Mitochondrial Haplotypes Research Articles

The “evolution” of the mitochondrial genome of the (<i>Phylloscopus borealis</i> sensu lato) occurs in its nuclear genome

Sequencing of a partial fragment of the ND5–cytb mithochondrial genes (1553 bp) and its nuclear copies was carried out to Phylloscopus borealis sensu lato, belonging to individual taxonomic groups from different parts of the range. It was shown that the majority of taxon-specific and unique mitochondrial substitutions in examinandus and xanthodryas forms were identical to those in nuclear copies of borealis mtDNA. Differences between mitochondrial haplotypes of examinandus and nuclear copies of mtDNA borealis were low (p = 0.02), at the same time the mtDNA genetic divergence in borealis–examinandus, borealis–xanthodryas and examinandus–xanthodryas significantly exceeded this value (p = 0.035, 0.044 and 0.046, respectively). A nuclear copy of the mitochondrial haplotype of the easternmost form of xanthodryas was first discovered in the nuclear genome of one borealis individual in the western part of the breeding range (Komi Republic). Alongside this, it was shown at the first time, the nuclear copies of xanthodryas mtDNA from Toyama Prefecture (Japan) were close to the mitochondrial haplotypes of borealis from Kytlym (Sverdlovsk region) (p = 0.018). Thus, the mutations emerging in the nuclear copies of mitochondrial genes are the source of most substitutions in the mitochondrial DNA of the studied forms. The origin of the mitochondrial haplotypes examinandus and xanthodryas from nuclear copies of mtDNA borealis and the close similarity of their nuclear genomes gives grounds to consider the mitogenomes of these forms as variants of the haplotype of the single species Ph. borealis sensu lato. With a high degree of probability, it can be argued that the divergence time of the haplotypes of the analyzed forms is significantly less than 2.5-3 million years, as previously assumed by a number of authors [Saitoh et al. 2010; Alström et al. 2011], and the “molecular clock” that do not take into account recombination events between the nuclear and mitochondrial genomes cannot be used in this case.

Archaeogenetic Data Mining Supports a Uralic–Minoan Homeland in the Danube Basin

Four types of archaeogenetic data mining are used to investigate the origin of the Minoans and the Uralic peoples: (1) six SNP mutations related to eye, hair, and skin phenotypes; (2) whole-genome admixture analysis using the G25 system; (3) an analysis of the history of the U5 mitochondrial DNA haplogroup; and (4) an analysis of the origin of each currently known Minoan mitochondrial and y-DNA haplotypes. The uniform result of these analyses is that the Minoans and the Uralic peoples had a common homeland in the lower and middle Danube Basin, as well as the Black Sea coastal regions. This new result helps to reconcile archaeogenetics with linguistics, which have shown that the Minoan language belongs to the Uralic language family.

Widespread Wolbachia infection is correlated with increased mtDNA diversity in native bees across the Fijian archipelago

AbstractInsects have a complex coevolutionary history with bacterial symbionts, among which Wolbachia pipientis stands out for its prevalence and role in reproductive manipulation. Wolbachia can induce cytoplasmic incompatibility, feminisation, male killing, and parthenogenesis, greatly influence the population genetics of their hosts and are potential drivers of invertebrate speciation. We might then assume that Wolbachia could act synergistically with other factors, such as niche conservation and isolation by distance, to drive speciation in hyper-diverse invertebrate taxa. The Fijian archipelago hosts a remarkable and recently diverged clade of Lasioglossum (Homalictus) bees. Some of these Lasioglossum have highly unusual species-level sex ratios and mitochondrial diversities, which can be hallmarks of infection by a bacterial reproductive manipulator. To examine the role of Wolbachia in Fijian Lasioglossum speciation, we screened the endemic Fijian bees for Wolbachia using the Wolbachia surface protein gene (wsp). We compare the distribution of Wolbachia infection across species with host mitochondrial haplotype diversity and conducted phylogenetic analyses to determine the relationship of host relatedness and symbiont infection status. We found that Wolbachia haplotypes probably span across supergroups A and B. In addition, we found multiple haplotypes were highly similar, with the most abundant group of wsp haplotypes being closely related with the drosophila Wolbachia strain wHa. We found evidence of mostly horizontal and limited vertical transmission, and little evidence for Wolbachia-host cospeciation. We show that, contrary to general patterns, Wolbachia-infected Lasioglossum species have higher mitochondrial diversity. Finally, we present evidence for the potential of multiple modes of host manipulation in this clade.

