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1.
The TTAA-specific lepidopteran transposon piggyBac has already proved useful as a gene-transfer vector for efficient transformation of a wide variety of insects. Transposable element excision and transposition assays are useful indicators of an element's ability to be mobilized in vivo and, thus, potentially serve as a transforming vector. Here, we report that this transposon is capable of excision and transposition in tobacco budworm embryos with relatively low frequency. 相似文献
2.
Stéphane Ronsseray Monique Lehmann Danielle Nouaud Dominique Anxolabéhère 《Genetica》1997,100(1-3):95-107
In Drosophila melanogaster, crossing males carrying autonomous P elements with females devoid of P copies results in hybrid
dysgenesis in the germline of progeny. The reciprocal cross produces non-dysgenic progeny due to a maternally inherited state
non-permissive for P transposition. The capacity of a P copy to repress transposition depends on both its structure and its
chromosomal location. Naturally occuring regulatory P elements inserted at the telomere of the X chromosome have been genetically
isolated in a genomic context devoid of other P elements. One or two copies of autonomous P elements at this site (1A) are
sufficient to elicit a strong P repression in the germline. These elements are flanked by Telomeric Associated Sequences,
previously identified and described by Karpen and Spradling (1992) as having heterochromatic properties. The regulatory properties
of P elements at 1A are strongly impaired by mutations affecting Su(var)205, which encodes Heterochromatin Protein 1, a non-histone
heterochromatin protein. The regulatory properties of classical P strains are not sensitive to Su(var)205. Models based on
chromatin structure or on nuclear localisation of the telomeres are discussed in order to explain both the strong regulatory
properties of P elements at the X chromosome telomere and their sensitivity to Su(var)205.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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4.
F. Zeng S. Shu Y.I. Park S.B. Ramaswamy 《Archives of insect biochemistry and physiology》1997,34(3):287-300
The characteristics of vitellogenin (Vg) and the relationship between Vg production and egg production in the tobacco budworm, Heliothis virescens, were studied. The relationship between Vg production and juvenile hormone (JH) and the impact of mating on Vg and egg production were also investigated. Vg appears in the hemolymph of H. virescens about 6 h after moth eclosion. Vg may be separated into two apoproteins (ApoVg-I and ApoVg-II) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights were calculated to be 156,065 ± 800 for ApoVg-I and 39,887 ± 323 for ApoVg-II. SDS-PAGE analysis revealed that the female hemolymph Vg polypeptides appear to be identical to those from eggs but are absent in male hemolymph. Vg concentration was significantly higher in mated females than in virgin females of the same age at 48 h after emergence. Rates of egg production increased as Vg production increased; rates of egg production in mated females were significantly higher than those of virgin females at 48, 72, 96, and 120 h postemergence. Vg production is dependent on JH, because hemolymph from decapitated females lacked Vg while that of decapitated females treated with synthetic JH had Vg at levels comparable to similarly aged, normal H. virescens females. Hemolymph JH titers in mated females were significantly higher compared with those in virgin females at all sampling periods. The high JH level in mated females may explain the high Vg and egg production in mated H. virescens. Arch. Insect Biochem. Physiol. 34:287–300, 1997. © 1997 Wiley-Liss, Inc. 相似文献
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Drosophila melanogaster are found in sympatry with Drosophila simulans, and matings between the species produce nonfertile hybrid offspring at low frequency. Evolutionary theory predicts that females choose mates, so males should alter their behaviour in response to female cues. We show that D. melanogaster males quickly decrease courtship towards D. simulans females. Courtship levels are reduced within 5 min of exposure to a heterospecific female, and overall courtship is significantly lower than courtship towards conspecific females. To understand changes at the molecular level during mate choice, we performed microarray analysis on D. melanogaster males that courted heterospecific D. simulans females and found nine genes have altered expression compared with controls. In contrast, males that court conspecific females alter expression of at least 35 loci. The changes elicited by conspecific courtship likely modulate nervous system function to reinforce positive conspecific signals and dampen the response to heterospecific signals. 相似文献
7.
