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11.
Young-Kyung Bae Nathanie Trisnadi Snehalata Kadam Angelike Stathopoulos 《Cell Adhesion & Migration》2012,6(5):397-403
Cell migration influences cell-cell interactions to drive cell differentiation and organogenesis. To support proper development, cell migration must be regulated both temporally and spatially. Mesoderm cell migration in the Drosophila embryo serves as an excellent model system to study how cell migration is controlled and influences organogenesis. First, mesoderm spreading transforms the embryo into a multilayered form during gastrulation and, subsequently, cells originating from the caudal visceral mesoderm (CVM) migrate along the entire length of the gut. Here we review our studies, which have focused on the role of fibroblast growth factor (FGF) signaling, and compare and contrast these two different cell migration processes: mesoderm spreading and CVM migration. In both cases, FGF acts as a chemoattractant to guide cells’ directional movement but is likely not the only signal that serves this role. Furthermore, FGF likely modulates cell adhesion properties since FGF mutant phenotypes share similarities with those of cell adhesion molecules. Our working hypothesis is that levels of FGF signaling differentially influence cells’ response to result in either directional movement or changes in adhesive properties. 相似文献
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MARIANNE IMHOF BETTINA HARR GOTTFRIED BREM & CHRISTIAN SCHLÖTTERER 《Molecular ecology》1998,7(7):915-917
The occurrence of multiple mating in Drosophila melanogaster is of particular interest to evolutionary biologists, as seminal fluid has some toxic effects for females. Thus, it has been predicted that the number of matings per females should be low. We have tested this prediction with seven highly polymorphic microsatellite loci in inseminated females from a Viennese D. melanogaster population. In contrast to the predicted low number of matings and previous studies in natural populations, we identified the genotypes of four to six different males fertilizing the offspring of each female tested. Potential causes and consequences are discussed. 相似文献
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G. Rai M. Stamenkovi-Radak T. Savi M. Andjelkovi 《Journal of Zoological Systematics and Evolutionary Research》2008,46(1):31-37
The adaptive significance of inversion polymorphism of Drosophila subobscura is well established. However, little is known about gene combinations within inversions which are coadapted because of population-specific effects. We studied this aspect of Dobzhansky's coadaptation hypothesis, using the systematic inbreeding method. Differences in magnitude and quality of inversion polymorphism in two ecologically and topologically distinct habitats were compared after several generations of continuous full-sib inbreeding. Populations from the two habitats differ in frequency of homokaryotypes after third and fifth generation of inbreeding and in the levels of homozygosity of different gene arrangements. The effect of homozygosity appears population and chromosome specific. 相似文献
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Our project identified GFP labeled glial structures at the developing larval fly neuromuscular synapse. To look at development of live glial-nerve-muscle synapses, we developed a larval tissue preparation that had features of live intact larvae, but also had good optical properties. This new preparation also allowed for access of perfusates to the synapse. We used fly larvae, immersed them in artificial hemolymph, and relaxed their normal rhythmic body contractions by chilling them. Next we dissected off the posterior segments of each animal and with a blunt insect pin pushed the mouth parts backward through the body cavity. This everted the larval body wall, like turning a sock inside-out. We completed the dissection with ultra-fine dissection scissors and thus exposed the visceral side of the body wall muscles. The glial structures at the NMJ expressed membrane targeted GFP under the control of glial specific promoters. The post-synaptic membrane, the SSR (Subsynaptic Reticula) in muscle expressed synaptically targeted dsRed. We needed to acutely label the motor neuron terminals, the third part of the synapse. To do this we applied primary antibodies to HRP, conjugated to a far-red emitting flurophore. To test for dye diffusion properties into the perisynaptic space between the motor neuron terminals and the SSR, we applied a solution of large Dextran molecules conjugated to far-red emitting flurophore and collected images. 相似文献
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The persistence of short‐term cold acclimation in Drosophila melanogaster (Diptera: Drosophilidae) 下载免费PDF全文
Elizabeth R. Everman Nicholus Ledbetter Theodore J. Morgan 《Physiological Entomology》2017,42(4):291-298
Daily and seasonal fluctuations in temperature present significant challenges for the survival of many ectothermic species that can be tempered via thermal acclimation. In the present study, we use multiple naturally derived genotypes of Drosophila melanogaster to determine the persistence of beneficial short‐term thermal acclimation on subsequent survival after cold shock. We found that the benefit of short‐term acclimation persisted for 2 h in most genotypes after a rapid cold hardening treatment. Genotype did not directly influence the persistence of short‐term acclimation benefits, indicating that environmental variation may be more important for the persistence of acclimation benefits rather than genetic capacity for acclimation. The present study extends the current understanding of the limits and importance of short‐term acclimation events, providing greater detail on the timing of the loss of short‐term acclimation benefits in a genetically variable natural population. 相似文献
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Amitabh Joshi Wendy A. Oshiro Jason Shiotsugu Laurence D. Mueller 《Journal of biosciences》1997,22(3):325-338
Oviposition preference for ureasupplemented food was assayed by simultaneous choice trials on five pairs of closely related
laboratory populations of
Drosophila melanogaster.Each pair of populations had been derived from a separate ancestral population about 85 generations prior to this study. One
population in each pair had been subjected to selection for larval tolerance to the toxic effects of urea; the other population
served as a control. Considerable variation in oviposition preference was seen both within and among populations, with four
of the ten populations showing a significant mean preference for ureasupplemented food. The degree of specificity shown by
individual females was surprisingly high, leading to a bimodal distribution of oviposition preference in some populations.
Overall, selection for larval tolerance to urea did not significantly affect oviposition preference. However, the data indicated
that pairwise comparisons between randomly selected populations from the two larval selection regimes would lead to a range
of possible outcomes, suggesting, in several cases, that selection for larval urea tolerance had led to significant differentiation
of adult oviposition preference for urea in one or the other direction. The results, therefore, highlight the importance of
population level replication and caution against the practice, common in ecological studies, of assaying oviposition preference
in two populations that utilize different hosts in nature, and then drawing broad evolutionary inferences from the results. 相似文献