Populations of the Invasive Mussel Mytella strigata in China Showed Lower Genetic Diversity in Autumn than in Spring.
Native to tropical America, the charru mussel, Mytella strigata, has been spreading rapidly in the West Pacific Ocean, including the South China Sea. In order to study the adaptive evolution of M. strigata and examine the present status of invasion in China, the mitochondrial nad2 gene fragment was employed to analyze the genetic variations of seven populations sampled in both spring and autumn 2023. Results showed that all the populations had high haplotype diversity (>0.5) and low nucleotide diversity (<0.005), suggesting the ongoing rapid expansion following a genetic bottleneck. The Zhanjiang population had the highest genetic diversity in spring with 22 haplotypes, 37 polymorphic sites, and haplotype diversity, nucleotide diversity, and the average number of nucleotide differences being 0.911, 0.00623, and 4.341, respectively. However, in autumn, the Shanwei population had the most haplotypes (11) and polymorphic sites (19), with the highest haplotype diversity value of 0.891, while the Qunjian population had the highest nucleotide diversity (0.00392) and average number of nucleotide differences (2.809). Combining geographic populations by seasons confirmed lower genetic diversity in autumn compared to spring, evidenced by fewer haplotypes and polymorphic sites, reduced haplotype diversity and nucleotide diversity, and lower genetic distance within populations. These findings provided evidence for understanding the molecular characteristics of M. strigata population expansion in China.
- Research Article
49
- 10.3390/d5010039
- Feb 4, 2013
- Diversity
In the terrestrial environment, endemic species and isolated populations of widespread species have the highest rates of extinction partly due to their low genetic diversity. To determine if this pattern holds in the marine environment, we examined genetic diversity in endemic coral reef angelfishes and isolated populations of widespread species. Specifically, this study tested the prediction that angelfish (genus: Centropyge) populations at Christmas and Cocos Islands have low genetic diversity. Analyses of a 436 base pair fragment of the mtDNA control region revealed that the endemic C. joculator exhibited high haplotype (h > 0.98 at both locations) and nucleotide (Christmas p% = 3.63, Cocos p% = 9.99) diversity. Similarly, isolated populations of widespread angelfishes (C. bispinosa and C. flavicauda) had high haplotype (h > 0.98) and nucleotide (p% = 2.81 and p% = 5.78%, respectively) diversity. Therefore, in contrast to terrestrial patterns, endemic and isolated populations of widespread angelfishes do not have low genetic diversity, rather their haplotype and nucleotide diversities were among the highest reported for marine fishes. High genetic diversity should reduce extinction risk in these species as it could provide the evolutionary potential to adapt to the rapidly changing environmental conditions forecast for coral reefs.
- Research Article
1
- 10.5846/stxb201204120521
- Jan 1, 2013
- Acta Ecologica Sinica
PDF HTML阅读 XML下载 导出引用 引用提醒 基于mtCOII基因对山东省越冬代亚洲玉米螟不同种群的遗传结构分析 DOI: 10.5846/stxb201204120521 作者: 作者单位: 山东省农业科学院植保所,山东省农业科学院植保所,青岛农业大学农学与植物保护学院,青岛农业大学农学与植物保护学院,青岛农业大学农学与植物保护学院 作者简介: 通讯作者: 中图分类号: 基金项目: 现代农业产业技术体系专项资金CARS-02;"泰山学者"建设工程专项 Genetic structure of the overwintering Asian corn borer,Ostrinia furnacalis (Guenée)collections in Shandong of China based on mtCOII gene sequences Author: Affiliation: SAAS,,,,QINGDAO AGRICULTURAL UNIVERSITY Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:亚洲玉米螟Ostrinia furnacalis(Guenée)是我国重要农业害虫。为了全面揭示亚洲玉米螟遗传分化以及山东省亚洲玉米螟不同种群的遗传结构,对山东省越冬代亚洲玉米螟不同种群mtCOII基因序列与来自GenBank的相关序列进行了遗传结构分析,并建立了鉴别不同遗传支系的PCR-RFLP方法。基于对340条mtCOII序列的分析结果表明:所有样本共获得62个单倍型,其中单倍型17(H17)广泛分布于各种群之间,有6个单倍体型为山东种群所特有;亚洲玉米螟分化为2个遗传支系(支系Ⅰ与支系Ⅱ);2个遗传支系均在山东省发现,但以支系I为主;亚洲玉米螟各单倍体型散布于山东省各地理种群中,缺乏明显的地理分布格局。山东亚洲玉米螟总体的单倍体型多样性指数Hd为0.695,种群内单倍型多样性指数在0.333-0.889之间;总体的核酸多样性指数π为0.00424,种群内核酸多样性指数在0.00061-0.00809之间。总群体的固定系数 Fst 为0.79421。AMOVA分析结果表明山东亚洲玉米螟的遗传分化主要来自于2个支系之间(79.42%)。构建的亚洲玉米螟2个支系鉴别方法为其生物学与生态学的进一步研究奠定了基础。 