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The autumn migration of Mythimna separata (Walker) (Lepidoptera: Noctuidae) across the Bohai Sea was observed with a scanning entomological radar and a searchlight trap at Beihuang, an island located in the center of the Bohai Gulf of northern China, in 2003-2006. During the autumn migration, M. separata flew at the altitudes of 50-500 m, with a displacement speed of 4-12 m/s, toward the southwest. Variations of area density of the radar targets and of catches in the searchlight trap through the night indicated that the flight duration of M. separata was approximately 10 h. Based on these observations, M. separata that originated in northeastern China (i.e., Liaoning, Jilin, and Heilongjiang provinces and part of the Inner Mongolia autonomous region) could immigrate into eastcentral China and subsequently to southern China (i.e., Fujian, Guangdong, and Guangxi provinces) within a week for overwintering.

Oncogene-mediated signaling to the host environment induces a subset of cytokines and chemokines. TheDrosophila Dacgene promotes migration of the morphogenetic furrow during eye development. Expression of the cell-fate determination factorDachshund(DACH1) was lost in poor prognosis invasive breast cancer. Mouse embryo fibroblasts derived fromDach1−/−mice demonstrated endogenousDach1constitutively represses cellular migration. DACH1 inhibited cellular migration and invasion of oncogene (Ras, Myc, ErbB2, c-Raf)-transformed human breast epithelial cells. An unbiased proteomic analysis identified and immunoneutralizing antibody and reconstitution experiments demonstrated IL-8 is a critical target of DACH1 mediating breast cancer cellular migration and metastasisin vivo. DACH1 bound the endogenousIL-8promoter in ChIP assays and repressed theIL-8promoter through the AP-1 and NF-κB binding sites. Collectively, our data identify a pathway by which an endogenous cell-fate determination factor blocks oncogene-dependent tumor metastasis via a key heterotypic mediator.

The soybean aphid, Aphis glycines (Matsumura), is native to eastern Asia and has recently invaded North America, where it is currently the most important insect pest of soybeans. The soybean aphid has spread rapidly within North America, presumably through a combination of active and passive (wind-aided) flight. Here, we studied the active flight potential of A. glycines under a range of environmental conditions using an aphid flight mill. Winged (alate) A. glycines were tested on a specially designed 32-channel, computer-monitored flight mill system. Aphids that were 12–24 h old exhibited the strongest flight behavior, with average flight durations of 3.3–4.1 h, which represented flight distances of 4.6–5.1 km. After the age of 72 h, A. glycines flight performance rapidly declined. The optimum temperature range for flight was 16–28°C, whereas optimum relative humidity was 75%. Our findings show that A. glycines posseses a fairly strong active flight aptitude (ability and inclination) and point to the possibility of flight initiation under a broad range of environmental conditions. These results have the potential to aid forecasting and management protocols for A. glycines at the landscape level.

The spread of metastatic tumors to different organs is associated with poor prognosis. The metastatic process requires migration and cellular invasion. The protooncogene c-jun encodes the founding member of the activator protein-1 family and is required for cellular proliferation and DNA synthesis in response to oncogenic signals and plays an essential role in chemical carcinogenesis. The role of c-Jun in cellular invasion remains to be defined. Genetic deletion of c-Jun in transgenic mice is embryonic lethal; therefore, transgenic mice encoding a c-Jun gene flanked by LoxP sites (c-junf/f) were used. c-jun gene deletion reduced c-Src expression, hyperactivated ROCK II signaling, and reduced cellular polarity, migration, and invasiveness. c-Jun increased c-Src mRNA abundance and c-Src promoter activity involving an AP-1 site in the c-Src promoter. Transduction of c-jun−/−cells with either c-Jun or c-Src retroviral expression systems restored the defective cellular migration of c-jun−/−cells. As c-Src is a critical component of pathways regulating proliferation, survival, and metastasis, the induction of c-Src abundance, by c-Jun, provides a novel mechanism of cooperative signaling in cellular invasion.

The changes of inheritance mode and fitness of resistance in Helicoverpa armigera (Hübner) along with its resistance evolution to Cry1Ac toxin were evaluated in the laboratory. The resistance levels reached 170.0-, 209.6- and 2893.3-fold, on selection of the field population in the 16th (BtR-F(16)), 34th (BtR-F(34)) and 87th (BtR-F(87)) generation with artificial diet containing Cry1Ac toxin, respectively. As the resistance levels increased, more larvae feeding on the Bt cotton expressing Cry1Ac toxin survived. Most larvae of BtR-F(87) could develop to the 5th instar and about 3% individuals reached the adult stage. The inheritance of Cry1Ac resistance trait at three resistant levels was autosomal and incompletely recessive, but the degree of dominance decreased as the resistance increased. The resistance was primarily monogenic in BtR-F(16) strain, but polygenic as resistance increased. The relative fitness of H. armigera, measured as a ratio of R(0) (the net replacement rate) of resistant strain divided by R(0) of the susceptible strain, decreased with an increase of the resistance levels, with ratios of 0.79, 0.64 and 0.59 in their respective BtR-F(16), BtR-F(34) and BtR-F(87) strains.

The sweet potato whitefly, Bemisia tabaci (Gennadius) biotype B was first found in southern China in 1994 and has since then become a pest of increasing importance throughout the nation. The population dynamics of this invasive species and the effect of natural enemies on its population dynamics were studied in commercial cotton fields during the summers of 2003 through 2005 in Langfang, Hebei (northern China). The abundance of Bemisia tabaci was found to increase rapidly in late July, and reached its first peak in mid-August, then followed by the second peak in early September. Whitefly populations subsequently declined slowly to attain a plateau after mid-September. A total of 13 natural enemy species were discovered in association with B. tabaci in cotton fields, including dominant species such as Chrysopa sinica Tjeder, Leis axyridis Pallas, Propylaea japonica Thunberg, Orius similis Zheng, and Eretmocerus sp. Caged experiments on velvetleaf, Abutilon theophrasti Medic, one of the preferred h...

