scholarly journals Infestation Pattern and Population Dynamics of the Tropical Bed Bug, Cimex hemipterus (F.) (Hemiptera: Cimicidae) Based on Novel Microsatellites and mtDNA Markers

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 472
Author(s):  
Wan Nur Fatanah Wan Mohammad ◽  
Li-Shen Soh ◽  
Wan Nurainie Wan Ismail ◽  
G. Veera Singham
Keyword(s):  
Genetic Diversity ◽  
Population Dynamics ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Restricted Gene Flow ◽  
Source Population ◽  
Bed Bug ◽  
Cimex Hemipterus ◽  
The Tropics ◽  
Mtdna Markers

The tropical bed bug, Cimex hemipterus (F.), has now emerged as an important public health pest in the tropics. Despite its alarming infestation rate, the information on its population genetics remains scarce. Here, we described the infestation structure and population dynamics of C. hemipterus in the tropics, especially Malaysia and Singapore, based on eight novel microsatellites and two mtDNA markers, including cytochrome c oxidase I (COI) and 16S rRNA genes. Across populations, microsatellite data revealed high genetic diversity with significant genetic differentiation and restricted gene flow. Analysis within populations revealed evidence of a recent bottleneck. Nonetheless, elevated genetic diversity in nearly all populations suggests that the propagule in C. hemipterus populations were much diverse, distantly related (mean r = 0.373), and not significantly inbred (mean FIS = 0.24) than that observed in Cimex lectularius from previous studies. We observed seven mtDNA haplotypes across the 18 populations studied (Hd = 0.593) and several populations displayed more than one matrilineal descent. The two markers were generally congruent in suggesting a common, genetically diverse (especially at the nuclear region) source population with possibilities of multiple introductions for the bed bug populations in the present study.

scholarly journals Low genetic diversity among Francisella-like endosymbionts within different genotypes of Hyalomma dromedarii ticks infesting camels in Saudi Arabia

2020 ◽  
Vol 13 (7) ◽  
pp. 1462-1472
Author(s):  
Haitham Elbir ◽  
Faisal Almathen ◽  
Ayman Elnahas
Keyword(s):  
Genetic Diversity ◽  
Saudi Arabia ◽  
Population Structure ◽  
16S Rrna ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Hyalomma Dromedarii ◽  
Low Genetic Diversity

Background and Aim: Hyalomma dromedarii ticks are vectors of disease agents and hosts of Francisella-like endosymbionts (FLEs). Knowledge about intraspecific genetic variation among H. dromedarii and its Francisella species is limited. The aims of this study were to investigate whether certain H. dromedarii genotypes are specialized in carrying specific Francisella species genotypes and scrutinize the population structure of H. dromedarii ticks in Saudi Arabia. Materials and Methods: We collected 151 H. dromedarii ticks from 33 camels from 13 locations in Saudi Arabia. The second internal transcribed spacer (ITS2), cytochrome c oxidase subunit-1(COI), and 16S rRNA genes were used for single-and multi-locus sequence typing and phylogenetic analyses. H. dromedarii-borne Francisella was screened using the tul4 gene and 16S rRNA Francisella-specific primers followed by amplicon Sanger sequencing. Results: Single-locus typing of ticks using ITS2, 16S rRNA, and COI genes yielded 1, 10, and 31 sequence types (ST), respectively, with pairwise sequence similarity of 100% for ITS2, 99.18-99.86% for COI, and 99.50-99.75% for 16S rRNA. COI sequence analysis indicated a lack of strict geographical structuration, as ST15 was found in both Saudi Arabia and Kenya. In contrast, multilocus sequence typing resolved 148 H. dromedarii ticks into 39 genotypes of ticks and three genotypes of FLEs. The ST2-FLE genotype was carried by the tick genotype ST35, while the ST1-FLE genotype and 41.89% of the ST3-FLE genotype were carried by the tick genotype ST32. Accordingly, there appeared to be no specialization of certain tick genotypes to harbor-specific FLE genotypes. Conclusion: For the 1st time, we have provided an overview of the population structure of H. dromedarii ticks and FLE strains. We found a low level of genetic diversity among FLEs and non-specialized circulation of FLEs among H. dromedarii ticks.

