The sensilla trichodea of the silkmoth Antheraea polyphemus are innervated by three types of receptor neurons each responding specifically to one of three pheromone components. The sensillum lymph of these sensilla surrounding the sensory dendrites contains three different types of pheromone-binding proteins (PBPs) in high concentrations. The sensilla trichodea of the silkmoth Bombyx mori are s...

RNA interference has been described as a powerful genetic tool for gene functional analysis and a promising approach for pest management. However, RNAi efficiency varies significantly among insect species due to distinct RNAi machineries. Lepidopteran insects include a large number of pests as well as model insects, such as the silkworm, Bombyx mori. However, only limited success of in vivo RNA...

We performed gene-based comparative FISH mapping between a wild silkmoth, Samia cynthia ssp. with a low number of chromosomes (2n=25-28) and the model species, Bombyx mori (2n=56), in order to identify the genomic components that make up the chromosomes in a low-number karyotype. Mapping of 64 fosmid probes containing orthologs of B. mori genes revealed that the homologues of either two or four...

Juvenile hormone (JH) contributes to the regulation of larval molting and metamorphosis in insects. Herein, we comprehensively identified 55 genes involved in JH biosynthesis, metabolism and signaling in the silkworm (Bombyx mori) as well as 35 in Drosophila melanogaster, 35 in Anopheles gambiae, 36 in Apis mellifera, 47 in Tribolium castaneum, and 44 in Danaus plexippus. Comparative analysis s...

We have expressed a male-specific, pheromone-sensitive odorant receptor (OR), BmorOR1, from the silkworm moth Bombyx mori in an "empty neuron" housed in the ab3 sensilla of a Drosophila Deltahalo mutant. Single-sensillum recordings showed that the BmorOR1-expressing neurons in the transgenic flies responded to the B. mori pheromone bombykol, albeit with low sensitivity. These transgenic flies r...

Lepidopteran nucleopolyhedroviruses (NPVs) show distinct tissue tropism in host insect larvae. However, the molecular mechanism of this tropism is largely unknown. We quantitatively investigated NPV tissue tropism by measuring mRNA levels of viral genes in 16 tissues from Bombyx mori NPV (BmNPV)-infected B. mori larvae and found clear tissue tropism, i.e., BmNPV replicates poorly in the silk gl...

The domesticated silkworm, Bombyx mori Linn., a lepidopteran molecular model and an important economic insect that are emerging as an ideal molecular genetic resource for solving a broad range of biological problems. The silkworm, B. mori produces massive amount of silk proteins during the final stage of larval development. These proteins are stored in the middle silk gland and they are dischar...

In our previous report, we demonstrated the possibility that various regulatory neuropeptides influence feeding behavior in the silkworm, Bombyx mori. Among these feeding-related neuropeptides, short neuropeptide F (sNPF) exhibited feeding-accelerating activity when injected into B. mori larvae. Like other insect sNPFs, the deduced amino acid sequence of the cDNA encoding the sNPF precursor app...

Female sex pheromones applied to freshly isolated, living antennae of male Antheraea polyphemus and Bombyx mori led to an increase of cGMP. A 1:1 mixture of 2 pheromone components of Antheraea polyphemus blown for 10 sec in physiological concentrations over their antennal branches raised cGMP levels about 1.34-fold (+/- 0.08 SEM, n = 23) from a basal level of 3.0 +/- 0.6 (SEM, n = 20) pmol/mg p...

Oral supplementation with potassium bromide (10, 20 and 40 μg/ml) to fifth instar larvae of CSR2, CSR4 and CSR2xCSR4 crossbreed races of the silkworm, Bombyx mori resulted in a significant increase in the fat body glycogen in all the treated groups and in all the three races of the silkworm, B. mori. The fat body protein content was increased with 20 and 40 μg/ml treated groups in CSR2 and CSR4...