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.

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.

Complex Epistasis and the Genetic Basis of Hybrid Sterility in the Drosophila pseudoobscura Bogota-USA Hybridization

Genetics ◽  
2001 ◽  
Vol 158 (3) ◽  
pp. 1089-1100 ◽  
Author(s):  
H Allen Orr ◽  
Shannon Irving
Keyword(s):  
Genetic Basis ◽  
Hybrid Sterility ◽  
F1 Hybrids ◽  
Large Chromosome ◽  
Drosophila Pseudoobscura ◽  
Postzygotic Isolation ◽  
Hybrid Male ◽  
Hybrid Fertility ◽  
The Right ◽  
Chromosome Regions

Abstract We analyzed the genetic basis of postzygotic isolation between the Bogota and USA subspecies of Drosophila pseudoobscura. These subspecies diverged very recently (perhaps as recently as 155,000 to 230,000 years ago) and are partially reproductively isolated: Bogota and USA show very little prezygotic isolation but form sterile F1 males in one direction of the hybridization. We dissected the basis of this hybrid sterility and reached four main conclusions. First, postzygotic isolation appears to involve a modest number of genes: we found large chromosome regions that have no effect on hybrid fertility. Second, although apparently few in number, the factors causing hybrid sterility show a remarkably complex pattern of epistatic interaction. Hybrids suffer no hybrid sterility until they carry the “right” allele (Bogota vs. USA) at at least four loci. We describe the complete pattern of interactions between all chromosome regions known to affect hybrid fertility. Third, hybrid sterility is caused mainly by X-autosomal incompatibilities. Fourth, hybrid sterility does not involve a maternal effect, despite earlier claims to the contrary. In general, our results suggest that fewer genes are required for the appearance of hybrid sterility than implied by previous studies of older pairs of Drosophila species. Indeed, a maximum likelihood analysis suggests that roughly 15 hybrid male steriles separate the Bogota and USA subspecies. Only a subset of these would act in F1 hybrids.

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 High Resistance to Rice Yellow Mottle Virus (RYMV) in Cultivars of Two Cultivated Rice Species

Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 931-935 ◽  
Author(s):  
M. N. Ndjiondjop ◽  
L. Albar ◽  
D. Fargette ◽  
C. Fauquet ◽  
A. Ghesquière
Keyword(s):  
Genetic Basis ◽  
Virus Isolate ◽  
Mottle Virus ◽  
F1 Hybrids ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rice Yellow Mottle Virus ◽  
Recessive Resistance ◽  
Cultivated Rice ◽  
Recessive Resistance Gene ◽  
Yellow Mottle

Three cultivars of Oryza sativa (IR64, Azucena, and Gigante) and four cultivars of O. glaberrima (Tog5681, Tog5673, CG14, and SG329) were evaluated for their resistance to two isolates of rice yellow mottle virus (RYMV) by enzyme-linked immunosorbent assay (ELISA) and symptomatology. Cultivars Tog5681 and Gigante were highly resistant, and no symptoms were observed when either virus isolate was inoculated at 10 or 20 days postgermination and assayed by ELISA at 7, 14, 22, 35, 50, or 64 days postinoculation. Azucena showed a partial resistance, whereas the other cultivars were susceptible. Symptom appearance was associated with increase in ELISA absorbance in the systemically infected leaves. The best discrimination among the cultivars occurred when the plants were inoculated at 10 days postgermination. Crosses were made between the highly resistant (Gigante and Tog5681) and the susceptible (IR64) cultivars to determine the genetic basis of resistance to RYMV. Evaluation of F1 hybrids and interspecific progenies, as well as the segregation of resistance in F2 and F3 lines of the IR64 × Gigante cross, provided results consistent with the presence of a single recessive resistance gene common to Tog5681 and Gigante.

scholarly journals Genetic basis for established and novel host plant use in a herbivorous ladybird beetle, Epilachna vigintioctomaculata

1999 ◽  
Vol 91 (1) ◽  
pp. 245-250 ◽  
Author(s):  
Hideki Ueno ◽  
Naoyuki Fujiyama ◽  
Kiyoshi Irie ◽  
Yuji Sato ◽  
Haruo Katakura
Keyword(s):  
Host Plant ◽  
Genetic Basis ◽  
Ladybird Beetle ◽  
Plant Use ◽  
Novel Host ◽  
Host Plant Use

Ecological constraints and distribution of the primitive and enigmatic endemic Mexican butterflyBaronia brevicornis(Lepidoptera: Papilionidae)

2014 ◽  
Vol 147 (1) ◽  
pp. 71-88 ◽  
Author(s):  
Luc Legal ◽  
Oscar Dorado ◽  
Salima Machkour-M’Rabet ◽  
Roxanne Leberger ◽  
Jérôme Albre ◽  
...  
Keyword(s):  
Host Plant ◽  
Geographic Distribution ◽  
Potential Distribution ◽  
Average Density ◽  
Ecological Constraints ◽  
Abiotic Conditions ◽  
Occurrence Data ◽  
The World ◽  
Ancient Lineage ◽  
Close Relatives

