1.Molecular Genetics of Emericella nidulans Sexual Development.
Mycobiology 2009;37(3):171-182
Many aspergilli that belongs to ascomycetes have sexuality. In a homothallic or self-fertile fungus, a number of fruiting bodies or cleistothecia are formed in a thallus grown from a single haploid conidia or ascospores. Genome-sequencing project revealed that two mating genes (MAT) encoding the regulatory proteins that are necessary for controlling partner recognition in heterothallic fungi were conserved in most aspergilli. The MAT gene products in some self-fertile species were not required for recognition of mating partner at pheromone-signaling stage but required at later stages of sexual development. Various environmental factors such as nutritional status, culture conditions and several stresses, influence the decision or progression of sexual reproduction. A large number of genes are expected to be involved in sexual development of Emericella nidulans (anamorph: Aspergillus nidulans), a genetic and biological model organism in aspergilli. The sexual development process can be grouped into several development stages, including the decision of sexual reproductive cycle, mating process, growth of fruiting body, karyogamy followed by meiosis, and sporulation process. Complicated regulatory networks, such as signal transduction pathways and gene expression controls, may work in each stage and stage-to-stage linkages. In this review, the components joining in the regulatory pathways of sexual development, although they constitute only a small part of the whole regulatory networks, are briefly mentioned. Some of them control sexual development positively and some do negatively. Regarding the difficulties for studying sexual differentiation compare to asexual one, recent progresses in molecular genetics of E. nidulans enlarge the boundaries of understanding sexual development in the non-fertile species as well as in fertile fungi.
Ascomycota
;
Aspergillus
;
Emericella
;
Fruit
;
Fungi
;
Gene Expression
;
Haploidy
;
Meiosis
;
Models, Biological
;
Molecular Biology
;
Nutritional Status
;
Proteins
;
Reproduction
;
Sex Differentiation
;
Sexual Development
;
Sexuality
;
Signal Transduction
;
Spores, Fungal
2.First Record of the Complete Mitochondrial Genome of a Saprotrophic and Opportunistic Human Pathogenic Fungus, Scopulariopsis brevicaulis
Jongsun PARK ; Woochan KWON ; Seung-Beom HONG ; Kap-Hoon HAN
Mycobiology 2020;48(6):528-531
Scopulariopsis brevicaulis is a widely distributed soil fungus known as a common saprotroph of biodegradation. It is also an opportunistic human pathogen that can produce various secondary metabolites. Here, we report the first complete mitochondrial genome sequence of S. brevicaulis isolated from air in South Korea. Total length of the mitochondrial genome is 28,829 bp and encoded 42 genes (15 protein-coding genes, 2 rRNAs, and 25 tRNAs). Nucleotide sequence of coding region takes over 26.2%, and overall GC content is 27.6%. Phylogenetic trees present that S. brevicaulis is clustered with Lomentospora prolificans with presenting various mitochondrial genome length.
3.First Record of the Complete Mitochondrial Genome of a Saprotrophic and Opportunistic Human Pathogenic Fungus, Scopulariopsis brevicaulis
Jongsun PARK ; Woochan KWON ; Seung-Beom HONG ; Kap-Hoon HAN
Mycobiology 2020;48(6):528-531
Scopulariopsis brevicaulis is a widely distributed soil fungus known as a common saprotroph of biodegradation. It is also an opportunistic human pathogen that can produce various secondary metabolites. Here, we report the first complete mitochondrial genome sequence of S. brevicaulis isolated from air in South Korea. Total length of the mitochondrial genome is 28,829 bp and encoded 42 genes (15 protein-coding genes, 2 rRNAs, and 25 tRNAs). Nucleotide sequence of coding region takes over 26.2%, and overall GC content is 27.6%. Phylogenetic trees present that S. brevicaulis is clustered with Lomentospora prolificans with presenting various mitochondrial genome length.
4.Expression of androgen receptors in astrocytoma.
Yong Gu CHUNG ; Han Kyeom KIM ; Hoon Kap LEE ; Ki Chan LEE
Journal of Korean Medical Science 1996;11(6):517-521
Thirty-two cases of surgically removed astrocytoma were evaluated for the expression of androgen receptors(ARs) immunohistochemically and the relationships between androgen receptors, DNA ploidy pattern, and survival of patients were studied. The cases included 18 grade I/II astrocytomas, 4 anaplastic astrocytomas, and 10 glioblastoma multiforme(GBM). Positive AR was present in 12 out of 32 cases(38%), which consisted of 5 cases in grade I/II(28%), 3 cases in anaplastic astrocytoma(75%), and 4 cases in GBM(40%). For both low and high grade astrocytomas, sex and ploidy pattern were not correlated with expression of the androgen receptors. Androgen receptor expression did not significantly affect the survival time. This study confirms previous reports of a low incidence of androgen receptors in astrocytomas. In addition, it shows that expression of androgen receptors is not correlated with DNA ploidy pattern and survival of patients in astrocytoma.
