scholarly journals Wolbachia infection in Argentinean populations of Anastrepha fraterculus sp1: preliminary evidence of sex ratio distortion by one of two strains

2019 ◽  
Author(s):  
CA Conte ◽  
DF Segura ◽  
FH Milla ◽  
AA Augustinos ◽  
JL Cladera ◽  
...  

ABSTRACTBackgroundWolbachia, one of the most abundant taxa of intracellular Alphaproteobacteria, is widespread among arthropods and filarial nematodes. The presence of these maternally inherited bacteria is associated with modifications of host fitness, including a variety of reproductive abnormalities, such as cytoplasmic incompatibility, thelytokous parthenogenesis, host feminization and male-killing. Wolbachia has attracted much interest for its role in biological, ecological and evolutionary processes as well as for its potential use in novel and environmentally-friendly strategies for the control of insect pests and disease vectors including a major agricultural pest, the South American fruit fly, Anastrepha fraterculus Wiedemann (Diptera: Tephritidae).ResultsWe used wsp, 16S rRNA and a multilocus sequence typing (MLST) scheme including gatB, coxA, hcpA, fbpA, and ftsZ genes to detect and characterize the Wolbachia infection in laboratory strains and wild populations of A. fraterculus from Argentina. Wolbachia was found in all A. fraterculus individuals studied. Nucleotide sequences analysis of wsp gene allowed the identification of two Wolbachia nucleotide variants (named wAfraCast1_A and wAfraCast2_A). After the analysis of 76 individuals, a high prevalence of the wAfraCast2_A variant was found both, in laboratory (82%) and wild populations (95%). MLST analysis identified both Wolbachia genetic variants as sequence type 13. Phylogenetic analysis of concatenated MLST datasets clustered wAfraCast1/2_A in the supergroup A. Paired-crossing experiments among single infected laboratory strains showed a phenotype specifically associated to wAfraCast1_A that includes slight detrimental effects on larval survival, a female-biased sex ratio; suggesting the induction of male-killing phenomena, and a decreased proportion of females producing descendants that appears attributable to the lack of sperm in their spermathecae.ConclusionsWe detected and characterized at the molecular level two wsp gene sequence variants of Wolbachia both in laboratory and wild populations of A. fraterculus sp.1 from Argentina. Crossing experiments on singly-infected A. fraterculus strains showed evidence of a male killing-like mechanism potentially associated to the wAfraCast1_A - A. fraterculus interactions. Further mating experiments including antibiotic treatments and the analysis of early and late immature stages of descendants will contribute to our understanding of the phenotypes elicited by the Wolbachia variant wAfraCast1_A in A. fraterculus sp.1.

2019 ◽  
Vol 19 (S1) ◽  
Author(s):  
Claudia Alejandra Conte ◽  
Diego Fernando Segura ◽  
Fabian Horacio Milla ◽  
Antonios Augustinos ◽  
Jorge Luis Cladera ◽  
...  

Abstract Background Wolbachia, one of the most abundant taxa of intracellular Alphaproteobacteria, is widespread among arthropods and filarial nematodes. The presence of these maternally inherited bacteria is associated with modifications of host fitness, including a variety of reproductive abnormalities, such as cytoplasmic incompatibility, thelytokous parthenogenesis, host feminization and male-killing. Wolbachia has attracted much interest for its role in biological, ecological and evolutionary processes as well as for its potential use in novel and environmentally-friendly strategies for the control of insect pests and disease vectors including a major agricultural pest, the South American fruit fly, Anastrepha fraterculus Wiedemann (Diptera: Tephritidae). Results We used wsp, 16S rRNA and a multilocus sequence typing (MLST) scheme including gatB, coxA, hcpA, fbpA, and ftsZ genes to detect and characterize the Wolbachia infection in laboratory strains and wild populations of A. fraterculus from Argentina. Wolbachia was found in all A. fraterculus individuals studied. Nucleotide sequences analysis of wsp gene allowed the identification of two Wolbachia nucleotide variants (named wAfraCast1_A and wAfraCast2_A). After the analysis of 76 individuals, a high prevalence of the wAfraCast2_A variant was found both, in laboratory (82%) and wild populations (95%). MLST analysis identified both Wolbachia genetic variants as sequence type 13. Phylogenetic analysis of concatenated MLST datasets clustered wAfraCast1/2_A in the supergroup A. Paired-crossing experiments among single infected laboratory strains showed a phenotype specifically associated to wAfraCast1_A that includes slight detrimental effects on larval survival, a female-biased sex ratio; suggesting the induction of male-killing phenomena, and a decreased proportion of females producing descendants that appears attributable to the lack of sperm in their spermathecae. Conclusions We detected and characterized at the molecular level two wsp gene sequence variants of Wolbachia both in laboratory and wild populations of A. fraterculus sp.1 from Argentina. Crossing experiments on singly-infected A. fraterculus strains showed evidence of a male killing-like mechanism potentially associated to the wAfraCast1_A - A. fraterculus interactions. Further mating experiments including antibiotic treatments and the analysis of early and late immature stages of descendants will contribute to our understanding of the phenotypes elicited by the Wolbachia variant wAfraCast1_A in A. fraterculus sp.1.


