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wolbachia infections and the expression of cytoplasmic incompatibility in drosophila sechellia and d. mauritiana.various stocks of drosophila mauritiana and d. sechellia were found to be infected with wolbachia, a rickettsia-like bacterium that is known to cause cytoplasmic incompatibility and other reproductive abnormalities in arthropods. testing for the expression of cytoplasmic incompatibility in these two species showed partial incompatibility in d. sechellia but no expression of incompatibility in d. mauritiana. to determine whether absence of cytoplasmic incompatibility in d. mauritiana was due to e ...19957498772
mariner transposase-like sequences from the hessian fly, mayetiola destructor.transposable genetic elements are assumed to be a feature of all eukaryotic genomes. they can serve as vectors in gene transfer systems and as mutagenic agents for isolation of genes. until recently their identification has been primarily limited to organisms subjected to extensive genetic or molecular study. the hessian fly, mayetiola destructor (say), is an agriculturally important pest of wheat, triticum aestivum l., in the united states and other parts of the world. we assessed the presence ...19957560872
the transposable element impala, a fungal member of the tc1-mariner superfamily.a new transposable element has been isolated from an unstable niad mutant of the fungus fusarium oxysporum. this element, called impala, is 1280 nucleotides long and has inverted repeats of 27 bp. impala inserts into a ta site and leaves behind a "foot-print" when it excises. the inserted element, impala-160, is cis-active, but is probably trans-defective owing to several stop codons and frameshifts. similarities exist between the inverted repeats of impala and those of transposons belonging to ...19957823909
the drosophila melanogaster dodecasatellite sequence is closely linked to the centromere and can form connections between sister chromatids during mitosis.we have used fluorescence in situ hybridisation to wild-type and rearranged mitotic chromosomes to map the drosophila melanogaster dodecasatellite sequence. it is located at a unique site, within the pericentric heterochromatin of the right arm of the third chromosome, closely linked to the primary constriction. in polytene chromosomes, dodecasatellite is found as one or a few dots in the central region of the chromocentre. in untreated diploid cells, dodecasatellite sequences are found as one o ...19938360277
interplasmid transposition of the mariner transposable element in non-drosophilid insects.plasmid-based transposition assays were performed in developing embryos of the australian sheep blowfly lucilia cuprina and the queensland fruit fly bactrocera tryoni, using the mariner transposable element from drosophila mauritiana. transposition products were recovered that were identical in structure to those recovered from d. melanogaster. only sequences delimited by the mariner terminal repeats were transposed and all insertions occurred at ta residues, and duplicated these. these are the ...19979079884
mariner: its prospects as a dna vector for the genetic manipulation of medically important insects.originally described in drosophila mauritiana, the mariner transposable element has very recently been identified in 63 other insect species, representing ten insect orders, and including the malaria-vector mosquito, anopheles gambiae. ann warren and julian crampton here discuss how transposable elements can be exploited as valuable research tools for the molecular characterization of genomes and as dna vectors for genome manipulation and the 'creation' of transgenic organisms.199415275500
the bandit, a new dna transposon from a hookworm-possible horizontal genetic transfer between host and parasite.an enhanced understanding of the hookworm genome and its resident mobile genetic elements should facilitate understanding of the genome evolution, genome organization, possibly host-parasite co-evolution and horizontal gene transfer, and from a practical perspective, development of transposon-based transgenesis for hookworms and other parasitic nematodes.200717989781
cloning and characterization of acmar1, a mariner-like element in the asiatic honey bee, apis cerana japonica (hymenoptera, apocrita).a mariner-like element was cloned from the genome of the asiatic honey bee, apis cerana japonica (hymenoptera, apocrita). the (composite) clone, named acmar1, was 1,378 bp long, and encoded 336 amino acids corresponding to a transposase-like putative polypeptide in a single open reading frame. the d,d(34)d motif, the catalytic domain of the mariner transposase, was present, although there was a deletion of five amino acid residues within it as compared with the active transposase in drosophila m ...200212125059
a comparison of frost expression among species and life stages of drosophila.frost (fst) is a gene associated with cold exposure in drosophila melanogaster. we used real-time pcr to assess whether cold exposure induces expression of fst in 10 different life stages of d. melanogaster, and adults of seven other drosophila species. we exposed groups of individuals to 0 °c (2 h), followed by 1 h recovery (22 °c). frost was significantly upregulated in response to cold in eggs, third instar larvae, and 2- and 5-day-old male and female adults in d. melanogaster. life stages in ...201221955087
purified mariner (mos1) transposase catalyzes the integration of marked elements into the germ-line of the yellow fever mosquito, aedes aegypti.derivatives of the mariner transposable element, mos1, from drosophila mauritiana, can integrate into the germ-line of the yellow fever mosquito, aedes aegypti. previously, the transposase required to mobilize mos1 was provided in trans by a helper plasmid expressing the enzyme under the control of the d. psuedoobscura heat-shock protein 82 promoter. here we tested whether purified recombinant mos1 transposase could increase the recovery of ae. aegypti transformants. mos1 transposase was injecte ...200010989286
factors acting on mos1 transposition efficiency.mariner-like elements (mles) are widespread dna transposons in animal genomes. although in vitro transposition reactions require only the transposase, various factors depending on the host, the physico-chemical environment and the transposon sequence can interfere with the mles transposition in vivo.200819036139
five major subfamilies of mariner transposable elements in insects, including the mediterranean fruit fly, and related arthropods.we have used a pcr assay to screen 404 insects and related arthropods for mariner elements using primers corresponding to amino acids conserved between the mariner elements of drosophila mauritiana and a moth, hyalophora cecropia. potential mariner elements were detected in sixty-three species, representing ten insect orders as well as a centipede and a mite. phylogenetic analysis of the pcr fragment sequences from thirty species identifies five major subfamilies of mariners. many species have r ...19939087550
the mariner transposable element is widespread in insects.the mariner transposable element is a small member of the short inverted terminal repeat class thought to transpose through a dna intermediate. originally described in drosophila mauritiana, it is now known in several species of the family drosophilidae, and in a moth hyalophora cecropia. here i use primers designed to represent regions of amino-acid conservation between the putative transposase genes of the d. mauritiana and h. cecropia elements to amplify equivalent regions of presumed mariner ...19938384700
