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971.
Ji Hee Jeong Eun Hye Kim Weihua Guo Ki Oug Yoo Dong Gwang Jo Zin Suh Kim 《Plant Systematics and Evolution》2010,289(1-2):67-76
The genetic diversity and structure of 12 populations of Megaleranthis saniculifolia, a rare endemic Korean plant, were analyzed using 14 allozyme loci coding 10 enzymes and 78 ISSR loci using seven primers. The genetic diversity of M. saniculifolia at the species level was similar to that observed in out-crossing and long-lived perennials, while at the population level, it was significantly low. The high F IS value of many populations as well as homozygote excess occurred relatively evenly in many populations in relation to the Hardy-Weinberg expectation, suggesting that inbreeding was occurring within the M. saniculifolia populations. The degree of genetic differentiation based on the two markers was high, and there was no correlation between geographic and genetic distance. Bayesian cluster analysis did not reveal any remarkable geographic trends. Positive correlations were observed between genetic diversity (H e and h) and population size. Therefore, low genetic diversity within the population and high population differentiation of M. saniculifolia were closely related to the influence of genetic drift, particularly in highly isolated populations. In addition, the fixation of the main alleles at several loci in the opposite direction provided good evidence for genetic drift. The genetic diversity of M. saniculifolia could be compromised if the distribution area or the size of the population were further reduced. In particular, the isolated populations that are fragmented within an area could be at high risk of extinction due to accelerated inbreeding or genetic drift. Considering this, a close monitoring of the population size and of the changes in the genetic structure must be performed. Some practical measures for genetic conservation are also proposed. 相似文献
972.
Sun Mi Shin Kyu Suk Cho Min Sik Choi Sung Hoon Lee Seol-Heui Han Young-Sun Kang Hee Jin Kim Jae Hoon Cheong Chan Young Shin Kwang Ho Ko 《Neurochemical research》2010,35(7):976-985
In response to brain injury, microglia migrate and accumulate in the affected sites, which is an important step in the regulation
of inflammation and neuronal degeneration/regeneration. In this study, we investigated the effect of urokinase-type plasminogen
activator (uPA) on the BV-2 microglial cell migration. At resting state, BV-2 microglial cells secreted uPA and the release
of uPA was increased by ATP, a chemoattractant released from injured neuron. The migration of BV-2 cell was significantly
induced by uPA and inhibited by uPA inhibitors. In this condition, uPA increased the activity of matrix metalloproteinase
(MMP-9) and the inhibition of MMP activity with pharmacological inhibitors against either uPA (amiloride) or MMP (phenanthrolene
and SB-3CT) effectively prevented BV2 cell migration. Interestingly, the level of MMP-9 protein and mRNA in the cell were
not changed by uPA. These results suggest that the increase of MMP-9 activity by uPA is regulated at the post-translational
level, possibly via increased activation of the enzyme. Unlike the uPA inhibitor, plasmin inhibitor PAI-1 only partially inhibited
uPA-induced cell migration and MMP-9 activation. The incubation of recombinant MMP-9 with uPA resulted in the activation of
MMP-9. These results suggest that uPA plays a critical role in BV-2 microglial cell migration by activating pro-MMP-9, in
part by its direct action on MMP-9 and also in part by the activation of plasminogen/plasmin cascade. 相似文献
973.
In Koo Hwang Sun Shin Yi Jae Hoon Shin Ki-Yeon Yoo Jung Hoon Choi Choong Hyun Lee Je Kyung Seong Yeo Sung Yoon Jeong Ho Park Moo-Ho Won 《Neurochemical research》2010,35(3):465-472
In the present study, we observed the effects of cyclosporine A (CsA), an efficient immunosuppressant, on cell proliferation
and neuroblast differentiation in the subgranular zone of the dentate gyrus (SZDG) in normal C57BL/6 mice using Ki67 and doublecortin
(DCX) immunohistochemical staining, respectively. At 8 weeks of age, vehicle (physiological saline) or CsA was daily administered
(40 mg/kg, i.p.) for 1 week. Animals were sacrificed at 2 weeks after last administration. CsA treatment did not show any
influences in neurons, astrocytes and microglia based on immunohistochemistry for its markers, respectively. However, in the
CsA-treated group, Fluoro-Jade B, a marker for neurodegeneration, positive cells were found in the SZDG, not in the vehicle-treated
group. In the vehicle-treated group, Ki67 immunoreactive (+) nuclei were clustered in the SZDG, whereas in the CsA-treated group Ki67+ nuclei were scattered in the SZDG, showing no difference in cell numbers. Numbers of DCX+ neuroblasts with well-developed processes (tertiary dendrites) were much lower in the CsA-treated group than those in the
vehicle-treated group; however, numbers of DCX+ neuroblasts with secondary dendrites were similar in both the groups. These results suggest that CsA significantly reduces
dendritic outgrowth and complexity from neuroblasts in the SZDG without any affecting in neurons, astrocytes and microglia
in normal mice. 相似文献
974.
