphisms of mtDNA hypervariable segment I (HVS –I) between nucleotide positions 16,004 –16,411 were identified using CLUSTALX option of MEGAVA 4.0 sequence alignment software. In order to investigate genetic affinity of Purana population, Arlequin software version 3.11 and analysis of molecular variance (AMOVA) were applied using reported similar genetic data of present Sri Lankans such as Sinhalese, Sri Lankan Tamils, Indian Tamils, Sri Lankan Moors and Vedda. Genetic relationships of Purana population with other Sri Lankans were further explored by phylogenetic analysis. Results and AnalysisGenetic dissimilarity among groups was higher (2.81%) when populations were grouped into two as modern and Purana than grouping them according to their ethnic basis (0.00%). This indicates a restricted mtDNA flow between the two groups (Purana and rest of the Sri Lankans) that made Purana population was maternally isolated from the rest of Sri Lankans. ConclusionDetailed phylogenetic analysis of the study revealed that they are maternally more related to Sri Lankan Tamil than to any other present Sri Lankans.

Multi-year genetic sampling indicates maternal gene flow via colony emigrations in the army ant Eciton burchellii parvispinum

Sex-biased dispersal occurs when one sex disperses more frequently or farther than the opposite sex. In ants, dispersal is often male biased and males typically contribute more strongly to gene flow within and among ant populations. However, army ants may offer an exceptional case of female-biased dispersal, because army ant colonies (particularly species in the Neotropical genus Eciton) routinely emigrate among nest sites. We hypothesized that maternal mobility via successive colony emigrations would reduce the relative male bias in dispersal, and that emigrations would contribute to gene flow within an Eciton population. We genotyped workers (highly variable DNA microsatellite loci) from Eciton burchellii parvispinum colonies collected over a 10 × 10 km area in Monteverde, Costa Rica. Samples were spaced approximately 3 years apart (in 2006 and 2009), the typical time between colony reproductive bouts. We used worker genotypes to reconstruct the genotypes of their mother queens and of a subset of the males that sired the workers. We then analyzed the population genetic structure of the queen and male genotypes by comparing individual-based relatedness estimates for each sex across geographic distance and over time. There was no significant difference in spatial genetic structure between the sexes, either within or between the 2006 and 2009 samples. There was some evidence against genetic philopatry: 2009 queens were significantly unrelated to 2006 queens collected nearby (within 0.5 km). The patterns suggest maternal dispersal via emigrations contributes to gene flow, reducing or eliminating male biases in dispersal. From two populations, we estimated average queen dispersal distance to be 0.63–1.04 km, a greater distance than many winged ant queens disperse. Because emigrations over the lifetime of army ant queens may contribute to gene flow across the landscape, habitat connectivity should be maintained to permit colony emigrations and support genetic diversity in populations of this keystone species.

Southern limit of Africanized honey bees in Argentina inferred by mtDNA and wing geometric morphometric analysis

African honey bee subspecies Apis mellifera scutellata began to spread in the American continent from southern Brazil in 1956. The process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honey bees. In Argentina, Africanized honey bees dominate in the northern semitropical regions and a hybrid area is defined between (ca. 32°–34°latitude). Although previous analysis has been carried out in Buenos Aires province, no analysis has been made south of this latitude. We used mitochondrial DNA (mtDNA) assays and wing geometric morphometrics to determine the prevalence of Africanized honey bees in managed populations. African mitotype origin and subspecies identity, were determined at three regions from Argentina. In our study, we analyzed 480 samples by wing morphometry and 157 by cytochrome-b assays, collected during 2013–2016. Our results show that North of 35°N latitude, honey bees with African mitotype were quite common (88.64%) finding high similarity with A. m. scutellata. South of that latitude, in temperate regions, we found African mitotype in only 18 of 133 colonies analyzed and a mixture of both European (A. m. ligustica, A. m. cárnica, A. m. mellifera) and African subspecies, most likely derived from North African honey bee (A. m. intermissa). Our results confirmed the existence of Africanized honey bee populations with a gradual cline from north to south, as a result from recent A. m. scutellata-derived bee expansion. Beyond the transition area between the 30°–35°S parallels bees carrying the European mitotype were fairly common.