Tumor necrosis factor (TNF) family member, the receptor activator of NF-κB ligand (RANKL) is expressed on marrow stromal/osteoblast cells in response to several osteotropic factors and is critical for osteoclast precursor differentiation to form multinucleated osteoclasts, which resorb bone [Lacey et al., 1998; Hsu et al., 1999; Kong et al., 1999]. Enhanced levels of RANKL are associated with pathologic conditions such as Paget's disease of bone [Menaa et al., 2000; Neale et al., 2000] and multiple myeloma [Roux et al., 2002]. Several osteotropic factors such as l,25-(OH)2D3, parathyroid hormone (PTH), interleukin 1β (IL-1β), interleukin-11, and prostaglandin E2 (PGE2) induce osteoclast differentiation through enhanced expression of RANKL in marrow stromal/osteoblast cells [Nakashima et al., 2000; Lee et al., 2002], but the molecular mechanisms which regulate RANKL gene expression are unclear. It has been reported that IL-1β and TNF-α stimulate RANKL expression in human bone marrow stromal cells through activation of p38 MAP kinase pathway [Rossa et al., 2006]. In addition, fibroblast growth factor-2 (FGF-2) has been shown to induce RANKL production through COX-2-mediated prostaglandin synthesis and by suppressing osteoclastogenesis inhibitory factor in mouse osteoblastic cells [Nakagawa et al., 1999]. Similarly, lipopolysaccharide treatment increased the levels of RANKL expression through activation of Toll-like receptors in primary murine osteoblast cells [Kikuchi et al., 2001]. Furthermore, transforming growth factor β (TGF-β) has been shown to increase RANKL expression in activated T-cells by increasing anti-CD3 [Wang et al., 2002]. Recently, it has also been reported that PTH stimulates RANKL expression through cAMP/protein kinase A/CREB cascade [Fu et al., 2006]. We recently demonstrated that heat shock factor-2 (HSF-2) is a downstream target of FGF-2 signaling to induce RANKL expression in bone marrow stromal/preosteoblast cells [Roccisana et al., 2004]. Heat shock proteins (HSP) are molecular chaperones expressed in cells in response to a variety of stimuli such as temperature and stimulation of membrane-bound receptors by hormones/cytokines and other chemical factors. Thus, HSP are an integral part of mammalian development [Christians et al., 2003]. Heat shock transcription factors (HSF), which binds to the heat shock responsive element (HSE), modulate expression of HSP and several other genes including TNF-α family [Mathew et al., 1998; Snoeckx et al., 2001]. Although multiple osteotropic factors including FGF-2 are known to modulate RANKL gene expression in the bone microenvironment, the transcriptional regulatory mechanisms operative in marrow stromal/preosteoblast cells are not well established. DACH1 is a human homolog of the Drosophila dachshund gene, which is a key regulator for organ development and is considered a cell fate determination factor. DACH1 contains a conserved domain (dachshund domain (DS)) in the N-terminal region that is structurally homologous with the Ski and Sno proto-oncogenes and interacts with the nuclear co-repressor NCoR to modulate transcription factor activity. We have previously reported that DACH1 represses TGF-β signaling through binding to Smad4 [Wu et al., 2003]. Two vertebrate homologues, Dach1 and Dach2 are partially functionally redundant, since Dach1−/− mice survive to birth but exhibit postnatal lethality associated with a failure to suckle, cyanosis, and respiratory distress [Davis et al., 2001]. DACH1 expression is lost in a subset of human breast cancers associated with poor prognosis. Reintroduction of DACH1 inhibits breast tumor cell proliferation and tumor growth through suppression of cyclin D1 [Wu et al., 2006]. DACH1 inhibits TGF-β signaling in ovarian cancer cells [Sunde et al., 2006]. These studies are part of a growing body of evidence that DACH1 may function as a tumor suppressor. Recent evidence indicates that DACH1 is associated with FGF signaling during limb and skeletal development and may regulate cell proliferation or differentiation [Horner et al., 2002]. Dach1 binds with Runx2/Cbfa1 and co-localizes with cyclin-dependent kinase inhibitor p27 (Kip1) and p57 (Kip2) at the growth plate region in chondrocytes [Horner et al., 2002]. In this study, we show that DACH1 negatively regulate RANKL gene expression in human bone marrow-derived stromal/preosteoblast cells and that FGF-2 signaling promotes HSF-2 binding to DACH1 to modulate RANKL gene expression in these cells.

Since the sweetpotato whitefly, Bemisia tabaci (Gennadius) biotype B invaded southern China in the mid-1990s, it had spread to most other regions of the country, and become an important pest in agricultural and horticultural production. Investigations on overwintering of B. tabaci biotype B and its spring reproduction in northern China were conducted to determine the main factors that might contribute to an understanding of the population dynamics of this pest for developing improved pest control strategies. A cold hardiness test showed that when exposed for 10 h at −10 °C, mortalities of eggs, nymphs, and adults reached to 86.6%, 88.4%, and 100%, respectively, suggesting that it is probably impossible for feral populations of B. tabaci to survive in the winter under natural environmental conditions in northern China. A survey on vegetables, ornamental plants and weeds in greenhouses at Hebei Province and Beijing in northern China revealed at least 14 species of plants on which B. tabaci fed during the winter and spring. Lycopersicon esculentum Mill, Brassica alboglabra Bailey, Ficus carica L., Euphorbia pulcerrima Wild, and Hemelia patens Haence were the main host plants. Further research on the population dynamics of B. tabaci on three major greenhouse hosts; tomato, cucumber, and melon, indicated that densities remained at a low level during the winter, but increased steadily from February to March until migration into field crops in April. It is concluded that the control of the insect in greenhouse in winter and spring can play an important role for seasonal management of this pest in northern China.

The diapause inducement condition, cold hardiness, and flight ability in Cry1Ac-resistant (BtR) and Cry1Ac-susceptible (96S) strains of Helicoverpa armigera (Hubner) were compared in the laboratory. The BtR strain was derived from the 96S strain and shows 1375-fold resistance to the Cry1Ac toxin after having been selected for 52 generations. Compared with the 96S strain, the Bt-resistant strain was more likely to go into diapause under a short-photoperiod environment. At 11L : 13D, 12L : 12D and 13L : 11D photoperiods, the percentages of BtR insects entering diapause were 72.7%, 82.9% and 68.7%, respectively, which were signifi- cantly higher than those in the 96S strain (58.6%, 67.4% and 46.3%, respectively) under the same conditions. The supercooling points (SCP) and freezing points (FP) were not significantly different between the BtR and 96S strains. The LT50 (50% lethal time) and LT90 (90% lethal time) of BtR pupae were also not significantly different from those of the 96S strain at -15°C. The moths from both strains had similar flight ability when their larvae were fed with nontoxic control diet. However, the total flight distance of these BtR moths was 56.2 km whose larvae fed on normal diet, which was more than twice as much as for those feeding on Bt diet (26.2 km). Flight duration for these BtR moths was longer after feeding on normal diet (11.6 h) than after feeding on Bt diet (7 .3 h).

To clarify the environmental fate of the Cry1Ac protein from Bacillus thuringiensis subsp. kurstaki (Bt) contained in transgenic rice plant stubble after harvest, degradation was monitored under field conditions using an enzyme-linked immunosorbent assay. In stalks, Cry1Ac protein concentration decreased rapidly to 50% of the initial amount during the first month after harvest; subsequently, the degradation decreased gradually reaching 21.3% when the experiment was terminated after 7 mo. A similar degradation pattern of the Cry1Ac protein was observed in rice roots. However, when the temperature increased in April of the following spring, protein degradation resumed, and no protein could be detected by the end of the experiment. In addition, a laboratory experiment was conducted to study the persistence of Cry1Ac protein released from rice tissue in water and paddy soil. The protein released from leaves degraded rapidly in paddy soil under flooded conditions during the first 20 d and plateaued until the termination of this trial at 135 d, when 15.3% of the initial amount was still detectable. In water, the Cry1Ac protein degraded more slowly than in soil but never entered a relatively stable phase as in soil. The degradation rate of Cry1Ac protein was significantly faster in nonsterile water than in sterile water. These results indicate that the soil environment can increase the degradation of Bt protein contained in plant residues. Therefore, plowing a field immediately after harvest could be an effective method for decreasing the persistence of Bt protein in transgenic rice fields.

