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Red Flour Beetle (red + flour_beetle)
Selected AbstractsProliferation and differentiation of intestinal stem cells during metamorphosis of the red flour beetle, Tribolium castaneumDEVELOPMENTAL DYNAMICS, Issue 4 2008R. Parthasarathy Abstract The insect midgut epithelium is remodeled during larval-pupal metamorphosis when larval polyploid cells (LPCs) are replaced by the daughters of intestinal stem cells (ISCs). We characterized the proliferation of ISCs during midgut remodeling in the red flour beetle, Tribolium castaneum. Midgut remodeling is initiated at 96 hr after ecdysis into the final instar larval stage. Immunocytochemistry with bromodeoxyuridine and phospho-histone H3 antibodies showed that the ISCs are the progenitors of the pupal/adult midgut epithelium and they undergo proliferation and differentiation to form new midgut epithelium. In vitro midgut culture experiments revealed that 20-hydroxyecdysone (20E) in the absence of juvenile hormone induces proliferation of ISCs. RNA interference (RNAi) mediated silencing of ecdysone receptors (EcRA and EcRB) and ultraspiracle (USP) identified EcRA and USP but not EcRB as the proteins involved in 20E regulation of ISCs proliferation. These data show that the proliferation of ISCs is under both developmental and endocrine regulation. Developmental Dynamics 237:893,908, 2008. © 2008 Wiley-Liss, Inc. [source] POPULATION DIFFERENTIATION IN THE BEETLE TRIBOLIUM CASTANEUM.EVOLUTION, Issue 3 2007We used joint-scaling analyses in conjunction with rearing temperature variation to investigate the contributions of additive, non-additive, and environmental effects to genetic divergence and incipient speciation among 12 populations of the red flour beetle, Tribolium castaneum, with small levels of pairwise nuclear genetic divergence (0.033 < Nei's D < 0.125). For 15 population pairs we created a full spectrum of line crosses (two parental, two reciprocal F1's, four F2's, and eight backcrosses), reared them at multiple temperatures, and analyzed the numbers and developmental defects of offspring. We assayed a total of 219,388 offspring from 5147 families. Failed crosses occurred predominately in F2's, giving evidence of F2 breakdown within this species. In all cases where a significant model could be fit to the data on offspring number, we observed at least one type of digenic epistasis. We also found maternal and cytoplasmic effects to be common components of divergence among T. castaneum populations. In some cases, the most complex model tested (additive, dominance, epistatic, maternal, and cytoplasmic effects) did not provide a significant fit to the data, suggesting that linkage or higher order epistasis is involved in differentiation between some populations. For the limb deformity data, we observed significant genotype-by-environment interaction in most crosses and pure parent crosses tended to have fewer deformities than hybrid crosses. Complexity of genetic architecture was not correlated with either geographic distance or genetic distance. Our results support the view that genetic incompatibilities responsible for postzygotic isolation, an important component of speciation, may be a natural but serendipitous consequence of nonadditive genetic effects and structured populations. [source] The Tribolium chitin synthase genes TcCHS1 and TcCHS2 are specialized for synthesis of epidermal cuticle and midgut peritrophic matrixINSECT MOLECULAR BIOLOGY, Issue 5 2005Y. Arakane Abstract Functional analysis of the two chitin synthase genes, TcCHS1 and TcCHS2, in the red flour beetle, Tribolium castaneum, revealed unique and complementary roles for each gene. TcCHS1- specific RNA interference (RNAi) disrupted all three types of moult (larval,larval, larval,pupal and pupal,adult) and greatly reduced whole-body chitin content. Exon-specific RNAi showed that splice variant 8a of TcCHS1 was required for both the larval-pupal and pupal-adult moults, whereas splice variant 8b was required only for the latter. TcCHS2 -specific RNAi had no effect on metamorphosis or on total body chitin content. However, RNAi-mediated down-regulation of TcCHS2, but not TcCHS1, led to cessation of feeding, a dramatic shrinkage in larval size and reduced chitin content in the midgut. [source] piggyBac -mediated germline transformation in the beetle Tribolium castaneumINSECT MOLECULAR BIOLOGY, Issue 5 2003M. D. Lorenzen Abstract The lepidopteran transposable element piggyBac can mediate germline insertions in at least four insect orders. It therefore shows promise as a broad-spectrum transformation vector, but applications such as enhancer trapping and transposon-tag mutagenesis are still lacking. We created, cloned, sequenced and genetically mapped a set of piggyBac insertions in the red flour beetle, Tribolium castaneum. Transpositions were precise, and specifically targeted the canonical TTAA recognition sequence. We detected several novel reporter-expression domains, indicating that piggyBac could be used to identify enhancer regions. We also demonstrated that a primary insertion of a non-autonomous element can be efficiently remobilized to non-homologous chromosomes by injection of an immobile helper element into embryos harbouring the primary insertion. These developments suggest potential for more sophisticated methods of piggyBac -mediated genome manipulation. [source] Transgenerational immune priming as cryptic parental careJOURNAL OF ANIMAL ECOLOGY, Issue 2 2010Jukka Jokela O. Roth, G. Joop, H. Eggert, J. Hilbert, J. Daniel, P. Schmid-Hempel & J. Kurtz (2009) Paternally derived immune priming for offspring in the red flour beetle, Tribolium castaneum. Journal of Animal Ecology, 79, 403,413. Eggs are relatively large and can provide offspring with resources that improve their survival. While such maternal effects are common, it has been difficult to imagine what, other than genes, individual offspring could receive from their fathers. The study byRoth et al. (2009a)suggests that we should look more