the transposable element mariner can excise in non-drosophilid insects.plasmid-based excision assays performed in embryos of two non-drosophilid species using the mariner transposable element from drosophila mauritiana resulted in empty excision sites identical to those observed after the excision of mariner from d. mauritiana chromosomes. in the presence of the autonomous mariner element mos1, excision products were recovered from d. melanogaster, d. mauritiana and the blowfly lucilia cuprina. when a hsp82 heat shock promoter-mos1 construct was used to supply mari ...19957500947
natural courtship song variation caused by an intronic retroelement in an ion channel gene.animal species display enormous variation for innate behaviours, but little is known about how this diversity arose. here, using an unbiased genetic approach, we map a courtship song difference between wild isolates of drosophila simulans and drosophila mauritiana to a 966 base pair region within the slowpoke (slo) locus, which encodes a calcium-activated potassium channel. using the reciprocal hemizygosity test, we confirm that slo is the causal locus and resolve the causal mutation to the evol ...201627509856
incomplete maternal transmission of mitochondrial dna in drosophila.the possibility of incomplete maternal transmission of mitochondrial dna (mtdna) in drosophila, previously suggested by the presence of heteroplasmy, was examined by intra- and interspecific backcrosses of drosophila simulans and its closest relative, drosophila mauritiana. mtdnas of offspring in these crosses were characterized by southern hybridization with two alpha-32p-labeled probes that are specific to paternal mtdnas. this method could detect as little as 0.03% paternal mtdna, if present, ...20062249764
copia expression is variable among natural populations of drosophila.a survey of copia (retroviral-like element) expression in flies representing 37 populations worldwide of drosophila melanogaster, drosophila simulans and drosophila mauritiana demonstrates that, although copia elements are present in all three species, copia-encoded transcripts are detectable only in d. melanogaster. levels of copia transcripts vary nearly 100-fold among flies representing geographically diverse populations of d. melanogaster and this variation is not correlated with variability ...19701700962
dna-binding activity and subunit interaction of the mariner transposase.mos1 is a member of the mariner/tc1 family of transposable elements originally identified in drosophila mauritiana. it has 28 bp terminal inverted repeats and like other elements of this type it transposes by a cut and paste mechanism, inserts at ta dinucleotides and codes for a transposase. this is the only protein required for transposition in vitro. we have investigated the dna binding properties of mos1 transposase and the role of transposase-transposase interactions in transposition. purifi ...200111522826
molecular and cytological analysis of a mariner transposon from hessian fly.degenerate pcr primers for conserved regions of the mariner transposase have been shown to amplify dna sequences from the hessian fly (mayetiola destructor). using one of these sequences as a hybridization probe, a clone from an m. destructor genomic library in phage lambda was recovered and sequenced. a transposable element, desmar 1, with perfect inverted terminal repeats and an open reading frame that encodes a mariner class transposase was found. when compared to mariner sequences in the gen ...19979048446
coupled instability of two x-linked genes in drosophila mauritiana: germinal and somatic mutability.a highly unstable allele has been isolated at the white locus of drosophila mauritiana, a sibling species of d. melanogaster. this allele, white-peach (wpch), mutates spontaneously in males and females to give both wild-type and bleached-white derivatives. the mutation frequency is about 10(-3) mutations/generation. there is no evidence for clustering among mutant progeny, and phenotypically wpch flies with mosaic patches of wild-type tissue in the eyes are frequently recovered. another x-linked ...19853928432
genetic architecture and functional characterization of genes underlying the rapid diversification of male external genitalia between drosophila simulans and drosophila mauritiana.male sexual characters are often among the first traits to diverge between closely related species and identifying the genetic basis of such changes can contribute to our understanding of their evolutionary history. however, little is known about the genetic architecture or the specific genes underlying the evolution of male genitalia. the morphology of the claspers, posterior lobes, and anal plates exhibit striking differences between drosophila mauritiana and d. simulans. using qtl and introgr ...201525783699
neighboring genes for dna-binding proteins rescue male sterility in drosophila hybrids.crosses between closely related animal species often result in male hybrids that are sterile, and the molecular and functional basis of genetic factors for hybrid male sterility is of great interest. here, we report a molecular and functional analysis of hms1, a region of 9.2 kb in chromosome 3 of drosophila mauritiana, which results in virtually complete hybrid male sterility when homozygous in the genetic background of sibling species drosophila simulans. the hms1 region contains two strong ca ...201627357670
high-resolution genome-wide dissection of the two rules of speciation in drosophila.postzygotic reproductive isolation is characterized by two striking empirical patterns. the first is haldane's rule--the preferential inviability or sterility of species hybrids of the heterogametic (xy) sex. the second is the so-called large x effect--substitution of one species's x chromosome for another's has a disproportionately large effect on hybrid fitness compared to similar substitution of an autosome. although the first rule has been well-established, the second rule remains controvers ...017850182
interspecific y chromosome variation is sufficient to rescue hybrid male sterility and is influenced by the grandparental origin of the chromosomes.y chromosomes display population variation within and between species. co-evolution within populations is expected to produce adaptive interactions between y chromosomes and the rest of the genome. one consequence is that y chromosomes from disparate populations could disrupt harmonious interactions between co-evolved genetic elements and result in reduced male fertility, sterility or inviability. here we address the contribution of 'heterospecific y chromosomes' to fertility in hybrid males car ...201626980343
a transposon-based tool for transformation and mutagenesis in trypanosomatid protozoa.the ability of transposable elements to mobilize across genomes and affect the expression of genes makes them exceptional tools for genetic manipulation methodologies. several transposon-based systems have been modified and incorporated into shuttle mutagenesis approaches in a variety of organisms. we have found that the mos1 element, a dna transposon from drosophila mauritiana, is suitable and readily adaptable to a variety of strategies to the study of trypanosomatid parasitic protozoa. trypan ...201525388118