Development of highly polymorphic genomic microsatellite markers and their application to gene flow in a natural population of Abies firma

ABSTRACTThe momi fir (Abies firma) has been targeted as a species for genetic resource conservation because of the recent decline in its natural populations. Additional molecular marker resources are needed to examine gene flow to understand the genetic dynamics of each population. We developed 15 genomic microsatellite (SSR) markers for A. firma and applied them to separate biparentage assignments of dispersed seeds in a natural population by assaying embryos and megagametophytes. The 15 markers were polymorphic, with the expected heterozygosity averaging greater than 0.74. Separate biparentage analysis, using the seven selected effective markers, was successful to assign paternal and maternal trees separately and thus estimate the paternal and maternal immigrant gene flow from nearby populations. The newly developed genomic SSR markers in the present study, by constructing a marker set together with previously developed markers, will provide higher discriminatory power for parentage analysis and should be useful for estimating gene flow for ongoing conservation genetics studies of A. firma.

MtDNA variations in three main ethnic groups in Tuzla Canton of Bosnia and Herzegovina

This study was based on the analysis of mtDNA polymorphisms in three ethnic groups of Tuzla Canton of Bosnia and Herzegovina (Bosniaks, Croats and Serbs). The main aim of this study was to analyze the influences of the maternal gene flow on the genetic profile of ethnic groups. The analysis of mtDNA variation based on relevant restriction fragment length polymorphisms (RFLP) in combination with HVSI variations of the control region enabled the identification of the Western - Eurasian haplogroups (H, I, J, T, W, U, HV, HVO, K, V, X), African/Near East lineages N1a and Asian haplogroup M. Our data indicate a close gene similarity among maternal gene pools of the ethnic groups of Tuzla Canton as well as similar influence of the maternal gene flow on genetic structure of those populations. The presence of important maternal determinants of the Late Glacial expansion (U5a), postglacial re-colonisation of Europe from refugia of southwestern Europe (H, V, U5b1), central-eastern European Plain (U4), Italian Peninsula (U5b3) and Neolithic expansion (U3, N1a, J, T) was noted in the genetic structure of the ethnic groups in Tuzla Canton. Conclusions in our study are consistent with the results of previous studies based on the distribution of mtDNA haplogroups and Y - chromosome haplogroups in three main ethnic groups of modern Bosnia and Herzegovina, suggesting similar effects of the paternal and maternal gene flows on genetic structure of the three main ethnic groups of modern Bosnia and Herzegovina.

Genetic ancestry of families of putative Inka descent

This study focuses on the descendants of the royal Inka family. The Inkas ruled Tawantinsuyu, the largest pre-Columbian empire in South America, which extended from southern Colombia to central Chile. The origin of the royal Inkas is currently unknown. While the mummies of the Inka rulers could have been informative, most were destroyed by Spaniards and the few remaining disappeared without a trace. Moreover, no genetic studies have been conducted on present-day descendants of the Inka rulers. In the present study, we analysed uniparental DNA markers in 18 individuals predominantly from the districts of San Sebastian and San Jerónimo in Cusco (Peru), who belong to 12 families of putative patrilineal descent of Inka rulers, according to documented registries. We used single-nucleotide polymorphisms and short tandem repeat (STR) markers of the Y chromosome (Y-STRs), as well as mitochondrial DNA D-loop sequences, to investigate the paternal and maternal descent of the 18 alleged Inka descendants. Two Q-M3* Y-STR clusters descending from different male founders were identified. The first cluster, named AWKI-1, was associated with five families (eight individuals). By contrast, the second cluster, named AWKI-2, was represented by a single individual; AWKI-2 was part of the Q-Z19483 sub-lineage that was likely associated with a recent male expansion in the Andes, which probably occurred during the Late Intermediate Period (1000–1450 AD), overlapping the Inka period. Concerning the maternal descent, different mtDNA lineages associated with each family were identified, suggesting a high maternal gene flow among Andean populations, probably due to changes in the last 1000 years.

