The phylogenetic relationship of the suborder Anisoptera distributed on Jeju Island, Korea, was analyzed by comparing partial mitochondrial 16S ribosomal RNA (rRNA) gene sequences. The length of the partial mitochondrial 16S rRNA genes for the 27 species of the Anisoptera studied ranged from 405 to 421 base pairs (bp). No intra-genus length-variations were identified in the genera Anax and Orthetrum, while the genes of Somatochlora and Sympetrum displayed lengths of 411 to 412 and 406 to 411 bp, respectively. The GC content of the partial mitochondrial 16S rRNA gene ranged from 26.76% to 30.83%. A parsimony analysis of the unambiguously aligned mitochondrial 16S rRNA gene sequences from 28 species, including outgroup species, produced eight equally most parsimonious trees. The strict consensus tree had three large independent groups: group I (family Aeshnidae), group II (family Libellulidae), and group III (family Corduliidae). Interestingly, the eight species of the genus Sympetrum were clearly distinguishable from the other species. The strict consensus tree, based on the mitochondrial 16S rRNA gene sequences, contained monophyletic groups. These results concurred with previous studies published by several researchers that were based on morphological characteristics.
Previous studies in many species suggested that the minichromosome maintenance complex is a major physiological target of Cdc7. In this study, we examined the cellular role of Mcm2 phosphorylation by Cdc7 kinase in Schizosaccharomyces pombe. The in vitro phosphorylation of several truncated Mcm2 proteins by Cdc7 kinase showed that the major phosphorylation sites were located at N-terminus of Mcm2 protein. Alanine substitutions of several putative Cdc7 phosphorylation sites in this region resulted in the mutant Mcm2 proteins which were hardly phosphorylated by Cdc7 kinase in vitro. When these proteins were expressed in mcm2 mutant cells, all of alanine substituted mutant proteins still complemented the temperature sensitive phenotype of mutant cells. These results suggest that the phosphorylation of Mcm2 protein by Cdc7 kinase is not essential for the initiation of DNA replication. Cdc7 may play its essential roles by phosphorylating other Mcm subunits or proteins involved in the initiation of DNA replication.
We examined the chromosomal distribution of the human endogenous retrovirus (HERV-W) family in humans. FISH data indicated that the HERV-W probe (fosWE1) derived from the gorilla fosmid library was clearly detected in all chromosomes except for chromosomes 13, 18, 21, and Y. Most of the HERV-W family seems to be proliferated during the course of primate radiation approximately 2545 Myr ago. The sequences of target site duplication (TSD) for the proliferation of HERV-W family were completely different in full length or processed pseudo HERV-W sequences, respectively. The HERV-W LTR elements, having biological roles of alternative promoter, exonization, alternative polyadenylation, were detected in several loci, and those elements are actively expressed in various tissues. Taken together, these data are valuable sources for understanding the biological roles of HERV-W family in humans.
Chromatin is structurally remodeled by various posttranslational modifications including acetylation, methylation, phosphorylation, and ubiquitination. Among histone modification, methylation reaction is preceded by utilizing S-adenosylmethionine (SAM) of metabolic methionine pathway as a methyl donor in the cells. To examine how dietary methionine pathway is connected with histone methylation, we have treated methionine metabolites and synthetic analogs on the culturing cells. Most of methionine metabolites had no effect on the cell growth, but synthetic analogs of S-adenosylhomocysteine (SAH) showed cell death-related inhibitory effect. Using western blot analysis, we found that dimethylation of histone 3 lysine 9 (H3K9) but not that of H3K4 or H3K36, was specifically reduced by metabolites treatment. However, methylation of H3K9 (di) was restored by withdrawal of the metabolites. When methionine was deprived from culturing condition, H3K9 (di) methylation be decreased, but restored by treatment of metabolites such as SAM or homocysteine. We also obtained specific reduction of H3K9 by metabolites treatment using the immunostaining analysis. Therefore, we suggest that there is a close link between dietary methionine pathway and methylation of H3K9.