Adolescent
;
Adult
;
Aged
;
Astrocytoma/*metabolism/pathology
;
Brain Neoplasms/*metabolism/pathology
;
Child
;
Female
;
Flow Cytometry
;
Glioma/metabolism/pathology
;
Human
;
Male
;
Middle Age
;
Ploidies
;
Receptors, Androgen/*biosynthesis/genetics
;
Support, Non-U.S. Gov't
;
Survival Analysis
5.Expression of androgen receptors in astrocytoma.
Yong Gu CHUNG ; Han Kyeom KIM ; Hoon Kap LEE ; Ki Chan LEE
Journal of Korean Medical Science 1996;11(6):517-521
Thirty-two cases of surgically removed astrocytoma were evaluated for the expression of androgen receptors(ARs) immunohistochemically and the relationships between androgen receptors, DNA ploidy pattern, and survival of patients were studied. The cases included 18 grade I/II astrocytomas, 4 anaplastic astrocytomas, and 10 glioblastoma multiforme(GBM). Positive AR was present in 12 out of 32 cases(38%), which consisted of 5 cases in grade I/II(28%), 3 cases in anaplastic astrocytoma(75%), and 4 cases in GBM(40%). For both low and high grade astrocytomas, sex and ploidy pattern were not correlated with expression of the androgen receptors. Androgen receptor expression did not significantly affect the survival time. This study confirms previous reports of a low incidence of androgen receptors in astrocytomas. In addition, it shows that expression of androgen receptors is not correlated with DNA ploidy pattern and survival of patients in astrocytoma.
Adolescent
;
Adult
;
Aged
;
Astrocytoma/*metabolism/pathology
;
Brain Neoplasms/*metabolism/pathology
;
Child
;
Female
;
Flow Cytometry
;
Glioma/metabolism/pathology
;
Human
;
Male
;
Middle Age
;
Ploidies
;
Receptors, Androgen/*biosynthesis/genetics
;
Support, Non-U.S. Gov't
;
Survival Analysis
6.The Effect of Halothane-induced Acidosis on Focal Cerebral Ischemia in Rat.
Ki Soo HAN ; Ki Chan LEE ; Jeong Wha CHU ; Hoon Kap LEE
Journal of Korean Neurosurgical Society 1993;22(8):877-883
The current study was performed to investigate the influence of acidosis on focal cerebral ischemia in view of morphometric assay and neuropathological examination. The acidosis was induced by increment of halothane concentration and by decreasing respiratory rate. The mean pH were 7.423+/-0.012 in control group and 7.184+/-0.038 in acidosis group. Twenty-four hours after MCA occlusion(MCAO), neutral red staining and perfusion fixation was performed. The ischemic area was measured and morphometric analysis was undertaken. In acidosis group, the infarct area was 25.23+/-4.78% of the total cerebral area;in control group, the infarct area was 27.69+/-4.05%. The histopathological findings were examined under light microscopy, in which the field scanning was carried out from the midline by 0.5mm interval at cortical and basal ganglia levels. These results indicated that although there was no satistically significant difference in infarct area between acidosis and control group, increased acidosis aggravated the extent of histopathologic ischemic neuronal damage.
Acidosis*
;
Animals
;
Basal Ganglia
;
Brain Ischemia*
;
Halothane
;
Hydrogen-Ion Concentration
;
Microscopy
;
Neurons
;
Neutral Red
;
Perfusion
;
Rats*
;
Respiratory Rate
7.Cavernous Malformation after Radiation Therapy for Pilocytic Astrocytoma: Case Report.
Jin Hoon LEE ; Joo Han KIM ; Yong Gu CHUNG ; Hoon Kap LEE
Journal of Korean Neurosurgical Society 2003;33(6):582-584
We report a case of de novo development of cavernous malformation after cranial irradiation. The patient was a 19-year-old male who had been operated on 10 years ago for cerebellar pilocytic astrocytoma. After subtotal tumor removal, he had received cranial irradiation for the residual tumor. He was readmitted for extraocular muscle palsy, dysarthria and facial weakness about 10 years after operation and irradiation. Magnetic resonance imaging of the brain showed an abnormal mixed signal lesion in the lower pons and pontomedullary junction. The patient underwent surgical removal of the hematoma in the pons and the cavernous malformation was identified.
Astrocytoma*
;
Brain
;
Cranial Irradiation
;
Dysarthria
;
Hematoma
;
Humans
;
Magnetic Resonance Imaging
;
Male
;
Neoplasm, Residual
;
Paralysis
;
Pons
;
Young Adult
8.Upregulation of VEGF and FGF2 in Normal Rat Brain after Experimental Intraoperative Radiation Therapy.