Lygus lucorum (Meyer-Dur) is a key pest of Bt cotton in China. This study reports on its flight potential examined by a flight-mill system. We found that 10-d-old mated females engaged in flight over the greatest distance (40.1 ± 5.2 km) and duration (7.7 ± 1.0 h) in 24-h flight assays in relation to age, sex, and mating status. Optimum temperature for flight was 20°C, and optimum relative humidity was 75% RH. Flight potential of 10-d-old mated females under the optimum conditions (20°C and 75% RH) was tested continuously for 48 h. Results showed that the flight distance amounted to 67.3 ± 9.7 km, with a maximum distance of 151.3 km. This study shows that L. lucorum has the potential to undertake long-distance flight. The information will help in the development of the forecast and management of L. lucorum.

Vip3 is a novel insect toxin isolated from Bacillus thuringiensis (Bt), and could be used as an alternative toxin for Bt δ-endotoxins for transgenic insect control. Vip3 mutants with deletion, addition or mutations at the very end of the C-terminus were generated. The deletion and addition of a few amino acid residues at the C-terminus totally abolished the insecticidal activity. The mutation of the last two residues from IK to LG also resulted in the total loss of its insecticidal activity; however, the mutation from IK to LR increased its activity substantially against beet armyworm. Interestingly, all the inactive mutants were found to be highly sensitive to trypsin digestion, while the active mutant generated a trypsin-resistant polypeptide of 62-kDa upon trypsin digestion. However, this 62-kDa polypeptide expressed in E. coli from the 5' end truncated vip3 gene was biologically inactive and sensitive to trypsin digestion. Thus, the N-terminal part of the protein is required to form the 62-kD...

Detached leaf bioassays, open field tests and cage tests were conducted to evaluate the control efficacy of two transgenic rice lines, expressing Cry1Ac and CpTI, against Cnaphalocrocis medinalis (Guenee) during 2005-2006 in Fuzhou, China. Bioassay results showed that cumulative feeding areas of C. medinalis on transgenic lines were significantly lower than that on control rice lines at different developmental stages. The corrected mortalities at 96 h after infestation on transgenic lines during six rice growth stages were >90% and 100% during experiments conducted in 2005 and 2006, respectively. In the open field test, there was no significant difference in egg density between transgenic and control lines during early days of infestation, but significant differences were detected in late season, due to serious damage on control lines. Larval densities on control lines were significantly higher than the low larval populations observed on transgenic lines during both seasons. The percentages of plants with folded leaves and percentages of folded leaves on transgenic lines were significantly lower than that on control lines with and without insecticide applications, during the entire season. In cage tests the cumulative numbers of C. medinalis adults derived from transgenic lines were significantly lower than that from control lines with and without insecticide treatments. The high level of efficacy of the two transgenic rice lines against C. medinalis may provide an important basis for reduced insecticide applications, an expansion of alternative pest-control strategies and insect resistance management of Bt rice in the future.

Field surveys of soybean aphid, Aphis glycines Matsumura, and its natural enemies, as well as natural enemy exclosure experiments, were conducted during 2003 and 2004 in soybean fields near Langfang, China. In 2003, aphid density increased six-fold during 12 d in July from 66 ± 12 per 10 plants to a seasonal peak of 401 ± 79 per 10 plants. Aphid density remained high for another 10 d and declined during late July and early August. In 2004, aphid density increased 29-fold during 13 d in July from 14 ± 2 per 10 plants to a seasonal peak of 375 ± 30 per 10 plants. Unlike 2003, aphid density remained relatively high during late July and August, peaking again at 296 ± 31 per 10 plants on 24 August. In both years, aphid density remained below economic injury level and seemed to be limited by natural enemies. Exclosure of natural enemies led to increases in A. glycines density in 2003 and 2004. In 2003, peak aphid densities in large- and medium-mesh cages were three- and seven-fold higher, respectively, than densities on uncaged plants. In 2004, peak aphid densities in large- and medium-mesh cages were 2-fold and 30-fold higher, respectively, than densities on uncaged plants in one experiment. In another experiment, peak aphid densities in large-, medium-, and small-mesh cages were 8-fold, 28-fold, and 68-fold higher, respectively, than densities on uncaged plants. Both predators and parasitoids were important in limiting aphid density. We compare our results with those from North America and discuss implications for biological control.

The cotton bollworm, Helicoverpa armigera, is one of the most important insect pests in cotton growing regions of China. Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating cotton bollworm since 1997. Natural refugees derived from the mixed planting system consisting of cotton, corn, soybean, vegetables, peanut and others on single-family farms of a small scale were used for delaying the evolution of resistance to Bt cotton. Susceptibility of H. armigera field populations to the Bt insecticidal protein Cry1Ac was monitored from 1997 to 2006. The results indicate that the field populations are still susceptible to Cry1Ac, and monitoring indication no apparent shifts in susceptibility in field populations of this important pest.

Bioassays and binding tests between Cry toxins (CrylAa, CrylAb, CrylAc, and Cry2Ab) and brush-border membrane vesicles (BBMVs) from larvae of a Bacillus thurningiensis (Bt)-susceptible (96S) and two CrylAc-resistant strains (BtR and LFR10) were conducted for investigating cross-resistance of CrylAc-resistant strains to Cry2Ab in Helicoverpa armigera (Hiibner) (Lepidoptera: Noctuidae). The resistance ratio (RR) values of the BtR and LFR10 strains to CrylAc and Cry2Ab were 2,971- and 1.1-fold and 253- and 1.0-fold, respectively, indicating that there was no cross-resistance to Cry2Ab. The binding experiments between Cry toxins and BBMVs from BtR, LFR10, and 96S larvae showed that all of the toxins could bind with these BBMVs, but the Cry2Ab could not displace 125I labeled CrylAc and CrylAb. The same results were observed in reciprocal binding tests, demonstrating that CrylA and Cry2Ab had different binding sites in H. armigera and providing a potential mechanism for the lack of cross-resistance between CrylA and Cry2Ab toxins. These results suggest that the transgenic cotton, Gossypium hirsutum L., expressing CrylAc and Cry2Ab genes may be deployed for management of CrylAc resistant H. armigera.