genome diversity and divergence in drosophila mauritiana: multiple signatures of faster x evolution.drosophila mauritiana is an indian ocean island endemic species that diverged from its two sister species, drosophila simulans and drosophila sechellia, approximately 240,000 years ago. multiple forms of incomplete reproductive isolation have evolved among these species, including sexual, gametic, ecological, and intrinsic postzygotic barriers, with crosses among all three species conforming to haldane's rule: f(1) hybrid males are sterile and f(1) hybrid females are fertile. extensive genetic r ...201425193308
intact mariner-like element in tobacco budworm, heliothis virescens (lepidoptera: noctuidae).an intact mariner-like element was isolated from the genome of tobacco budworm, heliothis virescens. this is the first report of an intact mariner element after the initial identification of mos1 from drosophila mauritiana. the full-length hvmar1 has 30 bp inverted terminal repeats and a complete 1065 bp open reading frame (orf) encoding the transposase with a 'd,d(34)d' motif in the catalytic domain. polymerase chain reaction results show that at least one insertion of the hvmar1 element is con ...200617201767
population genomics from pool sequencing.next generation sequencing of pooled samples is an effective approach for studies of variability and differentiation in populations. in this paper we provide a comprehensive set of estimators of the most common statistics in population genetics based on the frequency spectrum, namely the watterson estimator θw, nucleotide pairwise diversity π, tajima's d, fu and li's d and f, fay and wu's h, mcdonald-kreitman and hka tests and fst, corrected for sequencing errors and ascertainment bias. in a sim ...201324102736
maternal effect and speciation: maternal effect contributes to the evolution of hybrid inviability between drosophila simulans and drosophila mauritiana.haldane's rule has been the basis of speciation research during the last 30 years. most studies have focused on the nature of incompatibilities in the hybrid male, but not much attention has been given to the genetic basis of fertility and inviability in hybrid females. hybridizations between drosophila simulans and drosophila mauritiana produce fertile females and sterile males. here, we re-examined the level of fertility in reciprocal f1 females of these two species and looked for the presence ...201526436586
genome diversity and divergence in drosophila mauritiana: multiple signatures of faster x evolution. 201525991815
recurrent positive selection of the drosophila hybrid incompatibility gene hmr.lethality in hybrids between drosophila melanogaster and its sibling species drosophila simulans is caused in part by the interaction of the genes hybrid male rescue (hmr) and lethal hybrid rescue (lhr). hmr and lhr have diverged under positive selection in the hybridizing species. here we test whether positive selection of hmr is confined only to d. melanogaster and d. simulans. we find that hmr has continued to diverge under recurrent positive selection between the sibling species d. simulans ...200818755760
transposition of mboumar-9: identification of a new naturally active mariner-family transposon.although mariner transposons are widespread in animal genomes, the vast majority harbor multiple inactivating mutations and only two naturally occurring elements are known to be active. previously, we discovered a mariner-family transposon, mboumar, in the satellite dna of the ant messor bouvieri. several copies of the transposon contain a full-length open reading frame, including mboumar-9, which has 64% nucleotide identity to mos1 of drosophila mauritiana. to determine whether mboumar is curre ...200818675277
an intron loss of dfak gene in species of the drosophila melanogaster subgroup and phylogenetic analysis.drosophila focal adhesion kinase (dfak) gene is a single-copy nuclear gene. previous study revealed that drosophila melanogaster and drosophila simulans had lost an intron precisely within the tyrosine kinase (tyk) domain of this gene. however, this did not happen in several other drosophila species, including drosophila elegans, drosophila ficusphila, drosophila biarmipes, drosophila jambulina, drosophila prostipennis, drosophila takahashii, and drosophila pseudoobscura. in the current study, h ...200918310070
no evidence for external genital morphology affecting cryptic female choice and reproductive isolation in drosophila.genitalia are one of the most rapidly diverging morphological features in animals. the evolution of genital morphology is proposed to be driven by sexual selection via cryptic female choice, whereby a female selectively uptakes and uses a particular male's sperm on the basis of male genital morphology. the resulting shifts in genital morphology within a species can lead to divergence in genitalia between species, and consequently to reproductive isolation and speciation. although this conceptual ...201525962316
genetic and developmental analysis of differences in eye and face morphology between drosophila simulans and drosophila mauritiana.eye and head morphology vary considerably among insects and even between closely related species of drosophila. species of the d. melanogaster subgroup, and other drosophila species, exhibit a negative correlation between eye size and face width (fw); for example, d. mauritiana generally has bigger eyes composed of larger ommatidia and conversely a narrower face than its sibling species. to better understand the evolution of eye and head morphology, we investigated the genetic and developmental ...201723809700
mos1-mediated insertional mutagenesis in caenorhabditis elegans.we describe a protocol for mutating genes in the nematode caenorhabditis elegans using the mos1 transposon of drosophila mauritiana. mutated genes containing a mos1 insertion are molecularly tagged by this heterologous transposable element. mos1 insertions can therefore be identified in as little as 3 weeks using only basic molecular biology techniques. mutagenic efficiency of mos1 is tenfold lower than classical chemical mutagens. however, the ease and speed with which mutagenic insertions can ...200717546024
genome-wide patterns of expression in drosophila pure species and hybrid males. ii. examination of multiple-species hybridizations, platforms, and life cycle stages.species often produce sterile hybrids early in their evolutionary divergence, and some evidence suggests that hybrid sterility may be associated with deviations or disruptions in gene expression. in support of this idea, many studies have shown that a high proportion of male-biased genes are underexpressed, compared with non-sex-biased genes, in sterile f1 male hybrids of drosophila species. in this study, we examined and compared patterns of misexpression in sterile f1 male hybrids of drosophil ...200717032727
fast protein evolution and germ line expression of a drosophila parental gene and its young retroposed paralog.this is the first detailed study of the evolution, phylogenetic distribution, and transcription of one young retroposed gene, cg13732, and its parental gene cg15645, whose functions are unknown. cg13732 is a recognizable retroposed copy of cg15645 retaining the signals of this process. we name the parental gene cervantes and the retrogene quijote. to determine when this duplication occurred and the phylogenetic distribution of quijote, we employed polymerase chain reaction, southern blotting, an ...200616916943
