CRISPR/Cas9-mediated knockout of the eye pigmentation gene white leads to alterations in colour of head spots in the oriental fruit fly, Bactrocera dorsalis.

The intensely studied white gene is widely used as a genetic marker in Drosophila melanogaster. Here, we cloned and characterized the white gene in an important pest of the fruit industry, Bactrocera dorsalis, to understand its functional role in pigmentation. We obtained BdWhite knockout strains, based on the wild-type strain, using the CRISPR/Cas9 genome editing system, and found that mutants lost pigmentation in the compound eye and their black head spots. We then examined differences in the expression levels of genes associated with melanin pigmentation between mutants and the wild-type strain using quantitative reverse transcription PCR. We found that transcription levels of the Bd-yellow1 were lower in the head of mutants than in the wild-type strain, and there were no significant differences in expression of the other six genes between mutants and the wild type. Since yellow is critical for melanin biosynthesis (Heinze et al., Scientific Reports. 2017;7:4582), the lower levels of expression of Bd-yellow1 in mutants led to reduced dark pigmentation in head spots. Our results provide the first evidence, to our knowledge, that white may play a functional role in cuticle pigmentation by affecting the expression of yellow.

Short-term outcomes of laparoscopic ventral rectopexy for obstructed defecation in patients with overt pelvic structural abnormalities-a Chinese pilot study.

AIM: As laparoscopic ventral rectopexy (LVR) gained increasing popularity in the past decade, studies from non-western area remain rare. The aim of this pilot study is to evaluate the efficacy and safety of LVR for obstructed defecation (OD) in Chinese patients with overt pelvic structural abnormalities. METHODS: A series of 19 consecutive patients is presented undergoing LVR for OD. All patients showed various forms of pelvic structural abnormalities which were verified by dynamic defecography exam. Data was prospectively recorded and the functional outcomes were evaluated using the Cleveland Clinic Constipation Score (CCCS) and Patients Assessment of Constipation Quality of Life Score (PAC-QoL). RESULTS: Pelvic structural abnormalities of the 19 patients included external rectal prolapse (ER) in 10.5% (2/19), high grade internal rectal prolapse (IR) in 57.8% (11/19), rectocele in 52.6% (10/19), enterocele in 15.7% (3/19), cystocele/vaginal prolapse in 15.7 (3/19), descending perineum (DP) in 63.5% (12/19). 89.4% patients (17/19) showed at least two co-existed abnormalities and 15.7% (3/19) showed multicompartmental abnormalities. The mean follow-up was 9 months (range 1-18). No mesh-related complication was observed. At last available follow-up (LAFU), improvement of OD symptom was observed in 15 (78.9%) patients, the mean scores of CCCS decreased from 17 to 10 (p < 0.05), all four subsets of PAC-QoL scores improved, and three of them (physical discomfort, worries and concerns, satisfaction) showed statistical significance (p < 0.05). CONCLUSION: Laparoscopic ventral rectopexy appears to be a safe and effective procedure for obstructed defecation in Chinese patients with overt pelvic structural abnormalities in short-term follow-up.

A new family of insect muscarinic acetylcholine receptors.

Most currently used insecticides are neurotoxic chemicals that target a limited number of sites and insect cholinergic neurotransmission is the major target. A potential target for insecticide development is the muscarinic acetylcholine receptor (mAChR), which is a metabotropic G-protein-coupled receptor. Insects have A- and B-type mAChRs and the five mammalian mAChRs are close to the A-type. We isolated a cDNA (CG12796) from the fruit fly, Drosophila melanogaster. After heterologous expression in Chinese hamster ovary K1 cells, CG12796 could be activated by acetylcholine [EC50 (half maximal effective concentration), 73 nM] and the mAChR agonist oxotremorine M (EC50 , 48.2 nM) to increase intracellular Ca(2+) levels. Thus, the new mAChR is coupled to Gq/11 but not Gs and Gi/o . The classical mAChR antagonists atropine and scopolamine N-butylbromide at 100 µM completely blocked the acetylcholine-induced responses. The orthologues of CG12796 can also be found in the genomes of other insects, but not in the genomes of the honeybee or parasitoid wasps. Knockdown of CG12796 in the central nervous system had no effect on male courtship behaviours. We suggest that CG12796 represents the first recognized member of a novel mAChR class.

No direct effects of two transgenic Bt rice lines, T1C-19 and T2A-1, on the arthropod communities.

