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981.
982.
Yusuke Kazama Moe Kitoh Taiki Kobayashi Kotaro Ishii Marc Krasovec Yasuo Yasui Tomoko Abe Shigeyuki Kawano Dmitry A Filatov 《Molecular biology and evolution》2022,39(10)
How do separate sexes originate and evolve? Plants provide many opportunities to address this question as they have diverse mating systems and separate sexes (dioecy) that evolved many times independently. The classic “two-factor” model for evolution of separate sexes proposes that males and females can evolve from hermaphrodites via the spread of male and female sterility mutations that turn hermaphrodites into females and males, respectively. This widely accepted model was inspired by early genetic work in dioecious white campion (Silene latifolia) that revealed the presence of two sex-determining factors on the Y-chromosome, though the actual genes remained unknown. Here, we report identification and functional analysis of the putative sex-determining gene in S. latifolia, corresponding to the gynoecium suppression factor (GSF). We demonstrate that GSF likely corresponds to a Y-linked CLV3-like gene that is specifically expressed in early male flower buds and encodes the protein that suppresses gynoecium development in S. latifolia. Interestingly, GSFY has a dysfunctional X-linked homolog (GSFX) and their synonymous divergence (dS = 17.9%) is consistent with the age of sex chromosomes in this species. We propose that female development in S. latifolia is controlled via the WUSCHEL-CLAVATA feedback loop, with the X-linked WUSCHEL-like and Y-linked CLV3-like genes, respectively. Evolution of dioecy in the S. latifolia ancestor likely involved inclusion of ancestral GSFY into the nonrecombining region on the nascent Y-chromosome and GSFX loss of function, which resulted in disbalance of the WUSCHEL-CLAVATA feedback loop between the sexes and ensured gynoecium suppression in males. 相似文献
983.
Yukinori Noguchi Asako Ishii Ayako Matsushima Daisuke Haishi Ken-ichi Yasumuro Tomohisa Moriguchi Takeshi Wada Yoh Kodera Misao Hiroto Hiroyuki Nishimura Mitsuo Sekine Yuji Inada 《Marine biotechnology (New York, N.Y.)》1999,1(2):207-210
A fluorescent substance was isolated from the cyanobacterium with a yield of 4.5 mg per 10 g of dried Spirulina (Arthrospira) platensis cells by gentle extraction and ethanol fractionation followed by column chromatography. The fluorescent substance, which
has absorption maxima at 256 nm and 362 nm (pH 8.4), was identified as biopterin-α-glucoside by spectrophotometry and nuclear
magnetic resonance spectroscopy. Biopterin-α-glucoside prevented decolorization of the photosynthetic pigments, chlorophyll
a, phycocyanin, and carotenoids in photosynthetic vesicles of Spirulina platensis cells, by ultraviolet irradiation.
Received June 23, 1998; accepted September 10, 1998. 相似文献
984.
985.
M Ohnishi C Tanaka S Kuhara K Ishii M Hattori K Kurokawa T Yasunaga K Makino H Shinagawa T Murata K Nakayama Y Terawaki T Hayashi 《DNA research》1999,6(6):361-368
A complete Xba I and Bln I cleavage map was constructed for the chromosome of an enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain isolated from an outbreak in Sakai City, Japan, in 1996. A comparative chromosome analysis with E. coli K-12 strain MG1655 was made. The EHEC chromosome was approximately 5600 kb in length, 1 Mb larger than that of MG1655. Despite the marked difference in chromosome length, the location and direction of seven rRNA operons of the EHEC strain were similar to those for MG1655. Overall organization of genes common in both strains is also highly conserved. Chromosome expansion was observed throughout the EHEC chromosome, albeit in an uneven manner. A large portion of the chromosome enlargement was observed in the region surrounding the replication terminus, particularly in a segment containing the terA locus. Sample sequencing of 3627 random shotgun clones suggested the presence of approximately 1550 kb strain-specific DNAs on the EHEC chromosome, most of which are likely to be of foreign origin. 相似文献
986.
We examined the diurnal variations and the effects of 48-hour fasting on hematological and serum biochemical values to obtain basic physiological data on ten male and seven female G?ttingen minipigs 6 to 16 months of age. For all hematological parameters examined (RBC, HCT, HGB, WBC and PLT), there was no diurnal variation in either sex, but red blood cell parameters were affected by fasting, with an increase in males and a decrease in females. Three serum biochemical parameters (GOT, UN and i.p.) for males and four (GOT, UN, Ca and i.p.) for females exhibited diurnal variation. These variations were eliminated by fasting. The BIL level in males was increased by fasting, and the color of serum was yellowish. Fe concentration in both sexes and CRE and Mg levels in males were decreased by fasting. These findings are basic data for various experiments on minipigs, and indicate that great care is required in establishing feeding times and fasting intervals and in the analysis of results of experiments on minipigs. 相似文献
987.
Cutting edge: combined treatment of TNF-alpha and IFN-gamma causes redistribution of junctional adhesion molecule in human endothelial cells. 总被引:8,自引:0,他引:8
H Ozaki K Ishii H Horiuchi H Arai T Kawamoto K Okawa A Iwamatsu T Kita 《Journal of immunology (Baltimore, Md. : 1950)》1999,163(2):553-557
Proinflammatory cytokines such as TNF-alpha and IFN-gamma induce cell adhesion molecules in endothelial cells and promote transmigration of leukocytes across endothelial cells. However, when those two were administered together, leukocyte transmigration paradoxically decreased. We cloned a human and bovine homologue of the junctional adhesion molecule (JAM), a novel molecule at the tight junction, and examined the effects of proinflammatory cytokines on JAM in HUVECs. The combined treatment of TNF-alpha plus IFN-gamma caused a disappearance of JAM from intercellular junctions. However, flow cytometry, cell ELISA, and subcellular fractionation analysis demonstrated that the amount of JAM was not reduced. This suggested that JAM changed its distribution in response to proinflammatory cytokines. This redistribution of JAM might be involved in a decrease in transendothelial migration of leukocytes at inflammatory sites. 相似文献
988.
989.
990.
Morota S Hansson MJ Ishii N Kudo Y Elmér E Uchino H 《Journal of neurochemistry》2007,103(5):2066-2076
The mitochondrial permeability transition (mPT) is a potential pathogenic mechanism in neurodegeneration. Varying sensitivity to calcium-induced mPT has been demonstrated for regions within the CNS possibly correlating with vulnerability following insults. The spinal cord is selectively vulnerable in e.g. amyotrophic lateral sclerosis and increased mPT sensitivity of mitochondria derived from the spinal cord has previously been demonstrated. In this study, we introduce whole-body hypothermia prior to removal of CNS tissue to minimize the effects of differential tissue extraction prior to isolation of spinal cord and cortical brain mitochondria. Spinal cord mitochondria were able to retain considerably less calcium when administered as continuous infusion, which was not related to a general increased sensitivity of the mPT to calcium, its desensitization to calcium by the cyclophilin D inhibitor cyclosporin-A, or to differences in respiratory parameters. Spinal cord mitochondria maintained a higher concentration of extramitochondrial calcium during infusion than brain mitochondria possibly related to an increased set-point concentration for calcium uptake. A hampered transport and retention capacity of calcium may translate into an increased susceptibility of the spinal cord to neurodegenerative processes involving calcium-mediated damage. 相似文献