The hobo transposable element contains a polymorphic microsatellite sequence located in its coding region, the TPE repeats. Previous surveys of natural populations of Drosophila melanogaster have detected at least seven different hobo transposons. These natural populations are geographically structured with regard to TPE polymorphism, and a scenario has been proposed for the invasion process. Natural populations have recently been completely invaded by hobo elements with three TPE repeats. New elements then appeared by mutation, triggering a new stage of invasion by other elements. Since TPE polymorphism appeared over a short period of time, we focused on estimating the mutation rate of these TPE repeats. We used transgenic lines harboring three TPE and/or five TPE hobo elements that had been evolving for at least 16 generations to search for a new TPE repeat polymorphism. We detected three mutants, with four, seven, and eight TPE repeats, respectively. The estimated mutation rate of the TPE repeats is therefore higher than that of neutral microsatellites in D. melanogaster (4.2 x 10-4 versus 6.5 x 10-6). The role of the transposition mechanism and the particular structure of the TPE repeats of the hobo element in this increase in the mutation rate are discussed. 相似文献
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A. M. Angioy I. Tomassini Barbarossa S. Orrù K.-E. Kaissling 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1998,182(3):299-305
Electrocardiogram recordings were performed on intact Heliothis virescens moths using Ag-AgCl electrodes positioned on the body cuticular surface. Regular heart activity and its changes in response
to mechanical and olfactory stimulations were analysed. Moths were also tested in their anemotactic orientation in response
to olfactory stimulation. Results show that regular cardiac activity in Heliothis is cyclical and consists of the alternation of a high and a low spike-frequency period. This activity pattern is strongly
influenced by sensory stimulation. Both mechanical stimulations at various intensities and olfactory stimulations with sex
pheromone and 1-hexanol evoked tachycardiac effects when applied during low spike-frequency cardiac activity. In contrast,
they did not affect high spike-frequency cardiac activity. It is concluded that the cardiac response in Heliothis is an effective indicator of sensory reception. It would therefore appear to represent a valid tool for testing insect reactivity.
Accepted: 30 August 1997 相似文献
10.
The hemolymph osmotic pressure of male Heliothis virescens last instar larvae and pupae can be correlated with the state of spermatogenesis: intermediate (approx. 325 mOsm/kg) osmotic pressures are found in pre-meiotic animals, low (approx. 300 mOsm/kg) osmotic pressures characterize meiosis and elongation, and high (approx. 370 mOsm/kg) osmotic pressures, characterize the tests of diapausing pupae, where mature sperm have disappeared and only pre-meiotic sperm are found. In vitro studies show that, as the osmotic pressure of the medium is increased, spermatogenesis is inhibited and the survival of pre-meiotic cysts is enhanced. It is proposed that the osmotic pressure of the hemolymph plays a role in spermatogenesis and in the preservation of immature cysts during diapause. 相似文献
11.
Insulin‐like receptor substrate gene chico regulates octopamine metabolism in Drosophila melanogaster 下载免费PDF全文
Natalya V. Adonyeva Elena V. Burdina Inga Yu. Rauschenbach Petr N. Menshanov Nataly E. Gruntenko 《Physiological Entomology》2017,42(1):85-90
Octopamine, one of the main insect biogenic amines, plays an important role in the control of fitness in Drosophila melanogaster Meigen. The present study examines the effects of a null mutation of the gene of the insulin‐like receptor substrate (chico), in the heterozygous state, on octopamine metabolism, heat stress resistance and fecundity of D. melanogaster. A rise in the activity of one of the key enzymes of octopamine synthesis, tyrosine decarboxylase, as well as that of an enzyme of its degradation, octopamine‐dependent N‐acetyl transferase, is observed in chico1/+ females. It is also found that the resistance to heat stress is decreased and fecundity is reduced dramatically in chico1/+ flies. Such changes in these parameters in D. melanogaster females result from a rise in octopamine titre, which suggests that chico affects the octopamine level by regulating the activity of tyrosine decarboxylase. 相似文献
12.