The cell fate determination factor DACH1 plays a key role in cellular differentiation in metazoans. DACH1 is engaged in multiple context-dependent complexes that activate or repress transcription. DACH1 can be recruited to DNA via the Six1/Eya bipartite transcription (DNA binding/coactivator) complex. c-Jun is a critical component of the activator protein (AP)-1 transcription factor complex and can promote contact-independent growth. Herein, DACH1 inhibited c-Jun–induced DNA synthesis and cellular proliferation. Excision of c-Jun with Cre recombinase, in c-junf1/f1 3T3 cells, abrogated DACH1-mediated inhibition of DNA synthesis. c-Jun expression rescued DACH1-mediated inhibition of cellular proliferation. DACH1 inhibited induction of c-Jun by physiological stimuli and repressed c-jun target genes (cyclin A, β-PAK, and stathmin). DACH1 bound c-Jun and inhibited AP-1 transcriptional activity. c-jun and c-fos were transcriptionally repressed by DACH1, requiring the conserved N-terminal (dac and ski/sno [DS]) domain. c-fos transcriptional repression by DACH1 requires the SRF site of the c-fos promoter. DACH1 inhibited c-Jun transactivation through the δ domain of c-Jun. DACH1 coprecipitated the histone deacetylase proteins (HDAC1, HDAC2, and NCoR), providing a mechanism by which DACH1 represses c-Jun activity through the conserved δ domain. An oncogenic v-Jun deleted of the δ domain was resistant to DACH1 repression. Collectively, these studies demonstrate a novel mechanism by which DACH1 blocks c-Jun-mediated contact-independent growth through repressing the c-Jun δ domain.

Insecticidal proteins from Bacillus thuringiensis (Bt) are used widely in sprays and transgenic plants to control insect pests. Although much research has elucidated the effects of Bt toxins on larvae, relatively little is known about their effects on adults. Here, we evaluated the effects of exposing adults to Bt toxin Cry1Ac on the life span and reproduction of two strains of pink bollworm ( Pectinophora gossypiella (Saunders)). In larval diet bioassays, the concentration of Cry1Ac killing 50% of larvae (LC 50 ) was 640 times higher for the laboratory-selected resistant strain (AZP-R) than the susceptible strain (APHIS-S). In experiments with adults, the highest concentrations of Cry1Ac tested (160 and 640 µg Cry1Ac per ml of 5% honey water) reduced life span for both strains. Treatments with 10, 40, and 160 µg Cry1Ac per ml reduced the duration of the oviposition period as well as the number of eggs laid by both strains, but did not affect the percentage of pairs producing eggs, the duration of the preoviposition period, or the percentage of eggs hatching for either strain. Adult life span did not differ between strains at low to moderate concentrations of Cry1Ac, but it was significantly greater for the resistant strain than the susceptible strain at the two highest concentrations of Cry1Ac tested. The reduced susceptibility to high concentrations of Cry1Ac in adults of the AZP-R strain relative to the APHIS-S strain provides the first evidence of expression of resistance to a Bt toxin in adult Lepidoptera.

Apolygus lucorum (Hemiptera: Miridae) is an important insect pest of cotton and fruit trees in China. The adults prefer host plants at the flowering stage and their populations track flowering plants both spatially and temporally. In this study, we examine whether flower preference of its adults is mediated by plant volatiles and which volatile compositions play an important role in attracting them. In olfactometer tests with 18 key host species, the adults preferred flowering plants over non-flowering plants of each species. Coupled gas chromatography-electroantennography revealed the presence of seven electrophysiologically active compounds from flowering plants. Although the adults responded to all seven synthetic plant volatiles in electroantennography tests, only four (m-xylene, butyl acrylate, butyl propionate and butyl butyrate) elicited positive behavioral responses in Y-tube olfactometer bioassays. The adults were strongly attracted to these four active volatiles in multi-year laboratory and field trials. Our results suggest that these four fragrant volatiles, which are emitted in greater amounts once plants begin to flower, mediate A. lucorum’s preference to flowering host plants. We proved that the use of commonly occurring plant volatiles to recognize a large range of plant species can facilitate host selection and preference of polyphagous insect herbivore.

The Dachshund gene is a key component of the retinal determination gene network in Drosophila eye development. Recent studies have demonstrated an important role for the human Dachshund homologue 1 (DACH1) in tumorigenesis [1]. Mechanistic studies demonstrated that DACH1 regulates its target genes via either directly binding to specific DNA sequences within chromatin or indirectly through forming protein complex with other transcriptional factors, including c-Jun and Smad4. DACH1 restrained proliferation, migration in vitro and repressed tumor growth and metastasis in vivo. There prior observations were based on cultured cells engineering DACH1 expression. The physiological role of the endogenous DACH1 had not been determined in part because genetic deletion in the mice was periembryonic lethal. A recent study report in the May 15 issue of Cancer Research determined the role of endogenous Dach1 in the prostate using tissue specific deletion mice [2]. Using prostate cancer cell lines of distinct genetic background, DACH1 was shown to inhibit proliferation in vitro and tumor growth in vivo of both AR negative cancer cell (PC-3) and castration resistant AR positive cell (C4-2 and 22RV-1). Consistent with the prior finding that DACH1 inhibited cell cycle progression though inhibiting Cyclin D1 expression, conditional Dach1 knock out in the prostate by using Dach1 fl/fl/Probasin-Cre bi-transgenic increased the expression of cyclin D1, E and A, accompanied by enhanced DNA synthesis and reduced apoptosis [2]. Whole genomic expression profiling with functional pathway analysis identified the cytokine-cytokine receptor interaction as a key target of endogenous Dach1. CXCL family member CXCL-1, 2, 5, 6 and IL-6, 8 expressions were inhibited by DACH1 in PC-3 cell. DACH1 mRNA expression was reduced in metastatic human prostate cancer [3] and DACH1 abundance was inversely correlated with IL-6 and IL-8 (Fig. ​(Fig.1).1). In agreement, there was 1000 fold activation of IL-6 and IL-8 secretion when endogenous Dach1 was deleted in vivo from prostate epithelial cells (PEC). Functional assays, using immune neutralizing antibodies or purified recombinant cytokines to conditioned medium from wt or Dach1 KO PEC, proved that IL-6 and KC (homolog of IL-8 in mice) were the key downstream targets of Dach1 in governing cell migration. In addition, various single oncogene (c-Myc, NeuT, H-Ras or v-Src) transformed prostate epithelial cells (PEC) reduced Dach1 expression both in cultured cells and in extirpated tumor tissues [2]. Combined with previous finding that DACH1 represses ligand induced transcriptional activation of the androgen receptor and prostate cancer cellular proliferation in tissue culture [3], it is likely that DACH1 conveys distinct functions at different stages of prostate cancer onset and progression. Figure 1 Reduced expression of DACH1 activates heterotypic signaling in prostate cancer The transition from hormone-dependent to castrate-resistant prostate cancer (CRPC) is the major cause of therapeutic failure. Clinical studies have shown that increased IL-6 and IL-8 signaling correlates with CRPC and predicts poor prognosis [4]. IL-6 and IL-8 produced by prostate cancer cell promote cancer cell proliferation and invasion. Moreover, IL-8 signaling from tumor cells initiates cancer cell-stromal interaction to induce treatment resistance and angiogenesis [5]. The finding that DACH1 is a key endogenous gene that restrains cytokine signaling may have therapeutic relevance. The finding that DNA demethylation agents could restore DACH1 expression in PC-3 cells [2] suggests targeting DACH1 may be practical. DACH1 also directly suppressed IL-8 in breast cancer cells and inhibited KC-mediated lung metastasis [6]. A subsequent study in lung cancer has also demonstrated that DACH1 can suppress the secretion of CXCL5, thereby reducing CXCL5-mediated proliferation, migration and invasion. Moreover, as with prostate cancer, a reverse relationship between DACH1 and CXCL5 was reported in tumor samples and low DACH1 correlated with reduced survival in lung cancer patients [7]. Thus, DACH1 governs cell fate through intracellular transcriptional regulation and also through heterotypic signaling that determines cancer-stromal interaction, a key hallmark of cancer [8].

