scholarly journals The genetics of resistance to Morinda fruit toxin during the postembryonic stages in Drosophila sechellia

2015 ◽  
Author(s):  
Yan Huang ◽  
Deniz Erezyilmaz
Keyword(s):  
Host Plant ◽  
Genetic Basis ◽  
Octanoic Acid ◽  
Major Effect ◽  
Morinda Citrifolia ◽  
Host Plant Specialization ◽  
Drosophila Sechellia ◽  
Single Host ◽  
High Resolution Analysis ◽  
Resolution Analysis

Many phytophagous insect species are ecologic specialists that have adapted to utilize a single host plant. Drosophila sechellia is a specialist that utilizes the ripe fruit of Morinda citrifolia, which is toxic to its sibling species, D. simulans. Here we apply multiplexed shotgun genotyping and QTL analysis to examine the genetic basis of resistance to M. citrifolia fruit toxin in interspecific hybrids. We find that at least four dominant and four recessive loci interact additively to confer resistance to the M. citrifolia fruit toxin. These QTL include a dominant locus of large effect on the third chromosome (QTL-IIIsima) that was not detected in previous analyses. The small-effect loci that we identify overlap with regions that were identified in selection experiments with D. simulans on octanoic acid and in QTL analyses of adult resistance to octanoic acid. Our high-resolution analysis sheds new light upon the complexity of M. citrifolia resistance, and suggests that partial resistance to lower levels of M. citrifolia toxin could be passed through introgression from D. sechellia to D. simulans in nature. The identification of a locus of major effect, QTL-IIIsima, is an important step towards identifying the molecular basis of host plant specialization by D. sechellia.

scholarly journals The genetic basis of larval resistance to a host plant toxin in Drosophila sechellia

2001 ◽  
Vol 78 (3) ◽  
pp. 225-233 ◽  
Author(s):  
CORBIN D. JONES
Keyword(s):  
Host Plant ◽  
Genetic Basis ◽  
Octanoic Acid ◽  
Morinda Citrifolia ◽  
Fourth Chromosome ◽  
Plant Toxin ◽  
Factors Affecting ◽  
Resistance Factors ◽  
Drosophila Sechellia ◽  
Close Relatives

The larvae of Drosophila sechellia are highly resistant to octanoic acid, a toxin found in D. sechellia's host plant, Morinda citrifolia. In contrast, close relatives of D. sechellia, D. simulans and D. melanogaster, are not resistant. In a series of interspecific backcrosses, 11 genetic markers were used to map factors affecting egg-to-adult (‘larval’) resistance in D. sechellia. The third chromosome harbours at least one partially dominant resistance factor. The second chromosome carries at least two mostly dominant resistance factors but no recessive factors. However, neither the X chromosome – which contains 20% of D. sechellia's genome – nor the fourth chromosome appear to affect resistance. These data suggest that larval resistance to Morinda toxin may involve only a handful of genes. These results, when compared with a previous analysis of adult resistance to Morinda toxin in D. sechellia, suggest that larval resistance may involve a subset of the genes underlying adult resistance.

scholarly journals A potential role for the gut microbiota in the specialisation of Drosophila sechellia to its toxic host noni (Morinda citrifolia)

2019 ◽  
Author(s):  
Chloe Heys ◽  
Adam M Fisher ◽  
Andrea D Dewhurst ◽  
Zenobia Lewis ◽  
Anne Lize
Keyword(s):  
Gut Microbiota ◽  
Host Plant ◽  
Lactobacillus Plantarum ◽  
Potential Role ◽  
Octanoic Acid ◽  
Acid Resistance ◽  
Morinda Citrifolia ◽  
Risk Of Death ◽  
Drosophila Sechellia ◽  
Series Of Experiments