A 2-yr field trial was conducted to assess the impacts of two new transgenic Bt rice lines, T1C-19 expressing Cry1C protein and T2A-1 expressing Cry2A protein, on the arthropod community sampled via vacuum. All the arthropods were classified into five guilds, including herbivores, parasitoids, predators, detritivores, and others. The seasonal density and dominance distribution of each guild and community-level indices (species richness, Shannon-Wiener diversity index, Simpson diversity index, and evenness index) were compared among rice types. Principal response curves were used to investigate the differences of entire arthropod community of Bt rice plots relative to non-Bt rice plots. The results showed no significant difference was detected in the community-level indices and dominance distribution of guilds between Bt and non-Bt rice plots. The seasonal density of herbivores, detritivores, and others as well as density of the arthropod overall community were also not significantly affected by rice types in either year, although the density of predators and parasitoids in Bt rice plots was significantly lower than those in non-Bt rice plots. The lower abundances of Braconidae, Eulophidae, Cyrtorhinus lividipennis (Reuter) (Hemiptera: Miridae), and Theridiidae in Bt rice plots are likely attributed to the lower abundances of prey species or hosts. Principal response curves revealed that arthropod community in Bt was similar with that in non-Bt rice plots. In conclusion, our findings indicate that these two tested Bt rice lines had no marked negative effects on the arthropod community in the paddy fields.

Impacts of Bt rice expressing Cry1C or Cry2A protein on the performance of nontarget leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), under laboratory and field conditions.

Transgenic rice expressing Bacillus thuringiensis Berliner (Bt) protein can effectively control target insects including stem borers and leaf folders. However, the potential effects of Bt rice on nontarget organisms including nontarget herbivores have not been fully evaluated. In the current study, ecological fitness parameters of the nontarget herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae), fed on T1C-19 (Cry1C) or T2A-1 (Cry2A) rice were compared with non-Bt rice (MH63) under laboratory conditions. A 2-yr field trial was also conducted to monitor the population dynamics of N. cincticeps in the Bt and control rice plots using the vacuum-suction machine and yellow sticky card traps. Laboratory results showed that there were no significant differences in some of biological parameters including egg developmental duration, adult fresh weight, adult longevity, and oviposition period when N. cincticeps fed on Bt or non-Bt rice was compared. However, the survival rate of N. cincticeps nymphs fed on T2A-1 Bt rice plants was significantly higher than that on the control. When N. cincticeps fed on T1C-19 Bt rice plants, its nymphal duration was significantly longer and fecundity significantly lower compared with those fed on both T2A-1 Bt and non-Bt rice plants; the preoviposition period of N. cincticeps fed on T1C-19 and T2A-1 Bt rice was also significantly shorter than those on non-Bt rice. Nonetheless, both seasonal density and population dynamics of N. cincticeps adults and nymphs were similar between Bt (T1C-19 and T2A-1) and non-Bt rice plots under field conditions. In conclusion, our results indicate that our two tested Bt rice lines would not lead to higher population of N. cincticeps. Long-term experiments to monitor the population dynamics of N. cincticeps at large scale need to be carried out to confirm the current results.

1:4 matched case-control study on influential factor of early onset neonatal sepsis.

BACKGROUND: Bacteria, funghi, viruses and protozoa can lead to neonatal sepsis. Neonatal sepsis is the leading cause of infectious disease onset and death in many neonates. AIM: To explore the major risk factors of early-onset neonatal sepsis and provide a scientific basis for strategies of early-onset neonatal sepsis prevention. SUBJECTS AND METHODS: A 1:4 matched case-control study was adopted and 147 cases of early-onset neonatal sepsis were enrolled. Conditional logistic regression model was used to analyze the univariate and multivariate data to estimate the odds ratio (OR) and the 95% confidence interval (95% CI). RESULTS: Univariate analysis shows that the impact factors on the occurrence of early-onset neonatal sepsis include the following: Maternal age > 35, mother having fixed occupation, mother of urban residence, abnormal fetal position, fetal times, parity, caesarean section, premature rupture of membranes, amniotic fluid volume abnormalities, pregnancy-induced hypertension, placental abnormalities, fetal distress, newborn gender, low birth weight infants, neonatal Apgar scoring at one and five minutes, neonatal jaundice, wet lung, anemia, IVH, and premature infant. Multivariate logistic regression analysis showed that maternal age > 35 (OR = 4.835, OR 95% CI = 1.170-19.981), cesarean section (OR = 0.103, OR 95% CI = 0.041-0.258), premature rupture of membranes (OR = 0.207, OR 95% CI = 0.078-0.547), premature infants (OR = 0.059, OR 95% CI = 0.010-0.329) and newborn jaundice (OR = 0.092, OR 95% CI = 0.021-0.404) were the factors of early-onset neonatal sepsis. CONCLUSIONS: Early-onset neonatal sepsis could be affected by multi-factors, and targeted prevention may reduce the incidence of early-onset neonatal sepsis rates.