Abstract:Ostrinia furnacalis(Guenée), the Asian corn borer, is one of the most important agricultural pests in China. It can damage crops during different crop growth stages, and can affect the yield and quality of maize. In addition, the pest has a wide geographic distribution and host range. With global warming and the expansion of corn acreage in recent years, the occurrence of the pest and associated damages have been increasing. Studying the genetic structure of the Asian corn borer is necessary for understanding the pest's evolution and migration in Shandong, a critical corn production region in China. In order to reveal the genetic diversity and structure of O. furnacalis in Shandong, China, and throughout the world, we analyzed 340 mtCOII sequences of O. furnacalis obtained both from the present study and GenBank (updated to October 1st, 2011). Of the mtCOII sequences analyzed, 214 sequences were obtained from GenBank while 126 sequences were obtained during the present study. The mtCOII sequences were aligned using MEGA5.05 and were then checked for indels and numts. Using DnaSP 5.0, a set of genetic parameters for mtCOII were estimated including: the number of polymorphic (segregating) sites (S); the total number of mutations (η); the average number of nucleotide differences (K); the number of haplotypes (H); the haplotype diversity (Hd);the nucleotide diversity (π), defined as the average number of pairwise nucleotide differences per site; and the nucleotide diversity with Jukes and Cantor correction for different host collections from Shandong Province. The results revealed that there were a total of 62 haplotypes, among which the haplotype H17 was the most widely distributed. Using the 62 haplotypes, a phylogenetic tree was constructed with the maximum likehood (ML) method; two clades (Clade Ⅰ and Clade Ⅱ) were revealed. The populations from Shandong Province consisted of two clades, although Clade I was the dominant clade. The haplotypes from Shandong were distributed randomly among 17 populations with no obvious geographical pattern. The haplotype diversity (Hd) of the populations from Shandong ranged from 0.333 to 0.889, and the Hd of the entire populations in Shandong was 0.695. The nucleotide diversity (π) of the populations from Shandong ranged from 0.00061 to 0.00809 and the π of total populations was 0.00424. Analysis of molecular variance (AMOVA) showed that 79.42% of the total genetic variance was contributed by the inter-clade variation and only 20.58% contributed by the intra-clade variation. Finally, to rapidly differentiate the two clades, a PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism) method was developed. The PCR-RFLP method of differentiating the two clades within O. furnacalis will be helpful for future research on the biological and ecological differences between the two clades. Our work revealed that the incidence of Clade Ⅱ was less than Clade Ⅰ. This might suggest that they are different in biology, ecology and physiology. Such differences could affect the clade's geographic distributions and population diffusions. These studies' results serve as a guide for the sustainable control of the pest, however these issues need to be further studied. 参考文献 相似文献 引证文献
- Research Article
17
- 10.1371/journal.pone.0240339
- Dec 11, 2020
- PloS one
BackgroundHepatitis A virus (HAV) infection is one of the major causes of acute viral hepatitis. HAV genotypes and its genetic diversity is rarely investigated in our region as well as worldwide.AimsThe aims of the present study were to determine the HAV genotypes and its risk factors and to investigate the genetic diversity of the HAV isolates in the West Bank, Palestine.Study designA cohort of 161 clinically and laboratory-confirmed HAV (IgM-positive) cases and 170 apparently healthy controls from all the districts of the West Bank, Palestine during the period of 2014 to 2016 were tested for HAV infection using IgM antibodies, RT-PCR and sequence analysis of the VP3/VP1 junction region of the HAV genome. Phylogenetic analysis, genetic diversity and haplotypes analysis were used to characterize the VP3/VP1 sequences.ResultsAll the 34 sequences of the HAV were found to be of HAV-IB sub-genotype. The phylogenetic analysis showed four main clusters with cluster III exclusively consisting of 18 Palestinian isolates (18/23-78%), but with weak bootstrap values. A high haplotype diversity (Hd) and low nucleotide diversity (π) were observed. Cluster III showed high number of haplotypes (h = 8), but low haplotype (gene) diversity (Hd = 0.69). A total of 28 active haplotypes with some consisting of more than one sequence were observed using haplotype network analysis. The Palestinian haplotypes are characterized by closely related viral haplotypes with one SNV away from each other which ran parallel to cluster III in the phylogenetic tree. A smaller Palestinian haplotype (4 isolates) was three SNVs away from the major haplotype cluster (n = 10) and closer to others haplotypes from Iran, Spain, and South Africa. Young age, low level of parent’s education, infrequent hand washing before meals, and drinking of un-treated water were considered the major HAV risk factors in the present study.ConclusionHaplotype network analysis revealed haplotype variation among the HAV Palestinian sequences despite low genetic variation and nucleotide diversity. In addition, this study reconfirmed that age and parent’s level of education as HAV risk factors, while hand washing and treating drinking water as protective factors.
