Characterization of newly isolated monoclonal antibodies against MHC of a Japanese wild mouse

We have already developed nine B10.MOL congenic strains carrying H-2 haplotypes derived from Japanese wild mice, Mus musculus molossinus, with the C57BL/10 genetic background. To obtain monoclonal antibodies against the H-2 antigen of the Japanese wild mouse, we carried out cell fusion using spleen cells from the animal immunized with one of the B10.MOL strains, B10.MOL-SGR (H-2 ^wm7). As a result, 19 hybridomas producing monoclonal antibodies were produced. Analysis with the intro-H-2 recombinants derived from B10.MOL-SGR indicated that 8 of them reacted with the class I and II with the class II molecule. The class I antibodies were tested for their cross -reactivities on wild mice and on the panels of standard inbred and B10.MOL strains. Most of the antibodies reacted with both the Japanese wild mice and the other subspecies, including standard inbred, while two antibodies highly specific for the donor H-2K region reacted with only three wild-derived mice, two M. m. molossinus from Anj o and Shizuoka, Japan, and one M. m. domesticus from Pigeon, Canada. In addition, all of the other four antibodies reactive with the K antigen of B10.MOL-SGR also reacted with the same three wild mice. The wild mice belonging to different subspecies might share very similar H-2K antigenic determinants in spite of their genetic and geographical remoteness.     

Allelic constitution of the hemoglobin beta chain in wild populations of the house mouse,Mus musculus

We studied the allelic frequency of the hemoglobin beta chain (Hbb) of wild mice, Mus musculus, collected from 46 localities, mostly in Asia and surrounding areas. The wild populations in the northern part of China, Korea, and the central part of Japan exhibited an almost monomorphic distribution of Hbbp. In the southern part of Asia, the frequency of Hbbp decreased and Hbbd was predominant. Although Hbbs and Hbbd are generally found in Europe, the Hbbp allele was present in Southeastern Europe (Bulgaria). In the light of these results, the Hbbp allele might have originated in mice of northern Asia.     

The role of calcium cations in the mechanism of phytochrome-dependent regulation of the <Emphasis Type="Italic">sdh1-2</Emphasis> gene expression and succinate dehydrogenase activity in maize leaves

The regulation of succinate dehydrogenase (SDH) activity and its gene expression by the phytochrome system has been demonstrated: red light (660 nm) reduces the SDH activity and the level of expression of the sdh1-2 gene. At the same time, the content of calcium cations in the nuclear fraction increases; it seems to be one of the mechanisms of phytochrome signal transduction in plant cells. Far-red light (730 nm) had opposite effects, i.e., increased SDH activity and the level of expression of the sdh1-2 gene. The data suggest that the SDH activity can be regulated at the level of expression in the green leaves of Zea mays by the phytochrome system with the involvement of calcium ions as a signal transduction messenger.     

Genetic differentiation in Indonesian and French rats of the subgenus Rattus

The allozyme polymorphism at 28 loci was examined in four Indonesian species of Rattus (R. diardii, R. tiomanicus, R. argentiventer and R. exulans) and in two French species (R. rattus and R. norvegicus). R. diardii was the most polymorphic species (H = 0.089) and R. tiomanicus and R. exulans the least polymorphic (H = 0.026). The six species were found to differ from one another by 2–7 diagnostic loci. The use of allozyme characters for systematic identification is discussed. Genetic relationships between the six species were established using two different methods. In both cases, the results were different from those published earlier. These results are discussed in view of the representatives of the loci investigated.