Haplotype network analysis of wild banana relatives Ensete glaucum, Musa acuminata and Musa balbisiana based on cpDNA rbcL sequences in ex-situ collection

2020 ◽  
Vol 80 (03) ◽  
Author(s):  
Lia Hapsari ◽  
Dewi Ayu Lestari ◽  
Rasyadan Taufiq Probojati

Conservation and genetic assessment of wild banana relatives is important for future breeding purposes. Haplotype network analysis was conducted to wild banana relatives comprised Ensete glaucum, Musa acuminata and Musa balbisianausing rbcL gene sequences. Sequences characterization showed high conservation level (91%), low indels (1.83%), and low parsimony informatives (3.51%). However, it was powerfull to separate the dataset at families, genera and species level; and moderately to separate at intraspecies level of wild bananas. Haplotype and nucleotide diversity of wild bananas were high. At intraspecies level, both M. acuminata and M. balbisiana showed high haplotype diversity but low nucelotide diversity among haplotypes; M. acuminata has higher value than M. balbisiana. No haplotype and nucleotide diversity in E. glaucum. Wild bananas were separated into seven haplotypes, with four haplogroups. Mutational pathway revealed that E. glaucum haplotype became root; and was closely related to M. balbisiana than M. acuminata. M. acuminata var. malaccensis haplotype became root within all M. acuminata varieties, and each haplotype differed by single point mutation.

2020 ◽  
Author(s):  
Kamal Dumaidi ◽  
Hayah Qaraqe ◽  
Amer Al-Jawabreh ◽  
Rasmi Abu-Helu ◽  
Fekri Samarah ◽  
...  

AbstractBackgroundHAV 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 IgM negative individuals from all the districts of the West Bank, Palestine during the period of 2014-2016 were tested for VP3/VP1 junction of the HAV genome using RT-PCR and sequence analysis. Phylogenetic analysis, genetic diversity and haplotypes analysis were used to characterize the VP3/VP1 sequences.ResultsOverall, all the 34 sequences of the HAV was found to be HAV-IB sub-genotype. The phylogenetic analysis showed four main clusters with cluster III exclusively consisting of 18 Palestinian isolates (18/23-78%) 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 haplotypes from Iran, Spain, and South Africa. Young age, low level of parent’s education, poor hand washing and drinking of un-treated water was considered the major HAV risk factors in the present study.ConclusionHAV-IB subgentype is endemic in Palestine. HAV showed low genetic variation and nucleotide diversity. Furthermore, haplotype network analysis revealed haplotype variation among the Palestinian sequences.


2020 ◽  
Author(s):  
Kamal Dumaidi ◽  
Hayah Qaraqe ◽  
Amer Al-Jawabreh ◽  
Rasmi Abu-Helu ◽  
Fekri Samarah ◽  
...  

AbstractBackgroundHAV 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 IgM negative individuals from all the districts of the West Bank, Palestine during the period of 2014-2016 were tested for VP3/VP1 junction of the HAV genome using RT-PCR and sequence analysis. Phylogenetic analysis, genetic diversity and haplotypes analysis were used to characterize the VP3/VP1 sequences.ResultsOverall, all the 34 sequences of the HAV was found to be HAV-IB sub-genotype. The phylogenetic analysis showed four main clusters with cluster III exclusively consisting of 18 Palestinian isolates (18/23-78%) 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 haplotypes from Iran, Spain, and South Africa. Young age, low level of parent’s education, poor hand washing and drinking of un-treated water was considered the major HAV risk factors in the present study.ConclusionHAV-IB subgentype is endemic in Palestine. HAV showed low genetic variation and nucleotide diversity. Furthermore, haplotype network analysis revealed haplotype variation among the Palestinian sequences.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1094
Author(s):  
Andrea L. Joyce ◽  
Hannah Parolini ◽  
Harry Brailovsky

The leaffooted plant bug, Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae) is polyphagous and widely distributed in the Western Hemisphere. Although it has been recorded in California since around 1900, it has become a more common pest in almonds in the last decade. Other studies have shown that an established insect can become a pest when a new genotype is introduced. This study investigated the distribution of two lineages (strains) of L. zonatus in the Western Hemisphere. Specimens from the Leptoglossus collection in the national insect collection in Mexico were used to extract DNA and sequence the mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene, for use in population genetic and phylogenetic analyses. New sequences from Mexico, Central and South America were combined with those available in GenBank, from California and Brazil. Two lineages (strains) of L. zonatus were uncovered. One lineage occurs in California, Mexico and Ecuador. The second lineage is more widespread and found in California, Mexico, Guatemala, Nicaragua, Bolivia and Brazil. The haplotype number and diversity, and nucleotide diversity, were found for samples from California, Mexico, and Brazil, for the two lineages, and for all 118 sequences combined. All sequences combined produced five haplotypes, and a haplotype diversity of 0.54. California and Brazil had 3 haplotypes each, with one haplotype shared (5 total). Haplotype diversity in California and in Brazil were 0.526 and 0.505, respectively. A haplotype network found that one haplotype was most abundant and widespread. The small number of haplotypes, a range expansion, and economic pest status of L. zonatus in California, all contribute to this insect being a potentially invasive insect pest.


Author(s):  
Mohammad Akhoundi ◽  
Dahlia Chebbah ◽  
Denis Sereno ◽  
Anthony Marteau ◽  
Julie Jan ◽  
...  