Glutathione S-transferases (GSTs: EC2.5.1.18) are a superfamily of multifunctional dimeric enzymes that catalyze the conjugation of glutathione (GSH) to electrophilic chemicals. In most animals and in humans, GSTs are the principal enzymes responsible for detoxifying the mycotoxin aflatoxin B1 (AFB1) and GST dysfunction is a known risk factor for susceptibility towards AFB1. Turkeys are one of the most susceptible animals known to AFB1, which is a common contaminant of poultry feeds. The extreme susceptibility of turkeys is associated with hepatic GSTs unable to detoxify the highly reactive and electrophilic metabolite exo-AFB1-8,9-epoxide (AFBO). In this study, comparative genomic approaches were used to amplify and identify the α-class tGST genes (tGSTA1.1, tGSTA1.2, tGSTA1.3, tGSTA2, tGSTA3 and tGSTA4) from turkey liver. The conserved GST domains and four α-class signature motifs in turkey GSTs (with the exception of tGSTA1.1 which lacked one motif) confirm the presence of hepatic α-class GSTs in the turkey. Four signature motifs and conserved residues found in α-class tGSTs are (1) xMExxxWLLAAAGVE, (2) YGKDxKERAxIDMYVxG, (3) PVxEKVLKxHGxxxL and (4) PxIKKFLXPGSxxKPxxx. A BAC clone containing the α-class GST gene cluster was isolated and sequenced. The turkey α-class GTS genes genetically map to chromosome MGA2 with synteny between turkey and human α-class GSTs and flanking genes. This study identifies the α-class tGST gene cluster and genetic markers (SNPs, single nucleotide polymorphisms) that can be used to further examine AFB1 susceptibility and resistance in turkeys. Functional characterization of heterologously expressed proteins from these genes is currently underway. 相似文献
975.
Jung Eun Hwang Joon Ki Hong Chan Ju Lim Huan Chen Jihyun Je Kyung Ae Yang Dool Yi Kim Young Ju Choi Sang Yeol Lee Chae Oh Lim 《Plant cell reports》2010,29(8):905-915
The phytocystatins of plants are members of the cystatin superfamily of proteins, which are potent inhibitors of cysteine
proteases. The Arabidopsis genome encodes seven phytocystatin isoforms (AtCYSs) in two distantly related AtCYS gene clusters. We selected AtCYS1 and AtCYS2 as representatives for each cluster and then generated transgenic plants expressing the GUS reporter gene under the control of each gene promoter. These plants were used to examine AtCYS expression at various stages of plant development and in response to abiotic stresses. Histochemical analysis of AtCYS1 promoter- and AtCYS2 promoter-GUS transgenic plants revealed that these genes have similar but distinct spatial and temporal expression patterns
during normal development. In particular, AtCYS1 was preferentially expressed in the vascular tissue of all organs, whereas AtCYS2 was expressed in trichomes and guard cells in young leaves, caps of roots, and in connecting regions of the immature anthers
and filaments and the style and stigma in flowers. In addition, each AtCYS gene has a unique expression profile during abiotic stresses. High temperature and wounding stress enhanced the expression
of both AtCYS1 and AtCYS2, but the temporal and spatial patterns of induction differed. From these data, we propose that these two AtCYS genes play important, but distinct, roles in plant development and stress responses. 相似文献
976.