Impact of six transgenic Bacillus thuringiensis rice lines on four nontarget thrips species attacking rice panicles in the paddy field.

As a key component of ecological risk assessments, nontarget effects of Bacillus thuringiensis (Bt) rice have been tested under laboratory and field conditions for various organisms. A 2-yr field experiment was conducted to observe the nontarget effects of six transgenic rice lines (expressing the Cry1Ab or fused protein of Cry1Ab and Cry1Ac) on four nontarget thrips species including Frankliniella intonsa (Trybom), F. tenuicornis (Uzel), Haplothrips aculeatus (F.), and H. tritici (Kurd), as compared with their rice parental control lines. Two sampling methods including the beat plate and plastic bag method were used to monitor the population densities of the four thrips species for 2 yr. The results showed that the seasonal average densities of four tested thrips species in Bt rice plots were significantly lower than or very similar to those in the non-Bt rice plots depending on rice genotypes, sampling methods, and years. Among all six tested Bt rice lines, transgenic B1 and KMD2 lines suppressed the population of these tested thrips species the most. Our results indicate that the tested Bt rice lines are unlikely to result in high population pressure of thrips species in comparison with non-Bt rice. In some cases, Bt rice lines could significantly suppress thrips populations in the rice ecosystem. In addition, compatibility of Bt rice, with rice host plant resistance to nontarget sucking pests is also discussed within an overall integrated pest management program for rice.

Determining the age of adult flesh flies, Boettcherisca peregrina, using pteridine fluorescence.

To assess the potential application of pteridine fluorescence in determining the age of adult Boettcherisca peregrina (Diptera: Sarcophagidae) Robineau-Desvoidy and further for the postmortem interval, the age-dependent changes of pteridine fluorescence were investigated for the adults maintained at five constant temperatures. From the results, significant linear relationships were found between pteridine fluorescence and the age of the adults maintained at 16, 20, 24, 28 or 32 °C (P < 0.001, r(2) > 0.85). In addition, the relationships between the rate of pteridine accumulation and temperature were well described using linear equations for adult females and males. Then for each cohort of the flies at the ambient temperature, a calendar was constructed and used to determine the ages of females and males, respectively, in which was recorded in reverse time order the amount of pteridine accumulated per hour by the flies and their expected pteridine level when they emerged at the specified time. A significant linear relationship between estimated ages and chronological ages was observed for female or male adults, with the mean errors of the estimated ages of ±1.82 days for females and ±1.58 days for males. It is suggested that pteridine fluorescence analysis has a potential value in determining the age of adult B. peregrina.

Efficacy evaluation of two transgenic maize events expressing fused proteins to CrylAb-susceptible and -resistant Ostrinia furnacalis (Lepidoptera: Crambidae).

The Asian corn borer, Ostrinia furnacalis (GuenCe), is a major pest of maize in China. Transgenic Bt maize could provide an effective way to control this pest. However, the potential of resistance evolution has been documented in the laboratory-a CrylAb-resistant strain of Asian corn borer (Asian corn borer-AbR) could survive well on two Bt maize events, that is, MON810 and Bt11. Pyramided transgenic crops with multiple dissimilar Bt insecticidal proteins offer a superior route for pests control compared with that with one Bt single gene. In this study, two novel transgenic Bt maize events (N30 and V3), which contained a fused gene Cry1Ab/Cry2Aj and CrylAb /Vip3DA, respectively, were evaluated for their efficacy on protection against CrylAb-susceptible Asian corn borer (Asian corn borer-BtS) as well as their potential for dealing with the Asian corn borer-AbR. In laboratory bioassay, no neonate larvae of Asian corn borer-BtS fed on the whorl leaves, tassels, husks, silks, and kernels of N30 and V3 could survive at 96 h after infestation. In contrast, only 2.0-8.7% larvae died as they fed on non-Bt maize tissues. As Asian corn borer-AbR neonate larvae fed on N30 and V3 silks and kernels, 95.0% even more larvae were killed at 96 h after infestation, and all died at 168 h after infestation, while 10.0-11.67% larvae survived on non-Bt control. In the field test under artificial infestation at middle whorl leaf and silking stages of maize, there were no significant leaf, silk, and stalk damage on Bt maize plants by comparison with severe leaf feeding, stalk born, and ear damage in control, in addition, the expression profiles of a fused protein of CrylAb/Cry2Aj or CrylAb/Vip3DA in different tissues of N30 and V3 were also confirmed. In conclusion, it is clear that both Bt maize events (N30 and V3) show great potential for protecting maize from attack by Asian corn borer that has resistance to Cry1Ab protein.