Prostate cancer at advanced stages including metastatic and castration-resistant cancer remains incurable due to the lack of effective therapies. MiR-190a belongs to the small noncoding RNA family and has an important role in breast cancer metastasis. However, it is still unknown whether miR-190a plays a role in prostate cancer development. Herein, we first observed AR/miR-190a/YB-1 forms an auto-regulatory negative feedback loop in prostate cancer: miR-190a expression was down-regulated by AR activation; YB-1 functions are as an AR activator; miR-190a inhibited AR expression and transactivation through direct binding to 3′UTR of YB-1 gene. MiR-190a contributes the human prostate cancer cell growth through AR-dependent signaling. Moreover, we examined the expression of miR-190a and observed a significant decrease in human prostate cancers. Reduced expression of miR-190a was inversely correlated to AR levels of prostate cancer patients and patients with higher miR-190a expression in their tumor have improved tumor-free survival. Taken together, our findings identified a biochemical and functional link between miR-190a with reduced expression in advanced prostate cancer, YB-1 and AR signaling in prostate cancer.

Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are standard treatments for advanced non-small-cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations. Nowadays, tumor tissues acquired by surgery or biopsy are the routine materials for EGFR mutation analysis. However, the accessibility of tumor tissues is not always satisfactory in advanced NSCLC. Moreover, a high proportion of NSCLC patients will eventually develop resistance to EGFR-TKIs. Invasive procedures, such as surgery or biopsy, are impractical to be performed repeatedly to assess the evolution of EGFR-TKI resistance. Thus, exploring some convenient and less invasive techniques to monitor EGFR-TKI treatment is urgently needed. Circulating cell-free tumor DNA (ctDNA) has a high degree of specificity to detect EGFR mutations in NSCLC. Besides, ctDNA is capable of monitoring the disease progression during EGFR-TKI treatment. Certain serum microRNAs that correlate with EGFR signaling pathway, such as miR-21 and miR-10b, have been demonstrated to be helpful in evaluating the efficiency of EGFR-TKI therapeutics. A commercialized serum-based proteomic test, named VeriStrat test, has shown an outstanding ability to predict the clinical outcome of NSCLC patients receiving EGFR-TKIs. Analysis of EGFR mutations in circulating tumor cells (CTCs) is feasible, and CTCs represent a promising material to predict EGFR-TKI-treatment efficacy and resistance. These evidences suggested that non-invasive techniques based on serum or plasma samples had a great potential for monitoring EGFR-TKI treatment in NSCLC. In this review, we summarized these non-invasive approaches and considered their possible applications in EGFR-TKI-treatment monitoring.

The cabbage moth, Mamestra brassicae L. (Lepidoptera: Noctuidae), is a serious pest of vegetable crops throughout the world. In order to determine whether or not M. brassicae is a migrant, and if yes, what is the pattern of M. brassicae seasonal migration, a long-term study on M. brassicae from April to October in 2003–2014 was carried out by means of a searchlight trap on a small island located in the center of the Bohai Strait. The results show that a large number of M. brassicae were trapped every year on the island, which indicates that M. brassicae is a migrant and migrated at least 40–60 km across the Bohai Strait. The mean migration period of M. brassicae over the sea within one year is 151 ± 8 d in 2003–2014, with the shortest time span 78 d in 2003 and the longest 189 d in 2014, respectively. The number of M. brassicae captured, however, varies considerably between months or years. The majority of captures were female, with different levels of ovarian development and mating status. Most of the females trapped in May-July during 2010–2014 had a high mating rate and advanced level of ovarian development, suggesting that the migration of this species does not conform to the hypothesis of ‘oogenesis-flight syndrome’. The findings of the present study are beneficial to the development of forecasting systems and management strategies of M. brassicae.

Multiple lines of transgenic rice expressing insecticidal genes from the bacterium Bacillus thuringiensis (Bt) have been developed in China, posing the prospect of increases in production with decreased application of pesticides. We explore the issues facing adoption of Bt rice for commercial production in China. A body of safety assessment work on Bt rice has shown that Bt rice poses a negligible risk to the environment and that Bt rice products are as safe as non-Bt control rice products as food. China has a relatively well-developed regulatory system for risk assessment and management of genetically modified (GM) plants; however, decision-making regarding approval of commercial production has become politicized, and two Bt rice lines that otherwise were ready have not been allowed to enter the Chinese agricultural system. We predict that Chinese farmers would value the prospect of increased yield with decreased use of pesticide and would readily adopt production of Bt rice. That Bt rice lines may not be commercialized in the near future we attribute to social pressures, largely due to the low level of understanding and acceptance of GM crops by Chinese consumers. Hence, enhancing communication of GM crop science-related issues to the public is an important, unmet need. While the dynamics of each issue are particular to China, they typify those in many countries where adoption of GM crops has been not been rapid; hence, the assessment of these dynamics might inform resolution of these issues in other countries.

Migration behavior of the turnip moth, Agrotis segetum (Lepidoptera: Noctuidae), is not well known by far. Here, we present the data from an 11-year study on A. segetum by means of searchlight trapping and ovarian dissection on Beihuang (BH) Island, which located in the center of the Bohai Strait in northern China. The data showed a large number of A. segetum flight across the strait each year, which provides direct evidence that A. segetum is a long-distance migrant, migrating at least 40 - 60 km to reach the trapping site. The migration period during 2003-2013 ranged from 115 to 172 d. Among the catches, the proportion of females was significantly higher than that of males in each month from May to September. Ovarian dissection showed that the proportion of mated females and the proportion of sexually mature females was significantly higher than that of unmated females and sexually immature females in early summer, respectively, but conversely in autumn. The early summer populations migrate in a south-north direction, which might undertake a long-distance flight on several successive nights. The autumn populations migrate in a north-south direction, which might originate not far from the trapping site. Based on these findings, the migratory physiology of A. segetum was discussed.

