As a preliminary investigation into the effect of environmental factors control for gonadal development, we examined the involvement of photoperiod and water temperature in ovarian development of Epinephelus. akaara. For the induction of sexual maturation, E. akaara reared in recirculating aquaculture system (RAS). During November 2013, the photoperiod and water temperature was adjusted to 12L:12D and 18℃, respectively. In the photo-thermal treatment group, every 3 weeks daylight was increased as follows a 13L:11D and 14L:10D, and control group was maintained under natural condition. After 9 weeks, water temperature was increased 23℃ in photo-thermal treatment group. The sampled fish every 3 weeks revealed increase in gonadosomatic index (GSI; 5.18±1.38), oocyte diameter and vitellogenic oocytes (423.9±36.1 ㎛) were observed in gonads 12 weeks under photo-thermal treatment group. However, ovarian development was maintained immature stage in control group. In this environmental factors manipulation trial, seventy one of the 95 females (578.4 ± 25.4 g in mean body weight, 31.0 ± 0.5 cm mean total length) treated with HCG injection (doses 500 IU/kg BW) were induced ovulation by artificial stripping. The total volume of ovulated eggs were 3,470 ml and the total volume of fertilized eggs was 3,295 ml. The fertilization rate and hatching rate were 95% and 98%, respectively. These results suggest that the photoperiod as well as water temperature are major environmental factors in triggering the gonadal development of E. akaara.

Aromatase is an enzyme that converts testosterone to estrogen. This enzyme, present in the sperm as well as various tissue and cells, has been considered to be related to the fertility of human and mouse sperm. Therefore, we examined effect of aromatase inhibitor on viability and fertility of sperm, and quantity of aromatase in sperm groups with different density in pig. To analyze the effect of aromatase on sperm viability, we treated aromatase inhibitor to the sperm with different concentrations (0, 10, 20, 50, 100, 200, 500 μM) at different time (0.5, 1, 2, 4, 8 hours). After the treatment, the sperm viability was calculated by hypo-osmotic swelling test. We selected 0, 50, 100 μM concentration during 0.5 hour as inhibitor treatment condition before in vitro fertilization. Next, we examined fertility and quantified aromatase protein in sperms with different density. In the first experiment, viability of sperm was decreased following the increasement of inhibitor concentration. The aromatase inhibited sperm showed lower penetration rate and cleavage rate than those of non-treated sperm. Concentration of 50 μM inhibitor had no significant effect on the sperm viability, but it significantly reduced sperm fertility. Second, sperms with low density showed higher penetration rate, but no significant difference between sperms with high density. In conclusion, aromatase is responsible for viability and fertility of porcine sperm similar to mouse and human, however, density of sperm has no correlation with quantity of aromatase protein.

Sirt1 belongs to class III histone/protein deacetylase. Sirt1 KO mice have spermatogenic defects. In this study, expression of Sirt1 and acetylated histone 3k9 (H3k9ac) was examined in developing mouse testes. Among two splicing variants of sirt1 mRNA long form was dominant in developing testis. Testicular sirt1 mRNA levels were low at birth, increased until 14 days post partum (pp) and remained constant thereafter. Sirt1 immunoreactivity was weak to negligible in gonocytes, moderate in spermatogonia, absent in preleptotene spermatocytes, moderate in zygotene spermatocytes, strong in pachytene spermatocytes, and weak in diplotene spermatocytes. Round and elongating spermatids were negative for Sirt1. Acetylated histone 3k9 (H3k9ac) immunoreactivity was moderate in spermatogonia and weak to negligible in preleptotene to pachytene spermatocytes but strong in round and elongating spermatids. In Sertoli cells, nuclear Sirt1 immunoreactivity was absent at birth, increased at 14 days pp and markedly increased at 28 days pp onwards. In immature Sertoli cells culture, FSH and testosterone increased sirt1 mRNA, suggesting that Sirt1 participates in protein deacetylation events during the differentiation of Sertoli cells by gonadotropin. In the Leydig cells, nuclear Sirt1 immunoreactivity was weak until 2 weeks pp and decreased in 4 weeks pp onward. suggesting the protein deacetylation by Sirt1 in Leydig cell precursor/progenitor cells. Mutually exclusive expression between Sirt1 and H3k9ac in pachytene spermatocytes in testis suggests that deacetylation of H3K9ac by Sirt1 participates in the gene silencing and/or chromosome behavior in pachytene sspermatocytes.

