CHANGES IN ACTIVITY OF DGLUCOSE-6-PHOSPHATE: NADP AND 6-PHOSPHO-D-GLUCONATE: NADP OXIDOREDUCTASES IN RELATION TO LIGNIFICATION OF BAMBOO

D-Glucose-6-phosphate: NADP oxidoreductase (glucose-6-phosphatedehydrogenase; EC 1.1.1.49 [EC] ) and 6-phospho-D-gluconate: NADPoxidoreductase (6-phosphogluconate dehydrogenase; EC 1.1.1.44 [EC] )were found to be present in immature bamboo. Optimal pHs ofthe glucose-6-phosphate- and 6-phosphogluconate dehydrogenaseswere found to be 8.0 and 8.5, respectively. Both enzymes were demonstrated to be NADP-specific and NADPcould not be replaced by NAD. Fructose-6-phosphate was indirectlyutilized after convrsion to glucose-6-phosphate by glucose-6-phosphateisomerase coexisting in the enzyme preparation. Pattern of enzyme activity and of respiratory breakdown of glucose-1-¹⁴Cand glucose-6-¹⁴C were investigated in connection with lignificationof bamboo and discussed in comparison with sugar metabolismof fungi-infected plant tissues. As for the changes in the enzymeactivity with growth of bamboo, it was recognized that therewas a tendency that the activity of both enzymes increased andwas maintained at a certain level even in the aged tissues.In addition there was a drop of the C₆/C₁ ratio toward the tissuesof lower parts containing considerable amount of lignin andthis phenomenon was the same as that observed in pentose phosphatemetabolism of fungi-infected plant tissues. (Received September 5, 1966; )     

Melittin, a Component of Bee Venom, Activates Unfertilized Sea Urchin Eggs

Melittin, which is known to stimulate phospholipase A , in many cells, caused as much elevation of fertilization membranes and increase in respiration of unfertilized eggs of the sea urchins Anthocidaris crassispina and Hemicentrotus pulcherrimus as normal fertilization.
In melittin-activated eggs, amino acid transport was decreased to less than that of unfertilized eggs, nucleoside transport was only slightly, activated, protein synthesis was rather inhibited and neither DNA synthesis nor cleavage was observed. It is concluded that although melittin induces the cortical reaction and activation of respiration in unfertilized eggs, its cytotoxicity prevents any "late changes".     

History vs. habitat type: explaining the genetic structure of European nine‐spined stickleback (Pungitius pungitius) populations

The genetic structure of contemporary populations can be shaped by both their history and current ecological conditions. We assessed the relative importance of postglacial colonization history and habitat type in the patterns and degree of genetic diversity and differentiation in northern European nine‐spined sticklebacks (Pungitius pungitius), using mitochondrial DNA (mtDNA) sequences and 12 nuclear microsatellite and insertion/deletion loci. The mtDNA analyses identified – and microsatellite analyses supported – the existence of two historically distinct lineages (eastern and western). The analyses of nuclear loci among 51 European sites revealed clear historically influenced and to minor degree habitat dependent, patterns of genetic diversity and differentiation. While the effect of habitat type on the levels of genetic variation (coastal > freshwater) and differentiation (freshwater > coastal) was clear, the levels of genetic variability and differentiation in the freshwater sites were independent of habitat type (viz. river, lake and pond). However, levels of genetic variability, together with estimates of historical effective population sizes, decreased dramatically and linearly with increasing latitude. These geographical patterns of genetic variability and differentiation suggest that the contemporary genetic structure of freshwater nine‐spined sticklebacks has been strongly impacted by the founder events associated with postglacial colonization and less by current ecological conditions (cf. habitat type). In general, the results highlight the strong and persistent effects of postglacial colonization history on genetic structuring of northern European fauna and provide an unparalleled example of latitudinal trends in levels of genetic diversity.     