GENETIC DIFFERENTIATION BETWEEN TWO HUMAN POPULATIONS CONSIDERING ON SOME DYNAMIC AND STATIC MORPHOLOGICAL PROPERTIES

In this paper, we report on the first data connected to the phenotype diversity of the Roma population from north/eastern Bosnia and its genetic relations with neighboring non-Roma populations. Genetic structure of the Roma and non-Roma population was analyzed considering on four the static-morphological and three the dynamic-morphological properties. A total of 847 samples have been collected from unrelated individuals in the area of the north/eastern Bosnia. The investigated parameters of genetic heterogeneity were estimated by: the recessive phenotypes frequency observed property, chi-squared test, exact-test, pairwise FST and genetic distance analysis. Estimation of genetic variability of the analyzed populations showed significant genetic differentiation between of the Roma and non-Roma population. The basic factors of the found significant genetic differentiation between the Roma and non-Roma population are a result of a high level of endogamy, the reproductive isolation of the Roma population and limited maternal gene flow with neighboring populations.

Whole Mitogenomes Reveal the History of Swamp Buffalo: Initially Shaped by Glacial Periods and Eventually Modelled by Domestication

The newly sequenced mitochondrial genomes of 107 Asian swamp buffalo (Bubalus bubalis carabensis) allowed the reconstruction of the matrilineal divergence since ~900 Kya. Phylogenetic trees and Bayesian skyline plots suggest a role of the glacial periods in the demographic history of swamp buffalo. The ancestral swamp-buffalo mitogenome is dated ~232 ± 35 Kya. Two major macro-lineages diverged during the 2nd Pleistocene Glacial Period (~200–130 Kya), but most (~99%) of the current matrilines derive from only two ancestors (SA1′2 and SB) that lived around the Last Glacial Maximum (~26–19 Kya). During the late Holocene optimum (11–6 Kya) lineages differentiated further, and at least eight matrilines (SA1, SA2, SB1a, SB1b, SB2a, SB2b, SB3 and SB4) were domesticated around 7–3 Kya. Haplotype distributions support an initial domestication process in Southeast Asia, while subsequent captures of wild females probably introduced some additional rare lineages (SA3, SC, SD and SE). Dispersal of domestic buffaloes created local population bottlenecks and founder events that further differentiated haplogroup distributions. A lack of maternal gene flow between neighboring populations apparently maintained the strong phylogeography of the swamp buffalo matrilines, which is the more remarkable because of an almost complete absence of phenotypic differentiation.

Genetic assessment of the San Clemente Island loggerhead shrike reveals evidence of historical gene flow with Santa Catalina Island

The San Clemente loggerhead shrike (Lanius ludovicianus mearnsi) is an endangered species endemic to San Clemente Island in California. Previous genetic analyses of the California shrike populations have had mixed results due to small sample sizes and/or few genetic markers. Here we present a rigorous analysis of 381 historical and contemporary California shrike samples genotyped at 11 new polymorphic microsatellite loci and the mitochondrial DNA control region. Our results suggest generally high genetic diversity in all populations and that loggerhead shrikes on San Clemente Island are genetically differentiated from both the Mainland and other island populations. Bayesian clustering suggests primarily three genetically differentiated populations: (1) Mainland, (2) San Clemente Island, and (3) the islands of Santa Catalina, Santa Cruz and Santa Rosa. Historically, however, the San Clemente Island shrike cluster closely with the Santa Catalina Island population, suggesting historical gene flow between these populations. A Bayesian phylogeny of common mtDNA haplotypes across North America reveals two primary clades and a general division between western and eastern populations. Geographic patterns suggest maternal gene flow from mainland to the islands but not vice versa. These results indicate that the captive breeding program has been successful at maintaining genetic diversity in the San Clemente Island shrike population, but that allele frequencies have shifted significantly over the past 100 years. Overall, our results suggest the San Clemente shrike (L. l. mearnsi) is a validated subspecies that is morphologically and genetically distinct, and that ongoing conservation efforts are justified.