Joo Han KIM ; Yong Gu CHUNG ; Chul Young KIM ; Han Kyeom KIM ; Hoon Kap LEE
Journal of Korean Medical Science 2004;19(6):879-886
The expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)2 in the irradiated brain was examined to test how a single high dose radiation, similar to that used for intraoperative radiation therapy given to the normal cerebrum, can affect the vascular endothelium. After a burr hole trephination in the rat skull, the cerebral hemisphere was exposed to a single 10 Gy dose of gamma rays, and the radiation effect was assessed at 1, 2, 4, 6, and 8 weeks after irradiation. His-tological changes, such as reactive gliosis, inflammation, vascular proliferation and necrosis, were correlated with the duration after irradiation. Significant VEGF and FGF2 expression in the 2- and 8-week were detected by enzyme-linked immunosorbent assay quantification in the radiation group. Immunohistochemical study for VEGF was done and the number of positive cells gradually increased over time, compared with the sham operation group. In conclusion, the radiation injuries consisted of radiation necrosis associated with the expression of VEGF and FGF2. These findings indicate that VEGF and FGF2 may play a role in the radiation injuries after intraoperative single high-dose irradiation.
Animals
;
Brain/metabolism/pathology/radiation effects
;
Brain Injuries/etiology/*metabolism/*pathology
;
Fibroblast Growth Factor 2/*metabolism
;
Necrosis
;
Radiation Injuries/*pathology
;
Radiosurgery/*adverse effects
;
Rats
;
Rats, Sprague-Dawley
;
Up-Regulation/radiation effects
;
Vascular Endothelial Growth Factor A/*metabolism
9.Characterization of Fusarium oxysporum Isolated from Paprika in Korea.
Sang Do CHA ; Young Jae JEON ; Geum Ran AHN ; Jae In HAN ; Kap Hoon HAN ; Seong Hwan KIM
Mycobiology 2007;35(2):91-96
In the present study we first report in Korea the identification and characterization of Fusarium oxysporum isolated from rotten stems and roots of paprika (Capsicum annuum var. grossum) at Masan, Kyungsangnamdo in 2006. The fungal species produced white aerial mycelia accompanying with dark violet pigment on PDA. The optimal temperature and pH for the growth of the species was 25degrees C and pH 7, respectively. Microscopic observation of one of isolates of the species shows that its conidiophores are unbranched and monophialides, its microconidia have oval-ellipsoidal shape with no septate and are of 3.0~11 x 1.5~3.5 microm sizes, its macroconidia are of 15~20 x 2.0~3.5 microm sizes and have slightly curved or slender shape with 2~3 septate. The results of molecular analysis show that the ITS rDNA of F. oxysporum from paprika shares 100% sequence identity with that of known F. oxysporum isolates. The identified species proved it's pathogenicity by causing rotting symptom when it was inoculated on paprika fruits. The growth of F. oxysporum from paprika was suppressed on PDA by agrochemicals such as benomyl, tebuconazole and azoxystrobin. The identified species has the ability of producing extracelluar enzymes that degrade cellobiose and pectin.
Agrochemicals
;
Benomyl
;
Capsicum*
;
Cellobiose
;
DNA, Ribosomal
;
Fruit
;
Fusarium*
;
Gyeongsangnam-do
;
Hydrogen-Ion Concentration
;
Korea*
;
Viola
;
Virulence
10.Hyperacute Radiation Effect on Cerebral Cortex after Local Gamma-irradiation in the Rat Brain.
Shin Hyuk KANG ; Yong Gu CHUNG ; Han Kyum KIM ; Chul Yong KIM ; Hoon Kap LEE
Journal of Korean Neurosurgical Society 2005;37(5):370-374
OBJECTIVE: We investigated the morphologic changes within 24 hours after a single gamma-irradiation in the rat brain. METHODS: Forty Sprague-Dawley rats were used. After a burr hole trephination on right parietal area, cerebral hemisphere was irradiated with 2Gy and 5Gy using iridium-192(192Ir), respectively. The effect was assessed at 4, 8, 12 and 24 hours after irradiation. The histological changes were scored following the detection of edema or disarray severity. TUNEL-positive cells exhibiting apoptotic morphology were counted in irradiated region. RESULTS: Cortical edema and disarray were initially showed at 4 or 8hour and almost all defined at 24hour after irradiation. And the injury was wedge shape. TUNEL-positive cells were minimal at 8hour after irradiation as the number of positive cells were 2.6+/-5.27(n=5) after 2Gy, and 0.8+/-0.84(n=5) after 5Gy. But, the number of apoptotic cells were increased markedly to 60+/-6.24 at 12hour after 2Gy and to 104+/-19.7 at 24hour after 5Gy. CONCLUSION: There were prominent morphologic changes immediately after gamma-irradiation. And, apoptosis was increased according to the time period. These findings implicate that brain irradiation induces rapid apoptotic change, which may play an important role in the pathogenesis of radiation-induced pathologic conditions.
Animals
;
Apoptosis
;
Brain*
;
Cerebral Cortex*
;
Cerebrum
;
Cranial Irradiation
;
Edema
;
Rabeprazole
;
Radiation Effects*
;
Radiation Injuries
;
Rats*
;
Rats, Sprague-Dawley
;
Trephining