closely. Their experiments show that red flour beetle fathers can transfer specific biochemical information to their offspring, priming their immune system to combat pathogens better. When mothers do the same, the offspring get a double dose of protection. This discovery alerts us to re-evaluate the importance of cryptic parental care. [source] Deuterated analogues of 4,8-dimethyldecanal, the aggregation pheromone of Tribolium castaneum: synthesis and pheromonal activityJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 13 2004Junheon Kim Abstract To elucidate the deuterium isotope effect (DIE) in pheromonal activity and to investigate the biosynthetic pathway of 4,8-dimethyldecanal (4,8-DMD; 1), the aggregation pheromone of the red flour beetle (Tribolium castaneum), deuterated analogues of 4,8-DMDs (2, 3, 4, and 5), were synthesized and their pheromonal activities were tested using a two-hole pitfall olfactometer. Although no apparent DIE was observed in their pheromonal activities, 4,8-DMD- 1-d1 (2) was less attractive than other analogues, which suggested that the bond distance between the formyl group of 1 and its receptor was critical in pheromone recognition by T. castaneum. Copyright © 2004 John Wiley & Sons, Ltd. [source] Fumigation toxicity of volatile natural and synthetic cyanohydrins to stored-product pests and activity as soil fumigantsPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2004Dong-Sik Park Abstract Insecticidal fumigation toxicity of natural and synthetic cyanohydrins was evaluated with four stored-product pests: the lesser grain borer, Rhyzopertha dominica (F), the red flour beetle, Tribolium castaneum Herbst, the saw-toothed grain beetle Oryzaephilus surinamensis L, the maize weevil, Sitophilus zeamais (Motsch) and the house fly, Musca domestica L. The fumigation LC50 values were calculated by probit analysis. For house flies, all but one of the cyanohydrins tested were more potent than 1,3-dichloropropene (Telone®). Three were as efficacious as chloropicrin. For the lesser grain borer, all cyanohydrins tested were more insecticidal than dichloropropene, and all but one were more potent than chloropicrin. Four were as insecticidal as dichlorvos. The acetate of 1-cyano-1-hydroxy-2-propene (CHP-ace) was also tested in soil for antifungal and antibacterial activity, and inhibition of weed seed germination. CHP-ace reduced the total soil bacterial and fungal counts significantly, and was effective in inhibiting the germination of weed seeds in soil, indicating a broad spectrum of activity as a soil fumigant. Copyright © 2004 Society of Chemical Industry [source] Digestive proteolysis organization in two closely related Tenebrionid beetles: red flour beetle (Tribolium castaneum) and confused flour beetle (Tribolium confusum),ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2009K.S. Vinokurov Abstract The spectra of Tribolium castaneum and T. confusum larval digestive peptidases were characterized with respect to the spatial organization of protein digestion in the midgut. The pH of midgut contents in both species increased from 5.6,6.0 in the anterior to 7.0,7.5 in the posterior midgut. However, the pH optimum of the total proteolytic activity of the gut extract from either insect was pH 4.1. Approximately 80% of the total proteolytic activity was in the anterior and 20% in the posterior midgut of either insect when evaluated in buffers simulating the pH and reducing conditions characteristic for each midgut section. The general peptidase activity of gut extracts from either insect in pH 5.6 buffer was mostly due to cysteine peptidases. In the weakly alkaline conditions of the posterior midgut, the serine peptidase contribution was 31 and 41% in T. castaneum and T. confusum, respectively. A postelectrophoretic peptidase activity assay with gelatin also revealed the important contribution of cysteine peptidases in protein digestion in both Tribolium species. The use of a postelectrophoretic activity assay with p -nitroanilide substrates and specific inhibitors revealed a set of cysteine and serine endopeptidases, 8 and 10 for T. castaneum, and 7 and 9 for T. confusum, respectively. Serine peptidases included trypsin-, chymotrypsin-, and elastase-like enzymes, the latter being for the first time reported in Tenebrionid insects. These data support a complex system of protein digestion in the Tribolium midgut with the fundamental role of cysteine peptidases. © 2009 Wiley Periodicals, Inc. [source] Molecular analysis of juvenile hormone analog action in controlling the metamorphosis of the red flour beetle, Tribolium castaneumARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2009R. Parthasarathy Abstract The juvenile hormone analogs (JHA) are known to disrupt insect development but the molecular mechanisms of their action have been studied only in a few model insects belonging to orders Diptera and Lepidoptera. Here, we investigated the mechanisms of JHA action in red flour beetle, Tribolium castaneum, belonging to the order Coleoptera. Application of JHA during penultimate and final instar larval stages blocked larval-pupal metamorphosis and induced supernumerary larval molts. When compared to the control insects undergoing larval-pupal molt, down-regulation of expression of transcription factor, Broad, and up-regulation of other genes involved in 20-hydroxyecdysone (20E) action (FTZ-F1, E74) were observed in JHA-treated larvae undergoing supernumerary larval molts. The presence of JHA during the final instar larval stage blocked the midgut remodeling wherein programmed cell death (PCD) of larval cells and proliferation and differentiation of imaginal cells to pupal gut epithelium were impaired. The comparative analysis of 20E-induced gene expression in the midguts of JHA-treated and control insects revealed that JHA suppressed the expression of EcRA, EcRB, Broad, E74, E75A, and E75B, resulting in a block in PCD as well as proliferation and differentiation of imaginal cells. © 2008 Wiley Periodicals, Inc. [source] | |||||||||||||