Seasonal migration patterns of female sika deer in eastern Hokkaido,Japan

Fifty-seven female sika deer (Cervus nippon yesoensis), captured at the wintering area in the Shiranuka Hills in eastern Hokkaido, Japan, were radio-tracked during 1997–2001 to examine the factors affecting seasonal migration at the individual-landscape level. Ten of the 57 deers migrated between low-altitude summer home ranges and intermediate-altitude winter home ranges (the upward migrants). Twenty-nine migrated between high-altitude summer home ranges and intermediate-altitude winter home ranges (the downward migrants). Twelve used the intermediate-altitude home ranges all year round (the non-migrants). The remaining six were unknown. The summer home ranges of deer were widely scattered over an area of 5734km². Migration distances ranged between 7.2 and 101.7km. Deer showed high site fidelities to their seasonal home ranges. The upward migrants wintered in areas of less snow, higher quality of bamboo grass, and more coniferous cover than their summer home ranges. The downward migrants wintered in areas of less snow, higher quality of bamboo grass, higher winter temperature, and more southern slopes, but less coniferous cover than their summer home ranges. The non-migrants used year-round ranges with little snow, high quality of bamboo grass, and sufficient coniferous cover. We suggest that snow cover and bamboo grass are the factors affecting seasonal migration of the population and that coniferous cover is another factor for the upward migration.     

Genetic variation and population structure of the Japanese sika deer (Cervus nippon) in Hokkaido Island, based on mitochondrial D-loop sequences

Mitochondrial DNA (mtDNA) D -loop region sequences (602 bp) from 141 samples of the sika deer Cervus nippon collected from Hokkaido Island of Japan were investigated to elucidate population genetic structure. All animals possessed seven repeat units (38 or 39 bp each) in the sequences. Comparison of the 602-bp sequences showed four sites of transitional mutations (A↔G or C↔T). Based on combination of the substitutions, six D -loop haplotypes (a–f types) were identified in the Hokkaido population, suggesting the occurrence of at least six maternal lineages. Distribution maps of the haplotypes constructed using the Geographic Information System showed that the distribution patterns differed from haplotype to haplotype. In particular, distribution of the major three types (a-, b-, and c-types) almost overlapped with three main areas of coniferous forests in Hokkaido. These results suggest that expansion of the sika deer population could have occurred through the habitat of coniferous forests after the historical bottleneck in Hokkaido.     

CHANGE OF B-TYPE HAEM CONTENT IN RELATION TO PEROXIDASE BIOSYNTHESIS IN INJURED SWEET POTATO ROOTS

The methods of quantitative analysis of b-type haem in plantswere investigated. With an improved method developed was determinedthe haem content in the supernatant, mitochondrial, and microsomalfractions of sweet potato tissue. The activities of peroxidase,catalase, and cytochrome oxidase, as well as the contents ofb-type haem and acid-insoluble nitrogen in the cellular fractionswere determined at different incubation times after cuttingof sweet potato tissue. Peroxidase and catalase increased withtime in each celluler fraction, following a short lag phase.In the mitochondrial fraction, b-type haem, cytochrome oxidase,and acid insoluble nitrogen increased linearly with time. Inthe microsomal and supernatant fraction, b-type haem increasedwith time following a short lag phase. The increase in haemcontent of the supernatant fraction appeared to be associatedwith peroxidase formation. Time course analysis showed that ⁵⁹Fe-incorporation into b-typehaem of the supernatant fraction increased with time and thatincorporation was markedly inhibited by blasticidin S. The incorporationof ⁵⁹Fe into mitochondrial haem did not increase with time andwas not inhibited by blasticidin S. Blasticidin S inhibited⁵⁹Fe-incorporation into microsomal haem. Time course analysisof b-type haem content, ⁵⁹Fe-incorporation into b-type haem,and peroxidase activity suggest that in the injured tissue haemis synthesized from low molecular weight compounds and is incorporatedinto peroxidase as the haem moiety. ¹ This paper constitutes Part 57 of the Phytopathological Chemistryof Sweet Potato with Black Rot. ² Present address: Institute for Plant Virus Research, Chiba.     

Photosynthetic responses to temperature of phosphoenolpyruvate carboxykinase type C4 species differing in cold sensitivity

Photosynthetic rates, the activities of key enzymes associated with the C₄ cycle and ribulose-1,5-bisphosphate carboxylase (RuBPCase), and the levels of metabolites involved in the C₄ cycle were compared between the two phosphoenolpyruvate carboxykinase (PCK) type C₄ species Spartina anglica, which is cold-tolerant, and Zoysia japonica, which is cold-sensitive, during exposure to low temperature. Plants of both species grown outside in summer were placed in a growth chamber at 27/20 °C day/night temperatures. After 1 week, plants were exposed to 20/17 °C for 1 week and then to 10/7 °C for 2 weeks. Photosynthetic rates in Z. japonica decreased progressively to about 25% during the chilling treatments. In contrast, S. anglica exhibited a 43% increase in photosynthetic rates after exposure to 20 °C for 1 week, which remained relatively constant thereafter. Consistent with these observations, most of the C₄ enzymes and RuBPCase in Z. japonica declined. Phosphoenolpyruvate carboxylase (PEPC) and PCK activities declined particularly drastically during the treatments. However, the activities of these enzymes in S. anglica showed either a slight increase or decrease upon a mild cold treatment, and remained relatively constant during further chilling treatments. There was a sharp decline in phosphoenolpyruvate in Z. japonica after exposure to 10 °C. On the other hand, metabolite levels in S. anglica were largely unaffected by the chilling treatments. These results suggest that the drastic declines of both PEPC and PCK activities may be important limiting factors responsible for cold sensitivity in C₄ photosynthesis of Z. japonica.     

Fish Hereditary Melanoma Cell Lines of Different Degrees of Cell Differentiation

Four cell lines including two sublines were established from hereditary melanomas in interspecific hybrids between platyfish ( Xiphophorus maculatus ) carrying the Sp gene and swordtails ( X. helleri ) and maintained in vitro for more than 34 months. Cells in each cell line grew randomly across each other with an apparent lack of contact inhibition of growth and at a population doubling time of 50 to 72 hr. They retained the characteristics of young pigment cells in regard to ultrastructure, tyrosinase activity, the DOPA and combined DOPA-premelanin reactions. In the degree of differentiation, the cells of the three cell lines seemed comparable to early melanocytes close to melanoblasts, and those of the remaining one cell line seemed comparable to young melanocytes but were in a more differentiated state than the early melanocytes. Colony forming ability on plastic plates was at a level of 10% in the three cell lines but only 1% in the one cell line. All four cell lines failed to form colonies in soft agar. Chromosome analysis revealed that these four cell lines were heteroploid with many abnormal figures of chromosomes and double minute chromosomes. None of the cell lines showed transplantability to fish.