Ji‐Hyeon Lee Woong Seo Shin‐Hae Lee Hye‐Yeon Lee Kyung‐Jin Min 《Entomological Research》2019,49(5):187-202
Maternal age is generally known to be negatively correlated with the lifespan of offspring in several animal models including yeast, rotifers, flies, and possibly in humans. However, several reports have shown positive effects of parental age on offspring lifespan. Thus, there was a need to investigate further the inconsistent results on the effect of parental age on lifespan. In this study, the effects of parental age on offspring fitness and lifespan were examined by using Drosophila melanogaster. The lifespan of offspring from old parents was significantly increased compared with that of the young counterparts in the Canton‐S (CS) strain but not in other D. melanogaster strains, such as Oregon‐R (OR) and w1118. To find out why the lifespan is increased in the offspring from old parents in CS flies, fitness components that could modulate lifespan were examined in CS flies. Egg weight and body weight were reduced by parental aging and the offspring of old fathers or old mothers developed faster than that of the young. In addition, the offspring of old parents had increased resistance to oxidative and heat shock stresses. However, reproductive capacity, mating preference, and food intake were unaffected by parental aging. These results indicate that parental aging in CS strain D. melanogaster has beneficial effects on the lifespan and fitness of offspring. The presence of strain‐specific manner effects suggests that genetic background might be a significant factor in the parental age effect. 相似文献
13.
Previous studies of the mucin-type O-glycome of the fruit fly Drosophila melanogaster have revealed a restricted pattern of neutral core-type glycans corresponding to the Tn-(GalNAc) and the T-antigen (Galβ1-3GalNAc). In particular, no extension of the core 1 glycan with acidic sugars, like sialic acid, was detected. Here we report on the identification of an acidic O-linked trisaccharide expressed on secreted endogenous and recombinant glycoproteins of the embryonal hemocyte-like Drosophila Schneider-2 (S2) cell line. The glycan is composed of glucuronic acid, galactose and N-acetylgalactosamine and its structure was determined as GlcA1-3Gal1-3GalNAc. The O-linked trisaccharide resembles the peripheral structures of acidic D. melanogaster glycosphingolipids. Glucuronic acid may substitute for sialic acid in this organism, however its expression on the S2 cell surface may only marginally contribute to the negative surface charge as revealed by free-flow cell electrophoresis prior to and after β-glucuronidase treatment of the cells. 相似文献
14.
Testes of Heliothis virescens were examined in vitro for the ability to produce ecdysteroids. Production was detected in testes removed from larvae at mid and late periods in the last instar, in testes from pupae after the third day of purpal development, and in testes taken from young adult males. The testes in the isolated abdomens do not fuse during later stages of spermatogenesis as they do in intact insects. Spermatocysts in testes of larval abdomens isolated from the upper body early in the last instar developed to mature sperm despite low haemolyph and testis ecdysteroid titres. Gonadectomized animals developed and moulted normally, indicating that ecdysteroids from the testes are not essential to general development. 相似文献
15.
Origin and decay of the P element-associated latitudinal cline in Australian Drosophila melanogaster 总被引:1,自引:0,他引:1
The latitudinal cline in P transposable element-associated characteristics in eastern Australian populations of Drosophila
melanogaster has changed between 1986 and 1991–1994. New collections were made in 1991–1994 from localities along the eastern
coast of Australia. P element-associated properties of 256 isofemale lines from 43 localities were evaluated using gonadal
dysgenesis and/or singed-weak hypermutability assays. The overall results indicate that both P activity and P susceptibility
have declined, with all populations showing a tendency towards a state with little P activity potential but with P repressor
function (neutral or ‘Q’). P repressor function is strong in all populations except some of the most southerly. P activity
potential peaks at about 27° SLat, and drops off to the south (as in 1983–1986 collections) and to the north (in contrast
to 1983–1986 collections); thus the cline is no longer a simple P-to-Q-to-M pattern from north to south, but is now Q-P-Q-M.