Bed bugs, Cimex lectularius and C. hemipterus, are common blood-sucking ectoparasites of humans with a large geographical distribution, worldwide. In France, little is known about the status of bed bugs’ infestation and their resistance to insecticides, particularly, pyrethroids. Here, we aimed to find mutations in the kdr gene, known to be involved in resistance to insecticides. We gathered bed bugs from various infested locations, including 17 private houses, 12 HLM building complex, 29 apartments, 2 EHPAD, and 2 immigrants’ residences. A total of 1211 bed bugs were collected and morphologically identified as C. lectularius. Two fragments of the kdr gene, encompassing codons V419L and L925I, were successfully amplified for 156 specimens. We recorded sense mutation in the first amplified fragment (kdr1) in 89 out of 156 (57%) samples, in which in 61 out of 89 (68.5%) sequences, a change of valine (V) into leucine (L) V419L was observed. Within the second fragment (kdr2), a homozygous mutation was recorded in 73 out of 156 (46.7%) specimens at the codon 925. At this position, 43 out of 73 (58.9%) specimens had a sense mutation leading to the replacement of leucine (L) by isoleucine (I). Among 162 mutant sequences analyzed (89 for the kdr1 fragment and 73 for the kdr2 one), we detected single point mutation in 26.6%, while 73.4% presented the mutation in both kdr1 and kdr2 fragments. All modifications recorded in bed bug populations of Paris are described to be involved in the knockdown resistance (kdr) against pyrethroids.


2021 ◽  
Vol 7 (7) ◽  
pp. 553
Author(s):  
Bin Gao ◽  
Shunyi Zhu

Coronavirus Disease 2019 (COVID−19) elicited by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS−CoV−2) is calling for novel targeted drugs. Since the viral entry into host cells depends on specific interactions between the receptor−binding domain (RBD) of the viral Spike protein and the membrane−bound monocarboxypeptidase angiotensin converting enzyme 2 (ACE2), the development of high affinity RBD binders to compete with human ACE2 represents a promising strategy for the design of therapeutics to prevent viral entry. Here, we report the discovery of such a binder and its improvement via a combination of computational and experimental approaches. The binder micasin, a known fungal defensin from the dermatophytic fungus Microsporum canis with antibacterial activity, can dock to the crevice formed by the receptor−binding motif (RBM) of RBD via an extensive shape complementarity interface (855.9 Å2 in area) with numerous hydrophobic and hydrogen−bonding interactions. Using microscale thermophoresis (MST) technique, we confirmed that micasin and its C−terminal γ−core derivative with multiple predicted interacting residues exhibited a low micromolar affinity to RBD. Expanding the interface area of micasin through a single point mutation to 970.5 Å2 accompanying an enhanced hydrogen bond network significantly improved its binding affinity by six−fold. Our work highlights the naturally occurring fungal defensins as an emerging resource that may be suitable for the development into antiviral agents for COVID−19.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Bingran Wang ◽  
Tiancheng Lou ◽  
Lingling Wei ◽  
Wenchan Chen ◽  
Longbing Huang ◽  
...  

AbstractAlternaria alternata, a causal agent of leaf blights and spots on a wide range of hosts, has a high risk of developing resistance to fungicides. Procymidone, a dicarboximide fungicide (DCF), has been widely used in controlling Alternaria leaf blights in China for decades. However, the resistance of A. alternata against DCFs has rarely been reported from crucifer plants. A total of 198 A. alternata isolates were collected from commercial fields of broccoli and cabbage during 2018–2019, and their sensitivities to procymidone were determined. Biochemical and molecular characteristics were subsequently compared between the high-level procymidone-resistant (ProHR) and procymidone-sensitive (ProS) isolates, and also between ProHR isolates from broccoli and cabbage. Compared with ProS isolates, the mycelial growth rate, sporulation capacity and virulence of most ProHR isolates were reduced; ProHR isolates displayed an increased sensitivity to osmotic stresses and a reduced sensitivity to sodium dodecyl sulfate (SDS); all ProHR isolates showed a reduced sensitivity to hydrogen peroxide (H2O2) except for the isolate B102. Correlation analysis revealed a positive cross-resistance between procymidone and iprodione, or fludioxonil. When treated with 10 μg/mL of procymidone, both mycelial intracellular glycerol accumulations (MIGAs) and relative expression of AaHK1 in ProS isolates were higher than those in ProHR isolates. Sequence alignment of AaHK1 from ten ProHR isolates demonstrated that five of them possessed a single-point mutation (P94A, V612L, E708K or Q924STOP), and four isolates had an insertion or a deletion in their coding regions. No significant difference in biochemical characteristics was observed among ProHR isolates from two different hosts, though mutations in AaHK1 of the cabbage-originated ProHR isolates were distinct from those of the broccoli-originated ProHR isolates.


Author(s):  
Shereen A. Murugayah ◽  
Gary B. Evans ◽  
Joel D. A. Tyndall ◽  
Monica L. Gerth

Abstract Objective To change the specificity of a glutaryl-7-aminocephalosporanic acid acylase (GCA) towards N-acyl homoserine lactones (AHLs; quorum sensing signalling molecules) by site-directed mutagenesis. Results Seven residues were identified by analysis of existing crystal structures as potential determinants of substrate specificity. Site-saturation mutagenesis libraries were created for each of the seven selected positions. High-throughput activity screening of each library identified two variants—Arg255Ala, Arg255Gly—with new activities towards N-acyl homoserine lactone substrates. Structural modelling of the Arg255Gly mutation suggests that the smaller side-chain of glycine (as compared to arginine in the wild-type enzyme) avoids a key clash with the acyl group of the N-acyl homoserine lactone substrate. Conclusions Mutation of a single amino acid residue successfully converted a GCA (with no detectable activity against AHLs) into an AHL acylase. This approach may be useful for further engineering of ‘quorum quenching’ enzymes.


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