Water channel proteins, aquaporins (AQPs) contribute to transepithelial water movement in many tissues. To date, 13 mammalian AQPs have been identified. Of these, AQP5 plays an important role in the fluid homeostasis and cell volume control in epithelial cells. In an effort to understand the role of AQP5 in testis, we investigated the expression of AQP5 in developing mouse testis, its regulation by estrogen and LH, and the change of steroidogenesis by AQP5 knockdown. Testes and Leydig cells were isolated from male mice at postnatal day (PND) 1, 7, 14, 28, and 56 and estrogen receptor alpha knockout (ERαKO) mice. In mouse testis, AQP5 immunoreactivity was negligible by PND 14. From PND 28 onward, AQP5 immunoreactivity was found in Leydig cells. In ERαKO mouse Leydig cells, AQP5 mRNA level was significantly lower than wild type. In primary adult Leydig cell culture, the expression of AQP5 mRNA was increased by 17β-estradiol (E2) and human chorionic gonadotropin (hCG), but was not changed in ERαKO Leydig cells. Moreover, the expression of AQP5 mRNA was increased by E2 and ERα-selective agonist PPT, but was not changed by ERβ-selective agonist DPN in primary Leydig cells and mLTC-1. In silico analysis and chromatin immunoprecipitation (ChIP) assay revealed that there are putative estrogen response elements (EREs) and cAMP response elements (CRE) in AQP5 promoter region. Testosterone secretion and steroidogenic pathway genes (StAR, Cyp11a1, Cyp17a1, and 3β-HSD6) expression were decreased by AQP5 siRNA in primary Leydig cells. In conclusion, AQP5 expression was coupled with functional differentiation of adult Leydig cells. AQP5 may play an important role in the fluid homeostasis and cell volume control during development of adult Leydig cells. The expression of AQP5 in Leydig cells could be regulated by ERα and LH signaling and AQP5 may be involved in steroidogenesis.

Amnionless (AMN) is a plasma membrane protein that binds to cubilin and megalin in various epithelia and mediates endocytosis of extracellular ligands. This function has been studied in the kidney where it plays a key role in vitamin B12 and vitamin D homeostasis. Present study aimed to elucidate developmental pattern of expression of AMN during the peri-implantation period in mouse embryos. In an effort to understand functional role of AMN in the histiotropic nutrition in blastocyst, endocytotic function of AMN for apoplipoprotein was examined in blastocyst. Eight-week-old female mice were superovulated by intraperitoneal injection of 5 IU PMSG and 5 IU hCG 48h later. To obtain embryos, females were mated with males. Mouse embryos were collected at 12, 48, 56, 65, 72 and 96 h post-hCG by flushing oviducts and uterus, and we also obtained gestation day 6.5, 7.5 and 8.5 embryos in uterus. All samples were subjected to quantitative RT-PCR, whole-mount immunofluorescence and immunohistochemistry analysis. To analyze endocytotic function of AMN, we examined uptake experiment of FICT labeled apolipoprotein A-I (ApoA-I-FITC) following functional blocking of AMN in blastocysts. AMN and cubilin mRNA was expressed in all developmental stages of mouse embryos. Megalin was the first detected at morula stage. AMN protein was expressed in trophectoderm (TE) and inner cell mass (ICM). AMN and cubilin were expressed in visceral endoderm of GD 6.5 and 7.5 embryos and visceral yolk sec of GD 8.5 embryos. In normal IgG treated embryos, ApoA-I-FITC was detected in intracellular vesicles of TE and ICM. However, in the presence of anti-AMN antibody, ApoA-I-FITC was weakly detected in apical surface of plasma membrane of TE. To date, AMN has been believed to be expressed in visceral endoderm of post implantation embryos. Our results demonstrated that AMN is the important molecular partner of cubilin and megalin in the preimplantation embryos and that AMN mediates endocytosis of apoplipoprotein, which may play a crucial role in embryonic development and normal growth via supporting histiotropic nutrition during peri-implantation period.

