A system to efficiently maintain embryonic lethal mutations in the flour beetle Tribolium castaneum.

Due to its small size, short life cycle, and easy maintenance, the flour beetle Tribolium castaneum is well suited for the genetic analysis of development. One drawback of Tribolium as a genetic system is, however, the difficulty of keeping embryonic lethal lines. Presently, only few lethal mutations can be kept as balanced stocks. Therefore, heterozygous carriers must be identified anew in every generation in order to maintain a recessive embryonic mutation. To alleviate this problem we have devised a block system that allows the simultaneous processing of many mutant lines or test crosses for visual inspection of larval cuticle phenotypes. Using this technique, one person can maintain about 100 embryonic lethal stocks, which makes feasible the thorough genetic analysis of embryogenesis in this species.

Investigation of the social status of paraplegic individuals after medical rehabilitation.

The social services of the German centres for spinal cord injuries compiled social data on 2000 recently injured paraplegics. The aim of the study was to determine whether and to what extent patients had been reintegrated to jobs after completion of physical rehabilitation treatment. A 31-point questionnaire surveyed all relevant data pertaining to the projected professional vita. The results for the medically rehabilitated population (n = 651) indicate that 45% returned to their previous job, school or college. Intensified use of computers and advanced academic backgrounds of afflicted individuals contribute to a higher chance for reintegration at a previous job. Our social statistics also include data on living conditions and social support. Household caretaking support is offered by family members in 73% of cases, while 5% permanently live in nursing homes.

piggyBac-mediated germline transformation in the beetle Tribolium castaneum.

The lepidopteran transposable element piggyBac can mediate germline insertions in at least four insect orders. It therefore shows promise as a broad-spectrum transformation vector, but applications such as enhancer trapping and transposon-tag mutagenesis are still lacking. We created, cloned, sequenced and genetically mapped a set of piggyBac insertions in the red flour beetle, Tribolium castaneum. Transpositions were precise, and specifically targeted the canonical TTAA recognition sequence. We detected several novel reporter-expression domains, indicating that piggyBac could be used to identify enhancer regions. We also demonstrated that a primary insertion of a non-autonomous element can be efficiently remobilized to non-homologous chromosomes by injection of an immobile helper element into embryos harbouring the primary insertion. These developments suggest potential for more sophisticated methods of piggyBac-mediated genome manipulation.