Genetic Diversity of the Biofilm CoveringMontacuta ferruginosa (Mollusca, Bivalvia) as Evaluated by Denaturing Gradient Gel Electrophoresis Analysis and Cloning of PCR-Amplified Gene Fragments Coding for 16S rRNA†

1998 ◽  
Vol 64 (9) ◽  
pp. 3464-3472 ◽  
Author(s):  
David C. Gillan ◽  
Arjen G. C. L. Speksnijder ◽  
Gabriel Zwart ◽  
Chantal De Ridder
Keyword(s):  
Genetic Diversity ◽  
16S Rrna ◽  
Dna Extraction ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Gradient Gel Electrophoresis ◽  
Biofilm Bacteria ◽  
Sequence Types

The shell of the bivalve Montacuta ferruginosa, a symbiont living in the burrow of an echinoid, is covered with a rust-colored biofilm. This biofilm includes different morphotypes of bacteria that are encrusted with a mineral rich in ferric ion and phosphate. The aim of this research was to determine the genetic diversity and phylogenetic affiliation of the biofilm bacteria. Also, the possible roles of the microorganisms in the processes of mineral deposition within the biofilm, as well as their impact on the biology of the bivalve, were assessed by phenotypic inference. The genetic diversity was determined by denaturing gradient gel electrophoresis (DGGE) analysis of short (193-bp) 16S ribosomal DNA PCR products obtained with primers specific for the domain Bacteria. This analysis revealed a diverse consortium; 11 to 25 sequence types were detected depending on the method of DNA extraction used. Individual biofilms analyzed by using the same DNA extraction protocol did not produce identical DGGE profiles. However, different biofilms shared common bands, suggesting that similar bacteria can be found in different biofilms. The phylogenetic affiliations of the sequence types were determined by cloning and sequencing the 16S rRNA genes. Close relatives of the genera Pseudoalteromonas,Colwellia, and Oceanospirillum (members of the γ-Proteobacteria lineage), as well as Flexibacter maritimus (a member of theCytophaga-Flavobacter-Bacteroides lineage), were found in the biofilms. We inferred from the results that some of the biofilm bacteria could play a role in the mineral formation processes.

scholarly journals Genetic diversity of 16S rRNA and mcrA genes from methanogenic archaeas

2020 ◽  
Vol 42 ◽  
pp. e49877
Author(s):  
Keyla Vitoria Marques Xavier ◽  
Eden Silva e Souza ◽  
Erick de Aquino Santos ◽  
Michely Correia Diniz
Keyword(s):  
Genetic Diversity ◽  
16S Rrna ◽  
Descriptive Analysis ◽  
Methanogenic Archaea ◽  
Ribosomal Gene ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Terrestrial Environments ◽  
Methyl Coenzyme M Reductase ◽  
Potential Use

Methanogenic archaeas are found in aquatic and terrestrial environments and are fundamental in the conversion of organic matter into methane, a gas that has a potential use as renewable source of energy, which is also considered as one of the main agents of the greenhouse effect. The vast majority of microbial genomes can be identified by a conservative molecular marker, the 16S ribosomal gene. However, the mcrA gene have been using in studies of methanogenic archaea diversity as an alternative marker, highly conserved and present only in methanogens. This gene allows the expression of the enzyme Methyl-coenzyme M reductase, the main agent in converting by-products of anaerobic digestion into methane. In this context, we aimed to study the genetic diversity of mcrA and 16S rRNA genes sequences available in databases. The nucleotide sequences were selected from the NCBI. The heterozygosity and molecular diversity indexes were calculated using the Arlequin 3.5 software, with plots generated by package R v3.0. The diversity and heterozygosity indices for both genes may have been influenced by the number and size of the sequences. Descriptive analysis of genetic diversity generated by sequences deposited in databases allowed a detailed study of these molecules. It is known that the organisms in a population are genetically distinct, and that, despite having similarities in their gene composition, the differences are essential for their adaptation to different environments.

scholarly journals Exploring genetic diversity and phylogenic relationships of Chinese cattle using gene mtDNA 16S rRNA

2019 ◽  
Vol 62 (1) ◽  
pp. 325-333 ◽  
Author(s):  
Linjun Yan ◽  
Yifan She ◽  
Mauricio A. Elzo ◽  
Chunlei Zhang ◽  
Xingtang Fang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
16S Rrna ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Haplotype Diversity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Cattle Breeds ◽  
Chinese Cattle