Impacts of six bt rice lines on nontarget rice feeding thrips under laboratory and field conditions.

Nontarget impacts of six transgenic Bt rice lines (expressing the Cry1Ab or Cry1Ab/Cry1Ac protein) on the thrips, Stenchaetothrips biformis (Bagnall), attacking the rice seedling and tillering stages, were evaluated under laboratory and field conditions. Laboratory results showed relatively longer larval, pupal development and preoviposition durations of S. biformis. Although it had a shorter oviposition period, female adult longevity and less total laid eggs were found when fed on some tested Bt rice in comparison to non-Bt controls. S. biformis population dynamics in Bt and non-Bt plots were monitored using the plastic bag and beat plate methods. In the field, the temporal patterns of S. biformis population changes were similar between tested Bt rice lines and their respective control; however, the total number of S. biformis individuals collected from the Bt plots were significantly less or the same, varying from variety to variety, compared with those from the non-Bt plots. ELISA results showed that the Bt insecticidal protein could be transferred from Bt rice to the thrips, and the concentrations of the protein in rice leaves and thrips were not significantly correlated with some important biological parameters of the thrip. In addition, the potential effects of Bt rice on the abundance of S. biformis candidate predators are also discussed. In conclusion, our results show that the six Bt rice lines assessed may be less preferable host plants to S. biformis at the individual and population levels in comparison to the non-Bt rice plants.

Effects of transgenic rice expressing Bacillus thuringiensis Cry1Ab protein on ground-dwelling collembolan community in postharvest seasons.

During 2005-2008, field studies were conducted at two locations in Chongqing, China, to assess the potential effects of transgenic rice expressing Bacillus thuringiensis (Bt) Cry1Ab protein on the nontarget ground-dwelling collembolan community in three postharvest seasons. Collembolans in non-Bt and Bt rice fields were sampled with pitfall traps during each of two postharvest seasons of 2005/2006 and 2006/2007 and litterbag traps during each of three postharvest seasons of 2005/2006, 2006/2007, and 2007/2008. Ground-dwelling collembolans in rice fields during the postharvest seasons were abundant, whereas community densities varied considerably between the two locations and among the three seasons. A total of 67,310 collembolans, representing three species, Entomobrya griseoolivata, Hypogastrura matura, and Bourletiella christianseni, were captured during the three postharvest seasons. E. griseoolivata was the predominant species, accounting for 87.7% of the total captures, followed by H. matura (10.7%) and B. christianseni (1.6%). In general, there were no significant differences in species compositions and abundances of each species between Bt and non-Bt paddy fields, suggesting no significantly impact of plant residues of Cry1Ab rice on collembolan communities during postharvest seasons.

Laboratory and field assessments of prey-mediated effects of transgenic Bt rice on Ummeliata insecticeps (Araneida: Linyphiidae).

One major concern regarding the release of Bt rice is its potential impact through tritrophic interactions on nontarget arthropods, especially natural enemies. We studied the effects of two Bt transgenic rice varieties, TT9- 3 and KMD1, expressing Cry1Ab/Cry1Ac and Cry1Ab, respectively, on a predatory ground spider [Ummeliata insecticeps (Bösenberg et Strand)] supplied with Bt rice-fed brown planthopper [Nilaparvata lugens (Stål)] nymphs. Although immunoassays confirmed that U. insecticeps ingested Bt insecticidal protein when supplied with Bt rice-fed N. lugens, no negative effects were found on its survival and development. Furthermore, the fecundity of U. insecticeps fed prey reared on Bt rice was not significantly different from that of those fed prey reared on non-Bt rice. A 3-yr field trial indicated that Bt rice did not significantly affect the population density of U. insecticeps in comparison with non-Bt rice. In conclusion, the Bt rice lines tested in this study had no adverse effects on the survival, developmental time, or fecundity of U. insecticeps in the laboratory or on population dynamics in the field.

Molecular cloning and developmental expression of the vitellogenin gene in the endoparasitoid, Pteromalus puparum.