transposition of the mariner element from drosophila mauritiana in zebrafish.with the increased popularity of zebrafish (danio rerio) for mutagenesis studies, efficient methods for manipulation of its genome are needed. one approach is the use of a transposable element as a vector for gene transfer in this species. we report here the transformation of zebrafish and germ-line transmission of the mariner element from drosophila mauritiana. the mariner element was selected because its transposition is independent of host-specific factors. one- to two-cell-stage zebrafish em ...19989560250
complete nucleotide sequence of the a+t-rich region of drosophila mauritiana mitochondrial dna.we determined the complete nucleotide sequence of the a+t-rich region of the maii type of mtdna in d. mauritiana. the nucleotide sequence was found to contain 3,206 bp. three types of conserved element, i.e., type i element, type ii element, and t-stretch, were included in this sequence, as reported for d. melanogaster. comparison between the two species revealed that the type i elements were less conserved than the type ii elements. however, each of these type i elements contained a g-stretch w ...200616607038
the minimal interspecific introgression resulting in male sterility in drosophila.introgression of drosophila simulans genes into the drosophila melanogaster genome provides an ideal system for analysing genetic incompatibility between species. females and males homozygous for the introgression int(2l)s (cytologically, 30f3-31c5 to 36a2-7) are sterile. genetic dissection of the proximal part of the introgression (34d1-3 to 36a2-7) has indicated that introgressions of 0.7-1.6 mb size result in male sterility when homozygous. in the present analysis we examine the distal part o ...200415678745
localization of ribosomal dna insertion elements in polytene chromosomes of drosophila simulans, drosophila mauritiana and their interspecific hybrids.the locations of the ribosomal dna (rdna) insertion elements type i and type ii along the polytene chromosomes of three drosophila species of the melanogaster subgroup--d. simulans, d. mauritiana and d. melanogaster--have been compared. in situ hybridization has shown that the intragenomic distribution of type i as well as of type ii insertions is different for these related species. in particular, we have revealed rdna-free autosomal sites, containing type ii element sequences within the d. sim ...19921325940
mariner-like elements in hymenopteran species: insertion site and distribution.copies of mariner-like element (mle) transposons in two species, the bumble bee, bombus terrestris, and the ant, myrmica ruginodis, were sequenced. the full-sized elements are 1250 bp long in both species and include 28-bp inverted terminal repeats. the five copies sequenced were approximately 75% similar to a mariner element (peach) of drosophila mauritiana. the distribution of mle in 27 hymenopteran species was studied by pcr and southern blot hybridization; 93% of the species contained one or ...19948159761
reduction of germ cells in the odysseus null mutant causes male fertility defect in drosophila melanogaster.odysseus (odsh) has been identified as a hybrid male sterility gene between drosophila mauritiana and d. simulans with accelerated evolutionary rate in both expression and dna sequence. loss of a testis-specific expression of odsh causes male fertility defect in d. melanogaster. yet, the underlying mechanisms at the cellular level are unknown. in an attempt to identify the possible mechanisms and functional roles of odsh in spermatogenesis, the cell numbers at different developmental stages duri ...201223229314
genetic dissection of hybrid incompatibilities between drosophila simulans and d. mauritiana. ii. mapping hybrid male sterility loci on the third chromosome.hybrid male sterility (hms) is a rapidly evolving mechanism of reproductive isolation in drosophila. here we report a genetic analysis of hms in third-chromosome segments of drosophila mauritiana that were introgressed into a d. simulans background. qualitative genetic mapping was used to localize 10 loci on 3r and a quantitative trait locus (qtl) procedure (multiple-interval mapping) was used to identify 19 loci on the entire chromosome. these genetic incompatibilities often show dominance and ...200312930748
genetic dissection of hybrid incompatibilities between drosophila simulans and d. mauritiana. i. differential accumulation of hybrid male sterility effects on the x and autosomes.the genetic basis of hybrid incompatibility in crosses between drosophila mauritiana and d. simulans was investigated to gain insight into the evolutionary mechanisms of speciation. in this study, segments of the d. mauritiana third chromosome were introgressed into a d. simulans genetic background and tested as homozygotes for viability, male fertility, and female fertility. the entire third chromosome was covered with partially overlapping segments. many segments were male sterile, while none ...200312930747
genome-wide patterns of natural variation reveal strong selective sweeps and ongoing genomic conflict in drosophila mauritiana.although it is well understood that selection shapes the polymorphism pattern in drosophila, signatures of classic selective sweeps are scarce. here, we focus on drosophila mauritiana, an island endemic, which is closely related to drosophila melanogaster. based on a new, annotated genome sequence, we characterized the genome-wide polymorphism by sequencing pooled individuals (pool-seq). we show that the interplay between selection and recombination results in a genome-wide polymorphism pattern ...201323051690
sex-ratio segregation distortion associated with reproductive isolation in drosophila.sex-ratio distortion is the most common form of non-mendelian segregation observed in natural populations. it may occur even more frequently than direct observations suggest, because the dysgenic population consequences of a biased sex ratio are expected to result in the rapid evolution of suppressors, resulting in suppressed or "cryptic" segregation distortion. here we report evidence for cryptic sex-ratio distortion that was discovered by introgressing segments of the genome of drosophila maur ...200111687638
hsp70 duplication in the drosophila melanogaster species group: how and when did two become five?to determine how the modern copy number (5) of hsp70 genes in drosophila melanogaster evolved, we localized the duplication events that created the genes in the phylogeny of the melanogaster group, examined d. melanogaster genomic sequence to investigate the mechanisms of duplication, and analyzed the hsp70 gene sequences of drosophila orena and drosophila mauritiana. the initial two-to-four hsp70 duplication occurred 10--15 mya, according to fixed in situ hybridization to polytene chromosomes, ...200111420366
cis- and trans-acting genetic factors contribute to heterogeneity in the rate of crossing over between the drosophila simulans clade species.in the genus drosophila, variation in recombination rates has been found within and between species. genetic variation for both cis- and trans-acting factors has been shown to affect recombination rates within species, but little is known about the genetic factors that affect differences between species. here, we estimate rates of crossing over for seven segments that tile across the euchromatic length of the x chromosome in the genetic backgrounds of three closely related drosophila species. we ...201222817673