- Research Article
2
- 10.12933/therya-17-508
- Sep 30, 2017
- Therya
Mormoops megalophylla is a cave-dwelling bat distributed from southern United States across Central America to northern Peru. Its conservation status at a global level is of Least Concern, according to the IUCN Red List of Threatened Species; in Ecuador, however, it is included under the Vulnerable category due to the threats faced by the only two viable populations known. Individuals from each locality (Carchi and Pichincha) were captured and marked. The D-loop of the mitochondrial control region was obtained from wing membrane tissue samples, in order to analyze the geographic distribution of nucleotide and haplotype diversity of the populations, as well as gene flow between them. The molecular variation within and between populations was evaluated through a molecular variance analysis. A high haplotype diversity and a low nucleotide diversity were observed. The gene-flow estimator revealed that Carchi and Pichincha make up a single population coming from a single lineage. The network of haplotypes indicated that those with the highest frequency are shared in both localities; the largest number of unique haplotypes, however, was observed in Pichincha. The high haplotype diversity and low nucleotide diversity values in Ecuador are due to the fact that the ghost-faced bat populations may have experienced a fast-growing period from a low effective population size, with sufficient time to accumulate haplotype diversity, but insufficient to increase nucleotide diversity. The low genetic variability between both localities indicates the existence of a panmictic population that may have been split by factors such as habitat transformation, leading to isolated colonies. The preservation of this vulnerable species will depend on conservation efforts and studies that seek to supplement the analysis of genetic variability with other molecular markers, a continued monitoring of migratory processes, and inventorying of intermediate sites and localities with historical records.
- Research Article
1
- 10.56899/150.s1.15
- Jan 25, 2021
- Philippine Journal of Science
Species belonging to the genus Caranx, locally known as “talakitok,” belong to the economically important fish in the Philippines. The popularity of these species makes them prone to overexploitation, which may result to a decline in their population in the wild. Despite these circumstances, stock assessment and population genetic variation studies are scarce. In this study, three species from this genus (C. ignobilis, C. papuensis, C. ignobilis) from the Batangas region were subjected to genetic diversity and population structure analyses using the cytochrome b (cyt b) gene of the mitochondrial DNA (mtDNA) to address these information gaps. High haplotype and high nucleotide diversity were noted in C. ignobilis, which may indicate that the population is still large and stable. However, C. papuensis and C. sexfasciatus populations had a low nucleotide diversity and high haplotype diversity, which could mean a possible genetic bottleneck in the recent past. Likewise, each of these three species showed no genetic differentiation between marine and freshwater specimens, which can be attributed to their life history and biology. Analysis of molecular variance (AMOVA) revealed weak genetic structure, indicated by low percentage value between populations. Based on neutrality tests and mismatch distribution analysis, the three species may have possibly undergone demographic expansion. This study provides the genetic profile of Caranx species found in the Batangas region before the recent Taal Volcano eruption (January 2020), which can be used to investigate the effects of this eruption on the population of this species. Likewise, results obtained from this study served as preliminary data for the population genetics of Caranx spp. found in Batangas, Philippines.
