Reflections on the Limits of Science and Technology

SYNOPSIS. Exuberance over insights gained in the infant fieldof genetics early this centuryled scientists to extrapolatebeyond their data to heredity of behavioral traits in people.Oneof the direct consequences was the incarceration of Americansand Canadians of Japanese ancestry during World War II as enemyaliens. Drawing on this personal experience of the misapplicationof science, I describe the process of scientific indoctrinationand blindness to the limitations of this way of knowing. Thisled to my attempt to demystify science through the electronicmedia. Only recently have I come to understand that two assumptionsthat impelled me to use television in the first place are wrong.The first was that with access to more information about science,the general public would be in a position of making better informeddecisions on issues involving science and technology. The problemis that we are overwhelmed with information and most peoplelack the ability to distinguish meaningful "signal" (i.e., credibleinformation) from background "noise" (i.e., garbage). We believein phantoms created by the acceptance of anything because itexists as print or television programs. My second assumption had been that we need a mechanism to doan in-depth "cost/benefit" analysis of new technologies beforethey are actually made available. But history reveals that thebenefits of new technologies are immediate and obvious whilethe costs are usually hidden and completely unpredictable. But in the rush to exploit new scientific insights we ignorethe fact that science must lookat nature in isolated bits andpieces. Knowledge gained in fragments does not yield an understandingof the greater context from which the pieces are taken. Witheach new discovery, we itch to apply it, forgetting how muchwe have yet to learn. Our attempts to manipulate nature areoften illusions of control created by our ability to overpowernature by brute strength. In the area of genetic engineering,this could be truly disastrous.     

Stimulation of Spermatid Phosphofructokinase by Fructose 2,6-Bisphosphate from Rat Testes

Effect of fructose 2, 6-bisphosphate on 6-phosphofructokinase (ATP: D-fructose-6-phosphate 1-phosphotransferase, EC 2.7.1.11) in spermatid extract from rat testes was studied. Fructose 2, 6-bisphosphate stimulated the enzyme greatly by increasing its affinity for fructose 6-phosphate and relieving the inhibition by ATP. Fructose 2, 6-bisphosphate (0.8 μM) was required for 50% activation of 6-phosphofructokinase (PFK). In addition, fructose 2, 6-bisphosphate, AMP and fructose 6-phosphate acted cooperatively to stimulate the activity of PFK. This stimulation may play an important role in the regulation of glycolysis in spermatids of rat testes.     

Respiration of Sea Urchin Spermatozoa in the Presence of a Synthetic Jelly Coat Peptide and Ionophores

Sperm respiration and motility of the sea urchin Hemicentrotus pulcherrimus were studied at pH 6.8 in the presence of a synthetic jelly peptide (Gly-Phe-Asp-Leu-Asn-Gly-Gly-Gly-Val-Gly) and monovalent cationic ionophores. The synthetic peptide stimulated sperm respiration and motility to the level of that found in normal sea water (pH 8.2) with half-maximal stimulation at approximately 100 pM. Monensin and valinomycin also stimulated sperm respiration with half-maximal effects at 7 μM and 0.7 μM, respectively. The stimulation of sperm respiration by the peptide and monensin was dependent on external Na⁺, but was not dependent on the osmolarity of the suspending medium. Approximately 50 mM Na⁺ was required for half-maximal respiratory responses to the peptide and monensin.     

Female dimorphism in Japanese diving beetle Dytiscus marginalis czerskii (Coleoptera: Dytiscidae) evidenced by mitochondrial gene sequence analysis

Three species of the Japanese diving beetle Dytiscus have been identified: D. dauricus Gebler, 1832; D. marginalis czerskii Zeitzev, 1953; and D. sharpi. At present, the latter consists of the subspecies D. sharpi sharpi Wehncke, 1875 and D. sharpi validus Régimbart, 1899 based on the comparative data of mitochondrial DNA cytochrome‐c oxidase I (COI) sequences. Many Dytiscus species have smooth and grooved elytra, which are female dimorphic traits. For many years it has been thought that Japanese D. marginalis czerskii has a single morph, that is, only grooved females, although there were some collecting reports of smooth females occurring at the foot of Mt. Chokaisan in Yamagata and Akita Prefectures. However, the population of smooth females (smooth population) has not yet been identified by DNA markers. To understand the species status of the smooth population, we sequenced 769 bp of COI of a male derived from a smooth mother insect and compared it with the sequence from a known grooved female. The sequences of 769 bp of the COI gene in the smooth population were identical to that in the grooved female, indicating that Japanese D. marginalis czerskii has female dimorphic traits.     