Abstract. The objective of this research was to characterize the genetic diversity and phylogenetic diversity among 12 cattle breeds (10 Chinese breeds and two foreign taurine breeds as controls) utilizing gene mtDNA 16S rRNA. The complete sequences of the mtDNA 16S rRNA genes of the 251 animals were 1570 bp long. The mean percentages of the four nitrogen bases were 37.8 % for adenine (A), 23.7 % for thymine (T), 20.9 % for cytosine (C), and 17.6 % for guanine (G). The mtDNA 16S rRNA gene base percentages had a strong bias towards A + T. All detected nucleotide variations in gene mtDNA 16S rRNA were either transitions (62.3 %) or transversions (37.7 %); no indels (insertions and deletions) were found. A total of 40 haplotypes were constructed based on these mutations. A total of 36 haplotypes of these 40 haplotypes were present in 10 Chinese cattle breeds. The haplotype diversity of all Chinese cattle populations was 0.903±0.077, while the nucleotide diversity was 0.0071±0.0039. Kimura's two-parameter genetic distances between pairs of the studied 12 breeds ranged from 0.001 to 0.010. The phylogenetic analysis assigned the 10 Chinese breeds to two distinct lineages that likely differed in their percentage of Bos taurus and Bos indicus ancestry.

scholarly journals Effects of habitat fragmentation and human disturbance on the population dynamics of the Yunnan snub-nosed monkey from 1994 to 2016

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6633 ◽  
Author(s):  
Xumao Zhao ◽  
Baoping Ren ◽  
Dayong Li ◽  
Zuofu Xiang ◽  
Paul A. Garber ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Dynamics ◽  
Habitat Fragmentation ◽  
Population Size ◽  
Linear Models ◽  
Conservation Strategies ◽  
Source Population ◽  
Forest Patches ◽  
Current Conservation ◽  
Conservation Policies

In this study, we integrate data from field investigations, spatial analysis, genetic analysis, and Generalized Linear Models (GLMs) to evaluate the effects of habitat fragmentation on the population dynamics, genetic diversity, and range shifts in the endangered Yunnan snub-nosed monkey (Rhinopithecus bieti). The results indicate that from 1994 to 2016, R. bieti population size increased from less than 2,000 to approximately 3,000 individuals. A primary factor promoting population recovery was the establishment of protected nature reserves. We also found that subpopulation growth rates were uneven, with the groups in some areas, and the formation of new groups. Both the fragmentation index, defined as the ratio of the number of forest patches to the total area of forest patches (e.g., increased fragmentation), and increasing human population size had a negative effect on population growth in R. bieti. We recommend that government conservation plans prioritize the protection of particular R. bieti populations, such as the Baimei and Jisichang populations, which have uncommon haplotypes. In addition, effective conservation strategies need to include an expansion of migration corridors to enable individuals from larger populations such as Guyoulong (Guilong) to serve as a source population to increase the genetic diversity of smaller R. bieti subpopulations. We argue that policies designed to protect endangered primates should not focus solely on total population size but also need to determine the amount of genetic diversity present across different subpopulations and use this information as a measure of the effectiveness of current conservation policies and the basis for new conservation policies.

scholarly journals The Diversity of Endophytic Methylotrophic Bacteria in an Oil-Contaminated and an Oil-Free Mangrove Ecosystem and Their Tolerance to Heavy Metals

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Manuella Nobrega Dourado ◽  
Anderson Ferreira ◽  
Welington Luiz Araújo ◽  
João Lúcio Azevedo ◽  
Paulo Teixeira Lacava
Keyword(s):  
Heavy Metals ◽  
Genetic Diversity ◽  
Oil Spills ◽  
Mangrove Ecosystem ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Methylotrophic Bacteria ◽  
Toxic Heavy Metal ◽  
Oil Components ◽  
Cadmium Lead

Methylobacterium strains were isolated from mangrove samples collected in Bertioga, SP, Brazil, from locations either contaminated or uncontaminated by oil spills. The tolerances of the strains to different heavy metals were assessed by exposing them to different concentrations of cadmium, lead, and arsenic (0.1 mM, 0.5 mM, 1 mM, 2 mM, 4 mM, and 8 mM). Additionally, the genetic diversity of Methylobacterium spp. was determined by sequence analysis of the 16S rRNA genes. The isolates from the contaminated locations were grouped, suggesting that oil can select for microorganisms that tolerate oil components and can change the methylotrophic bacterial community. Cadmium is the most toxic heavy metal assessed in this work, followed by arsenic and lead, and two isolates of Methylobacterium were found to be tolerant to all three metals. These isolates have the potential to bioremediate mangrove environments contaminated by oil spills by immobilizing the heavy metals present in the oil.