Genetic bottlenecks in Pristis sawfishes in northern Australian waters

Northern Australia has been identified as the last stronghold for the dwarf sawfish Pristis clavata, green sawfish P. zijsron, and largetooth sawfish P. pristis, making these populations key in global conservation efforts for each species. This research assesses the levels of genetic diversity in these 3 sawfishes in Australian waters, testing for the presence of population bottlenecks using data at microsatellite loci. Levels of observed heterozygosity in each species from the west coast of Australia and the north-eastern Gulf of Carpentaria were generally high. M ratio tests suggest that assemblages of P. zijsron and P. pristis on the west coast and P. clavata and P. zijsron in the Gulf of Carpentaria may have experienced population bottlenecks. The bottlenecks are especially pronounced in P. zijsron populations and in P. clavata from the Gulf of Carpentaria. Demographic analyses, based on mtDNA data, indicate relatively recent (evolutionarily) range expansions in Pristis sawfishes in northern Australian waters, which could account for the population bottlenecks. A more recent range expansion in each of P. clavata and P. zijsron, as evidenced by more recent population divergence and more recent/higher rates of historic maternal gene flow, could account for the more pronounced bottlenecks in these species when compared to P. pristis. Given that Pristis sawfishes in Australian waters have experienced population bottlenecks, whether they be historic, contemporary or both, the preservation of remaining genetic diversity should be a high conservation priority.

Examining the evolutionary relationships amongst three species of West African freshwater crabs Liberonautes Bott, 1955 (Brachyura: Potamonautidae) using mtDNA sequence data

Evolutionary relationships amongst three species of freshwater crabs, Liberonautes latidactylus (De Man, 1903), L. nimba Cumberlidge, 1999, and L. rubigimanus Cumberlidge and Sachs, 1989, were examined using DNA sequence data of the mitochondrial cytochrome oxidase subunit I (COI) locus. The latter three species are listed in the IUCN Red List for 2008 as least concerned, vulnerable, and endangered, respectively. Specimens of the three species were collected in Liberia and neighbouring Guinea, West Africa. Phylogenetic results derived from maximum parsimony, maximum likelihood, and Bayesian inference revealed the monophyly of all three species. Moderate genetic variation was observed within L. latidactylus . Within the narrow endemic, montane species, L. nimba shallow divergence was observed, whereas marked genetic divergence was observed within L. rubigimanus . Three statistically well-supported clades were observed within the latter taxon, two of these clades were sympatric at Simandou, Liberia (clades A and B), and characterised by a 10% uncorrected sequence divergence for the COI locus, whereas the divergence between the latter two clades and the larger L. rubigimanus clade was 8%. Haplotype networks corroborate the absence of maternal gene flow amongst the three L. rubigimanus clades suggesting possible reproductive isolation and the presence of two novel species. Our results suggest that Liberonautes harbours undescribed, narrowly distributed species. The results are discussed in a conservation framework for the three Liberonautes species.

Social structure and landscape genetics of the endemic New Caledonian ant Leptomyrmex pallens Emery, 1883 (Hymenoptera: Formicidae: Dolichoderinae), in the context of fire-induced rainforest fragmentation