Coxsackievirus and adenovirus receptor (CAR) is a member of the Ig-type superfamily of cell adhesion molecules. In polarized epithelial cells CAR is expressed at the tight junction. The mouse CAR gene is composed of at least eight exons, and CAR splice variants that differ at the end of the cytoplasmic tail have been identified in a number of tissues. The present study aimed to examine the expression of (CAR), a TJ protein sealing the muticellular contact point during preimplantation embryos and role of CAR in the formation and integrity of the blastocoel. Eight-week-old female mice were superovulated by intraperitoneal injection of 5 IU PMSG and 5 IU hCG 48h later. Mouse embryos were collected at 12, 48, 56, 65, 72 and 96 h post-hCG in oviducts and uterus, and we also obtained gestation day 5 and 6.5 embryos in uterus. All samples were subjected to RT-PCR, immunofluorescence and immunohistochemistry analysis. To analyze epithelial permeability of CAR, we examined permeability of FITC-labeled dextran (MW 40 kDa) following functional blocking of CAR in blastocysts. Long isoform of CAR mRNA was expressed from throughout the preimplantation development and markedly increased at morulae stage onward. Small amount of short isoform CAR mRNA was expressed at blastocyst stage. On Western blot, 64 kDa protein was detected together with 43 kDa protein corresponding to short and long forms CAR, respectively in blastocysts. CAR immunoreactivity was found in cell contacts between blastomeres from 4-cell stage onward. Under Ca2+ switching condition blocking antibodies for CAR increased the permeability of blastocysts to FITC-dextran, a permeability tracer. At 5 dpc, trophoblasts of the implanting embryos were immunoreactive with anti-CAR IgG. At 6.5 dpc, the egg cylinder stage in mouse, the visceral and parietal endoderm were immunoreactive with anti-CAR IgG. Our results suggest that alternative splicing of CAR transcript is highly dependent on the development of expanding blastocyst. CAR may play a crucial role as a barrier to adenovirus infection and adhesion molecule for epithelial permeability during peri-implantation period.

We investigated the change mRNA expression of GtHs subunits (FSHβ, LHβ) in the pituitary, androgen receptor (AR), estrogen receptor (ERα) in gonad and histological observation of gonads in longthooth grouper Epinephelus bruneus by treatment Femara, an aromatase inhibitor (AI). Longtooth grouper (body weight 408±43.1 g; one year) cultured in Future Aquaculture Research Center, NFRDI were used in the experiments. The experiment was conducted for 12 weeks from 21 August 2013. Fish received intramuscular injection of AI at 5 mg/g BW dose in three times every 3 weeks. Fish were sampled pituitary and gonads at 3, 6, 12 weeks post-injection (n=50). The mRNA levels of FSH-β, LH-β in pituitary and AR, ERα mRNA in gonad were evaluated using qRT-PCR and qPCR. The histological change of gonads observed on light microscope. The gonads of control group contained most perinucleolus oocyte. At 3 to 6 weeks post-injection, the gonads of AI-treated group contained a few degenerated oocytes, spermatogonia and spermatocytes. At 12 weeks post-injection, gonads contained spermatids undergoing spermatogenesis. From 6 to 12 weeks post-injection, the expression level of GtHs subunits mRNA in pituitary was significantly higher than control group. The expression level of AR mRNA in gonad was higher than control group from 3 to 12 weeks post-injection. The expression level of ERα mRNA in gonad was lower than control group from 6 to 12 weeks post-injection. These results suggest that immature longtooth grouper with AI treatment induced masculinization via change of GtH subunits in pituitary, AR and ERα mRNA in gonad.

Epigenetic regulations including DNA methylation, long noncoding RNAs and histone modification are considered to be involved in many biological processes. Such regulations in general begin with change of covalent bonds on the substrates. Moieties involving the covalent bond include methyl- and acetyl-group, glucose, SUMO and etc. Among them, methyl group-mediated modulation is commonly observed in all three substrates. Mouse primordial germ cells (PGCs) first appear at embryonic day (E)7.25 on the base of the allantois, and then migrate through the hindgut to the genital ridge. Once PGCs reach genital ridge, they become dimorphic, in that female PGCs undergo meiosis whereas male PGCs are mitotically arrested. Meiosis is a germ-cell-specific cell division process through which haploid gametes are produced for sexual reproduction. Before the initiation of meiosis, mouse primordial germ cells undergo a series of epigenetic reprogramming steps including the global erasure of DNA methylation at the 5-position of cytosine (5mC) in CpG-rich DNA. I will discuss role of Ten-to-Eleven translocation (Tet) in DNA demethylation in the process of PGC reprogramming.