regulatory potential of nonautonomous mariner elements and subfamily crosstalk.two naturally occurring nonautonomous mariner elements were tested in vivo for their ability to down-regulate excision of a target element in the presence of functional mariner transposase. the tested elements were the peach element isolated from drosophila mauritiana, which encodes a transposase that differs from the autonomous element mos1 in four amino acid replacements, and the dtbz1 element isolated from d. teissieri, which encodes a truncated protein consisting of the first 132 residues at ...199910952200
the phylogeny of closely related species as revealed by the genealogy of a speciation gene, odysseus.molecular differentiation between races or closely related species is often incongruent with the reproductive divergence of the taxa of interest. shared ancient polymorphism and/or introgression during secondary contact may be responsible for the incongruence. at loci contributing to speciation, these two complications should be minimized (1, 2); hence, their variation may more faithfully reflect the history of the species' reproductive differentiation. in this study, we analyzed dna polymorphis ...200010779562
mariner, mos and associated aberrant traits in drosophila mauritiana.a suite of aberrant genetic traits, including increased mutation rate, sex-limited mutation and distorted transmission ratios, was produced among progeny of genetic crosses between two strains of drosophila mauritiana when a paternally contributed mos excision factor is placed into a non-mos genetic background. in the reciprocal cross, involving maternally contributed mos and mos associated cytoplasm, the same genetic abnormalities are not observed. differential effects on mariner excision in ge ...20072168336
hidden effects of x chromosome introgressions on spermatogenesis in drosophila simulans x d. mauritiana hybrids unveiled by interactions among minor genetic factors.one of the most frequent outcomes of interspecific hybridizations in drosophila is hybrid male sterility. genetic dissection of this reproductive barrier has revealed that the number of responsible factors is very high and that these factors are frequently engaged in complex epistatic interactions. traditionally, research strategies have been based on contrasting introgressions of chromosome segments that produce male sterility with those that allow fertility. few studies have investigated the p ...19989755205
factors affecting transposition of the himar1 mariner transposon in vitro.mariner family transposable elements are widespread in animals, but their regulation is poorly understood, partly because only two are known to be functional. these are particular copies of the dmmar1 element from drosophila mauritiana, for example, mos1, and the consensus sequence of the himar1 element from the horn fly, haematobia irritans. an in vitro transposition system was refined to investigate several parameters that influence the transposition of himar1. transposition products accumulat ...19989584095
the genetic basis of behavioral isolation between drosophila mauritiana and d. sechellia.understanding how species form is a fundamental question in evolutionary biology. identifying the genetic bases of barriers that prevent gene flow between species provides insight into how speciation occurs. here, i analyze a poorly understood reproductive isolating barrier, prezygotic reproductive isolation. i perform a genetic analysis of prezygotic isolation between two closely related species of drosophila, d. mauritiana and d. sechellia. i first confirm the existence of strong behavioral is ...201222759294
nucleotide sequence divergence in the a+t-rich region of mitochondrial dna in drosophila simulans and drosophila mauritiana.we have determined the nucleotide sequences of two regions within the a+t-rich region of mitochondrial dna (mtdna) in the siiii type of drosophila simulans and the mai type of d. mauritiana. the sequences of the two regions in siiii and mai are almost identical. the sequences include elements corresponding to the type i and type ii repeats elements and the t-stretches as reported in d. melanogaster; an approximately 340-bp region (a region) adjacent to the trna(ile) gene includes a part of the t ...19979254919
inter-island divergence within drosophila mauritiana, a species of the d. simulans complex: past history and/or speciation in progress?speciation with gene flow may be more common than generally thought, which makes detailed understanding of the extent and pattern of genetic divergence between geographically isolated populations useful. species of the drosophila simulans complex provide a good model for speciation and evolutionary studies, and hence understanding their population genetic structure will increase our understanding of the context in which speciation has occurred. here, we describe genetic diversity and genetic dif ...201121599771
genetic and molecular investigations on the endogenous mobile elements of non-drosophilid fruitflies.a syndrome of abnormal genetic effects, resembling drosophila hybrid dysgenesis, occurs in ceratitis capitata when strains of different origin are mated. the pattern of abnormal traits observed appears to be the phenotypic expression of a complex interacting dysgenic system of inducer and suppressor effects; probably more than one system is activated in the crosses. this suggests that different systems of mobile elements occur in different strains and populations of c. capitata. using a pcr prim ...19979440264
naturally occurring variation in copia expression is due to both element (cis) and host (trans) regulatory variation.significant differences in levels of copia [drosophila long terminal repeat (ltr) retrotransposon] expression exist among six species representing the drosophila melanogaster species complex (d. melanogaster, drosophila mauritiana, drosophila simulans, drosophila sechellia, drosophila yakuba, and drosophila erecta) and a more distantly related species (drosophila willistoni). these differences in expression are correlated with major size variation mapping to putative regulatory regions of the co ...19968692951
the broom of the sorcerer's apprentice: the fine structure of a chromosomal region causing reproductive isolation between two sibling species of drosophila.how many genes contribute to reproductive isolation between closely related species? we determined the number of genes located in the 9d-12b region of the drosophila mauritiana x chromosome that cause hybrid male sterility in a d. simulans background. previous low resolution studies suggested that a single hybrid sterility factor was associated with this region. in this study, by taking advantage of a cluster of visible and dna markers, we identified three d. mauritiana factors in this region an ...19968807300
wolbachia enhance drosophila stem cell proliferation and target the germline stem cell niche.wolbachia are widespread maternally transmitted intracellular bacteria that infect most insect species and are able to alter the reproduction of innumerous hosts. the cellular bases of these alterations remain largely unknown. here, we report that drosophila mauritiana infected with a native wolbachia wmau strain produces about four times more eggs than the noninfected counterpart. wolbachia infection leads to an increase in the mitotic activity of germline stem cells (gscs), as well as a decrea ...201122021671