Su Yeon Jeon Hyun‐Jung Lee Ji Myeong Park Hyun Min Jung Jung Ki Yoo Hey‐Jin Lee Jong‐Sung Lee Dong‐Hyun CHA Jin Kyeoung Kim Gi Jin Kim 《Journal of cellular biochemistry》2010,110(2):522-530
In regulation of the developmental process, the balance between cellular proliferation and cell death is critical. Placental development tightly controls this mechanism, and increased apoptosis of placental trophoblasts can cause a variety of gynecological diseases. Members of the immortalization‐upregulated protein (IMUP) family are nuclear proteins implicated in SV40‐mediated immortalization and cellular proliferation; however, the mechanisms by which their expression is regulated in placental development are still unknown. We compared IMUP‐2 expression in normal and pre‐eclamptic placental tissues and evaluated the function of IMUP‐2 in HTR‐8/SVneo trophoblast cells under hypoxic conditions. IMUP‐2 was expressed in syncytiotrophoblasts and syncytial knots of the placental villi. IMUP‐2 expression was significantly higher in preterm pre‐eclampsia patients than in patients who went to term (P < 0.001); however, we observed no differences in IMUP‐2 expression between normal term patients with and without pre‐eclampsia. Hypoxic conditions increased apoptosis of HTR8/SVneo trophoblast cells and induced IMUP‐2 expression. Also, apoptosis of HTR‐8/SVneo trophoblast cells was increased after IMUP‐2 gene transfection. These results suggest that IMUP‐2 expression is specifically elevated in preterm pre‐eclampsia and under hypoxic conditions, and that IMUP‐2 induces apoptosis of the trophoblast. Therefore, IMUP‐2 might have functional involvement in placental development and gynecological diseases such as pre‐eclampsia. J. Cell. Biochem. 110: 522–530, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
977.
Hyeong Cheol Park Chan Young Park Sung Cheol Koo Mi Sun Cheong Kyung Eun Kim Min Chul Kim Chae Oh Lim Sang Yeol Lee Dae-Jin Yun Woo Sik Chung 《Plant cell reports》2010,29(11):1297-1304
Plants express many calmodulins (CaMs) and calmodulin-like (CML) proteins that sense and transduce different Ca2+ signals. Previously, we reported divergent soybean (Glycine max) CaM isoforms (GmCaM4/5) with differential abilities to activate CaM-dependent enzymes. To elucidate biological functions
of divergent CaM proteins, we isolated a cDNA encoding a CML protein, AtCML8, from Arabidopsis. AtCML8 shows highest identity with GmCaM4 at the protein sequence level. Expression of AtCML8 was high in roots, leaves, and flowers but low in stems. In addition, the expression of AtCML8 was induced by exposure to salicylic acid or NaCl. AtCML8 showed typical characteristics of CaM such as Ca2+-dependent electrophoretic mobility shift and Ca2+ binding ability. In immunoblot analyses, AtCML8 was recognized only by antiserum against GmCaM4 but not by GmCaM1 antibodies.
Interestingly, AtCML8 was able to activate phosphodiesterase (PDE) but did not activate NAD kinase. These results suggest
that AtCML8 acts as a CML protein in Arabidopsis with characteristics similar to soybean divergent GmCaM4 at the biochemical levels. 相似文献
978.
979.
980.
Joo Hyun Nam Dong Hun Shin Jung Eun Min Sang-Kyu Ye Ju-Hong Jeon Sung Joon Kim 《Molecules and cells》2010,29(1):85-91
Lysophospholipids (LPLs) such as lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are chemotactic for lymphocytes,
and increases of in cytosolic [Ca2+] signal the regulation of lymphocyte activation and migration. Here, the authors investigated the effects of LPA and S1P
on [Ca2+]c in mouse B cell lines (WEHI-231 and Bal-17) and primary B cells isolated from mouse spleen and bone marrow, and focused on
the modulation of store-operated Ca2+ entry (SOCE) by LPLs. In Bal-17 (a mature B cell line) both LPA and S1P induced a transient [Ca2+]c increase via a phospholipase C pathway. In addition, pretreatment with LPLs was found to augment thapsigargin-induced SOCE
in Bal-17 cells. However, in WEHI-231 (an immature B cell line) LPLs had no significant effect on [Ca2+]c or SOCE. Furthermore, in freshly isolated splenic B cells (SBCs) and bone marrow B cells (BMBCs), LPLs induced only a small
increase in [Ca2+]c. Interestingly, however, pretreatment with LPLs markedly increased SOCE in primary B cells, and this augmentation was more
prominent in BMBCs than SBCs. The unidirectional influx of Ca2+ was measured using Ba2+ as a surrogate ion. Similarly, Ba2+ influx was also found to be markedly increased by LPLs in SBCs and BMBCs. Summarizing, LPLs were found to strongly augment
SOCE-mediated Ca2+-signaling in mouse B cells. However, unlike the mature Bal-17 cell line, PLC-dependent Ca2+ release was insignificant in primary B cells and inWEHI-231. 相似文献