Next Generation Small Satellite-1 (NEXTSat-1) is scheduled to launch in 2017 and Instruments for the Study of Space Storm (ISSS) is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD) is one of the equipment comprising ISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt during the event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For the design of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement and the structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of the detector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on the simulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placed right in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electron channel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV, the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of 0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detects electrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the study on the dynamic mechanism of these particles in the Earth radiation belt will be performed.

The Amon-Ra instrument is the main optical payload of the proposed EARTHSHINE satellite. It consists of a visible wavelength instrument and an IR energy channel instrument to measure a global Earth albedo. We report a new sensitivity technique for efficient alignment of the visible channel instrument. Whilst the sensitivity table method has been widely used in the alignment process, the straightforward application of the method tends to produce slow process convergence because of shop floor alignment practice uncertainties. We investigated the error sources commonly associated with alignment practices and used them when estimating the Zernike polynomial coefficients. Aided with single center field wavefront error (WFE) measurements and their corresponding Zernike polynomial coefficients, the method involves the construction and use of an experimental, instead of simulated, sensitivity table to be used for alignment state estimations. A trial alignment experiment for the Amon Ra optical system was performed and the results show that 71.28 nm in rms WFE was achieved only after two alignment iterations. This tends to demonstrate its superior performance to the conventional method.

The communications link in a space program is a crucial point for upgrading its performance by handling data between spacecraft bus and payloads, because spacecraft’s missions are related to the data handling mechanism using communications ports such as a controlled area network bus (CAN Bus) and a universal asynchronous receiver and transmitter (UART). The NEXTSat-1 has a lot of communications ports for performing science and technology missions. However, the top level system requirements for the NEXTSat-1 are mass and volume limitations. Normally, the communications for units shall be conducted by using point to point link which require more mass and volume to interconnect. Thus, our approach for the novel communications link in the NEXTSat-1 program is to use CAN and serializer and deserializer low voltage differential signal (SerDesLVDS) to meet the system requirements of mass and volume. The CAN Bus and SerDesLVDS were confirmed by using already defined communications link for our missions in the NEXTSat-1 program and the analysis results were reported in this study in view of data flow and size analysis.

The first Korean satellite laser ranging (SLR) system, Daedeok SLR station (DAEK station) was developed by Korea Astronomy and Space Science Institute (KASI) in 2012, whose main objectives are space geodesy researches. In consequence, Korea became the 25th country that operates SLR system supplementing the international laser tracking network. The DAEK station is designed to be capable of 2 kHz laser ranging with precision of a few mm both in daytime and nighttime observation of satellites with laser retro-reflector array (LRA) up to the altitude of 25,000 km. In this study, characteristics and specifications of DAEK station are investigated and its data quality is evaluated and compared with International Laser Ranging Service (ILRS) stations in terms of single-shot ranging precision. The analysis results demonstrated that the DAEK station shows good ranging performance to a few mm precision. Currently, the DAEK station is under normal operations at KASI headquarters, however, it will be moved to Sejong city in 2014 to function as a fundamental station for space geodesy researches in combination with other space geodesy systems (GNSS, VLBI, DORIS, etc.).

Legume and rhizobia symbiosis plays an important role in conversion of atmospheric dinitrogen to ammonia. On a global scale, this interaction represents a key entry point for reduced nitrogen into the biosphere, and as a consequence this symbiosis is important in both natural and agricultural systems. Symbiotic development of nodule organ is triggered by chito-oligosaccharide signals (Nod factors) from the bacterium which are perceived by the legume root. Understanding the molecular and cellular processes that underlie Nod factor perception is one focus of legume biology. Although forward genetics has proved to be an important tool to identify key players in Nod factor perception, we still know relatively little regarding the functional networks of genes and proteins that connect the earliest steps of Nod factor perception to immediate downstream outcomes. To elucidate genes and proteins that link Nod factor perception to cellular and physiological responses we are taking a discovery-based strategy based on whole transcriptome profiling using RNA-seq analysis in the roots of Medicago truncatula in response to Sinorhizobium meliloti. Functional characterization of a number of candidate genes is currently in progress to further examine their role in nodulation such as generating transgenic plants