a genome-wide survey of hybrid incompatibility factors by the introgression of marked segments of drosophila mauritiana chromosomes into drosophila simulans.in hybrids between drosophila simulans and d. mauritiana, males are sterile and females are fertile, in compliance with haldane's rule. the genetic basis of this phenomenon was investigated by introgression of segments of the mauritiana genome into a simulans background. a total of 87 positions throughout the mauritiana genome were marked with p-element insertions and replicate introgressions were made by repeated backcrossing to simulans for 15 generations. the fraction of hemizgyous x chromoso ...19968849890
multiple hybridization events between drosophila simulans and drosophila mauritiana are supported by mtdna introgression.the study of speciation has advanced considerably in the last decades because of the increased application of molecular tools. in particular, the quantification of gene flow between recently diverged species could be addressed. drosophila simulans and drosophila mauritiana diverged, probably allopatrically, from a common ancestor approximately 250,000 years ago. however, these species share one mitochondrial dna (mtdna) haplotype indicative of a recent episode of introgression. to study the exte ...201020958812
[transposable element mariner].mariner and mariner-like elements (mles) have been found in a wide range of organisms including human since its discovery in drosophila mauritiana. mles belong to the mariner/tc1 superfamily, one of the most diverse and widespread class ii transposable elements. mles have a conserved "d,d(34)d" motif in their transposases and they transpose by cut-and-paste mechanisms. their extraordinarily wide host range and horizontal transmission in distantly related species indicate that they do not need ad ...200415640098
ethanol tolerance and variation at the alcohol dehydrogenase (adh) locus of drosophila mauritiana.drosophila mauritiana larvae are tolerant to ethanol as a supplementary nutritional resource at low concentrations. higher levels of ethanol (5 per cent) in the food adversely affect larval behaviour causing reduced rates of locomotion and feeding which are associated with low larva-to-adult survival. two codominant autosomal alleles adhs and adhf controlling variant electromorphs of alcohol dehydrogenase are indistinguishable in their effects on ethanol tolerance in this species. a comparison o ...19957759290
altered heterochromatin binding by a hybrid sterility protein in drosophila sibling species.hybrid sterility of the heterogametic sex is one of the first postzygotic reproductive barriers to evolve during speciation, yet the molecular basis of hybrid sterility is poorly understood. we show that the hybrid male sterility gene odysseus-site homeobox (odsh) encodes a protein that localizes to evolutionarily dynamic loci within heterochromatin and leads to their decondensation. in drosophila mauritiana x drosophila simulans male hybrids, odsh from d. mauritiana (odshmau) acts as a steriliz ...200919933102
genetics and lineage-specific evolution of a lethal hybrid incompatibility between drosophila mauritiana and its sibling species.the dobzhansky-muller model posits that intrinsic postzygotic reproductive isolation--the sterility or lethality of species hybrids--results from the evolution of incompatible epistatic interactions between species: favorable or neutral alleles that become fixed in the genetic background of one species can cause sterility or lethality in the genetic background of another species. the kind of hybrid incompatibility that evolves between two species, however, depends on the particular evolutionary ...200919189951
the roles of cis- and trans-regulation in the evolution of regulatory incompatibilities and sexually dimorphic gene expression.evolutionary changes in gene expression underlie many aspects of phenotypic diversity within and among species. understanding the genetic basis for evolved changes in gene expression is therefore an important component of a comprehensive understanding of the genetic basis of phenotypic evolution. using interspecific introgression hybrids, we examined the genetic basis for divergence in genome-wide patterns of gene expression between drosophila simulans and drosophila mauritiana. we find that cis ...201424043293
genetics of a nonoptimal behavior: oviposition preference of drosophila mauritiana for a toxic resource.among three sibling species of the d. melanogaster subgroup, two are generalists (d. simulans and d. mauritiana), while the third, d. sechellia, specializes on a single toxic resource, the fruit of morinda citrifolia. d. sechellia, resistant to the toxics, prefers to oviposit on morinda; d. simulans, which is very sensitive, is strongly repelled. d. mauritiana exhibits an aberrant behavior since it prefers to lay its eggs on morinda, where its embryos are killed. oviposition behavior, studied in ...19947993320
rapid diversification of sperm precedence traits and processes among three sibling drosophila species.postcopulatory sexual selection is credited with driving rapid evolutionary diversification of reproductive traits and the formation of reproductive isolating barriers between species. this judgment, however, has largely been inferred rather than demonstrated due to general lack of knowledge about processes and traits underlying variation in competitive fertilization success. here, we resolved processes determining sperm fate in twice-mated females, using transgenic drosophila simulans and droso ...201323888856
origination of an x-linked testes chimeric gene by illegitimate recombination in drosophila.the formation of chimeric gene structures provides important routes by which novel proteins and functions are introduced into genomes. signatures of these events have been identified in organisms from wide phylogenic distributions. however, the ability to characterize the early phases of these evolutionary processes has been difficult due to the ancient age of the genes or to the limitations of strictly computational approaches. while examples involving retrotransposition exist, our understandin ...200616715176
a new hybrid rescue allele in drosophila melanogaster.crosses of drosophila melanogaster females to males of its sibling species drosophila simulans, drosophila mauritiana and drosophila sechellia produce no sons and daughters that are viable only at low temperatures. we describe here a novel rescue allele df(1)ep307-1-2 isolated on the basis of its suppression of high temperature hybrid female lethality. df(1)ep307-1-2 also rescues hybrid males to the pharate adult stage, the same stage at which it is lethal to d. melanogaster pure species males. ...200415088664
a reanalysis of protein polymorphism in drosophila melanogaster, d. simulans, d. sechellia and d. mauritiana: effects of population size and selection.comparison of synonymous and nonsynonymous variation/substitution within and between species at individual genes has become a widely used general approach to detect the effect of selection versus drift. the sibling species group comprised of two cosmopolitan (drosophila melanogaster and drosophila simulans) and two island (drosophila mauritiana and drosophila sechellia) species has become a model system for such studies. in the present study we reanalyzed the pattern of protein variation in thes ...200415088651
cloning and characterization of a mariner-like element in the silkworm, bombyx mori.we have identified a mariner-like element (mle) in the genome of the silkworm, bombyx mori. the cloned mle, desiqnated as bmmle, contained an orf that was interrupted by insertions, stop codons, and frameshifts. the complete orf sequence was estimated by sequencing the pcr products. the hypothetical protein coded by this orf showed 34% homology to the mos1 element of drosophila mauritiana, and is phylogenetically very close to mle of hyalophora cecropia. bmmle is present in 80 to 100 copies in t ...19979418262