Human CD99 is an integral transmembrane protein, which was recently suggested as a potential tumor suppressor in the certain types of tumors. It has been previously shown that CD99 is underexpressed in malignant Hodgkin and Reed-Sternberg (H-RS) cells of Hodgkin's lymphoma (HL). In this study, to investigate the mechanism by which the downregulation of CD99 molecules in H-RS cells takes place, the expression and gene methylation of human CD99 were analyzed in an H-RS cell line, L428. First, CD99 mRNA and protein expression of the cells were analyzed using RT-PCR and Western analysis. In addition, methylation profile of the CD99 promoter region was analyzed using methylation specific PCR (MSP) and subsequent DNA sequencing. In LA28, the CD99 mRNA level as well as the protein level was substantially lower than those in a corresponding normal cell line. MSP analysis of the CD99 promoter region of the L428 cells, revealed the high incidence of methylated CpG dinucleotides in the CD99 promoter. Furthermore, demethylation by the treatment of 5'-azacytidine induced CD99 expression in the L428 cells, indicating a critical role of methylation in CD99 gene silencing in H-PS cells. Taken together, these results indicate that the downregulation of CD99 in malignant H-RS cells is, at least in part, associated with methylation of the gene, suggesting a potential link between the gene hypermethylation and HL pathogenesis.
Homeotic genes are responsible for the specification of segment identity during embryonic development. The homeotic genes of Drosophila are clustered in the Antennapedia complex (ANT-C) and bithorax complex (BX-C). The expression of Distalless (Dll) is initiated from late stage 10 in the thoracic limb primordia and it is specifically required for limb development in the Drosophila embryo. In this study we investigated the temporal regulation of Dll expression in the thoracic segments. Dll expression was expanded to the abdominal region in the loss-of-function mutation of the Ubx, abdA or AbdB gene. When Ox, abdA or AbdB was ectopically expressed in the thorax using the GAL4/UAS system, Dll expression was not observed in the thorax. However, when the BX-C genes were ectopically expressed at stage 11 of Polycomb mutant embryo, the repression of Dll expression by the ectopic homeotic gene products was restricted to the third thoracic segment. This result suggested that Dll expression pattern was determined at embryonic stage 11 and that the ectopic expression of BX-C genes after stage 11 did not affect Dll expression.
We report on a 10-year-old boy with severe psychomotor retardation and craniofacial anomalies. Using high resolution GTG banding, SKY FISH, and CGH analysis, he was found to be carrying a del(7)(q34) inherited from a paternal balanced translocation t(6;7)(qter;q34). Reported deletions of the terminal part of the 7q chromosome have not been associated with a clearly distinctive and recognizable phenotype. Frequent findings included: pre/postnatal growth and developmental retardation, microcephaly, eye anomalies, flat/broad nasal bridge with bulbous nasal tip, genital abnormalities and brain defects. In addition to the typical abnormalities, this case further provides evidence for a pituitary dwarfism. The patient was beneficially treated with human growth hormone.
The quantitative fluorescent PCR (QF-PCR) assay for prenatal diagnosis of common chromosome aneuploidies introduced during the last few years. We report the first assessment of QF-PCR aneuploidy testing performed on a large Korean population. Blind prospective study was performed in 3700 amniotic fluid samples. All samples were analyzed by QF-PCR using with four STR markers located on chromosome 21 (D21S1435/D21S11/D21S1411/ D21S1412) and subsequently performed by conventional cytogenetic analysis. Trisomy 21 was identified in 35 samples. The informative rate for at least two STR markers was 97.3%. The uninformative rate by maternal cell contamination (MCC) and inconclusive results were 0.8%, 1.9% respectively. Rare polymorphic STR duplication and somatic microsatellite mutation were detected respectively. There were no false-positive or false-negative results. QF-PCR for the rapid identification of fetus with trisomy 21 is a reliable, accurate, and speedy technique.
X-chromosomal short tandem repeat (X-STR). markers can be used to determine paternity in deficiency paternity cases with a female child(s) and in other kinship tests. In the present study, we established two X-STR hexaplex PCR systems. One set includes DXS6789, DXS6810, DXS7132, GATA172D05, DXS7423, and ARA, while the other set includes GATA165B12, DXS981, DXS6797, DXS9898, DXS8377, and DXS7424. These STR loci were genotyped in a Korean population (149 males and 121 females), and the allele frequency was obtained using the established multiplex PCR reactions and an automatic sequencing analyzer. None of the loci in female samples deviated from Hardy-Weinberg equilibrium. The combined probabilities of match (PM) calculated from 12 X-STR loci were 2.04 x 10(-12) in females and 7.46 x 10(-8) in males, which is highly informative. The high polymorphism of these X-STRs indicated the suitability of their use in kinship tests, and both hexaplex systems mill be used directly to analyze forensic cases.