AbstractBaronia brevicornisSalvin (Lepidoptera: Papilionidae) is one of the most enigmatic butterflies in the world and possibly represents the most ancient lineage among the superfamily Papilionoidea. Its geographic distribution is remote from that of all its potential close relatives and many of its biological and ecological characteristics are unique among the suborder Rhopalocera. One of its particularities is that the occurrence plots of this species seem to be independent, each representing individual populations, despite the fact that the host plant:Acacia cochliacanthaHumboldt and Bonpland ex Willdenow (Fabaceae), is one of the most common Mexican Fabaceae species. Our results show that noB. brevicornispopulations occur if the host plant does not cover at least two-thirds of the locality. Even in the most favourable zones, the landscape occupancy of the butterfly does not exceed 2.5% of the available habitat even when its host plant covers 50% of the area. The average density of adults was 840 individuals/ha in favourable habitats, frequently on areas of around 3 ha, below of 1400 m. Using the BIOMOD2 package and the largest available set of abiotic conditions for Mexico implemented in the WorldClim database, we propose a revised potential distribution and discuss the results of our model with field occurrence data. Evolutionary and conservation issues are discussed in the light of our results.

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 Induksi Pembentukan Gaharu Menggunakan Berbagai Media Tanam dan Cendawan Acremonium sp. dan Fusarium sp. Pada Aquilaria crassna

2016 ◽  
Vol 2 (1) ◽  
pp. 1-6
Author(s):  
TRIADIATI . ◽  
DIANA AGUSTIN CAROLINA ◽  
MIFTAHUDIN .
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Ecological Interaction ◽  
Two Factors ◽  
Fusarium Sp ◽  
Npk Fertilizer ◽  
Aquilaria Crassna

Aquilaria crassna is one of the Aquilaria species that could produce agarwood. agarwood production of A. crassna can be induced by microfungi as an inoculant. Ecological interaction between the host plant, wounding and inoculant in the formation of agarwood has not yet clearly. other factors like the plant ages, plant species, environ- ment also played important roles in the formation of agarwood. This research aimed to determine the influence of the combination between planting media and Acremonium sp. and Fusarium sp. to agarwood quality of Aquilaria crassna. The experiment was consisted of two factors, which were five planting media and two inoculants fungi i.e. Acremonium sp. and Fusarium sp. The observed parameters were the percentage of senescence leaves, color of wood, level of fragrant and terpenoid content. The best agarwood fragrant was produced by the seedlings that were treated with either combination of husk charcoal media enriched with NPK fertilizer and Acremonium sp. or the combina- tion between husk charcoal media enriched with Hoagland modified solution and Fusarium sp.. The darkest color of wood was produced by the seedlings that were treated with combination of husk charcoal media enriched with NPK fertilizer and Acremonium sp., as well as for the same media with Fusarium sp.. during the experiment terpenoid could not be detected from the treated seedlings. Acremonium sp. caused more leave senescence than that of Fusarium sp.. 

scholarly journals The role of transposable elements for gene expression in Capsella hybrids and allopolyploids

2016 ◽  
Author(s):  
Kim Steige ◽  
Johan Reimegård ◽  
Carolin A Rebernig ◽  
Claudia Köhler ◽  
Douglas G Scofield ◽  
...  
Keyword(s):  
F1 Hybrids ◽  
Regulatory Evolution ◽  
Flower Buds ◽  
Read Mapping ◽  
Future Studies ◽  
Capsella Rubella ◽  
Expression Bias ◽  
Affect Expression ◽  
Close Relatives

The formation of an allopolyploid species involves the merger of two genomes with separate evolutionary histories. In allopolyploids, genes derived from one progenitor species are often expressed at higher levels than those from the other progenitor. It has been suggested that this could be due to differences in transposable element (TE) content among progenitors, as silencing of TEs can affect expression of nearby genes. Here, we examine the role of TEs for expression biases in the widespread allotetraploid Capsella bursa-pastoris and in diploid F1 hybrids generated by crossing Capsella orientalis and Capsella rubella, two close relatives of the progenitors of C. bursa-pastoris. As C. rubella harbors more TEs than C. orientalis, we expect C. orientalis alleles to be expressed at higher levels if TE content is key for expression biases. To test this hypothesis, we quantified expression biases at approximately 5800 genes in flower buds and leaves, while correcting for read mapping biases using genomic data. While three of four C. bursa-pastoris accessions exhibited a shift toward higher relative expression of C. orientalis alleles, the fourth C. bursa-pastoris accession had the opposite direction of expression bias, as did diploid F1 hybrids. Associations between TE polymorphism and expression bias were weak, and the effect of TEs on expression bias was small. These results suggest that differences in TE content alone cannot fully explain expression biases in these species. Future studies should investigate the role of differences in TE silencing efficacy, as well as a broader set of other factors. Our results are important for a more general understanding of the role of TEs for cis-regulatory evolution in plants.

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