Habitat fragmentation is a major threat to biodiversity, as it can alter ecological processes at various spatial and trophic scales. At the species level, fragmentation leading to the isolation of populations can trigger reductions in genetic diversity, potentially having detrimental effects on population fitness, adaptability and ultimately population persistence. Leptomyrmex pallens is a widespread rainforest ant endemic to New Caledonia but now confined to habitat patches that have been fragmented by anthropogenic fire regimes over the last 200 years. We investigated the social structure of L. pallens in the Aoupinie region (c.a. 4900 ha), and assessed the impacts of habitat fragmentation on its population genetic structure. Allele frequencies at 13 polymorphic microsatellite loci were compared among 411 worker ants from 21 nests distributed across the region. High within-nest relatedness (r = 0.70 ± 0.02), and a single queen found in 38 % of the nests by pedigree analysis indicate that the species is monogynous to weakly polygynous. Estimates of gene flow and genetic structure across the region were subsequently determined using a combined dataset of single workers per nest and of unrelated foraging workers. These estimates coupled with a comprehensive landscape genetic analysis revealed no evidence of significant population structure or habitat effects, suggesting that the Aoupinie region harbours a single panmictic population. In contrast, analyses of mitochondrial DNA sequence data revealed a high degree of genetic structuring, indicating limited maternal gene flow and suggesting that gene flow among nests is driven primarily by winged males. Overall these findings suggest that fire-induced habitat fragmentation has had little impact on the population dynamics of L. pallens. Additional studies of less mobile species should therefore be conducted to gain further insights into fire related disturbances on the unique biodiversity and function of New Caledonian ecosystems.

Phylogeography and genealogy of the tsetse fly Glossina pallidipes (Diptera: Glossinidae)

Glossina pallidipes, a widely but discontinuously distributed African savanna species, is one of the economically important tsetse flies because it is a vector of trypanosomiasis, a lethal disease of cattle and other domestic animals. DNA sequences of ribosomal (r16S2, 249 bp) and cytochrome oxidase I (COI, 421 bp) concatenated mitochondrial genes were analysed in 23 geographically diverse samples ofG. pallidipesfrom Ethiopia, Kenya, Tanzania, Zambia and Zimbabwe. Among 873 flies, we detected 181 composite haplotypes and found that their spatial diversities and frequency distributions were heterogeneous. Haplotype and nucleotide diversities were greatest in Ethiopia and least in southern Africa. We observed little haplotype and nucleotide diversity among regions, and detected severely limited maternal gene flow among the sampled populations (ΦST= 0.42). Tests for demographic stability and analysis of mismatch distributions revealed regionally contrasting demographic histories. The Ethiopian populations were phylogenetically the oldest and genetically the most diverse, and exhibited successive waves of contraction and expansion. The southern African populations were phylogenetically the youngest and genetically the least diverse, and showed only a single, recent expansion. Likely ecological correlates of historical tsetse fly demography include population suppression trials in East Africa and recurring rinderpest epizootics in southern Africa, beginning in the late nineteenth century that reduced host mammalian populations.

The role of East Asian monsoon system in shaping population divergence and dynamics of a constructive desert shrub Reaumuria soongarica.

Both of the uplift of Qinghai-Tibet Plateau (QTP) and the development of East Asian monsoon system (EAMS) could have comprehensively impacted the formation and evolution of Arid Central Asia (ACA). To understand how desert plants endemic to ACA responded to these two factors, we profiled the historical population dynamics and distribution range shift of a constructive desert shrub Reaumuria soongarica (Tamaricaceae) based on species wide investigation of sequence variation of chloroplast DNA and nuclear ribosomal ITS. Phylogenetic analysis uncovered a deep divergence occurring at ca. 2.96 Mya between the western and eastern lineages of R. soongarica, and ecological niche modeling analysis strongly supported that the monsoonal climate could have fragmented its habitats in both glacial and interglacial periods and impelled its intraspecific divergence. Additionally, the population from the east monsoonal zone expanded rapidly, suggesting that the local monsoonal climate significantly impacted its population dynamics. The isolation by distance tests supported strong maternal gene flow along the direction of the East Asian winter monsoon, whose intensification induced the genetic admixture along the latitudinal populations of R. soongarica. Our results presented a new case that the development of EAMS had prominently impacted the intraspecific divergence and population dynamics of this desert plant.

Comment on a research note reporting new populations of the northern quoll in Western Australia

The recent report by Turpin and Bamford (2015) notes a range extension for northern quolls in the Pilbara Bioregion of Western Australia. Mitochondrial DNA sequences derived from five scats show that the new individuals nest within a clade containing all other Pilbara animals. Northern quolls from the Pilbara Bioregion are genetically distinct from congeners from the Kimberley Bioregion. We note that there is no evidence for maternal gene flow between these two regions.