Adaptation to a novel food source can have significant evolutionary advantages. The fruit fly, Drosophila sechellia, is a specialist of the toxic plant noni (Morinda citrifolia). Little is known as to how D. sechellia has become resistant to the toxins in the fruit - comprised predominantly of octanoic acid - but to date, the behavioural preferences for the fruit and genetic architecture underlying them, have been well studied. Here, we examine whether the gut microbiota could have played a role in adaptation to the fruit. In the first series of experiments, we examine the gut microbiota of wild-type, laboratory reared flies and characterise the gut microbiota when reared on the natural host plant, versus a standard Drosophila diet. We show a rapid transition in the core bacterial diversity and abundance within this species and discover sole precedence of Lactobacillus plantarum when reared on M. citrifolia. We also discover that flies reared on a laboratory diet are more likely to carry bacterial pathogens such as Bacillus cereus, although their function in Drosophila is unknown. Flies reared on a laboratory diet have a significantly reduced weight but with no impact on the risk of death before adulthood, when compared to the wild noni diet. In the second series of experiments, we examine the potential role of the gut microbiota in adaptation to octanoic acid resistance in this species and its sister species, Drosophila melanogaster, to which the fruit is usually fatal. We use a combination of methods to analyse resistance to octanoic acid by conducting life history analysis, behavioural assays and bacterial analysis in both D. sechellia and D. melanogaster. We find that by creating experimental evolution lines of D. melanogaster supplemented with gut microbiota from D. sechellia, we can decrease D. melanogaster aversion to octanoic acid, with the flies even preferring to feed on food supplemented with the acid. We suggest this represents the first step in the evolutionary and ecological specialisation of D. sechellia to its toxic host plant, and that the gut microbiota, Lactobacillus plantarum in particular, may have played a key role in host specialisation.

scholarly journals The Genetic Basis of Drosophila sechellia's Resistance to a Host Plant Toxin

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1899-1908 ◽  
Author(s):  
Corbin D Jones
Keyword(s):  
Host Plant ◽  
Genetic Basis ◽  
Morinda Citrifolia ◽  
F1 Hybrids ◽  
Large Chromosome ◽  
Plant Toxin ◽  
Ecological Isolation ◽  
Two Factors ◽  
Close Relatives ◽  
Chromosome Regions

Abstract Unlike its close relatives, Drosophila sechellia is resistant to the toxic effects of the fruit of its host plant, Morinda citrifolia. Using 15 genetic markers, I analyze the genetic basis of D. sechellia's resistance to this fruit's primary toxin, octanoic acid. D. sechellia's resistance is dominant in F1 hybrids between it and its sister species D. simulans. All chromosomes, except the Y and the dot fourth, carry genes affecting resistance. The third chromosome has the greatest effect and carries at least two factors. The X chromosome has an intermediate effect and harbors at least two genes, whereas the second chromosome carries at least one gene of weak effect. Thus, at least five loci are involved in this adaptation. However, I also identified large chromosome regions having no effect on resistance, suggesting that D. sechellia's resistance is neither very simple nor highly polygenic. Instead, resistance appears to have an oligogenic basis. D. sechellia's resistance to its host may contribute to ecological isolation between it and D. simulans.

Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker
Keyword(s):  
High Resolution ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Field Of View ◽  
Small Field ◽  
High Resolution Analysis ◽  
Ccd Observations ◽  
Resolution Analysis ◽  
Very High ◽  
Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

Host Plant Specialization Driven by Sexual Selection

2007 ◽  
Vol 169 (6) ◽  
pp. 830
Author(s):  
Tiago B. Quental ◽  
Manus M. Patten ◽  
Pierce
Keyword(s):  
Sexual Selection ◽  
Host Plant ◽  
Host Plant Specialization

scholarly journals The draft genome of the specialist flea beetle Altica viridicyanea (Coleoptera: Chrysomelidae)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Huai-Jun Xue ◽  
Yi-Wei Niu ◽  
Kari A. Segraves ◽  
Rui-E Nie ◽  
Ya-Jing Hao ◽  
...  
Keyword(s):  
Host Plant ◽  
Plant Cell Wall ◽  
Flea Beetle ◽  
Repetitive Sequences ◽  
Draft Genome ◽  
Gene Families ◽  
Ecological Speciation ◽  
Secondary Chemistry ◽  
Host Plant Specialization ◽  
Insight Into

Abstract Background Altica (Coleoptera: Chrysomelidae) is a highly diverse and taxonomically challenging flea beetle genus that has been used to address questions related to host plant specialization, reproductive isolation, and ecological speciation. To further evolutionary studies in this interesting group, here we present a draft genome of a representative specialist, Altica viridicyanea, the first Alticinae genome reported thus far. Results The genome is 864.8 Mb and consists of 4490 scaffolds with a N50 size of 557 kb, which covered 98.6% complete and 0.4% partial insect Benchmarking Universal Single-Copy Orthologs. Repetitive sequences accounted for 62.9% of the assembly, and a total of 17,730 protein-coding gene models and 2462 non-coding RNA models were predicted. To provide insight into host plant specialization of this monophagous species, we examined the key gene families involved in chemosensation, detoxification of plant secondary chemistry, and plant cell wall-degradation. Conclusions The genome assembled in this work provides an important resource for further studies on host plant adaptation and functionally affiliated genes. Moreover, this work also opens the way for comparative genomics studies among closely related Altica species, which may provide insight into the molecular evolutionary processes that occur during ecological speciation.

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