mariner (mos1) transposase and genomic integration of foreign gene sequences in bombyx mori cells.widespread occurrence in insects and the capacity to transpose in the absence of host-derived factors means that mariner-like elements are considered to be attractive candidates for the development of a universal insect genetic transformation system. here we show that the mos1 mariner element of drosophila mauritiana is capable of mediating excision and transposition events in a silkmoth (bombyx mori) derived tissue culture cell line (bm5 cells). plasmid rescue assays, in combination with southe ...200010762422
patterns of microsatellite variability in the drosophila melanogaster complex.forty-seven microsatellite loci were amplified in drosophila melanogaster, drosophila simulans, drosophila mauritiana and drosophila sechellia. the two cosmopolitan species d. melanogaster and d. simulans were found to be the most variable ones, followed by d. mauritiana and d. sechellia. a model based clustering algorithm was applied to the population samples of d. melanogaster, d. simulans and d. sechellia. no evidence for population substructure was detected within species--most likely due to ...200415088648
further observation of paternal transmission of drosophila mitochondrial dna by pcr selective amplification method.by designing 3' ends of primers in pcr (polymerase chain reaction), a specific dna fragment was selectively amplified in the presence of a 10(3)-fold excess of highly homologous (sequence difference ca. 2%) opponent dna. this technique was applied in detecting paternal leakage of mitochondrial dna (mtdna) in intraspecific crosses of drosophila simulans and interspecific crosses of drosophila simulans and drosophila mauritiana. the mtdna types of their progeny were analysed by selective amplifica ...19921628820
sequence analysis of active mariner elements in natural populations of drosophila simulans.active and inactive mariner elements from natural and laboratory populations of drosophila simulans were isolated and sequenced in order to assess their nucleotide variability and to compare them with previously isolated mariner elements from the sibling species drosophila mauritiana and drosophila sechellia. the active elements of d. simulans are very similar among themselves (average 99.7% nucleotide identity), suggesting that the level of mariner expression in different natural populations is ...19921312979
evidence for interspecific transfer of the transposable element mariner between drosophila and zaprionus.the transposable element mariner occurs widely in the melanogaster species group of drosophila. however, in drosophilids outside of the melanogaster species group, sequences showing strong dna hybridization with mariner are found only in the genus zaprionus. the mariner sequence obtained from zaprionus tuberculatus is 97% identical with that from drosophila mauritiana, a member of the melanogaster species subgroup, whereas a mariner sequence isolated from drosophila tsacasi is only 92% identical ...19911664000
identification of nucleotide substitutions necessary for trans-activation of mariner transposable elements in drosophila: analysis of naturally occurring elements.six copies of the mariner element from the genomes of drosophila mauritiana and drosophila simulans were chosen at random for dna sequencing and functional analysis and compared with the highly active element mos1 and the inactive element peach. all elements were 1286 base pairs in length, but among them there were 18 nucleotide differences. as assayed in drosophila melanogaster, three of the elements were apparently nonfunctional, two were marginally functional, and one had moderate activity th ...19911655567
a highly repetitive, mariner-like element in the genome of hyalophora cecropia.a highly repetitive dna element, homologous to the mariner transposon of drosophila mauritiana was found in the intron of the gene for cecropin a, an antibacterial peptide from the cecropia moth. the mariner-like elements (mle) represent a homogeneous population with a copy number of about 1000/genome. sequencing analysis showed it to be 1255 base pairs long, including 38-base pair terminal inverted repeats. the mle contains a defective reading frame. nevertheless, the putative product is clearl ...19911646809
do deletions of mos1-like elements occur randomly in the drosophilidae family?we compared deleted copies of the seven mauritiana subfamilies of mariner transposable elements in species of the drosophilidae. all elements were detected by pcr using the inverted terminal repeats of the mos1 element of drosophila mauritiana as primers. a higher frequency of breakpoints in the 5prime prime or minute part of the element compared to the 3prime prime or minute part was observed. of the 27 deletions, 9 (33%) occurred between short direct repeats (sdr) of 5 to 8 bp. the sdrs can be ...200211821915
molecular and functional analysis of the mariner mutator element mos1 in drosophila.the white-peach allele in drosophila results from insertion of the transposable element mariner. the particular copy that is inserted in white-peach is an inactive copy referred to as the peach element. the peach element is excised at a high rate in the presence of active copies of mariner located elsewhere in the genome, and the excision of peach in somatic cells is recognized phenotypically by the occurrence of eye-color mosaicism in white-peach flies. active mariner elements identified by the ...19911649068
a bend, flip and trap mechanism for transposon integration.cut-and-paste dna transposons of the mariner/tc1 family are useful tools for genome engineering and are inserted specifically at ta target sites. a crystal structure of the mariner transposase mos1 (derived from drosophila mauritiana), in complex with transposon ends covalently joined to target dna, portrays the transposition machinery after dna integration. it reveals severe distortion of target dna and flipping of the target adenines into extra-helical positions. fluorescence experiments confi ...201627223327
evolution of drosophila mitochondrial dna and the history of the melanogaster subgroup.the nucleotide sequences of a common region of 15 mitochondrial dnas (mtdnas) sampled from the drosophila melanogaster subgroup were determined. the region is 2527 base pairs long, including most of the nadh dehydrogenase subunit 2 and cytochrome oxidase subunit 1 genes punctuated by three trna genes. the comparative study revealed (i) the extremely low saturation level of transitional differences, (ii) recombination or variable substitution rates even within species, (iii) long persistence time ...19902124697
sex in drosophila mauritiana: a very high level of amino acid polymorphism in a male reproductive protein gene, acp26aa.many genes pertaining to male reproductive functions have been shown to evolve rapidly between species, and evidence increasingly suggest the influence of positive darwinian selection. the accessory gland protein gene (acp26aa) of drosophila is one such example. in order to understand the mechanism of selection, it is often helpful to examine the pattern of polymorphism. we report here that the level of amino acid polymorphism in the n-terminal quarter of acp26aa is high in drosophila melanogast ...200111141189
