Convergence of insular dwarfism in damselflies (Euphaea) and dobsonflies (Protohermes)

SUMMARY. 1. The life history was compared between mainland and island congeners of Protohermes (Megaloptera: Corydalidae) and also between those of Euphaea (Odonata: Euphaeidae). Larvae of these genera coexisted in stream riffles, and prey availability for them was assessed to examine the effects on their body size at maturation.
2. Body size of P. costalis on the 'mainland'. Taiwan, was larger than that of an insular congener, P . sp., on Iriomotc and Ishigaki Islands about 200 km east from Taiwan. Insular dwarfism also occurred between E. formosa on the mainland and E. yayeyamana on the islands. All species had an annual life cycle.
3. Prey availability was much lower in the island streams than in mainland streams throughout the year. Convergence of insular dwarfism in these phylogenetically distant but ecologically similar taxa (both predatory insects) suggested that prey availability is an important factor affecting their body size determination.
4. Seasonal changes in body size occurred within a population of Euphaea which lacked synchronous emergence. Adults emerging from larvae spending their late instars in the warm season were smaller than those in the cold season. However, the size differences between species always exceeded the range of such intraspecific variation.
5. Dwarfism in E. yayeyamana was probably achieved by decreasing the size of first-instar larvae without changing the number of instars and with the size ratio at each moult constant. The mechanisms producing the dwarf form of Protohermes are also discussed.     

Induction of Plant Tubers and Flower Buds under Noninducing Photoperiod Conditions by a Natural Product, Theobroxide

   apd: 9 May 2001     

Identification of the redox partners of ERdj5/JPDI,a PDI family member,from an animal tissue

ERdj5 (also known as JPDI) is a member of PDI family conserved in higher eukaryotes. This protein possesses an N-terminal J domain and C-terminal four thioredoxin domains each having a redox active site motif. Despite the insights obtained at the cellular level on ERdj5, the role of this protein in vivo is still unclear. Here, we present a simple method to purify and identify the disulfide-linked complexes of this protein efficiently from a mouse tissue. By combining acid quenching and thiol-alkylation, we identified a number of potential redox partners of ERdj5 from the mouse epididymis. Further, we show that ERdj5 indeed interacted with two of the identified proteins via formation of intermolecular disulfide bond. Thus, this approach enabled us to detect and identify redox partners of a PDI family member from an animal tissue.     

Evidence for Cd101 but not Fcgr1 as candidate for type 1 diabetes locus, Idd10

Among polygenes conferring susceptibility to type 1 diabetes in the NOD mouse, Idd10 on distal chromosome 3 has been shown to be important for disease susceptibility. In this study, we investigated the candidacy of Fcgr1 and Cd101 for Idd10, by congenic mapping and candidate gene sequencing. Among seven NOD-related strains studied, the IIS mouse was found to possess a recombinant Idd10 interval with the same sequence at Fcgr1 as the NOD mouse, but a different sequence at Cd101 from that in the NOD mouse with 10 amino acid substitutions. The frequency of type 1 diabetes in NOD mice congenic for IIS Idd10 (NOD.IISIdd10) was significantly reduced as compared to that in the NOD mouse, despite the presence of the identical Fcgr1 sequence. These data indicate that IIS mice possess a resistant allele at Idd10, and suggest that Cd101, but not Fcgr1, is responsible for the Idd10 effect.