Correlative studies were made between mating success and Ming length in a drosophilid insect Phorticella striata. Mating latency (time elapsed until mating from introduction) noted for all the matings. Observations were made for one hour considering number of pairs mated in every 15 minutes as one group. Mating latency of the flies gradually increased from 0-15 min to 45-60 min. Data showed that difference in mean number of flies mated during different time intervals was significant, but the difference was non-significant between age groups, suggesting age has no influence on mating latency. Males mating in the first fifteen minutes (0-15 min) time interval had significantly longer wings. In females also there was significant difference in wing length that mate in different time intervals. Females mating in the first thirty minutes (0-30 min) bear significantly longer wings when compared with those that mate during 31-60 min. This showed large flies mate early in both the sexes. Thus the present study shows a direct relationship between wing length and mating success. So there is sexual selection acting on body size.
The genetic relationships among 17 clones of Vaccinium (Vaccinium spp.), including 2 Northeast Chinese wild species and 15 commercial cultivars were evaluated through a Random Amplified Polymorphic DNA (RAPD) analysis of young leaves. The Rapids generated a total of 115 markers with 15 random primers, of which 98.26% were found to be polymorphic. These RAPD markers could successfully separate individuals from the 17 samples and detect variations in the Vaccinium species. Genetic similarity and genetic distance were measured by Nei's unbiased measurement. Using arithmetic averages (UPGMA) dendrogram, the unweighted pair-group method indicated that 17 samples were classified into three major groups: two groups of each mild species, and one group of 15 cultivars. The 15 cultivars could be clearly assigned into two subgroups of which the only lowbush sample (Blomidon) was clustered in one subgroup and the other 14 cultivars were clustered in one subgroup. The cluster results had some relativity with the pedigree of cultivars. These indicated that the polymorphic RAPD markers developed in this study should have general utility for identification of the varieties and examination of genetic relationships in blueberry.
Cellular programs that control lysosome activity and biosynthesis are largely unexplored. We found that the lysosome number and the expression of lysosomal genes increase substantially in normal fibroblasts undergoing replicative or induced senescence and in HeLa cervical carcinoma cells undergoing induced senescence. This suggests that cellular programs that control lysosomogenesis are activated in senescence regardless of the cell type and the nature of the senescence stimulus. However, there was a substantial discordance in the extent of induction among different lysosomal genes and in different types of senescence, suggesting heterogeneity in regulatory mechanisms within the family of lysosomal genes as well as in the senescence programs themselves.
Genetic diversity of Bachaur cattle- a draft breed of India bordering Nepal, was investigated by utilizing microsatellite markers. Forty seven random animals of the breed were typed with a set of 23 microsatellites proposed by the FAO for the biodiversities studies. All the microsatellites amplified well and exhibited polymorphism. The observed number of alleles (N-o) per locus varied from 3 (ILSTS011) to 13 (ILSTS034) with the mean number of alleles 6.30 2.16. Our results showed that this draft breed which is still relevant in its breeding tract due to socio-economic conditions possesses sufficient genetic variability as demonstrated by the values for the expected and observed mean heterozygosity (0.694 and 0.534, respectively). Twelve microsatellite loci are in Hardy- Weinberg equilibrium and F-IS shows higher value (0.228), suggesting heterozygote deficiency in the population. The results reflect the need for a conservation plan for this breed.
BAFF, one of the TNF ligand family, is primarily expressed by APCs such as macrophages and dendritic cells. This molecule is known to stimulate proliferation, differentiation, survival, and Ig production of B cells. In the present study, we aimed to elucidate the molecular mechanisms by which TGF-beta 1 induce BAFF expression in order to gain a clue if TGF-beta 1 may regulate B cell differentiation through influencing APCs. We found that TGF-beta 1 potentiates mouse dendritic cells to express BAFF and that a typical TGF-beta signaling pathway is involved. Thus, Smad3 and Smad4 promoted BAFF promoter activity in mouse dendritic cells and macrophages. Further, from the analysis of the BAFF mutated promoters, we identified three putative Smad binding elements (SBEs) where Smad3 actually binds. These elements were indispensable for the promoter activity.