A cDNA of the vitellogenin (Vg) protein gene was isolated from the endoparasitoid Pteromalus puparum and characterized. The putative coding sequence was found to be 5634 bp long, encoding 1803 amino acids in a single open reading frame. The chemically determined N-terminal amino acid sequence of vitellin completely matched the deduced amino acid sequence that follows a putative signal peptide of 17 amino acid residues. The Vg mRNA was detected in the fat body of late female pupae, whereas the ovary and male fat body lacked the Vg transcript. The Vg mRNA level in the fat body depended significantly on the developmental stage, reaching the highest level 0 h after eclosion. The haemolymph Vg titre appeared 24 h after the appearance of Vg transcript. A positive correlation between the titre and transcript level of Vg in individual female wasps was found.

Temperature-related fitness costs of resistance to spinosad in the diamondback moth, Plutella xylostella (Lepidoptera: Plutelidae).

Fitness costs associated with resistance genes expressed in the absence of insecticides affect the evolution of insecticide resistance and the outcome of resistance management programmes. However, measurements of fitness costs may not be straightforward as they vary with environmental conditions. The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), has developed resistance to spinosad, the first insecticide of the Naturalyte class, after only a few years of field application of this product. In this study, we compared the performance of two homogenous strains of P. xylostella, one susceptible (SS) and the other resistant (RR) to spinosad at an unfavourable, low natural temperature regime, a favourable median-fluctuating temperature regime and an unfavourable high-fluctuating temperature regime. The RR strain showed only marginal fitness cost at the median temperature regime. At the low temperature regime, the RR strain failed to produce any viable offspring, while the SS strain achieved positive population growth. At the high temperature regime, the RR strain showed a 33% decrease in intrinsic rate of increase compared to the SS strain. The results demonstrate that fitness costs of resistance to spinosad are temperature-dependent, increasing in scale at unfavourably low and high temperatures; costs were particularly high at low temperatures. Suggestions for designing effective management programmes are made to delay or avoid development of resistance to spinosad by P. xylostella under different temperature conditions.

Development changes of cuticular hydrocarbons in Chrysomya rufifacies larvae: potential for determining larval age.

Age determination is the basis of determining the postmortem interval using necrophagous fly larvae. To explore the potential of using cuticular hydrocarbons for determining the ages of fly larvae, changes of cuticular hydrocarbons in developing larvae of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) were investigated using gas chromatography with flame-ionization detection and gas chromatography-mass spectrometry. This study showed that the larvae produced cuticular hydrocarbons typical of insects. Most of the hydrocarbons identified were alkanes with the carbon chain length of 21-31, plus six kinds of alkenes. The hydrocarbon composition of the larvae correlated with age. The statistical results showed that simple peak ratios of n-C29 divided by another eight selected peaks increased significantly with age; their relationships with age could be modelled using exponential or power functions with R(2) close to or > 0.80. These results suggest that cuticular hydrocarbon composition is a useful indicator for determining the age of larval C. rufifacies, especially for post-feeding larvae, which are difficult to differentiate by morphology.

Studies on mode of detection of leprosy in China during the years 1981-1998.

Along with the nationwide economic reform initiated in the early 1980s and the rapid decrease of leprosy endemic after the implementation of multi-drug therapy (MDT), the leprosy programme changed from 'vertical' to 'horizontal'. An evolution in the mode of detection of leprosy cases has consequently taken place. Based on the nationwide registration of newly detected cases, the profile of patients at detection has been studied. The proportions of cases corrected significantly with calendar years in detection by dermatological clinics, contact checks, 'clue survey' and mass survey, showing a significant increase in percentage of cases detected through dermatological clinics and contact checks, and decreases through 'clue survey' and mass survey. Detection of cases through dermatological clinics and voluntary reporting have become the main modes of case-finding during 1997-1998, accounting for 37.3% and 28.6%, respectively, where contact check accounts for only 9.1%. In areas with good dermatological services, a significantly higher proportion (75.9%) of cases was detected through dermatological clinics, where voluntary reporting and 'clue survey' were the main modes of detection in endemic areas. As regards confirmation of diagnosis, the great majority of cases were confirmed by leprosy units, even though they were detected in various other situations. Only 6.5% of leprosy cases were detected and subsequently confirmed by doctors in dermatologic clinics. The present modes of detection and their relation to demographical, epidemiological, clinical factors and health services are discussed. This study emphasizes the cardinal importance of the dermatological clinics in the detection of leprosy cases in China at the present time and hence the need to strengthen the training of doctors in these clinics, while continuously encourage their involvement in leprosy control.