Chrysanthemums (Asteraceae) are important ornamental crops in worldwide that are well known as commercial valuable cultivars for cut flowers, potted plants, and garden flowering plants. Genus chrysanthemum consisted of 41 species that are mostly distributed in East Asia. Chrysanthemum has diverse ploidy levels with the basic chromosome number of x=9 from 2n=2x=18 (diploid) to 2n=10x=90 (decaploid). Fluorescence in situ hybridization (FISH) is a useful tool for studying the distribution of ribosomal DNAs. In this study, we have confirmed ploidy level by chromosome counting method. The somatic metaphase chromosome numbers were observed 2n=2x=18 in Chrysanthemum boreale, and 2n=6x=54 in C. indicum and C. zawadskii. More detailed Karyotype was constructed based on FISH method using 5S and 45S rDNA probes. Two (2) loci of 5S rDNA signals were detected in interstitial region of long arm chromosome in C. boreale and six (6) loci were in C. indicum and C. zawadskii. All of 45S rDNAs were located in terminal region of short arm chromosome which were visualize in six (6) loci in C. boreale and C. indicum and twelve(12) loci in C. zawadskii. In this study, it was the main topic to perform physical mapping of the location of 5S and 45S rDNA. Three of wild chrysanthemum showed variations in number of ribosomal DNAs. In the present investigation will help to further study of genome sequencing project in chrysanthemum.

Fluorescence in situ hybridization (FISH) is a powerful tool for the detection of DNA sequences in the specific region of the chromosomes. As well as for the integrated physical mapping, FISH karyotype analysis has to be preceded. The detailed karyotypes of two onion cultivars, which are resources for onion genome sequencing project (‘Eumginara’ and ‘Sinsunhwang’), were constructed based on triple color fluorescence in situ hybridization (FISH) using 5S rDNA, 45S rDNA, and tandem repeat sequence. All used our materials showed 2n=2x=16 with x=8 as basic chromosome number. 5S rDNAs were located on 4 loci in one pair of interstitial region of short arm chromosome in both onion cultivars. Two pairs of 45S rDNAs were positioned in distal region of short arm chromosome in ‘Eumginara’. Otherwise 5 loci of 45S rDNAs were located in distal region of two pairs of short arm chromosome in ‘Sinsunhwang’. Among them, two signals of 45S rDNAs were co-localized in distal part of short arm and long arm chromosome, respectively. In case of tandem repeat sequence was detected on telomeric region of 8 pairs of chromosomes except on 45S ribosomal DNA sites. These results will provide a valuable background for physical mapping and help to further more understand the genome sequencing project in Allium cepa.

The newly developed varieties, Jayoung (violet flesh color) and Hongyoung (red flesh color) that harboring various anthocyanins and flavonoids in flesh colored potato are highly increase their interesting not only for food but also functional characteristics such as anti-inflammatory effects. Up to date, most of the molecular markers developed in potato are linked to disease resistance including late blight and PVY, nematode. A few markers linked to economically important functional materials such as anthocyanin biosynthesis are published. With the low cost and high throughput of NGS (Next Generation Sequencing) technology, numerous molecular markers are highly increased in may crops. Among the molecular markers, SNPs (Single nucleotide Polymorphisms) are most useful markers owing to their large numbers in inter and intra varieties in potato. Here we reported SNPs discovery from transcriptome sequencing data acquired from colored flesh potato cultivars, Jayoung and Hongyoung with white flesh color Atlantic. Total RNA was isolated from shoot in tuber after breaking dormancy about 2cm length. Short read sequence data were obtained form Illumina Hiseq2000 and the raw dat set were trimmed with Q socore over 20. Sequencing data were align to reference genome (Solanum tuberosum v4.03, http://potatogeomics.plantbiolgy.msu.edu). About 70% of sequence read were mapped int to reference genome. 139,050, 140,976 and 146,429 total SNPs were discovered in Hongyoung, Jayoung and Atlantic, respectively. All SNPs are mapped into the psedomolecules in reference genome by chromosome. SNPs are also analyzed with homozygous and heterozygous SNPs and genic and intergenic region. SNPs are compared with Potato Infinium 8K Chip data. SNPs found in candidate genes of anthocyanin biosynthesis were discovered. These SNPs information of flesh colored potato will be further analyzed for the allele mining for anthocyanin syhthesis and control region