induction of mitochondrial dna heteroplasmy by intra- and interspecific transplantation of germ plasm in drosophila.a new experimental system for inducing mitochondrial dna heteroplasmy in drosophila was developed. by transplanting the germ plasm of drosophila melanogaster and drosophila mauritiana into the posterior pole of the recipient eggs of d. melanogaster, it was possible to introduce foreign mitochondria into the recipient female germline. heteroplasmic individuals containing both donor and recipient mtdna were obtained in intra- and interspecific combinations at similar frequencies. the proportion of ...198917246507
genetics of sexual isolation between two sibling species, drosophila simulans and drosophila mauritiana.drosophila simulans and drosophila mauritiana are sibling species that show substantial sexual isolation in one of their two reciprocal hybridizations. genetic analysis reveals that in females this isolation is caused by at least one recessive gene on each autosome, while the x chromosome has little or no effect. our results, combined with those of previous studies, show that in drosophila the genetics of sexual isolation differs from that of postzygotic reproductive isolation, which invariably ...19892748596
phylogenetic analysis of mos1-like transposable elements in the drosophilidae.we have performed a phylogenetic analysis of 59 mariner elements in 14 drosophilidae species that are related to the active drosophila mauritiana mos1 element. this includes 38 previously described sequences and 21 new sequences amplified by pcr from 10 species. most of the elements detected are nonfunctional due to several frameshifts and deletions. they have been subdivided into four groups according to specific signatures in the nucleotidic and amino acid sequences. the mean nucleotide divers ...199910594177
excision of the drosophila transposable element mariner: identification and characterization of the mos factor.genetic and molecular evidence presented in this paper demonstrate that the mos factor for inherited mosaicism is a special copy of the transposable element mariner. mosaicism observed in the presence of the mos (mosaic) factor results from a high frequency of excision of the mariner element from an insertion site near the white-eye gene in drosophila mauritiana. the mos factor promotes the excision of mariner elements from genomic insertion sites other than the site in wpch, and it also promote ...19882843360
maternally inherited transposon excision in drosophila simulans.a mutation in the white gene of drosophila mauritiana resulting from insertion of the transposable element mariner exhibits genetic instability in germline and somatic cells. the instability is greatly enhanced in the presence of the trans-acting autosomal factor mos, giving eye-color mosaics with pigmented sectors of tissue on an otherwise peach-colored background. the mos factor, when introduced into the genome of the sibling species drosophila simulans, exhibited a dramatic maternal effect on ...19882832948
nonrandom partition of mitochondria in heteroplasmic drosophila.in order to understand the status of heteroplasmy and its evolution within the drosophila melanogaster subgroup, cytoplasm microinjections between eggs were performed involving three lineages of drosophila simulans, carrying the sii, siii or siiii mtdna type, respectively, and two strains of drosophila mauritiana carrying the mai or maii mtdna type. progeny of eggs from all combinations of injection were analysed. the maii or sii molecules, when provided by the donor, were never detected in the ...19979418268
heritable somatic excision of a drosophila transposon.a mutation in the white gene of drosophila mauritiana that results from insertion of the transposable element mariner is genetically unstable in both germ cells and somatic cells. somatic instability is indicated by the occurrence of animals having mosaic eyes with patches of pigmented cells on a peach-colored background. normally uncommon, the frequency of mosaicism is so greatly enhanced in a particular mutant strain that virtually every animal in the strain is an eye-color mosaic. the molecul ...19873029874
molecular structure of a somatically unstable transposable element in drosophila.a transposable element has been isolated from an unstable white mutation in drosophila mauritiana, a sibling species of drosophila melanogaster. the unstable white-peach (wpch) allele exhibits a spectrum of germ-line and somatic mutability more similar to insertion mutations in maize and in the nematode caenorhabditis elegans than has been reported for insertion mutations in drosophila. the inserted element mariner is 1286 nucleotides long and has terminal inverted repeats. the element contains ...19863022302
genetics of a pheromonal difference affecting sexual isolation between drosophila mauritiana and d. sechellia.females of the sibling species drosophila sechellia and d. mauritiana differ in their cuticular hydrocarbons: the predominant compound in d. sechellia is 7,11-heptacosadiene (7,11-hd), while that in d. mauritiana is 7-tricosene (7-t). we investigate the genetic basis of this difference and its involvement in reproductive isolation between the species. behavioral studies involving hydrocarbon transfer suggest that these compounds play a large role in the sexual isolation between d. mauritiana mal ...19979093854
genetic basis of male sterility in hybrids between two closely related species of drosophila.drosophila simulans and drosophila mauritiana are closely related sibling species, the former cosmopolitan and the latter restricted to the small oceanic island of mauritius. genetic analysis of male sterility in hybrids between these species shows that at least five loci (one on each chromosome arm) are responsible for this reproductive isolation. this is the most loci that could have been detected with the techniques used and implies that the true genetic divergence for sterility is even great ...19846589604
mitochondrial dna heteroplasmy in drosophila mauritiana.mitochondrial dna extracted from an isofemale strain of drosophila mauritiana (subgroup melanogaster) appeared to be heterogeneous in size. a short genome [s; 18,500 base pairs (bp)] and a longer one (l; 19,000 bp) coexist in the preparation. the additional 500 bp have been located within the a+t-rich region. hpa i digest patterns suggest that the s genome may carry a duplication of a 500-bp sequence including an hpa i site and that the l genome may carry a triplication of the same sequence. at ...19836316335
crossing-over in the female hybrids between drosophila simulans and drosophila mauritiana.the cross between d. simulans and d. mauritiana yields fertile hybrid females. crossing-over occurs in such female hybrids. this system allows the transfer of pieces of chromosomes from one species into another, thus providing an experimental tool to analyze the genetic basis of evolutionary problems, as well as the regulation of gene expression during development.19827200915
germline transformation of drosophila virilis with the transposable element mariner.an important goal in molecular genetics has been to identify a transposable element that might serve as an efficient transformation vector in diverse species of insects. the transposable element mariner occurs naturally in a wide variety of insects. although virtually all mariner elements are nonfunctional, the mos1 element isolated from drosophila mauritiana is functional. mos1 was injected into the pole-cell region of embryos of d. virilis, which last shared a common ancestor with d. mauritian ...19968722788
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