Detection of recombinant haplotypes in wild mice (Mus musculus) provides new insights into the origin of Japanese mice

Japanese house mice (Mus musculus molossinus) are thought to be a hybrid lineage derived from two prehistoric immigrants, the subspecies M. m. musculus of northern Eurasia and M. m. castaneus of South Asia. Mice of the western European subspecies M. m. domesticus have been detected in Japanese ports and airports only. We examined haplotype structuring of a 200 kb stretch on chromosome 8 for 59 mice from throughout Eurasia, determining short segments (≈ 370–600 bp) of eight nuclear genes (Fanca, Spire2, Tcf25, Mc1r, Tubb3, Def8, Afg3l1 and Dbndd1) which are intermittently arranged in this order. Where possible we identified the subspecies origin for individual gene alleles and then designated haplotypes for concatenated alleles. We recovered 11 haplotypes among 19 Japanese mice examined, identified either as ‘intact’ haplotypes derived from the subspecies musculus (57.9%), domesticus (7.9%), and castaneus (2.6%), or as ‘recombinant’ haplotypes (31.6%). We also detected recombinant haplotypes unique to Sakhalin. The complex nature of the recombinant haplotypes suggests ancient introduction of all three subspecies components into the peripheral part of Eurasia or complicated genomic admixture before the movement from source areas. ‘Intact’domesticus and castaneus haplotypes in other Japanese wild mice imply ongoing stowaway introductions. The method has general utility for assessing the history of genetic admixture and for disclosing ongoing genetic contamination.     

Arabidopsis thaliana ASN2 encoding asparagine synthetase is involved in the control of nitrogen assimilation and export during vegetative growth

We investigated the function of ASN2, one of the three genes encoding asparagine synthetase (EC 6.3.5.4), which is the most highly expressed in vegetative leaves of Arabidopsis thaliana. Expression of ASN2 and parallel higher asparagine content in darkness suggest that leaf metabolism involves ASN2 for asparagine synthesis. In asn2‐1 knockout and asn2‐2 knockdown lines, ASN2 disruption caused a defective growth phenotype and ammonium accumulation. The asn2 mutant leaves displayed a depleted asparagine and an accumulation of alanine, GABA, pyruvate and fumarate, indicating an alanine formation from pyruvate through the GABA shunt to consume excess ammonium in the absence of asparagine synthesis. By contrast, asparagine did not contribute to photorespiratory nitrogen recycle as photosynthetic net CO₂ assimilation was not significantly different between lines under both 21 and 2% O₂. ASN2 was found in phloem companion cells by in situ hybridization and immunolocalization. Moreover, lack of asparagine in asn2 phloem sap and lowered ¹⁵N flux to sinks, accompanied by the delayed yellowing (senescence) of asn2 leaves, in the absence of asparagine support a specific role of asparagine in phloem loading and nitrogen reallocation. We conclude that ASN2 is essential for nitrogen assimilation, distribution and remobilization (via the phloem) within the plant.     

SOME ENZYMES RELATING TO THE METABOLISM OF STARCH IN A SEA-LETTUCE

The occurrence of a phosphorylase in the extracts of a greenseaweed, Ulva pertusa was demonstrated. In addition, a sugarphosphatase different from non-specific acid phosphatase andan amylase, which are involved in the starch degradation, werealso detected in this sea-lettuce. ¹Contributions from the Shimoda Marine Biological Station, No.147.