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Cannibalism of pupae by larvae has been documented In many species of Insects, but the features of larval cannibalism and pupal defensive mechanisms against larval cannibalism have been largely Ignored. Pupae of tenebrionld beetles rotate their abdominal segments in a circular motion in response to the tactile stimulation of appendages, including legs, antennae, maxillary pulps, and wings. When the pupal abdominal rotation responses of Tenebrio molitor and Zophobas atratus were completely blocked by transecting the ventral nerve cord (VNC) of the pupae, the appendages of the paralytic pupae became initial, major targets for attack by larval cannibals. The majority of 20 paralytic pupae was cannibalized by 100 larvae within 6 h, and almost all the pupae were killed within 2-3 days. In contrast, only a few pupae of Z. atratus and several pupae of T. molitor were cannibalized when the VNC was Intact. The abdominal rotation response of the pupae thus functions as an effective defense against larval cannibalism.

A urate oxidase (uricase) gene was cloned from Candida utilis with an oligonucleotide probe based on the amino acid sequence of cyanogen bromide-cleaved uricase. The uricase gene contains 909 base pairs and encodes a protein with a predicted mass of 34,193 Da. Candida uricase was similar (49% match in amino acid sequence) to the uricase from Aspergillus flavus. The uricase from Candida utilis has four cysteines and one of them, Cys168, participates in the enzyme activity. This enzyme was expressed to a level of about 20% of total cellular protein in an Escherichia coli cell as a soluble and functional form.

The suboesophageal ganglion of the silkworm, Bombyx mori, contains three clusters of neurosecretory cells that are immunoreactive with antisera against the diapause hormone (DH) and the pheromone biosynthesis-activating neuropeptide (PBAN), the two neurohormones that are generated from a common precursor protein. The cells lie on the ventral midline of the ganglion. Neurosecretory cell clusters responsible for the diapause induction activity and the pheromonotropic activity of females were determined by surgically removing one or two of the three clusters of the DH/ PBAN immunoreactive cells. A potent diapause induction activity was obtained in females retaining a posterior cluster of cells while a strong pheromonotropic activity was obtained in case of females with a medial cluster. The functional differentiation of these cells may relate to different biochemical and/or physiological natures.

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