A mtDNA RFLP that putatively distinguishes North American and European populations varies in frequency among the populations
but the frequency does not vary clinally with latitude, ruling out massive introductions from North America and Europe as
causing the cline.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
John C. Biwot Hua‐Bao Zhang Chen Liu Jun‐Xue Qiao Xiao‐Qiang Yu Yu‐Feng Wang 《Insect Science》2020,27(5):869-882
Wolbachia are Gram‐negative endosymbionts that are known to cause embryonic lethality when infected male insects mate with uninfected females or with females carrying a different strain of Wolbachia, a situation characterized as cytoplasmic incompatibility (CI). However, the mechanism of CI is not yet fully understood, although recent studies on Drosophila melanogaster have achieved great progress. Here, we found that Wolbachia infection caused changes in the expressions of several immunity‐related genes, including significant upregulation of kenny (key), in the testes of D. melanogaster. Overexpression of key in fly testes led to a significant decrease in egg hatch rates when these flies mate with wild‐type females. Wolbachia‐infected females could rescue this embryonic lethality. Furthermore, in key overexpressing testes terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick‐end labeling signal was significantly stronger than in the control testes, and the level of reactive oxygen species was significantly increased. Overexpression of key also resulted in alterations of some other immunity‐related gene expressions, including the downregulation of Zn72D. Knockdown of Zn72D in fly testes also led to a significant decrease in egg hatch rates. These results suggest that Wolbachia might induce the defect in male host fertility by immunity‐related pathways and thus cause an oxidative damage and cell death in male testes. 相似文献
17.
M.J. Loeb 《Journal of insect physiology》1982,28(8):667-673
The signal to induce diapause in H. virescens comes early in development (prior to the third instar in most insects), but the signal to break diapause can come shortly after entrance into diapause at pupation. Haemolymph ecdysteroid titres in both diapause-bound and non-diapause-bound Heliothis virescens larvae were similar in the first two thirds of the last-larval instar, when similar changes in morphology and behaviour occurred. However, the number of stepwise increases in titre and the timing of the steps was different in the two groups of larvae. Haemolymph ecdysteroid titres in the last third of the instar were approx, five times higher in non-diapause than in diapause-bound larvae. In diapausing pupae, haemolymph ecdysteroid titres dropped to levels found in larvae which had completed two thirds of the last instar. When diapausing pupae were warmed to break diapause, haemolymph ecdysteroid titres rose again. However, 2 of the 4 high ecdysteroid levels detected in pupae developing after diapause break were considerably lower than those detected for non-diapause pupae. 相似文献
18.
Contemporary evolution of a Lepidopteran species,Heliothis virescens,in response to modern agricultural practices 下载免费PDF全文
Megan L. Fritz Alexandra M. DeYonke Alexie Papanicolaou Stephen Micinski John Westbrook Fred Gould 《Molecular ecology》2018,27(1):167-181
Adaptation to human‐induced environmental change has the potential to profoundly influence the genomic architecture of affected species. This is particularly true in agricultural ecosystems, where anthropogenic selection pressure is strong. Heliothis virescens primarily feeds on cotton in its larval stages, and US populations have been declining since the widespread planting of transgenic cotton, which endogenously expresses proteins derived from Bacillus thuringiensis (Bt). No physiological adaptation to Bt toxin has been found in the field, so adaptation in this altered environment could involve (i) shifts in host plant selection mechanisms to avoid cotton, (ii) changes in detoxification mechanisms required for cotton‐feeding vs. feeding on other hosts or (iii) loss of resistance to previously used management practices including insecticides. Here, we begin to address whether such changes occurred in H. virescens populations between 1997 and 2012, as Bt‐cotton cultivation spread through the agricultural landscape. For our study, we produced an H. virescens genome assembly and used this in concert with a ddRAD‐seq‐enabled genome scan to identify loci with significant allele frequency changes over the 15‐year period. Genetic changes at a previously described H. virescens insecticide target of selection were detectable in our genome scan and increased our confidence in this methodology. Additional loci were also detected as being under selection, and we quantified the selection strength required to elicit observed allele frequency changes at each locus. Potential contributions of genes near loci under selection to adaptive phenotypes in the H. virescens cotton system are discussed. 相似文献
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