Various studies have assessed the clinicopathological and prognostic value of Notch1 and Notch3 expression in Non-small cell lung cancer (NSCLC), but their results remain controversial. This meta-analysis was conducted to address the above issues by using a total of 19 studies involving 3663 patients. The correlations between Notch1 and Notch3 expression and clinicopathological features and NSCLC prognosis were analyzed. The meta-analysis indicated that higher expression of Notch1 was associated with greater possibility of lymph node metastasis and higher TNM stages. Moreover, patients with Notch1 overexpression and Notch3 overexpression showed significantly poor overall survival (Notch1: HR, 1.29; 95% CI, 1.06–1.57, p = 0.468 and I2 = 0.0%; Notch3: HR, 1.57; 95%CI, 1.04-2.36, p = 0.445 and I2 = 0.0%). Furthermore, there are statistically significant association between overall survival of NSCLC patients and the expression of Notch signaling ligand DLL3 and target gene HES1. Our meta-analysis supports that Notch signaling is a valuable bio-marker to predict progression and targeting Notch signaling could benefit subpopulation of NSCLC patients.

To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. We conducted laboratory diet experiments with the cotton bollworm, Helicoverpa armigera, to evaluate cross-resistance and interactions between two toxins in pyramided Bt cotton (Cry1Ac and Cry2Ab). Selection with Cry1Ac for 125 generations produced 1000-fold resistance to Cry1Ac and 6.8-fold cross-resistance to Cry2Ab. Selection with Cry2Ab for 29 generations caused 5.6-fold resistance to Cry2Ab and 61-fold cross-resistance to Cry1Ac. Without exposure to Bt toxins, resistance to both toxins decreased. For each of the four resistant strains examined, 67 to 100% of the combinations of Cry1Ac and Cry2Ab tested yielded higher than expected mortality, reflecting synergism between these two toxins. Results showing minor cross-resistance to Cry2Ab caused by selection with Cry1Ac and synergism between these two toxins against resistant insects suggest that plants producing both toxins could prolong the efficacy of Bt cotton against this pest in China. Including toxins against which no cross-resistance occurs and integrating Bt cotton with other control tactics could also increase the sustainability of management strategies.

Prostate cancer is the second leading form of cancer-related death in men. In a subset of prostate cancer patients, increased chemokine signaling IL8 and IL6 correlates with castrate-resistant prostate cancer (CRPC). IL8 and IL6 are produced by prostate epithelial cells and promote prostate cancer cell invasion; however, the mechanisms restraining prostate epithelial cell cytokine secretion are poorly understood. Herein, the cell-fate determinant factor DACH1 inhibited CRPC tumor growth in mice. Using Dach1fl/fl/Probasin-Cre bitransgenic mice, we show IL8 and IL6 secretion was altered by approximately 1,000-fold by endogenous Dach1. Endogenous Dach1 is shown to serve as a key endogenous restraint to prostate epithelial cell growth and restrains migration via CXCL signaling. DACH1 inhibited expression, transcription, and secretion of the CXCL genes (IL8 and IL6) by binding to their promoter regulatory regions in chromatin. DACH1 is thus a newly defined determinant of benign and malignant prostate epithelium cellular growth, migration, and cytokine abundance in vivo. Cancer Res; 75(10); 1992–2004. ©2015 AACR.

Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry) proteins from the bacterium Bacillus thuringiensis (Bt) in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50) of activated Cry1Ac ranging from 22 to 1700. Reduced activity and reduced transcription of an alkaline phosphatase protein that binds Cry1Ac was associated with resistance to Cry1Ac in the four most resistant strains. A Cry1Ac-binding fragment of alkaline phosphatase from H. armigera (HaALP1f) was not toxic by itself, but it increased mortality caused by Cry1Ac in a susceptible strain and in all five resistant strains. Although synergism of Bt toxins against susceptible insects by toxin-binding fragments of cadherin and aminopeptidase N has been reported previously, the results here provide the first evidence of synergism of a Bt toxin by a toxin-binding fragment of alkaline phosphatase. The results here also provide the first evidence of synergism of a Bt toxin by any toxin-binding peptide against resistant insects.

The field efficacy of two transgenic rice lines, containing the Cry1Ac gene from Bacillus thuringiensis (Bt) and the CpTI (cowpea trypsin inhibitor) gene, on the striped stem borer, Chilo suppressalis (Walker), and population variation in susceptibility of C. suppressalis to the Bt insecticidal protein Cry1Ac were evaluated in Fuzhou, Fujian Province of China. The results of an open field test showed that the two transgenic lines exhibited high efficacy against natural infestations of C. suppressalis. In contrast, the untransformed parental control line showed serious damage symptoms not only in untreated plots, but also in plots treated with insecticides. The cumulative number of C. suppressalis adults derived from transgenic rice lines was significantly lower than that from control lines with and without chemical control treatments. Our results show that transgenic rice lines expressing Cry1Ac and CpTI have great potential for protecting rice from C. suppressalis damage with reduced use of inse...

1. A sudden increase and subsequent sharp decrease of catches of dragonflies in a searchlight trap, with Pantala flavescens Fabricius (Odonata: Libellulidae) predominating, observed at Beihuang Island in the centre of the Bohai Gulf, in 2003 and 2004, indicated a seasonal migration of these insects over the sea during the night in China. The movements were associated with the onset of fog. 2. Simultaneous radar observations indicated that the nocturnally migrating dragonflies generally flew at altitudes of up to 1000 m above sea level, with high density concentrations at about 200–300 or 500 m; these concentrations were coincident with the temperature inversion. 3. During early summer, the dragonflies oriented in a downwind direction, so that the displacement direction varied between different altitudes. In contrast, during late summer, the dragonflies were able to compensate for wind drift, even headwind drift, so as to orient south-westward no matter how the wind changed, and thus the displacement direction was towards the south-west. 4. The duration of flight, estimated from the variation of area density derived from radar data and hourly catches in the searchlight trap through the night, was about 9–10 h. The displacement speed detected using radar was ≈5–11 m s−1. Therefore, the dragonflies might migrate 150–400 km in a single flight. 5. The dragonflies were thought to originate in Jiangsu province and they migrated into north-east China to exploit the temporary environment of paddy fields in early summer. Their offspring probably migrated back south during late summer and autumn.