Morphological and molecular characterisation of Mordellistenapeloponnesensis Batten, 1980 (Coleoptera, Mordellidae), with first records from Italy and Turkey.

Mordellistenapeloponnesensis Batten, 1980, previously known from Cyprus and Greece, is reported from Italy and Turkey for the first time. The species is redescribed based on type specimens and additional material from its entire known distributional range. Eighteen DNA barcoding sequences of M.peloponnesensis from Greece, Cyprus, and Italy were generated, and genetic variability across the sampling localities was examined. Three mitochondrial haplotypes were detected within M.peloponnesensis. Specimens from mainland Italy share the same haplotype as those from Rhodes and Cyprus, whereas Sardinian specimens exhibit a distinct haplotype. The third haplotype is represented by one specimen from Cyprus. The DNA barcoding sequences of M.peloponnesensis were compared with those of the morphologically allied M.gemellata Schilsky, 1898, and M.pyrenaea Ermisch, 1966, to reveal the phylogenetic relationships between the species.

The biogeographic patterns of the olive fly and its primary symbiont Candidatus Erwinia dacicola across the distribution area of the olive tree.

The olive fly, Bactrocera oleae (Rossi, 1790), is the major insect pest of olives attacking both cultivated and wild olive. Bactrocera oleae carries a primary and vertically transmitted symbiont, the bacterium Candidatus Erwinia dacicola. As any primary symbiont, it plays an important role in the reproduction and lifespan of the fly. The genetic 16S rRNA diversity of the primary symbiont and the mitochondrial haplotype variation of the insect host were simultaneously examined in 54 olive fly populations. The aim was to unravel the biogeographic patterns of this economically relevant host-bacteria interaction across a wide distribution area. Three symbiont haplotypes were identified. The primary symbiont showed a lower haplotype diversity than that of its host, a characteristic indicative of a long-term interaction. A significant genetic and geographic association between host and primary symbiont was observed, with an East-West genetic differentiation pattern in the Mediterranean basin, coinciding with the historical genetic distribution of the olive tree. The study shows promise, informing and aiding the development of future tools for the control of the olive fly.

Genetic Re-assessment of Population Subdivision in Yellowstone National Park Bison.

Yellowstone National Park is home to the only plains bison population that has continually existed as wildlife, on the same landscape, through the population bottleneck of the late 19th century. Nevertheless, by the early 1900s, only 23 wild bison were known to have survived poaching. Salvation efforts included the addition of 18 females from Montana and 3 bulls from Texas to augment this population. A century later, nuclear microsatellite-based population level assessment revealed two genetically distinct bison sub-populations. However, in 2016 an analysis of mitochondrial haplotypes showed the two founding lineages were distributed throughout the park. This study is designed to delineate any current sub-structure in the Yellowstone bison population by strategically sampling the two major summer breeding herds and the two major winter ranges. Population level metrics were derived using the same microsatellite loci as the original study along with a newly developed set of highly informative bison specific Single Nucleotide Polymorphisms (SNPs). Our analyses reveal that the modern bison in Yellowstone National Park currently consist of one interbreeding population, comprised of two subunits.