T helper cells play a distinct role in activating and regulating immune responses. Th1 cells mediate cellular immunity by activating macrophages, whereas Th2 cells mediate Immoral immunity by activating B cells. The differentiation of Th1 and Th2 cells accompany drastic changes in immune function, cellular metabolism, gene expression, chromatin structure, and cell morphology. To search for more information on the immune functions of Th1 and Th2 cells, we examined a gene expression profile in immune related genes by microarray analysis. As expected many differentiation-specific cytokine, chemokine, and transcription factor genes are differentially expressed. I also discovered that a group of interferon-regulated genes is selectively expressed in Th1 cells, and that a group of immunoglobulin genes and various types of cell surface receptors are selectively expressed in Th2 cells. These studies extend the current understanding of immune function of T helper cells and rind more molecules involved in the T helper cell differentiation.
Genus Malus is a long-lived woody species primarily distributed throughout Asia. Many species of this genus are regarded as agriculturally and ecologically important. The phylogenetics: and genetic diversity among eight species of genus Malus were reconstructed using the ISSR (inter-simple sequence repeats) markers. Overall, 82 fragments were generated among the tested Malus array. The M. pumila showed the highest variation (57.3%). Mean number of alleles per locus (A) ranged from 1.415 to 1.573 with a mean of 1.489. The phenotypic frequency of each band was calculated and used in estimating genetic diversity (H) within species. The mean H was 0.194 across species, varying from 0.164 to 0.217. In particular, both cultivated species, M. pumila and M. asiatica, had high expected diversity. On a per locus basis, the proportion of total genetic variation due to differences among species ranged from 0.274 for ISSR-05 to 0.818 for ISSR-09 with a mean of 0.310, indicating that about 31% of the total variation was among species. In an assessment of the proportion of diversity present within species, 69% of genetic variation resided within taxa. The phylogenic tree showed three distinct clades. One includes M. pumila and M. asiatica. Another includes three M. baccata taxa. The other includes M. sieboldii, M. floribunsa and M. micromalus. Species-specific hands which showed in only one species are useful in germ-plasm classification and evolutionary studies.
Molecular cytogenetic analysis was carried out in the ancestral genome donors to polyploid wheats, T turgidum, and T. aestivum, with a fungus derived TC/AG microsatellite sequence, pKFJ660. The 45S rRNA gene was also used for chromosome identification in FISH analysis. The A and D genome donors, T monococcum and T. tauchii, showed no hybridization signals with the pKFJ660. The hybridization sites were variable in the chromosomes of S genome Sitopsis species which were the putative B genome donors to the polyploid wheats. Four pairs of chromosomes showed pKFJ660 hybridization signals in T turgidum (1B, 3B, 5B and 6B) and T. aestivum (3B, 413, 513, and 6B). Differences of hybridization signal intensities and FISH signal distributions were high among the S genome diploids and polyploid wheats, which hindered providing unequivocal explanations for the wheat evolution with this microsatellite sequence. With the evidences obtained, it seemed to be evident that the pKFJ660 microsatellite sequence had undergone restructuring and reorganization in its sequence along the chromosomes during wheat evolution. Since the pKFJ660 contained AluI transposon related direct repeat, possibilities of transposon mediated genome instability by allopolyploidization were discussed.
DNA methylation and histone modifications are two major epigenetic mechanisms that can affect gene expression through chromatin structure. Although many dietary polyphenolic compounds have strong cancer-preventive effects in various cancers, the modulating effect of dietary polyphenols on DNA methylation and histone methylation status has still not been characterized very well. DNA methylation and histone methylation. can each modulate gene expression separately, there is growing evidence that an interplay exists between cytosine methylation and histone modification to from a transcriptionally inactive chromatin state. Therefore, the ability of dietary polyphenols to inhibit DNA methylation may also modulate the key parameters of histone methylation and reactivate the expression of tumor suppressor genes in cancer cells. However, it is hypothesized that all dietary polyphenols may not be the same in terms of reactivating silenced genes and modulating the methylation status of histone proteins due to the fact that each polyphenol has varying degrees of inhibition protencies and dfficacies. More studies are warranted to further test these unknown hypotheses.
