Identification and Characterization of a Novel Trans-membrane Protein Gene, pdh1, from Schizosaccharomyces pombe

We have cloned a new gene, pdh1, from genomic DNA of fissionyeast Schizosaccharomyces pombe. pdh1 is actively transcribedas 1400-nucleotide mRNA in vegetatively growing cells and cancode for a 226 amino acid polypeptide (pdh1p). Computationalstructural prediction has revealed that the pdh1p is a highlyhydrophobic protein with seven transmembrane domains. The predictionhas also detected a possible C-kinase phosphorylation site withinthe longest hydrophilic loop.     

A Lagrangian model of phytoplankton photosynthetic response in the upper mixed layer

A previously developed Lagrangian model considered the distributionand light exposure of individual phytoplankton cells in a weaklystratified upper ocean layer mixed by depth-dependent turbulence.This model is coupled with a phytoplankton photoresponse model,previously applied in a Eulerian context, that includes a temporallydecaying dependence on inhibitory light exposure. The combinedmodel output provides the trajectory, light experience and photoresponseof each individual, or the photoresponse central tendency andvariability of the population that occurs at a given depth ata given time. The time dependence of the photoresponse is themain variable considered and determines the shape of the verticalprofile of primary production. Shorter response times yielda strong photoinhibition event that is nearly synchronous withinhibiting incident radiation. Longer response times are characterizedby weaker photoinhibition events that outlive the occurrenceof the inhibiting incident radiation for an interval relatedto the imposed time constant. Under the depth-dependent turbulentmixing regime imposed, photoinhibition is detectable even atwind speeds up to 10 m s^–1. Modeling and technologicalapproaches that compare the bulk characteristics of populationsto the statistical characteristics of the individuals formingthose populations are both under active development. A fruitfulfeedback relationship is likely in the near future.     

Separation characteristics of animal cells using a dielectrophoretic filter

The separation characteristics of a wire–wire type dielectrophoretic (DEP) filter were evaluated using animal cells. The separation of cells with different activities was examined using a DEP filter. The specific growth rate of the cells in retention liquid was larger than that in permeation liquid. From the culture results of the separated cells, it becomes clear that the specific growth rate of the cells of the retention liquid was higher than that of the cells of the permeation liquid. Furthermore, as a result of separating cells two kinds of cell suspensions using the DEP filter, the difference between the retention ratios of the two groups of obtained cells was about 20% at maximum.     

Modulation of testicular receptors for LH, FSH and prolactin by the administration of ovine prolactin in mature rat

To elucidate the role of prolactin on testicular function, we treated mature rats with ovine prolactin (oPRL) and investigated the dose and time-dependent changes in testicular LH, FSH and prolactin receptors as well as in serum gonadotropin and steroid levels. Twelve week-old rats were injected sc with a single dose of various amounts of oPRL (0.2, 1 and 5 IU) and killed on the first, second and third days after the treatment. Testicular LH receptor decreased to 59% of the control level as a function of time while prolactin receptor increased to 244% maximally of the control level on the second day. In contrast, FSH receptor changed in a different fashion. Smaller amounts of oPRL (0.2 and 1 IU) raised the receptor level to 193% of the control level on the first day whereas a larger amount (5 IU) did not change the receptor, which tended to remain in a low level throughout the experimental period. The serum FSH level significantly increased in every group on the second day, then returned to the control range by the third day. On the other hand, the serum testosterone level changed in a characteristic manner, decreased significantly in every group on the first day though not in a dose-dependent fashion, returned to normal on the second day and significantly increased in the 0.2 IU group on the third day (p less than 0.01). Similarly, the serum estradiol level decreased in the oPRL-treated groups on the first day and was restored on the second day.(ABSTRACT TRUNCATED AT 250 WORDS)     

Purification and some properties of Monilinia fructicola DNase

DNase was extracted and purified about 1,000-fold from the myceliaof a phyto-pathogenic fungus, Monilinia fructicola. The DNasewas an endonucleolytic enzyme and digested both native and heat-denaturedDNA’s into oligonucleotides having 5'-phosphoryl and 3'-hydroxyltermini. The DNase required Mg ions for full activity. The isoelectricpoint of this enzyme was 9.0, and the molecular weight was about36,000 daltons. (Received January 18, 1980; )