Opioid receptors have been pharmacologically classified as µ, δ, κ and ε. We have recently reported that the antinociceptive effect of morphine (a µ-opioid receptor agonist), but not that of β-endorphin (a novel µ/ε-opioid receptor agonist), is attenuated by whole body irradiation (WBI). It is unclear at present whether WBI has differential effects on the antinociceptive effects of µ-, δ-, κ- and ε-opioid receptor agonists. In our current experiments, male ICR mice were exposed to WBI (5Gy) from a 60 Co gamma-source and the antinociceptive effects of opioid receptor agonists were assessed two hours later using the hot water (52℃) tail-immersion test. Morphine and D-Ala2,N-Me-Phe4,Gly-ol-enkephalin (DAMGO), [D-Pen2-D-Pen5]enkephalin (DPDPE), trans-3,4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl)- cyclohexyl]¬benzeneacetamide (U50,488H), and β-endorphin were tested as agonists for µ, δ, κ, and ε-opioid receptors, respectively. WBI significantly attenuated the antinociceptive effects of morphine and DAMGO, but increased those of β-endorphin. The antinociceptive effects of DPDPE and U50,488H were not affected by WBI. In addition, to more preciously understand the differential effects of WBI on µ- and ε¬opioid receptor agonists, we assessed pretreatment effects of β-funaltrexamine (β-FNA, a µ-opioid receptor antagonist) or β-endorphin1-27 (β-EP1-27, an ε-opioid receptor antagonist), and found that pretreatment with β-FNA significantly attenuated the antinociceptive effects of morphine and β endorphin by WBI. significantly reversed the β-EP1-27 attenuation of morphine by WBI and significantly attenuated the increased effects of β-endorphin by WBI. The results demonstrate differential sensitivities of opioid receptors to WBI, especially for µ- and ε-opioid receptors.

Leaflet number of soybean controlled by Lf2 locus is the important trait in photosynthesis and plant type. The objective of this research was to identity molecular markers linked to the lf2 locus. A total of 115F2 plants were derived from a cross between normal three-leaflet type Sinpaldalkong (Lf2Lf2) and seven-leaflet mutant type T255 (lf2lf2). All leaflet counts of parents and F2 individual plants were made in the field on fully expanded leaves on the main stem when terminal growth of the main stem had ceased. One-thousand 10-mer oligonucleotide RAPD primers and 664 SSR primers were used. The segregation ratios of 3 : 1 were observed in the F2 population and the Chi-square values strongly suggested that the seven-leaflet was controlled by a single recessive gene. A genetic map was constructed from the 15 segregating markers (9 RAPDs, 5 SSRs, 1 lf2 locus). OPAD03 and OPAI13 RAPD markers were linked to the lf2 locus that controlled seven-leaflet type at a distance of 20.5 and 23.5 cM, respectively. Molecular markers identified in this study linked with lf2 locus will be helpful to locate lf2 locus on the public soybean molecular linkage map and would be useful for tagging the lf2 locus that controls seven-leaflet trait.

Soybean seeds contain high amounts of isoflavones that display biological effects and isoflavone content of soybean seed can vary by year, environment, and genotype. Objective of this study was to identify quantitative trait loci that underlie isoflavone content in soybean seeds. The study involved 85 F2 populations derived from Korean soybean cultivar 'Kwangkyo' and wild type soybean 'IT182305' for QTL analysis associated with isoflavone content. Isoflavone content of seeds was determined by HPLC. The genetic map of 33 linkage groups with 207 markers was constructed. The linkage map spanned 2,607.5 cM across all 33 linkage groups. The average linkage distance between pair of markers among all linkage groups was 12.6 cM in Kosambi map units. Isoflavone content in F2 generations varied in a fashion that suggested a continuous, polygenic inheritance. Eleven markers (4 RAPD, 3 SSR, 4 AFLP) were significantly associated with isoflavone content. Only two markers, Satt419 and CTCGAG3 had F-tests that were significant at P<0.01 in F2 generation for isoflavone content. Interval mapping using the F2 data revealed only two putative QTLs for isoflavone content. The peak QTL region on linkage group 3, which was near OPAG03c, explained 14~% variation for isoflavone content. The peak QTL region on linkage group 5, which was located near OPN14 accounted for 35.3~% variation for isoflavone content. Using both Map-Maker-QTL (LOD~geq2.0) and single-factor analysis (P~leq0.05) , one marker, CTCGAG3 in linkage group 3 was associated with QTLs for isoflavone content. This information would then be used in identification of QTLs for isoflavone content with precision

Soybean is a major source of protein meal in the world. Kunitz trypsin inhibitor (KTI) protein is responsible for the inferior nutritional quality of unheated or incompletely heated soybean meal. The objective of this research was to identify RAPD markers linked to KTI protein allele using bulked segregant analysis. Cultivar Jinpumkong2 (TiTi) was crossed with C242 (titi, absence of KTI protein) and F. seeds were planted. The F1 . plants were grown in the greenhouse to produce F2 seeds. Each F2 seed from F1 . plants was analysed electrophoretically to determine the presence of the KTI protein band. The present and absent bulks contained twenty individuals each, which were selected on the basis of the KTI protein electrophoresis, respectively. Total 94 F2 individuals were constructed and 1,000 Operon random primers were used to identify RAPD primers linked to the Ti locus. The presence of KTI protein is dominant to the lack of a KTI protein and Kunitz trypsin inhibit protein band is controlled by a single locus. Four RAPD primers (OPAC12, OPAR15, OPO12, and OPC08) were linked to the Ti locus. RAPD primer OPO12 was linked to Ti locus, controlling kunitz trypsin inhibitor protein at a distance of 16.0 cM. This results may assist in study of developing fine map including Ti locus in soybean.

Genetic linkage maps serve the plant geneticist in a number of ways, from marker assisted selection in plant improvement to map-based cloning in molecular genetic research. Genetic map based upon DNA polymorphism is a powerful tool for the study of qualitative and quantitative traits in crops. The objective of this study was to develop genetic linkage map of soybean using the population derived from the cross of Korean soybean cultivar 'Kwangkyo, and wild accession 'IT182305'. Total 1,000 Operon random primers for RAPD marker, 49 combinations of primer for AFLP marker, and 100 Satt primers for SSR marker were used to screen parental polymorphism. Total 341 markers (242 RAPD, 83 AFLP, and 16 SSR markers) was segregated in 85 ~textrmF2 population. Forty two markers that shown significantly distorted segregation ratio (1:2:1 for codominant or 3:1 for domimant marker) were not used in mapping procedure. A linkage map was constructed by applying the computer program MAPMAKER/EXP 3.0 to the 299 marker data with LOD 4.0 and maximum distance 50 cM. 176 markers were found to be genetically linked and formed 25 linkage groups. Linkage map spanned 2,292.7 cM across all 25 linkage groups. The average linkage distance between pair of markers among all linkage groups was 13.0 cM. The number of markers per linkage group ranged from 2 to 55. The longest linkage group 3 spanned 967.4 cM with 55 makers. This map requires further saturation with more markers and agronomically important traits will be joined over it.