Schizosaccharomyces japonicus is a member of genus Schizosaccharomyces, which was originally isolated by Matao Yukawa and Tetsuo Maki from strawberry field of Kyusyu University in Japan (1). They have reported as follows, “In the May in 1928, we have harvested strawberries from a farm yard of Kyusyu University, and clushed , and cane sugar and tartaric aid was added to adjust the sugar concentration of 20 % and the acidity of 1 % (as tartaric acid). We let them fermented in 15 litre of fermentation glass tube. Day 2, they start to bubble, …..” (1).

One of the striking feature of S. japonicus is its size of the cell, and visibly condensed mitotic chromosomes (2, 3). CF Robinow and JS Hyams have reported “The behaviour of the chromosomes in dividing nuclei of vegetative cells is best studied in the larger species of fission yeasts, namely, S.japonicus and S. japonicus var. versatilis.” (3). There are clear difference from S. pombe, not only its size, but also the ability to make mycelia (4, 5, see also Figure 1 and 2). It should be noted that S. japonicus forms ascospore with eight spores and is iodine negative (1, 6, 7).

This less characterised fission yeast has been sequenced of its genome. The data is obtained from the Broad Institute website (http://www.broad.mit.edu/) . The “type” strain is IFO1609 (ATCC10660), and that is the strain sequenced. The true-heterothallic strains (h- like: NIG5872, h+ like: NIG2017) are also available from this website of National Institute of Genetics (8). Using this larger-sized, and dimorphic fission yeast, we are hoping it will provide a new insigt on chromosome metabolism, or diffrentiation.