Distribution of honey bee mitochondrial DNA haplotypes in an Italian region where a legislative act is protecting the Apis mellifera ligustica subspecies

The conservation of the genetic integrity of Apis mellifera subspecies has emerged as an important objective. In 2019, the Emilia-Romagna region became the first Italian regional authority to issue a law specifically addressing the protection of the native Apis mellifera ligustica subspecies. In this study we analysed a highly informative portion of the mitochondrial DNA (mtDNA), widely used for assessing genetic diversity of honey bee populations. By analysing 1143 honey bees sampled after the introduction of this law, we provided a snapshot of the distribution of mtDNA haplotypes in this region. The two most frequent mtDNA haplotypes were C1 (characteristic of A. m. ligustica) and C2 (characteristic of A. m. carnica), reported in 86.5% and 11.0% of the analysed bees, respectively. About 1.3% and 1.1% of the analysed bees carried mtDNA haplotypes of the A and M lineages (haplotypes A1a, A1e, A4, A26, A65 and two novel ones, A2w and A6a; M3, M3a, M4 and M79). Continued genetic monitoring will be important to assess the impact of this regional law over the coming years. Based on the obtained results, we recommend a more stringent policy to prevent the erosion of the genetic integrity of the native subspecies A. m. ligustica.

Paternal Mitochondrial DNA Leakage in Natural Populations of Large-Scale Loach, Paramisgurnus dabryanus.

Animal mitochondrial DNA is usually considered to comply with strict maternal inheritance, and only one mitochondrial DNA haplotype exists in an individual. However, mitochondrial heteroplasmy, the occurrence of more than one mitochondrial haplotype, has recently been reported in some animals, such as mice, mussels, and birds. This study conducted extensive field surveys to obtain representative samples to investigate the existence of paternal inheritance of mitochondrial DNA (mtDNA) in natural fish populations. Evidence of paternal mitochondrial DNA leakage of P. dabryanus was discovered using high-throughput sequencing and bioinformatics methods. Two distinct mitochondrial haplotypes (16,569 bp for haplotype I and 16,646 bp for haplotype II) were observed, differing by 18.83% in nucleotide sequence. Phylogenetic analysis suggests divergence between these haplotypes and potential interspecific hybridization with M. anguillicaudatus, leading to paternal leakage. In natural populations of P. dabryanus along the Yangtze River, both haplotypes are present, with Type I being dominant (75% copy number). Expression analysis shows that Type I has higher expression levels of ND3 and ND6 genes compared to Type II, suggesting Type I's primary role. This discovery of a species with two mitochondrial types provides a model for studying paternal leakage heterogeneity and insights into mitochondrial genome evolution and inheritance.

Temporal stability of sex ratio distorter prevalence in natural populations of the isopod Armadillidium vulgare.

In the terrestrial isopod Armadillidium vulgare, many females produce progenies with female-biased sex ratios due to two feminizing sex ratio distorters (SRD): Wolbachia endosymbionts and a nuclear non-mendelian locus called the f element. To investigate the potential impact of these SRD on the evolution of host sex determination, we analyzed their temporal distribution in six A. vulgare populations sampled between 2003 and 2017, for a total of 29 time points. SRD distribution was heterogeneous among populations despite their close geographic locations, so that when one SRD was frequent in a population, the other SRD was rare. In contrast with spatial heterogeneity, our results overall did not reveal substantial temporal variability in SRD prevalence within populations, suggesting equilibria in SRD evolutionary dynamics may have been reached or nearly so. Temporal stability was also generally reflected in mitochondrial and nuclear variation. Nevertheless, in a population, a Wolbachia strain replacement coincided with changes in mitochondrial composition but no change in nuclear composition, thus constituting a typical example of mitochondrial sweep caused by endosymbiont rise in frequency. Rare incongruence between Wolbachia strains and mitochondrial haplotypes suggested the occurrence of intraspecific horizontal transmission, making it a biologically relevant parameter for Wolbachia evolutionary dynamics in A. vulgare. Overall, our results provide an empirical basis for future studies on SRD evolutionary dynamics in the context of multiple sex determination factors co-existing within a single species, to ultimately evaluate the impact of SRD on the evolution of host sex determination mechanisms and sex chromosomes.

Evidence for feminized genetic males in a flea beetle using newly identified X-linked markers.