- Research Article
8
- 10.1002/vms3.996
- Nov 11, 2022
- Veterinary Medicine and Science
Kurdish horse is one of the most valuable horse genetic resources in the Middle East. To assess the genetic diversity of Kurdish horses, Mitochondrial DNA D-loop hyper-variable region1 (HVR1) was sequenced in 29 non-related Kurdish horses which were sampled from diverse geographic regions of Iran. Total DNA was extracted from the collected blood samples by modified salting out method. The HVR1 was amplified by PCR and then sequenced using ABI PRISM BigDyeTM Terminator Cycle Sequencing Ready Reaction Kit. Consequently, the sequences were trimmed to 294bp using BIOEDIT to become comparable with other reported HVR1 sequences in GeneBank. Sequence alignment was performed using CLUSTALW package. Haplotype and nucleotide diversity were estimated using DNASP5.10 and phylogenetic tree was constructed by neighbour joining method. Fourteen different haplotypes and 22 polymorphic sites were detected. Haplotype diversity, nucleotide diversity and Tajima D values were 0.901 ± 0.001, 0.01153 ± 0.0020 and -1.378, respectively. Kurdish horse showed a high haplotype and low nucleotide diversity. The compositional frequency of consensus sequences for base A was the highest (29.93%) compared to other three nucleotides (C = 28.91%, T = 26.53% and G = 14.63%). As expected, all of the detected Kurdish horse haplotypes belonged to haplogroup K (i.e., Kurdish horses). According to the phylogenetic analysis, Kurdish horses were genetically more closely related to Tibetan, Chinese, Bulgarian and Iranian native horse breeds, compared to other Asian horse breeds, but some traces of European horse breeds were detected in their maternal lines.
- Research Article
27
- 10.1016/j.jgeb.2017.11.003
- Nov 23, 2017
- Journal of Genetic Engineering & Biotechnology
Molecular insights into the genetic and haplotype diversity among four populations of Catla catla from Madhya Pradesh revealed through mtDNA cyto b gene sequences
- Research Article
- 10.1186/s12917-026-05356-4
- Feb 7, 2026
- BMC veterinary research
Hippobosca longipennis (Diptera: Hippoboscidae) is an obligate haematophagous fly of domestic and wild vertebrate hosts across the arid and semi-arid regions of Asia, Africa, Southern Europe, and the Middle East. Being a potential vector for many pathogens and a tormenting ectoparasite, the present study was envisaged to perform molecular characterization, phylogeny, and population structure analysis of H. longipennis infesting dogs in Haryana, India. The molecular characterization and phylogeny of the flies collected from the infested dogs (n = 8) were performed by targeting the partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. A global analyses of genetic differentiation, haplotype, and population structure were carried out on the present study isolates with GenBank-catalogued sequences of H. longipennis. Phylogenetic analysis revealed that the present study sequences of H. longipennis clustered within a monophyletic clade together with sequences from Morocco, Egypt, and Kenya. However, two sequences (OL505727 and MK405667) from Portugal and Romania, respectively, assorted with the out-group species sequence of Hippobosca equina. High haplotype (0.561 ± 0.154) and low nucleotide diversities (0.0019 ± 0.0009) were recorded for the complete dataset, whereas present study isolates exhibited low haplotype (0.250 ± 0.180) and nucleotide diversities (0.0003 ± 0.0002). Non-significant negative values were recorded for the neutrality indices Tajima’s D, Fu and Li’s D and Fu and Li’s F for the overall dataset (-1.428, -1.713, and − 1.859, respectively) as well as for the present study isolates (-1.054, -1.126, and − 1.203, respectively). The present study addresses an existing research gap and provides novel insights into the population genetic structure of H. longipennis, based on the mitochondrial cox1 gene analysis. These genetic data can contribute to epidemiological and vector management studies on dog louse flies.
- Research Article
- 10.3724/sp.j.1141.2008.04353
- Apr 22, 2008
- Zoological Research
According to the distribution of Phrynocephalus vlangalii hongyuanensis in Zoige Wetland,three geographic units: Zoige Xiaman (XM),Hongyuan (HY),both in Sichuan Province and Maqu (MQ) in Gansu Province were defined. We used molecular methods to reveal these unit’s genetic variation and diversity. A 785bp fragment of the mtDNA ND4-tRNAleu was determined from 72 samp1es in seven populations of P. vlangalii hongyuanensis. Seven variable nucleotide sites and nine haplotypes were identified in the 785bp fragments. As a whole,the haplotype diversity was high (0.806±0.024),but the nucleotide diversity was low (0.00231±0.00016). In a single population,MQa,MQb and XMb had very low genetic diversities,and XMc had a much higher one. The Kimura 2-parameter distances among all the populations were small (0.001-0.005),and the distance between MQa and XMa was the greatest. Analysis of molecular variance (AMOVA) showed that the three units were distinctly different (P<0.01),and 62.61% of the total genetic diversity was attributable to variation among units. There were 3 haplotypes shared among XM and HY,and no geographic clustering was observed except MQ from the TCS network. The results from the mismatch distribution analysis and Fu’s Fs test (Fs=-2.21937) implied that there might be a recent population expansion in the XM unit,and this may be the reason why XM had a high haplotype diversity but a low nucleotide diversity. We estimate that the MQ and XMb have lower diversities because of some very recent geographic events,such as the formation of the Yellow river’s upriver and the Zoige Wetland. Although they are distinctly different,not enough time has passed for them to have diverged a great genetic distance.
