Testes‐derived unipotent male germ‐line stem (GS) cells can acquire multipotency under appropriate culture conditions to become mGS cells which can contribute to all three germ‐layers. This study was designed to investigate the epigenetic characteristics of mGS cells derived from adult mouse testes (maGS cells). The GS cells were isolated from 4 6 week DBA mouse and were cultured in Dulbecco’s modified Eagle Medium supplemented with 15% (v/v) fetal bovine serum, 1,000 U/ml LIF, 4 ng/ml GDNF at 37℃ in an humidified atmosphere of 5% CO2 in air to derive the maGS cells. The multipotency of maGS cells were verified by morphological and gene expression analyses, teratoma formation upon transplantation into nude mouse and in vitro differentiation ability. Bisulfite genomic sequencing revealed that GS cells had androgenetic DNA methylation pattern at the Igf2‐H19, Gnas‐Nespas , and Dlk1‐Dio3 imprinted gene clusters which changed to hemi‐zygotic embryonic stem (ES)‐cell like pattern in the maGS cells. Western blot analysis, using modification‐ and residue‐specific antibodies, revealed that both maGS and ES cells had similar level of histone di‐methylation at 4th and 27th lysine residue of histone 3 (H3K4me2 and H3K27me2) which represent “bivalent domain” for regulating self‐renewal and differentiation of mouse ES cells. Both maGS and ES cells also shared similar hisone modification for H3K9me2, H3K79me2, H3K9ac and H3K18ac. However, maGS cells had higher level of H3K- 36me2 and H3S10p. These data suggest that maGS and ES cells share several epigenetic characteristics but they also have their own unique epigenetic marks that may be useful as a molecular marker for their identification.

Soybean is a crop of importance economically and nutritionally in many parts of the world. Thanks to many new genes brought from genomic research, It is possible to introduce various candidate genes through genetic transformation to see the performance of the genes in field. In our lab, soybean transformations have been tried for last 10 years to probe the possibility of traits improvement by transformation of new gene into soybean. For this purpose, three different genes were transformed into Korean soybean variety, Kwangan. First, the gene that controls early flowering of plant was transformed into Kwangan. Second, a candidate gene for soybean mosaic virus (SMV) resistance was transformed to produce transgenic plants. Third, another candidate gene for drought tolerance was transformed. All the transgenic plants from three genes transformation were produced for their gene insertion and their expression using PCR, qRT-PCR. Further analysis including harvesting seeds is currently undertaken.

Genome sequencing researches for considerable numbers of crops and wild plants are being developed. Cytogenetic researches according to chromosome number and size are essential to confirm and comprehend ploidy level and genome size before genome sequencing project is actually conducted. Cytogenetic researches on six food crop plants were carried out by DAPI staining and fluorescence in situ hybridization (FISH) method. Fagopyrum esculentum Moench showed 2n=2x=16, each chromosome length of 1.42㎛ to 1.77㎛, total chromosome length of 13.31㎛, and karyotypic formula of 2n=8m; Phaseolus angularis W.F. Wight, 2n=2x=22, 2.01㎛ to 3.84㎛, total 28.03㎛, 2n=9m+2sm, Perilla frutescens var. japonica Hara, 2n=2x=40, 1.73㎛ to 2.76㎛, total 44.36㎛, 2n=5m+13sm+2st. Chromosome sizes of the other three species such as, Panicum miliaceum L., 2n=2x=36, total chromosome length of 30.83㎛, Sesamum indicum L., 2n=2x=26, 27.39㎛, lpomoea batatas L., 2n=2x=30, total 33.51㎛ were too small for each chromosome type to be identified and analyzed. The result of FISH analysis using 5S and 45S rDNA probe showed species-specific chromosome locations in the genome. These preliminary analyses were carried out to decide which food crop to prioritize for genome sequencing. This work was supported by the “Cooperative Research Program for Agriculture Science & Technology Development (No.PJ009837), Rural Development Administration, Republic of Korea.