The equilibrium of sex ratios in sexually reproducing species is often disrupted by various environmental and genetic factors, including endosymbionts like Wolbachia. In this study, we explore the highly female-biased sex ratio observed in the flea beetle, Altica lythri, and its underlying mechanisms. Ancient hybridization events between Altica species have led to mitochondrial DNA introgression, resulting in distinct mitochondrial haplotypes that go along with different Wolbachia infections (HT1-wLytA1, HT1*- uninfected, HT2-wLytA2, and HT3-wLytB). Notably, beetles with some haplotypes exclusively produce female offspring, suggesting potential Wolbachia-induced phenomena such as feminization of genetic males. However, the observed female bias could also be a consequence of the ancient hybridization resulting in nuclear-cytoplasmic conflicts between introgressed mtDNA and nuclear genes. Through transcriptomic analysis and the program SEX-DETector, we established markers for genotypic sex differentiation for A. lythri, enabling genetic sexing via qPCR. Our findings suggest that feminization of genetic males is contributing to the skewed sex ratios, highlighting the intricate dynamics of sex determination and reproductive strategies in this flea beetle. This study provides valuable insights into the dynamics of genetic conflicts, endosymbionts, and sex ratios, revealing the novel phenomenon of genetic male feminization in the flea beetle A. lythri.

The first complete genome of the extinct European wild ass (Equus hemionus hydruntinus).

We present palaeogenomes of three morphologically unidentified Anatolian equids dating to the first millennium BCE, sequenced to a coverage of 0.6-6.4×. Mitochondrial DNA haplotypes of the Anatolian individuals clustered with those of Equus hydruntinus (or Equus hemionus hydruntinus), the extinct European wild ass, secular name 'hydruntine'. Further, the Anatolian wild ass whole genome profiles fell outside the genomic diversity of other extant and past Asiatic wild ass (E. hemionus) lineages. These observations suggest that the three Anatolian wild asses represent hydruntines, making them the latest recorded survivors of this lineage, about a millennium later than the latest observations in the zooarchaeological record. Our mitogenomic and genomic analyses indicate that E. h. hydruntinus was a clade belonging to ancient and present-day E. hemionus lineages that radiated possibly between 0.6 and 0.8 Mya. We also find evidence consistent with recent gene flow between hydruntines and Middle Eastern wild asses. Analyses of genome-wide heterozygosity and runs of homozygosity suggest that the Anatolian wild ass population may have lost genetic diversity by the mid-first millennium BCE, a possible sign of its eventual demise.

Evaluation of cryptic invasion in Japanese Undaria populations based on mitochondrial haplotypic analysis

Abstract To improve the quality and quantity of seaweed mariculture harvests, seedlings are frequently introduced from regions geographically apart from cultivation sites. The effects of such introduction have been insufficiently studied, despite increasing demands on seaweed cultivation as a measure against global warming. We here evaluated the degree of cryptic invasion occurring through mariculture using a brown algal species, Undaria pinnatifida. Cultivated materials used in the Seto Inland Sea, Japan, were introduced from northern Japan in the 1970s. Based on the clear genetic structure among Japanese Undaria populations, we compared mitochondrial haplotypes between wild populations and cultivated materials in the Seto Inland Sea. All cultivated materials analyzed had haplogroups native to northern Japan. Multiple haplogroups were observed in the wild populations, especially those in the eastern Seto Inland Sea, which is exceptional considering the reported genetic structure. Some northern Japan haplotypes were observed both in cultivated materials and wild individuals. A northern Japan haplogroup was predominant at several sites near Undaria-cultivation sites. These results strongly suggested that cryptic invasion through Undaria mariculture occurred here, although its ecological impact remains unclear. There is a clear risk of invasion by mariculture seedlings from other regions, even when native conspecific populations are present.

Morphological and Genetic Assessment of Invasive Corbicula Lineages in Southern South America: A Case Study in Argentina.