- Research Article
1
- 10.1155/2024/8492751
- Jan 1, 2024
- Aquaculture Research
Silver carp’s (Hypophthalmichthys molitrix) traits and genetic structure are being impacted by artificial proliferation and restocking enhancement. A clear genetic background of cultured silver carp is helpful for exploitation and utilization. Limited research reported the germplasm resources of cultured silver carp. This study was conducted to investigate the genetic diversity of cultured silver carp. Two hundred thirty‐three silver carps were sampled from eight cultured populations in Hubei province, and their population structures were analyzed by mitochondrial COI gene. Average contents of bases T, C, A, and G in the 659 bp COI gene sequence were 30.03%, 26.62%, 26.08% and 17.32%, respectively. And 18 haplotypes were defined from 77 variable nucleotides in COI gene. The haplotypes and nucleotide diversities were 0.604 and 0.00325, respectively. Meanwhile, the highest genetic diversity and lowest genetic diversity were detected in cultured populations from Jianli population (Hd: 0.883 and π: 0.00699) and Yaowan population (Hd: 0.186 and π: 0.00085), respectively. Pairwise fixation index (Fst) analysis revealed that the level of genetic diversity was moderate (Fst: 0.06). The genetic distance between and within populations were 0.00353 and 0.00329, respectively. And the genetic variation occurred mainly within populations (93.42%), but genetic variation between the population was only 6.58%. Therefore, moderate‐level genetic diversity was observed with high haplotype diversity and low nucleotide diversity, suggesting that inbreeding should be avoided among the eight cultured populations in Hubei.
- Research Article
5
- 10.1186/s12936-024-04887-1
- Feb 23, 2024
- Malaria Journal
BackgroundPlasmodium vivax Duffy binding protein (PvDBP) is a merozoite surface protein located in the micronemes of P. vivax. The invasion of human reticulocytes by P. vivax merozoites depends on the parasite DBP binding domain engaging Duffy Antigen Receptor for Chemokine (DARC) on these red blood cells (RBCs). PvDBPII shows high genetic diversity which is a major challenge to its use in the development of a vaccine against vivax malaria.MethodsA cross-sectional study was conducted from February 2021 to September 2022 in five study sites across Ethiopia. A total of 58 blood samples confirmed positive for P. vivax by polymerase chain reaction (PCR) were included in the study to determine PvDBPII genetic diversity. PvDBPII were amplified using primers designed from reference sequence of P. vivax Sal I strain. Assembling of sequences was done using Geneious Prime version 2023.2.1. Alignment and phylogenetic tree constructions using MEGA version 10.1.1. Nucleotide diversity and haplotype diversity were analysed using DnaSP version 6.12.03, and haplotype network was generated with PopART version 1.7.ResultsThe mean age of the participants was 25 years, 5 (8.6%) participants were Duffy negatives. From the 58 PvDBPII sequences, seven haplotypes based on nucleotide differences at 8 positions were identified. Nucleotide diversity and haplotype diversity were 0.00267 ± 0.00023 and 0.731 ± 0.036, respectively. Among the five study sites, the highest numbers of haplotypes were identified in Arbaminch with six different haplotypes while only two haplotypes were identified in Gambella. The phylogenetic tree based on PvDBPII revealed that parasites of different study sites shared similar genetic clusters with few exceptions. Globally, a total of 39 haplotypes were identified from 223 PvDBPII sequences representing different geographical isolates obtained from NCBI archive. The nucleotide and haplotype diversity were 0.00373 and 0.845 ± 0.015, respectively. The haplotype prevalence ranged from 0.45% to 27.3%. Two haplotypes were shared among isolates from all geographical areas of the globe.ConclusionsPvDBPII of the Ethiopian P. vivax isolates showed low nucleotide but high haplotype diversity, this pattern of genetic variability suggests that the population may have undergone a recent expansion. Among the Ethiopian P. vivax isolates, almost half of the sequences were identical to the Sal-I reference sequence. However, there were unique haplotypes observed in the Ethiopian isolates, which does not share with isolates from other geographical areas. There were two haplotypes that were common among populations across the globe. Categorizing population haplotype frequency can help to determine common haplotypes for designing an effective blood-stage vaccine which will have a significant role for the control and elimination of P. vivax.