2021 ◽  
Vol 288 (1943) ◽  
pp. 20202125
Author(s):  
Kazuki Yoshida ◽  
Sachiyo Sanada-Morimura ◽  
Shou-Horng Huang ◽  
Makoto Tokuda

According to evolutionary theory, sex ratio distortions caused by reproductive parasites such as Wolbachia and Spiroplasma are predicted to be rapidly normalized by the emergence of host nuclear suppressors. However, such processes in the evolutionary arms race are difficult to observe because sex ratio biases will be promptly hidden and become superficially unrecognizable. The evolution of genetic suppressors has been reported in just two insect species so far. In the small brown planthopper, Laodelphax striatellus , female-biases caused by Spiroplasma , which is a ‘late’ male-killer, have been found in some populations. During the continuous rearing of L. striatellus , we noted that a rearing strain had a 1 : 1 sex ratio even though it harboured Spiroplasma . Through introgression crossing experiments with a strain lacking suppressors, we revealed that the L. striatellus strain had the zygotic male-killing suppressor acting as a dominant trait. The male-killing phenotype was hidden by the suppressor even though Spiroplasma retained its male-killing ability. This is the first study to demonstrate the existence of a late male-killing suppressor and its mode of inheritance. Our results, together with those of previous studies, suggest that the inheritance modes of male-killing suppressors are similar regardless of insect order or early or late male killing.


2011 ◽  
Vol 46 (6) ◽  
pp. 669-671 ◽  
Author(s):  
Adrise Medeiros Nunes ◽  
Dori Edson Nava ◽  
Fernanda Appel Müller ◽  
Rafael da Silva Gonçalves ◽  
Mauro Silveira Garcia

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.


Parasitology ◽  
2006 ◽  
Vol 132 (6) ◽  
pp. 757-765 ◽  
Author(s):  
M. C. TINSLEY ◽  
M. E. N. MAJERUS

Whilst most animals invest equally in males and females when they reproduce, a variety of vertically transmitted parasites has evolved the ability to distort the offspring sex ratios of their hosts. One such group of parasites are male-killing bacteria. Here we report the discovery of females of the ladybirdAnisosticta novemdecimpunctatathat produced highly female-biased offspring sex ratios associated with a 50% reduction in egg hatch rate. This trait was maternally transmitted with high efficiency, was antibiotic sensitive and was infectious following experimental haemolymph injection. We identified the cause as a male-killingSpiroplasmabacterium and phylogenetic analysis of rDNA revealed that it belongs to theSpiroplasma ixodetisclade in which other sex ratio distorters lie. We tested the potential for interspecific horizontal transfer by injection from an infectedA. novemdecimpunctataline into uninfected individuals of the two-spot ladybirdAdalia bipunctata. In this novel host, the bacterium was able to establish infection, transmit vertically and kill male embryos.


2020 ◽  
Vol 17 (2) ◽  
pp. 97
Author(s):  
Andi Nurdaaniyah ◽  
Dadang Dadang ◽  
I Wayan Winasa

<p>Brown planthopper (<em>Nilaparvata lugens</em> (Stål)) is one of the major rice insect pests that is known to cause high loss of rice production. One of the strategies to control this pest is by using resistant rice varieties. The aim of this research was to study the resistance of IPB 3S variety to BPH by measuring BPH fecundity, sex ratio, feeding activity as well as population increase compared to Ciherang variety against brown planthopper (<em>N. lugens</em>). Fecundity test used a pair of BPH adult infested on 21 days after planting (DAP) of rice plants. Eggs laid in rice stalks and the rest of eggs in the ovary were counted. In order to know the change of sex ratio, a pair of BPH adults was infested on 30 DAP rice plants and allowed to lay eggs. The calculation of sex ratio was conducted at adult stage of BPH by segregation between male and female adults. Feeding activity of BPH was evaluated using ninhydrin and analyzed qualitatively using spectrophotometer. Ten fourth instar nymphs of BPH was infested on 30 DAP old of rice seedlings. Honeydew secreted by BPH was collected to filter paper sprayed with ninhydrin. Population increased test was conducted by infesting five pairs of BPH adults on 35 DAP old rice plants. Observations was conducted on nymph and adult stages. Each test was replicated 10 times. In general, IPB 3S is slightly resistant to BPH, compared to Ciherang variety. The feeding activity of BPH is higher in Ciherang compared to IPB3S. However, the fecundity and population increased of BPH in Ciherang is similar to IPB3S.</p>


2018 ◽  
Vol 285 (1877) ◽  
pp. 20180369 ◽  
Author(s):  
Masayuki Hayashi ◽  
Masashi Nomura ◽  
Daisuke Kageyama

Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing Mallada desjardinsi . An M. desjardinsi population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing Spiroplasma endosymbiont, had a sex ratio near parity in 2016, despite a consistent Spiroplasma prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing Spiroplasma variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly Hypolimnas bolina in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated.


2002 ◽  
Vol 32 (12) ◽  
pp. 1457-1468 ◽  
Author(s):  
M Casiraghi ◽  
J.W McCall ◽  
L Simoncini ◽  
L.H Kramer ◽  
L Sacchi ◽  
...  

Parasitology ◽  
1982 ◽  
Vol 84 (4) ◽  
pp. 241-268 ◽  
Author(s):  
J. K. Waage ◽  
M. P. Hassell

SUMMARYThis review begins with a description of the parasitoid life-style and the ecological and evolutionary factors which generate the remarkable diversity of insect parasitoids. We then describe the various ways that parasitoids have been used in the biological control of insect pests, and survey their success to date. The use of parasitoids remains largely an art, aided by past experience of success and failure. A more fundamental approach, involving basic research and theory, has not as yet contributed significantly to practical biological control. We explore the potential for such a science of parasitoid use and review basic research on parasitoid ecology and evolution which is of particular relevance to biological control. Mathematical models are used to identify and examine those parasitoid and host attributes which lead to successful biological control. Factors such as parasitoid foraging behaviour, fecundity, larval survival and sex ratio are shown to be important in influencing the depression of host populations and/or the stability of host–parasitoid interactions after depression. Multiple release is discussed and a model for inundative release of parasitoids is explored.


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