Expression of the cyclin-dependent kinase (Cdk) inhibitor (p27Kip1) is frequently reduced in human tumors, often correlating with poor prognosis. p27Kip1 functions as a haploinsufficient tumor suppressor; however, the mechanism by which one allele of p27Kip1 regulates oncogenic signaling in vivo is not well understood. We therefore investigated the mechanisms by which p27Kip1 inhibits mammary tumor onset. Using the common background strain of FVB, p27Kip1 heterozygosity (p27+/−) accelerated ErbB2-induced mammary tumorigenesis. We conducted microarray analyses of mammary tumors developing in mice with genetic haploinsufficiency for p27Kip1 expressing a mammary-targeted ErbB2 oncogene. Global gene expression profiling and Western blot analysis of ErbB2/p27+/− tumors showed that the loss of p27Kip1 induced genes promoting lymphangiogenesis, cellular proliferation, and collaborative oncogenic signaling (Wnt/β-catenin/Tcf, Cdc25a, Smad7, and Skp2). Skp2 expression was induced by ErbB2 and repressed by p27Kip1. Degradation of p27Kip1 involves an SCF-type E3 ubiquitin ligase, including Skp2. The Skp2 component of the SCFSKP2 complex that degrades p27Kip1 was increased in ErbB2 tumors correlating with earlier tumor onset. In both murine and human ErbB2-overexpressing breast cancers, p27Kip1 levels correlated inversely with Skp2. p27Kip1 haploinsufficiency activated Wnt/β-catenin/hedgehog signaling. Reintroduction of p27Kip1 inhibited β-catenin induction of Tcf-responsive genes (Siamosis, c-Myc, and Smad7). p27Kip1 is haploinsufficient for ErbB2 mammary tumor suppression in vivo and functions to repress collaborative oncogenic signals including Skp2 and Wnt/β-catenin signaling. (Cancer Res 2006; 66(17): 8529-41)

The potential and propensity in flight of Pectinophora gossypiella (Saunders) in the laboratory were measured using a 32-channel, computer-monitored flight-mill system. Females flew significantly farther within a 72-h flight period than did males. The mean accumulated flight distance and flight duration of 1-d-old female individuals in a tethered-flight test were 41.25 ± 7.76 km and 23.87 ± 2.55 h, respectively, whereas for male individuals, the same parameters were 23.46 ± 2.13 km and 14.12 ± 1.12 h. The flight ability of adults was significantly positively correlated with pupal weight. The flight activity of unmated pink bollworm moths increased daily from the time of eclosion, reaching a peak at 3≈5 d and reducing gradually. All the moths could fly normally at 16≈36°C; however, the optimum temperature for flight ranged from 24 to 28°C, whereas the optimum relative humidity ranged from 75 to 90%.

Susceptibility of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) field populations to the Cry1Ac toxin of Bacillus thuringiensis Berliner (Bt) were monitored from 1997 to 2004 in China. During 2001–2004, 53 strains from the Bt cotton planting region were sampled. The range of concentration producing 50% inhibition of larval development to third instar (IC50) values among different populations in 2001, 2002, 2003, and 2004 was 0.014–0.046, 0.010–0.062, 0.005–0.062, and 0.005–0.035 μg/ml, respectively. Diagnostic concentration studies (IC99) showed that the percentage of individuals reaching third instar ranged from 0 to 9.09%, with only four of the 53 tested populations showing values above 0%. Considering these data, it was determined that the susceptibility to Cry1Ac of the field populations sampled was not different from the baseline in 1997, and no movement toward resistance among H. armigera populations was apparent.

Evolution of resistance by pests is the greatest threat to the continuous success of the Bacillus thuringiensis (Bt) toxins used in conventional sprays or in transgenic plants. The most common mechanism of insect resistance to Bt is reduced binding of toxins to target sites in the brush border membrane of the larval mid-gut. In this paper, binding experiments were performed with three 125 I-Cry1A toxins and the brush border membrane vesicles from Cry1Ac resistant or susceptible strains of Helicoverpa armigera . The homologous competition test showed that there was no significant difference in Cry1Ac-binding affinity, but the concentration of Cry1Ac-binding sites dramatically decreased in the resistant strain ( R t decreased from 5.87 ± 1.40 to 2.23 ± 0.80). The heterologous competition test showed that there were three Cry1Ac-binding sites in the susceptible strain. Among them, site 1 bound with all three Cry1A toxins, site 2 bound with both Cry1Ab and Cry1Ac, and site 3 only bound with Cry1Ac. In the Cry1Ac resistant strain, the binding capability of site 1 with Cry1Ab decreased and site 2 did not bind with Cry1Ac. It is suggested that the absence of one binding site is responsible for H. armigera resistance to Cry1Ac. This result also showed that the resistance fitted the “mode 1” pattern of Bt resistance described previously.

Flavopiridol and UCN-01 are two novel protein kinase inhibitors with diverse cellular effects that may complement each other with regards to induction of apoptosis. HeLa cells engineered to overexpress human survivin (HeLa-S) were at least approximately 4.8-fold resistant to UCN-01 relative to proliferation observed in control HeLa cells (HeLa-V). Flavopiridol cytotoxicity as measured using the MTT assay was unaffected in HeLa-S cells when compared with HeLa-V cells. Similarly, simultaneous treatment of HeLa-V cells with flavopiridol and UCN-01 for 72 hours did not result in synergistic inhibition of proliferation; however, in HeLa-S cells, this combination resulted in synergistic inhibition of cell proliferation. Flavopiridol and UCN-01 augmented apoptosis in HeLa-S cells (as compared with HeLa-V cells) as measured by caspase-3 cellular activity assay, DNA fragmentation and PARP cleavage by western blot. In HeLa-V and -S cells, combination treatment resulted in caspase-8 cleavage. Caspase-9 was expressed in HeLa-V cells; however, there was a marked reduction of caspase-9 content in HeLa-S cells only. Combination treatment resulted in a significant reduction in survivin abundance in HeLa-S and SKBR3-UR cells, but not in their respective parental lines. The synergy of Flavopiridol and UCN-01 are selectively toxic to survivin-overexpressing cell lines and the mechanism of toxicity involves caspase-dependent cell death.

The tussah silkworm, Antheraea pernyi (Lepidoptera: Saturniidae), is an important natural resource for the silk industry and has been cultured using wild host plants for >2,000 yr in China. To clarify whether there is any risk from pollen of Cry1Ab-containing corn varieties on this insect, the frequency of pollen dispersal and deposition of corn pollen near cornfields and impact on the development of tussah silkworm larvae were studied separately in the field and laboratory. The field survey showed that the pollen density was the highest inside the cornfield with a value of ≈1,000 grains/cm2. The pollen deposition rapidly declined with distance from the edge of the cornfield as expected in most cases. No significant differences were observed in the amounts of pollen deposited on glass slides positioned at different heights from the ground at each distance. In the laboratory bioassays, there were no significant differences in the larval mortality and weight of Chinese tussah silkworm between treat...

The autumn migration ofHelicoverpa armigera(Hübner) was observed with radar and two types of light-trap at Langfang, Hebei province, China in 2001 and 2002. The sudden increase in the proportion ofH. armigeramoths in the searchlight trap indicated migration into the area and catches increased 10-fold during the second half of the night due to the landing of migrants before dawn. The moths’ migratory flights took place at up to 2000 m above the ground, and moths flew differentially at times, and heights, when favourable (i.e. northerly) winds occurred. This facilitated the maximum displacement of moths towards the south during these ‘return’ migrations. The moths flew over the radar site at consistently high densities through the night, and the resulting flight durations ofc. 10 h, at displacement speeds of 30–33 km h−1, would allow moths emerging in the far northeast of China (i.e. Liaoning and Jilin provinces and the Inner Mongolia autonomous region) to migrate into northern China (Hebei, Shandong and Henan provinces). The association of the seasonal migratory movements ofH. armigerawith crops in northern China is briefly discussed.