Evaluation of diagnostic criteria for atopic dermatitis: validity of the criteria of Williams et al. in a hospital-based setting.

BACKGROUND: Surveys of the prevalence of atopic dermatitis (AD) have been carried out world-wide, but the results vary widely. The differences probably result from the use of different diagnostic criteria. Williams et al. proposed minimum, simplified, diagnostic criteria that require no invasive test and are easy to use. Pilot studies in European countries showed their suitability for implementation both in hospitals and in the community, and their high sensitivity and specificity. OBJECTIVES: To evaluate the potential practical value of the criteria of Williams et al. in the Chinese population. METHODS: The criteria of Hanifin and Rajka (gold standard), Williams et al. and Kang and Tian were applied and compared in 111 patients with AD and 121 control subjects with other skin diseases in three out-patient centres in China. RESULTS: The criteria of Williams et al. showed a similar diagnostic efficiency to that of the gold standard, with the sensitivity, specificity and kappa value reaching 95.50%, 97.52% and 0.93, respectively. No significant difference was found between the criteria of Williams et al. and those of Kang and Tian (chi2 = 0.69, P > 0.05). 'Onset under the age of 2 years', a criterion of Williams et al. could be used in subjects of any age. CONCLUSIONS: The diagnostic efficiency of the criteria of Williams et al. was basically similar to those of Hanifin and Rajka and of Kang and Tian in our out-patient settings. However, those of Williams et al. were easier to apply and required no invasive tests.

Leprosy in China: epidemiological trends between 1949 and 1998.

OBJECTIVE: To report the epidemiological trends of leprosy in China from 1949 to 1998. METHOD: Data for the study were obtained from the computerized database of the National System of Leprosy Surveillance. FINDINGS: A total of 474,774 leprosy patients were detected during this 50-year period. Case detection rates per 100,000 population were highest in the 1950s and 1960s, with peaks appearing in 1957-58, 1963-66, 1969-70, and 1983-84, corresponding to mass surveys or screening surveys carried out in most areas or selected areas of the country. While the duration of the disease at the time of detection fell over the period, the disability rates, which were > 50% in the early 1950s, have decreased gradually to 20.8% by 1997-98 but are still too high. More than 50% of cases were found through active methods in the periods 1955-58, 1965-66, and 1969-76, but in recent years cases are mostly detected through dermatological clinics or by voluntary reporting. The peak prevalences of the 1960s (i.e. > 2 per 10,000 population) decreased annually from the 1970s onwards. By the end of 1998 the prevalence was 0.05 per 10,000 population. CONCLUSIONS: This study shows that leprosy was well controlled in China and that the WHO goal of elimination of leprosy as a public health problem has been achieved at the national and subnational levels. However, leprosy is still unevenly distributed in the country. According to the criterion for leprosy elimination in China--defined as a prevalence of < 1 per 100,000 in county or city--there are still more than 10% of counties or cities where this target has not yet been reached. Special attention must therefore be given to achieve elimination and final eradication of leprosy in China.

Field evaluation of resistance of transgenic rice containing a synthetic cry1Ab gene from Bacillus thuringiensis Berliner to two stem borers.

Two transgenic rice (Oryza sativa L.) lines, KMD1 and KMD2 at the R4 generation, transformed with a synthetic cry1Ab gene from Bacillus thuringiensis Berliner, were first evaluated for stem borer resistance in the field during the rice growing season of 1998 in two areas of Zhejiang Province, China. Both KMD1 and KMD2 were highly resistant to the stem borers Chilo suppressalis (Walker) and Scirpophaga incertulas (Walker), and were completely undamaged during the whole rice growing season. In contrast, damage to the plants of the untransformed parental control (Xiushui 11) was in the form of deadhearts or whiteheads. Under natural infestation by the C. suppressalis, the damage to control plants reached a peak of 88.7% of plants and 20.1% of tillers encountered with deadhearts. Under artificial and natural infestation of neonate striped stem borers at the vegetative stage and booting stage, 100% of plants and 25.6% of tillers, 78.9% of plants and 15.6% of productive tillers among artificially infested control plants were observed with the symptom of deadhearts and whiteheads, respectively. Damage to the control plants from artificial infestation by the S. incertulas reached a peak of 97.0% of plants and 22.9% of tillers damaged. The field research indicated that both KMD1 and KMD2 show great potential for protecting rice from attack by these two stem borers.