Genetic Diversity of Blattella germanica Isolates from Central China based on Mitochondrial Genes

2019 ◽  
Vol 14 (7) ◽  
pp. 574-580 ◽  
Author(s):  
Pan Wei ◽  
XiaoDong Xie ◽  
Ran Wang ◽  
JianFeng Zhang ◽  
Feng Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
16S Rrna ◽  
Population Expansion ◽  
Blattella Germanica ◽  
Central China ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Coi Gene ◽  
Single Population

Background: Blattella germanica is a widespread urban invader insect that can spread numerous types of human pathogens, including bacteria, fungi, and protozoa. Despite the medical significance of B. germanica, the genetic diversity of this species has not been investigated across its wide geographical distribution in China. Objective: In this study, the genetic variation of B. germanica was evaluated in central China. Methods: Fragments of the mitochondrial cytochrome c oxidase subunit I (COI) gene and the 16S rRNA gene were amplified in 36 B. germanica isolates from 7 regions. The sequence data for COI and 16S rRNA genes were analyzed using bioinformatics methods. Results: In total, 13 haplotypes were found among the concatenated sequences. Each sampled population, and the total population, had high haplotype diversity (Hd) that was accompanied by low nucleotide diversity (Pi). Molecular genetic variation analysis indicated that 84.33% of the genetic variation derived from intra-region sequences. Phylogenetic analysis indicated that the B. germanica isolates from central China should be classified as a single population. Demographic analysis rejected the hypothesis of sudden population expansion of the B. germanica population. Conclusion: The 36 isolates of B. germanica sampled in this study had high genetic variation and belonged to the same species. They should be classified as a single population. The mismatch distribution analysis and BSP analysis did not support a demographic population expansion of the B. germanica population, which provided useful knowledge for monitoring changes in parasite populations for future control strategies.

scholarly journals The influence of light and water mass on bacterial population dynamics in the Amundsen Sea Polynya

Elem Sci Anth ◽  
2015 ◽  
Vol 3 ◽  
Author(s):  
Inga Richert ◽  
Julie Dinasquet ◽  
Ramiro Logares ◽  
Lasse Riemann ◽  
Patricia L. Yager ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Organic Carbon ◽  
Southern Ocean ◽  
Austral Summer ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Environmental Drivers ◽  
Nutrient Loads ◽  
Amundsen Sea ◽  
Bacterial Populations

Abstract Despite being perpetually cold, seasonally ice-covered and dark, the coastal Southern Ocean is highly productive and harbors a diverse microbiota. During the austral summer, ice-free coastal patches (or polynyas) form, exposing pelagic organisms to sunlight, triggering intense phytoplankton blooms. This strong seasonality is likely to influence bacterioplankton community composition (BCC). For the most part, we do not fully understand the environmental drivers controlling high-latitude BCC and the biogeochemical cycles they mediate. In this study, the Amundsen Sea Polynya was used as a model system to investigate important environmental factors that shape the coastal Southern Ocean microbiota. Population dynamics in terms of occurrence and activity of abundant taxa was studied in both environmental samples and microcosm experiments by using 454 pyrosequencing of 16S rRNA genes. We found that the BCC in the photic epipelagic zone had low richness, with dominant bacterial populations being related to taxa known to benefit from high organic carbon and nutrient loads (copiotrophs). In contrast, the BCC in deeper mesopelagic water masses had higher richness, featuring taxa known to benefit from low organic carbon and nutrient loads (oligotrophs). Incubation experiments indicated that direct impacts of light and competition for organic nutrients are two important factors shaping BCC in the Amundsen Sea Polynya.

Differentiation Of Clarias Batrachus, C. Gariepinus And Heteropneustes Fossilis By Pcr-Sequencing Of Mitochondrial 16s Rrna Gene

2015 ◽  
Vol 41 (1) ◽  
pp. 51-58
Author(s):  
Mohammad Shamimul Alam ◽  
Hawa Jahan ◽  
Rowshan Ara Begum ◽  
Reza M Shahjahan
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Fish Larva ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Valuable Insight ◽  
Multiple Sequence ◽  
Pcr Rflp ◽  
Alternative Means

Heteropneustesfossilis, Clariasbatrachus and C. gariepinus are three major catfishes ofecological and economic importance. Identification of these fish species becomes aproblem when the usual external morphological features of the fish are lost or removed,such as in canned fish. Also, newly hatched fish larva is often difficult to identify. PCRsequencingprovides accurate alternative means of identification of individuals at specieslevel. So, 16S rRNA genes of three locally collected catfishes were sequenced after PCRamplification and compared with the same gene sequences available from othergeographical regions. Multiple sequence alignment of the 16S rRNA gene fragments ofthe catfish species has revealed polymorphic sites which can be used to differentiate thesethree species from one another and will provide valuable insight in choosing appropriaterestriction enzymes for PCR-RFLP based identification in future. Asiat. Soc. Bangladesh, Sci. 41(1): 51-58, June 2015

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