CHANGES IN ACTIVITY OF SHIKIMATE : NADP OXIDOREDUCTASE IN RELATION TO LIGNIFICATION OF BAMBOO

Shikimate : NADP oxidoreductase (5-dehydroshikimate reductase;EC 1.1.1.25 [EC] ) was extracted from immature bamboo and partiallypurified. The optimal pH of the enzyme was found to be 11.0.The enzyme was demonstrated to be NADP specific. Michaelis constants (Km) for NADP and shikimic acid as substratewere found to be 1.4 10^–4M and 2.0 10^–4M, respectively,at pH 8.0. No metal requirement could be demonstrated sincelittle change in enzyme activity was observed on addition ofethylenediamine-tetraacetic acid (EDTA). On the other hand,the enzyme was potently inhibited by p-chloromercuribenzoicacid (PCMB). 5-Dehydroshikimate reductase was demonstrated to be widely distributedin woody plants such as bamboo, udo (Aralia cordata), asparagus(Asparagus officinalis) and tulip tree (Liriodendron tulipifera)as well as other higher plants. Shikimic acid content was comparatively low at the top, butafter reaching maximal content in the part just below the top,it began to decrease toward lower parts of bamboo. The enzymeactivity at the top was the highest and seemed to decrease towardthe tissues of lower parts. However the fact that the activitywas still maintained at a certain level even in the aged tissuessuggests that 5-dehydroshikimate reductase might play a significantrole for biosynthesis of lignin. (Received September 5, 1966; )     

Additional notes on Anisopteromalus sp. (Hymenoptera: Pteromalidae), the sibling species of a parasitic wasp of stored‐product pests,Anisopteromalus calandrae (Howard): A new alternative host,an eye color mutant and DNA barcodes

A parasitic wasp of stored‐product pests, Anisopteromalus calandrae (Howard), is known to have a sibling species with a different chromosome number. Here, we report establishment and characterization of an eye color mutant in this sibling species. The phenotype of the mutant is red eye in adults, and crossing experiments revealed that the mutant phenotype is recessive to wild type (brown eye color). We also report DNA barcode sequences (a partial sequence of mitochondrial cytochrome‐c oxidase subunit I) of A. calandrae and the sibling species to enable accurate identification of these morphologically similar species. Analyses of our laboratory strains showed that 12.6% of the analyzed sequences (82 of 652 bp) differed between the two species. Finally, we note that the seed beetle Callosobruchus chinensis (Linné) (family Bruchidae), host of our laboratory strains of the sibling species, is a new record of alternative host at the family‐level for the wasp (known hosts: Anobiidae (natural host) and Curculionidae (alternative host)).     

Female-biased sex ratio in a wild bruchid seed-predator, Kytorhinus sharpianus. I. Larval competition and other factors

Abstract.

• 1 A wild bruchid seed-predator, Kytorhinus sharpianus, has a complex life cycle consisting of bi- and trivoltinism on a wild leguminous plant, Sophola flavescens. Observations of adults showed significant female-biased sex ratios (from 1:2 to 1:6) for nine generations over 4 years.
• 2 To investigate the potential effects of larval competition on the sex ratio, we altered the number of hatched eggs per seed and counted emergent males and females under laboratory conditions. Although only one adult could emerge per seed, the ratio of the females that emerged increased with the number of hatched eggs per seed. However, the sex ratio was not significantly different from 1:1 in the case of one hatched egg per seed.
• 3 We dissected seeds bearing two hatched eggs at regular intervals, and classified the surviving and the dead larvae according to their developmental stage. Over time, one larva within each seed always survived, while the other larva died from the second to fourth instar before the seed resource became exhausted.
• 4 In order to study the effects of the difference in the stages of two larvae in a seed on the emergence sex ratio, we manipulated intervals between the first and second ovipositions in the laboratory. As the difference in developmental stages of the two larvae increased, the closer to 1:1 the emergence sex ratio became.
• 5 Field observations, however, showed that about 60% of infested seeds were bored by only one K.sharpianus larva. This suggests that female dominance in larval competition within a seed may be relatively unimportant in causing the female-biased sex ratio in the field.