The broad global distribution of freshwater clams belonging to the genus Corbicula is driven by multiple hermaphroditic lineages. These lineages, characterized by shared morphological traits and phenotypic plasticity, pose challenges to morphological identification. Genetic markers, such as the mitochondrial COI gene, play a crucial role in delineating these lineages and their ranges. Morphotypes represent observed phenotypic variations, while lineages are defined based on genetic markers. Here, we comprehensively review Corbicula's distribution in Argentina, discriminate extant lineages based on both morphological and genetic (COI) data, and describe variations in internal and external morphologies using 15 Argentine populations. Genetic analyses identified two mitochondrial lineages: the AR morphotype (FW5 haplotype) and CS morphotype (FW17 haplotype). Strikingly, despite having similar vectors, origins, and invasive stages, Corbicula lineages exhibit virtually segregated distributions. However, mitochondrial haplotypes are found in sympatry mainly in northeastern Argentina where individuals with intermediate morphotypes exist, suggesting the presence of hybrids due to maternal genome retention. These findings contribute to the clarification of the identity and distribution of Corbicula lineages in Argentina, where the genus has been found for over half a century. Similar studies are needed in other areas to better understand the invasion patterns of this successful and adaptable group.

Population-specific responses to pollution exposure suggest local adaptation of invasive red swamp crayfish Procambarus clarkii along the Mediterranean French coastline

Anthropogenic stressors can have an impact in a broad range of physiological processes and can be a major selective force leading to rapid evolution and local population adaptation. In this study, three populations of the invasive crayfish Procambarus clarkii were investigated. They are geographically separated for at least 20 years, and live in different abiotic environments: a freshwater inland lake (Salagou lake) with no major anthropogenic influence and two other coastal wetlands regularly polluted by pesticides along the Mediterranean coast (Camargue region and Bages-Sigean lagoon). Collected adults were genetically characterized using the mitochondrial COI gene and haplotype frequencies were analyzed for genetic variability within and between populations. Results revealed a higher genetic diversity for these invasive populations than any previous report in France, with more than seven different haplotypes in a single population. The contrasting genetic diversity between the Camargue and the other two populations suggest different times and sources of introduction. To identify differences in key physiological responses between these populations, individuals from each population were maintained in controlled conditions. Data on oxygen consumption rates indicate that the Salagou and Bages-Sigean populations possess a high inter-individual variability compared to the Camargue population. The low individual variability of oxygen consumption and low genetic diversity suggest a specific local adaptation for the Camargue population. Population-specific responses were identified when individuals were exposed to a pesticide cocktail containing azoxystrobin and oxadiazon at sublethal concentrations. The Salagou population was the only one with altered hydro-osmotic balance due to pollutant exposure and a change in protease activity in the hepatopancreas. These results revealed different phenotypic responses suggesting local adaptations at the population level.

Limited variation in microbial communities across populations of Macrosteles leafhoppers (Hemiptera: Cicadellidae).

Microbial symbionts play crucial roles in insect biology, yet their diversity, distribution, and temporal dynamics across host populations remain poorly understood. In this study, we investigated the spatio-temporal distribution of bacterial symbionts within the widely distributed and economically significant leafhopper genus Macrosteles, with a focus on Macrosteles laevis. Using host and symbiont marker gene amplicon sequencing, we explored the intricate relationships between these insects and their microbial partners. Our analysis of the cytochrome oxidase subunit I (COI) gene data revealed several intriguing findings. First, there was no strong genetic differentiation across M. laevis populations, suggesting gene flow among them. Second, we observed significant levels of heteroplasmy, indicating the presence of multiple mitochondrial haplotypes within individuals. Third, parasitoid infections were prevalent, highlighting the complex ecological interactions involving leafhoppers. The 16S rRNA data confirmed the universal presence of ancient nutritional endosymbionts-Sulcia and Nasuia-in M. laevis. Additionally, we found a high prevalence of Arsenophonus, another common symbiont. Interestingly, unlike most previously studied species, M. laevis exhibited only occasional cases of infection with known facultative endosymbionts and other bacteria. Notably, there was no significant variation in symbiont prevalence across different populations or among sampling years within the same population. Comparatively, facultative endosymbionts such as Rickettsia, Wolbachia, Cardinium and Lariskella were more common in other Macrosteles species. These findings underscore the importance of considering both host and symbiont dynamics when studying microbial associations. By simultaneously characterizing host and symbiont marker gene amplicons in large insect collections, we gain valuable insights into the intricate interplay between insects and their microbial partners. Understanding these dynamics contributes to our broader comprehension of host-microbe interactions in natural ecosystems.

