Knockdown of genes in the Toll pathway reveals new lethal RNA interference targets for insect pest control.

RNA interference (RNAi) is a promising alternative strategy for ecologically friendly pest management. However, the identification of RNAi candidate genes is challenging owing to the absence of laboratory strains and the seasonality of most pest species. Tribolium castaneum is a well-established model, with a strong and robust RNAi response, which can be used as a high-throughput screening platform to identify potential RNAi target genes. Recently, the cactus gene was identified as a sensitive RNAi target for pest control. To explore whether the spectrum of promising RNAi targets can be expanded beyond those found by random large-scale screening, to encompass others identified using targeted knowledge-based approaches, we constructed a Cactus interaction network. We tested nine genes in this network and found that the delivery of double-stranded RNA corresponding to fusilli and cactin showed lethal effects. The silencing of cactin resulted in 100% lethality at every developmental stage from the larva to the adult. The knockdown of pelle, Dorsal-related immunity factor and short gastrulation reduced or even prevented egg hatching in the next generation. The combination of such targets with lethal and parental RNAi effects can now be tested against different pest species in field studies.

RNA-sequencing analysis reveals abundant developmental stage-specific and immunity-related genes in the pollen beetle Meligethes aeneus.

The pollen beetle (Meligethes aeneus) is a major pest of oilseed rape (Brassica napus) and other cruciferous crops in Europe. Pesticide-resistant pollen beetle populations are emerging, increasing the economic impact of this species. We isolated total RNA from the larval and adult stages, the latter either naïve or immunized by injection with bacteria and yeast. High-throughput RNA sequencing (RNA-Seq) was carried out to establish a comprehensive transcriptome catalogue and to screen for developmental stage-specific and immunity-related transcripts. We assembled the transcriptome de novo by combining sequence tags from all developmental stages and treatments. Gene expression data based on normalized read counts revealed several functional gene categories that were differentially expressed between larvae and adults, particularly genes associated with digestion and detoxification that were induced in larvae, and genes associated with reproduction and environmental signalling that were induced in adults. We also identified many genes associated with microbe recognition, immunity-related signalling and defence effectors, such as antimicrobial peptides (AMPs) and lysozymes. Digital gene expression analysis revealed significant differences in the profile of AMPs expressed in larvae, naïve adults and immune-challenged adults, providing insight into the steady-state differences between developmental stages and the complex transcriptional remodelling that occurs following the induction of immunity. Our data provide insight into the adaptive mechanisms used by phytophagous insects and could lead to the development of more effective control strategies for insect pests.

Sequence characterization of an unusual lysozyme gene expressed in the intestinal tract of the reduviid bug Triatoma infestans (Insecta).

Antibacterial proteins like lysozyme are important components of the insect non-specific immune response against bacteria. The complementary deoxyribonucleic acid (cDNA) encoding a new lysozyme from Triatoma infestans, named lysozyme2, has been amplified by polymerase chain reaction and the rapid amplification of cDNA ends technique. The gene is expressed in the small intestine of the insect. The deduced protein sequence shows up to 70% similarity to lysozymes from other species. Furthermore, the protein exhibits significant structural concordance to other insect lysozymes. A striking feature of the lysozyme2 protein is the replacement of the conserved amino acid residues of the active site of classical c-type lysozymes, glutamate and aspartate, by valine and tyrosine.

Cervical rib variant: report of a case.

It is taught that, when a cervical rib is present, the subclavian vessels and brachial plexus always arch over it. The present case reemphasizes that the brachial plexus may be split by the cervical rib.

[Post-hypoglycemic encephalopathy in type I diabetes mellitus in childhood and its treatment]. / Die posthypoglykämische Enzephalopathie beim Typ I-Diabetes mellitus im Kindesalter und ihre Behandlung.

In type-I-diabetes insuline-induced hypoglycaemia is the most frequent and permanent therapeutic complication. In severe courses proceeding to unconciousness, it is essential to decide on the irritation of exclusively cortical or subcortical structures. The latter one is classified as posthypoglycaemic encephalopathy correlated with a relatively high lethality. Consequently, differential diagnosis and carefully calculated treatment are of vital importance.

[Early development of a child following rabies of the mother during pregnancy (author's transl)]. / Frühkindliche Entwicklung nach manifester rabies in der Schwangerschaft

A case of rabies in a pregnant woman who spontaneously delivered a premature baby before dying is presented. Although not vaccinated the baby did not develop rabies. The possibility of displacental transmission of rabies in humans is judged as highly improbable on the basis of findings in other publications and in the case presented here.

[Ectopic pregnancy near term (case-report) (author's transl)]. / Die Abdominalgravidität in Terminnähe (Fallbericht)

Description of a case of ectopic pregnancy during the last 3 months with a living, malformed and underdeveloped neonate. Possible treatment is discussed: where as in our case there is a secondary ectopic pregnancy (i.e.a pregnancy started primarily in the tube and still in vascular contact with it but secondarily ectopic) removal of placenta following ligation of the main vessels arising from the tube is possible and recommended. In the much rarer primary ectopic pregnancy with primary nidus in the abdomen, removal of the placenta is dangerous and not advised because of the danger of diffuse hemorrhage.