A cDNA encoding aminopeptidase N3 was cloned by degenerated PCR and RACE techniques. The full-length of APN3harm is 3486bp. Open reading frame is 3042bp in length, encoding 1014 amino acid residues. Its predicted molecular weight and isoelectric point are 117.04 kDa and 5.14, respectively. This deduced amino acid sequence shares some common structural fea- tures with aminopeptidase N from Lepidoptera, including the consensus zinc-binding motif HEXXHX18E and the GAMEN motif common to gluzincin aminopeptidases. The full-length of the APN3harm gene from three susceptible and three resistant strains were cloned and sequenced. Comparison analysis revealed fourteen amino acid differences in the APN3harm gene from resistant and sus- ceptible strains and six mutations of amino acids exist in all resistant strains. It is possible that these mutations are related to the resistance of Helicoverpa armigera to Cry1Ac toxin. The results of semi-quantitative RT-PCR showed that the resistance of H. armigera to Cry1Ac is unrelated to the amount of APN3harm mRNA in midgut tissue. In susceptible strains, APN3harm is highly expressed in mid-gut, foregut and hindgut but not in other tissues. To determine if the APN3harm is the receptor of Cry1Ac, recom- binant APN3harm protein was successfully expressed in E. coli. A ligand binding experiment showed purified product could bind Cry1Ac toxin. So it is proposed that APN3harm is a putative receptor of Cry1Ac in H. armigera. The sequence of APN3harm was deposited in GenBank with the accession number AY052651.

▪ Abstract The development of cotton pest management practices in China has followed a pattern seen for many crops that rely heavily on insecticides. Helicoverpa armigera resistance to chemical pesticides resulted in the unprecedented pest densities of the early 1990s. Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating H. armigera since 1997. The pest management tactics associated with Bt cotton have resulted in a drastic reduction in insecticide use, which usually results in a significant increase in populations of beneficial insects and thus contributes to the improvement of the natural control of some pests. Risk assessment analyses show that the natural refuges derived from the mixed-planting system of cotton, corn, soybean, and peanut on small-scale, single-family-owned farms play an important function in delaying evolution of cotton bollworm resistance, and that no trend toward Bt cotton resistance has been apparent despite intensive planting of Bt cotton over the past several years.

The northward migration of Helicoverpa armigera (Hübner) and other moths in early summer was observed with radar in 2001 and 2002 at Langfang, Hebei province, China. Migratory flights typically occurred at heights up to 1.2 km above ground level (AGL), and high density layer concentrations frequently formed at 200-300 m AGL. Adult moths of local populations took off at dusk and ceased flight approximately 0.5 h before sunrise with area density peaking approximately 35 min after dusk. A strong dumb-bell pattern of echoes on the plan position indicator screen, indicating collective orientation of the targets, was evident in 2001, when targets were typically moving toward the northeast and when layering was associated with a temperature inversion and maximum wind speed. By contrast, there was no notable dumb-bell pattern in 2002, when targets were moving toward the northwest. However, orientations calculated from target and wind velocities showed that downwind common orientation also was occurring in 2002 and that the direction varied with the wind direction. The probable sources of the H. armigera observed at Langfang were deduced to be Henan province in 2001 and Shandong province in 2002, and the destination regions were Liaoning and Inner Mongolia.

The high-altitude wind-borne migration of beet webworm, Loxostege sticticalis, moths with other insects and their short-distance dispersal were observed with a digital scanning radar and twin light-traps (a vertical-pointing searchlight trap operated alongside a ground-based conventional light-trap) in northern China in 2002. Catches in both light traps suggested there were four flight periods of L. sticticalis during our study. The ovarian development stage of females caught in the light traps coupled with radar observations indicated that L. sticticalis migrated to the northeast in early June, whereas locally bred moths dispersed over shorter distances in mid-July and early August. The variation of the area density of insects through time during the spring migration was different from that during the summer dispersal; there was no density peak during spring, but such a peak occurred every evening in summer. Collective orientation by the moths was observed in the spring migration, with the direction of orientation being toward the northeast. In contrast, there was no common orientation in summer. Multilevel layering of migrants was seen every night in our observations in both spring and summer. The layering phenomenon was related to wind speed maxima rather than to temperature inversions when the air temperature was above the threshold for migration.

Bt cotton has been widely planted in the Yellow River valley of China since 1998. Anci County in Hebei Province and Xiajin County in Shandong Province are two areas where almost 100% of the cotton grown produces Cry1A(c) toxin. These areas were therefore selected for analysis of the frequency of genes coding for resistance to Cry1A(c) in field populations of the bollworm, Helicoverpa armigera Hubner (Lepidoptera: Noctuidae). In 2002, adult females were collected using light traps. Females were caged individually and were allowed to lay eggs. At hatch, 25 ‐35 larvae from each female were screened for growth rate on normal artificial diet, and on diet containing 1.0 µg of Cry1A(c) toxin per ml of diet. This growth rate bioassay was designed to detect non-recessive resistance genes in heterozygous genotypes and to detect recessive resistance genes only when present in a homozygous resistant genotype. The bioassay detected one resistant individual out of 234 screened in Anci and one resistant individual out of 420 in Xiajin. These results suggest that a conservative estimate of the resistance gene frequency is 0.00107 in the Anci population, and 0.00059 in the Xiajin population. Our results indicate that minor resistance genes or less dominant genes for resistance may occur at higher frequencies, especially in the Xiajin population.

The androgen receptor (AR) regulates ligand-dependent gene transcription upon binding specific DNA sequences. The AR conveys both trans-activation and trans-repression functions, which together contribute to prostate cellular growth, differentiation, and apoptosis. Like histone H3, the AR is post-translationally modified by both acetylation and phosphorylation. The histone acetyltransferase p300 transactivates the AR and directly acetylates the AR in vitro at a conserved motif. Point mutations of the AR acetylation motif that abrogate acetylation reduce trans-activation by p300 without affecting the trans-repression function of the AR. The current studies assessed the functional relationship between acetylation and phosphorylation of the AR. Herein trans-activation of the AR acetylation site mutants were enhanced by the p42/p44 MAPK pathway but were defective in regulation by protein kinase A (PKA) signaling. PKA inhibition augmented ARwt activity but not AR acetylation mutant gene reporter activity and association at an androgen response element in chromatin immunoprecipitation assays. Mutations of the lysine residues at the AR acetylation site reduced trichostatin A (TSA) responsiveness and ligand-induced phosphorylation of the AR. The AR acetylation site mutant formed ligand-induced phosphorylation-dependent isoforms with distinguishable characteristics from wild type AR as determined with two-dimensional electrophoresis. Conversely, point mutation of a subset of AR phosphorylation sites reduced trichostatin A responsiveness and trans-activation by histone acetyltransferases. Together these studies suggest that acetylation and phosphorylation of the AR are linked events and that the conserved AR lysine motif contributes to a select subset of pathways governing AR activity.