Steroidal glycoalkaloids which serve the plant defense, are toxic secondary metabolites present in the plants of solanaceae family. The upper safe limit of glycoalkaloids for human consumption is 20mg/KG FW, excess of which may cause severe health disorders. Several factors like drought, high temperature, light exposure, and wounding increase tuber glycoalkaloid content. Among these, drought is an important factor which causes a rapid increase in potato glycoalkaloid content. Glycoalkaloid biosynthetic genes and their expression pattern need to be characterized to regulate the glycoalkaloid accumulation. Three key genes SGT1, SGT2 and SGT3 are demonstrated to be directly participated in the biosynthetic pathway for glycoalkaloid formation. Present study was focused on the study of expression pattern of key genes in GA pathway under drought stress in two different potato cultivars Atlantic and Haryoung which are low and high glycoalkaloid accumulating respectively. Drought stress was imposed by withholding water to the plants grown in pots and control plants kept irrigated. Expression analysis of SGT1, SGT2 and SGT3 was done from the leaf and tuber sample of three time intervals i.e 5, 10 and 20 days after imposing stress. Variation in the expression level of genes was observed in leaf and tuber where the fold increase in expression over control was higher in tuber sample compared to leaf. Expression levels also varied in leaf and tuber among two cultivars. However, expression of SGT1, SGT2 and SGT3 is significant indicating the involvement of these genes in glycoalkaloid accumulation under drought stress.

Sorghum (Sorghum bicolor (L.) Moench) has been cultivated for cereal grain which has been traditionally used for steaming with rice in Korea. Various Korean sorghum varieties have been developed and distributed for farmers and consumers to meet their needs. Korean sorghum grains have been mostly sold at higher price in the market than sorghum grains imported from abroad. However, no varietal identification method was established to support fair trade in the cereal market. The objective of this study is to develop the identification method of Korean sorghum varieties using a multiplexed fingerprinting platform of SSR markers. One marker for the waxy allele and nine SSR markers were carefully selected based on their product sizes for the multiplexing. A robust multiplexed combination was revealed from serially designed experiments for the optimization of multiplex PCR. Five varieties and two elite breeding lines could be separated with their unique fingerprinting pattern from other sorghum individuals collected over the world. The platform separated most of individuals tested in this study, remaining three genotypes contained two or three identical individuals. The technique may be applied to detect closely-related individuals including full sibling progeny

The correct development of male gametophytes (pollen grains) in flowering plants is essential for proliferate in gamete production. Here we have taken a map-based cloning approach using Arabidopsis male gametophytic mutant, named gemini pollen3 (gem3) to identify and characterize key gene that is expressed gametophytically for the completion of microgametogenesis focusing on genes which control cell division and cell fate determination. Previously reported gem1 and gem2 mutants with similar characteristics to gem3 that are disturbed at asymmetric division and cytokinesis at pollen mitosis I (PMI) in Arabidopsis. However, gem3 was mapped to a different genetic locus, and pollen developmental analysis revealed that gem3 exert an effect at meiosis and mitosis causing complete sterility. We also discovered that gem3 homozygous lines produce aberrant pollen grains, arising from incomplete cytokinesis during male meiosis with sporophytic phenotypes of twisted-shape leaves, large flowers. This mutation shows reduced genetic transmission of gem3 allele through male gametophyte. In previous results, the gem3 locus was confirmed by mapping to the region located on chromosome 5. To further confirm strong candidate gene, we performed sequencing and genetic complementation analysis. Currently, we are performing functional studies of the gem3 gene for the better understanding of molecular mechanisms that control asymmetric division at meiosis and mitosis during pollen development.

Plastochron and phyllotaxy are important traits to determine plant architecture. A plastochron 1-6 mutant was derived from japonica rice cultivar Koshihikari treated with ethylmethane sulfonate (EMS). The plastochron 1-6 mutant showed reduced plant height, shorter internode length, smaller and more leaves than Koshihikari, its wild type. In addition, the mutant has abnormal panicle, abnormal seed and upper node tillers. The F1 plants between mutant and Koshihikari were normal. In F2 population, segregation ratio between the wild type and mutant was fitted to 3:1. This genetic analysis indicated that plastochron 1-6 is controlled by a single recessive gene. Bulked segregant analysis revealed that the gene was located on chromosome 10. Through sequencing analysis, we found that plastochron 1-6 mutant had a single nucleotide transition occurred in the first exon of LOC_Os10g26340 (encoding P450 CYP78A11). This work was supported by a grant from the Next-Generation BioGreen 21 Program (Plant Molecular Breeding Center No. PJ008125), Rural Development Administration, Republic of Korea.