Dispersal restriction and facilitation in species with differing tolerance to development: A landscape genetics study of native and introduced lizards

AbstractAimThe development of natural habitats into urban land uses has greatly accelerated in the recent past due to human activities. This habitat development disrupts species' natural dispersal processes and can lead to both direct and indirect impacts on dispersal. Whether human activities result in restricted or facilitated dispersal may depend on a species' development tolerance; however, this premise has not been tested. We examined the impact of urbanization and road networks on the dispersal of three lizard species in the context of their development tolerance.LocationCuraçao.MethodsTo quantify species' development tolerance, we modelled three lizard species abundances at sites based on surrounding landscape development. Using microsatellite genotypes, we conducted individual‐based resistance surface analyses and modelled the effect of habitat development on genetic admixture to assess indirect dispersal restriction and facilitation. We explored direct facilitation of dispersal using network analysis of mitochondrial haplotypes.ResultsPhyllodactylus martini, a native gecko species, was the least tolerant of development and experienced indirect dispersal restriction due to roads, according to resistance surface analyses. Anolis lineatus, a native anole species, exhibited a neutral relationship with development. Resistance surfaces and Structure analyses showed that A. lineatus faced indirect dispersal restrictions from roads and developed areas, while mitochondrial haplotype networks suggested they benefited from occasional human‐facilitated long‐distance dispersal events. Hemidactylus mabouia, an introduced gecko species, was the most tolerant of development, and experienced no dispersal restriction, but mitochondrial haplotypes suggest direct long‐distance dispersal facilitation.Main ConclusionsOur findings highlight development tolerance as a key predictor of dispersal impact for these species and future work should test whether these patterns are upheld in other systems. Understanding how human activities affect species' dispersal will aid in managing introduced species while promoting connectivity for native species navigating dispersal challenges in dynamic landscapes.

Quantifying wildlife conflicts with metabarcoding and traditional dietary analyses: applied to seabird predation by long-nosed fur seals

Wildlife conflicts require robust quantitative data on incidence and impacts, particularly among species of conservation and cultural concern. We apply a multi-assay framework to quantify predation in a southeastern Australian scenario where complex management implications and calls for predator culling have grown despite a paucity of data on seabird predation by recovering populations of long-nosed fur seals (Arctocephalus forsteri). We apply two ecological surveillance techniques to analyze this predator’s diet – traditional morphometric (prey hard-part) and environmental DNA metabarcoding (genetic) analyses using an avian specific primer for the 12S ribosomal RNA (rRNA) gene – to provide managers with estimated predation incidence, number of seabird species impacted and inter-prey species relative importance to the predator. DNA metabarcoding identified additional seabird taxa and provided relative quantitative information where multiple prey species occur within a sample; while parallel use of both genetic and hard-part analyses revealed a greater diversity of taxa than either method alone. Using data from both assays, the estimated frequency of occurrence of predation on seabirds by long-nosed fur seals ranged from 9.1–29.3% of samples and included up to 6 detected prey species. The most common seabird prey was the culturally valued little penguin (Eudyptula minor) that occurred in 6.1–25.3% of samples, higher than previously reported from traditional morphological assays alone. We then explored DNA haplotype diversity for little penguin genetic data, as a species of conservation concern, to provide a preliminary estimate of the number of individuals consumed. Polymorphism analysis of consumed little penguin DNA identified five distinct mitochondrial haplotypes – representing a minimum of 16 individual penguins consumed across 10 fur seal scat samples (equivalent to 10.1% of samples). We recommend rapid uptake and development of cost-effective genetic techniques and broader spatiotemporal sampling of fur seal diets to further quantify predation and hotspots of concern for wildlife conflict management.

Geographical distribution of close kin in southern right whales on feeding grounds.