- Research Article
3
- 10.7717/peerj.16519
- Dec 11, 2023
- PeerJ
Malaria remains a global public health challenge. The disease has a great impact in sub-Saharan Africa among children under five years of age and pregnant women. Malaria control programs targeting the parasite and mosquitoes vectors with combinational therapy and insecticide-treated bednets are becoming obsolete due to the phenomenon of resistance, which is a challenge for reducing morbidity and mortality. Malaria vaccines would be effective alternative to the problem of parasite and insecticide resistance, but focal reports of polymorphisms in malaria candidate antigens have made it difficult to design an effective malaria vaccine. Therefore, studies geared towards elucidating the polymorphic pattern and how genes targeted for vaccine design evolve are imperative. We have carried out molecular and genetic analysis of two genes encoding vaccine candidates-the Plasmodium falciparum cell traversal ookinetes and sporozoites (Pfceltos) and P. falciparum reticulocyte binding protein 5 (Pfrh5) in parasite isolates from malaria-infected children in Ibadan, Nigeria to evaluate their genetic diversity, relatedness and pattern of molecular evolution. Pfceltos and Pfrh5 genes were amplified from P. falciparum positive samples. Amplified fragments were purified and sequenced using the chain termination method. Post-sequence edit of fragments and application of various population genetic analyses was done. We observed a higher number of segregating sites and haplotypes in the Pfceltos than in Pfrh5 gene, the former also presenting higher haplotype (0.942) and nucleotide diversity (θ=0.01219 and π=0.01148). In contrast, a lower haplotype (0.426) and nucleotide diversity (θ=0.00125; π=0.00095) was observed in the Pfrh5 gene. Neutrality tests do not show deviation from neutral expectations for Pfceltos, with the circulation of multiple low frequency haplotypes (Tajima's D = -0.21637; Fu and Li's D = -0.08164; Fu and Li's F = -0.14051). Strong linkage disequilibrium was observed between variable sites, in each of the genes studied. We postulate that the high diversity and circulation of multiple haplotypes has the potential of making a Pfceltos-subunit vaccine ineffective, while the low genetic diversity of Pfrh5 gene substantiates its evolutionary conservation and potential as a malaria vaccine candidate.
- Research Article
6
- 10.1007/s00248-023-02237-3
- May 11, 2023
- Microbial Ecology
To understand the disease-mediated invasion of exotic plants and the potential risk of disease transmission in local ecosystems, it is necessary to characterize population genetic structure and spatio-temporal dynamics of fungal community associated with both invasive and co-occurring plants. In this study, multiple genes were used to characterize the genetic diversity of 165 strains of Colletotrichum gloeosporioides species complex (CGSC) isolated from healthy leaves and symptomatic leaves of invasive plant Ageratina adenophora, as well as symptomatic leaves of its neighbor plants from eleven geographic sites in China. The data showed that these CGSC strains had a high genetic diversity in each geographic site (all Hd > 0.67 and Pi > 0.01). Haplotype diversity and nucleotide diversity varied greatly in individual gene locus: gs had the highest haplotype diversity (Hd = 0.8972), gapdh had the highest nucleotide diversity (Pi = 0.0705), and ITS had the lowest nucleotide diversity (Pi = 0.0074). Haplotypes were not clustered by geographic site, invasive age, or isolation source. AMOVA revealed that the genetic variation was mainly from within-populations, regardless of geographic or isolation origin. Both AMOVA and neutrality tests indicated these CGSC strains occurred gene exchange among geographic populations but did not experience population expansion along with A. adenophora invasion progress. Our data indicated that A. adenophora primarily accumulated these CGSC fungi in the introduced range, suggesting a high frequency of CGSC transmission between A. adenophora and co-occurring neighbor plants. This study is valuable for understanding the disease-mediated plant invasion and the potential risk of disease transmission driven by exotic plants in local ecosystems.
