In the current work, regulation of the pap1(+) gene was investigated by the use of the pap1(+)-lacZ fusion gene and semi-quantitative reverse transcriptase-PCR. The synthesis of beta-galactosidase from the pap1(+)-lacZ fusion gene was significantly enhanced by nitric oxide (NO)-generating sodium nitroprusside (SNP) and nitrogen starvation. However, the induction by SNP and nitrogen starvation was observed to be much less in the Pap1p-negative cells harboring the fusion gene. Exogenous NO was more effectively scavenged in the Pap1p-positive cells than in the Pap1p-negative cells. Oxidative stress such as superoxide anion, hydrogen peroxide and cadmium could not give rise to an effect on the synthesis of beta-galactosidase from the fusion gene. The pap1(+) mRNA level was elevated in the wild-type cells by SNP and nitrogen starvation. Catalase activity, a major enzyme positively regulated by Pap1p, was significantly increased only in the Pap1p-positive cells by SNP. In brief, it is demonstrated that transcription of the Schizosaccharomyces pombe pap1(+) gene is positively regulated by nitrosative and nutritional stress in a Pap1p-dependent manner.

To understand the environmental factors affecting the spatiotemporal distribution of copepods, sampling was conducted seasonally in a small mesotidal inlet and estuary located in Doam Bay of southwestern Korea. The study area was divided seasonally into two or three station groups (estuarine, mixed, and coastal) by a cluster analysis and non-metric multidimensional scaling based on copepod abundance. Acartia forticrusa, A. hudsonica, A. ohtsukai, Paracalanus parvus s. l., Pseudodiaptomus marinus, Tortanus derjugini, T. dextrilobatus, T. forcipatus, Oithona spp., and harpacticoids were important species for grouping the stations. The spatiotemporal distribution of the first two species was restricted to the estuarine area in summer and significantly correlated with temperature, salinity, and chlorophyll-a concentration. The distribution of other brackish species, such as T. derjugini and T. dextrilobatus, significantly correlated with temperature, salinity, and chlorophyll-a concentration. In contrast, A. hudsonica significantly correlated with dinoflagellate density and turbidity in winter, in addition to the abovementioned environmental factors. Acartia hudsonica also maintained a large population in the estuarine area in fall and winter, and its distribution extended across the entire bay in spring. Other coastal species occurred in all areas and did not significantly correlate with environmental factors. Therefore, brackish species in the study area may have developed seasonally different behaviors to sustain their populations.

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