This study investigated the close kinship structure of southern right whales on feeding grounds during austral summer seasons. The study was based on biopsy samples of 171 individual whales, which were genotyped with 14 microsatellite DNA loci. Kinship was investigated by using the LOD (Log Odds) score, a relatedness index for a pair of genotypes. Based on a cut-off point of LODPO > 6, which was chosen to balance false positives and negatives, a total of 28 dyads were inferred. Among these, 25 were classified as parent-offspring pairs. Additional genetic (mitochondrial DNA haplotypes) and biological (estimated body length, sex) data were used to provide additional information on the inferred close kin pairs. The elapsed time between sampling varied from 0 (close kin detected in the same austral summer season) to 17 years. All the kin pairs occurred within the Antarctic Indo sector (85°-135°E) and no pair occurred between whales within and outside of this sector. Six pairs were between individuals in high (Antarctic) and lower latitudes. Results of the present analysis on kinship are consistent with the views that whales in the Indo sector of the Antarctic are related with the breeding ground in Southwest Australia, and that whales from this population can occupy different feeding grounds. The present study has the potential to contribute to the conservation of the southern right whales through the monitoring of important population parameters such as population sizes and growth rate, in addition to assist the interpretation of stock structure derived from standard population genetic analyses.

Missing history of a modern domesticate: Historical demographics and genetic diversity in farm-bred red fox populations.

The first record of captive-bred red foxes (Vulpes vulpes) dates to 1896 when a breeding enterprise emerged in the provinces of Atlantic Canada. Because its domestication happened during recent history, the red fox offers a unique opportunity to examine the genetic diversity of an emerging domesticated species in the context of documented historical and economic influences. In particular, the historical record suggests that North American and Eurasian farm-bred populations likely experienced different demographic trajectories. Here, we focus on the likely impacts of founder effects and genetic drift given historical trends in fox farming on North American and Eurasian farms. A total of 15 mitochondrial haplotypes were identified in 369 foxes from 10 farm populations that we genotyped (n = 161) or that were previously published. All haplotypes are endemic to North America. Although most haplotypes were consistent with eastern Canadian ancestry, a small number of foxes carried haplotypes typically found in Alaska and other regions of western North America. The presence of these haplotypes supports historical reports of wild foxes outside of Atlantic Canada being introduced into the breeding stock. These putative Alaskan and Western haplotypes were more frequently identified in Eurasian farms compared to North American farms, consistent with historical documentation suggesting that Eurasian economic and breeding practices were likely to maintain low-frequency haplotypes more effectively than in North America. Contextualizing inter- vs. intra-farm genetic diversity alongside the historical record is critical to understanding the origins of this emerging domesticate and the relationships between wild and farm-bred fox populations.

Genetic composition of green sea turtles (Chelonia mydas) at coastal feeding areas of Uruguay

The highly migratory and marine nature of species such as green sea turtles (Chelonia mydas) may hinder understanding of basic life history and impact ensuing management and conservation applications across their full range. To elucidate the linkages between juvenile green turtles foraging in coastal waters of Uruguay in the Southwestern Atlantic Ocean to their future nesting or feeding grounds, this study investigated their genetic composition . A total of 201 tissue samples were collected from turtles that had stranded or were intentionally captured for scientific research along the Uruguayan coast (ca. 33°–35°S) during two sampling periods (2003–2005 and 2009–2014). Samples were pooled for analysis. Twelve mitochondrial control region haplotypes and ten subhaplotypes were identified, all of which had been previously detected at Atlantic or Caribbean nesting beaches. Mixed Stock Analysis revealed that most turtles traced to the Ascension Island rookery, representing a substantial connection to the remote mid-Atlantic island thousands of kilometers distant. Other nesting areas, such as Guinea Bissau in Africa and Trindade Island in Brazil, represented less significant sources. There was no significant temporal or spatial genetic structure within Uruguayan waters, suggesting dispersion along this coast. Despite the geographic distance from the nesting beach, the significant connection to the Ascension Island rookery underscores the importance of considering rookery population size and ocean current influences in understanding source contributions. These findings emphasize the need for conservation efforts, including the maintenance of existing protected areas and the creation of new ones, to ensure the long-term conservation of green turtles connected to various nesting colonies and feeding grounds.