- Research Article
9
- 10.1111/j.1749-4877.2008.00096.x
- Sep 1, 2008
- Integrative Zoology
The oriental white stork (Ciconia boyciana) is a threatened species, and their numbers are still in decline due to habitat loss and poaching. China is a breeding and main wintering area for this animal and in recent years some individuals have been found breeding in wintering areas and at some stopover sites. These new breeding colonies are an exciting sign, however, little is understood of the genetic structure of this species. Based on the analysis of a 463-bp mitochondrial DNA (mtDNA) control region, we investigated the genetic structure and genetic diversity of 66 wild oriental white storks from a Chinese population. We analyzed the sequences of 66 storks obtained in this study and the data of 17 storks from a Japanese population. Thirty-seven different haplotypes were detected among the 83 samples. An analysis of molecular variance showed a significant population subdivision between the two populations (F(ST) = 0.316, P < 0.05). However, the phylogenetic analysis revealed that the samples from the different populations did not form separate clusters and that there were genetic exchanges between the two populations. Compared with the Japanese population, the Chinese population had a relatively higher genetic diversity with a haplotype diversity (hπ SD) of 0.953 ± 0.013 and a nucleotide diversity (π± SD) of 0.013 ± 0.007. The high haplotype diversity and low nucleotide diversity indicate that this population might be in a rapidly increasing period from a small effective population. A neighbor-joining tree analysis indicated that genetic exchange had occurred between the newly arisen southern breeding colony and the northern breeding colony wintering in the middle and lower Yangtze River floodplain. These results have important implications for the conservation of the oriental white stork population in China.
- Research Article
4
- 10.1371/journal.pone.0291378
- Nov 14, 2023
- PLOS ONE
The rapid spread of HBV has resulted in the emergence of new variants. These viral genotypes and variants, in addition to carcinogenic risk, can be key predictors of therapy response and outcomes. As a result, a better knowledge of these emerging HBV traits will aid in the development of a treatment for HBV infection. However, many Sub-Saharan African nations, including Kenya, have insufficient molecular data on HBV strains circulating locally. This study conducted a population-genetics analysis to evaluate the genetic diversity of HBV among Kenyan blood donors. In addition, within the same cohort, the incidence and features of immune-associated escape mutations and stop-codons in Hepatitis B surface antigen (HBsAg) were determined. In September 2015 to October 2016, 194 serum samples were obtained from HBsAg-positive blood donors residing in eleven different Kenyan counties: Kisumu, Machakos, Uasin Gishu, Nairobi, Nakuru, Embu, Garissa, Kisii, Mombasa, Nyeri, and Turkana. For the HBV surface (S) gene, HBV DNA was isolated, amplified, and sequenced. The sequences obtained were utilized to investigate the genetic and haplotype diversity within the S genes. Among the blood donors, 74.74% were male, and the overall mean age was 25.36 years. HBV genotype A1 (88.14%) was the most common, followed by genotype D (10.82%), genotype C (0.52%), and HBV genotype E (0.52%). The phylogenetic analysis revealed twelve major clades, with cluster III comprising solely of 68 blood donor isolates (68/194-35.05%). A high haplotype diversity (Hd = 0.94) and low nucleotide diversity (π = 0.02) were observed. Kisumu county had high number of haplotypes (22), but low haplotype (gene) diversity (Hd = 0.90). Generally, a total of 90 haplotypes with some consisting of more than one sequence were observed. The gene exhibited negative values for Tajima's D (-2.04, p<0.05) and Fu's Fs (-88.84). Several mutations were found in 139 isolates, either within or outside the Major Hydrophilic Area (MHR). There were 29 mutations found, with 37.9% of them situated inside the "a" determinant. The most common mutations in this research were T143M and K122R. Escape mutations linked to diagnostic failure, vaccination and immunoglobulin treatment evasion were also discovered. Also, one stop-codon, W163STP, inside the MHR, was found in one sample from genotype A. In Kenya, HBV/A1 is still the most common genotype. Despite limited genetic and nucleotide diversity, haplotype network analysis revealed haplotype variance among HBV genotypes from Kenyan blood donors. The virological properties of immune escape, which may be the source of viral replication endurance, were discovered in the viral strains studied and included immune-escape mutations and stop-codon. The discovery of HBsAg mutations in MHR in all isolates highlighted the need of monitoring MHR mutations in Kenya.