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131.
Human spermatogonial stem cells (SSCs) play critical roles in lifelong maintenance of male fertility and regeneration of spermatogenesis. These cells are expected to provide an important resource for male fertility preservation and restoration. A basic strategy has been proposed that would involve harvesting testis biopsy specimens from a cancer patient prior to cancer therapies, and transplanting them back to the patient at a later time; then, SSCs included in the specimens would regenerate spermatogenesis. To clinically apply this strategy, isolating live human SSCs is important. In this study, we investigated whether CD9, a known rodent SSC marker, is expressed on human male germ cells that can repopulate recipient mouse testes upon transplantation. Testicular tissues were obtained from men with obstructive azoospermia. Using immunohistochemistry, we found that CD9 was expressed in human male germ cells in the basal compartment of the seminiferous epithelium. Following immunomagnetic cell sorting, CD9-positive cells were enriched for germ cells expressing MAGEA4, which is expressed by spermatogonia and some early spermatocytes, compared with unsorted cells. We then transplanted CD9-positive cells into nude mouse testes and detected an approximately 3- to 4-fold enrichment of human germ cells that repopulated mouse testes for at least 4 mo after transplantation, compared with unsorted cells. We also observed that some cell turnover occurred in human germ cell colonies in recipient testes. These results demonstrate that CD9 identifies human male germ cells with capability of long-term survival and cell turnover in the xenogeneic testis environment. 相似文献
132.
Slotte T Hazzouri KM Stern D Andolfatto P Wright SI 《Evolution; international journal of organic evolution》2012,66(5):1360-1374
The transition from outcrossing to predominant self-fertilization is one of the most common evolutionary transitions in flowering plants. This shift is often accompanied by a suite of changes in floral and reproductive characters termed the selfing syndrome. Here, we characterize the genetic architecture and evolutionary forces underlying evolution of the selfing syndrome in Capsella rubella following its recent divergence from the outcrossing ancestor C. grandiflora. We conduct genotyping by multiplexed shotgun sequencing and map floral and reproductive traits in a large (N= 550) F2 population. Our results suggest that in contrast to previous studies of the selfing syndrome, changes at a few loci, some with major effects, have shaped the evolution of the selfing syndrome in Capsella. The directionality of QTL effects, as well as population genetic patterns of polymorphism and divergence at 318 loci, is consistent with a history of directional selection on the selfing syndrome. Our study is an important step toward characterizing the genetic basis and evolutionary forces underlying the evolution of the selfing syndrome in a genetically accessible model system. 相似文献
133.
Abid G Muhovski Y Jacquemin JM Mingeot D Sassi K Toussaint A Baudoin JP 《Molecular biology reports》2012,39(2):1133-1143
A full-length cDNA encoding common bean (Phaseolus vulgaris L.) sucrose synthase (designated as Pv_BAT93 Sus), which catalyses the synthesis and cleavage of sucrose, was isolated from
seeds at 15 days after pollination (DAP) by rapid amplification of cDNA ends (RACE). The full-length cDNA of Pv_BAT93 Sus
had a 2,418 bp open reading frame (ORF) encoding a protein of 806 amino acid residues. Sequence comparison analysis showed
that Pv_BAT93 Sus was very similar to several members of the sucrose synthase family of other plant species. Tissue expression
pattern analysis showed that Pv_BAT93 Sus was expressed in leaves, flowers, stems, roots, cotyledons, and particularly during
seed development. Expression studies using in situ hybridization revealed altered spatial and temporal patterns of Sus expression
in the EMS mutant relative to wild-type and confirmed Sus expression in common bean developing seeds. The expression and accumulation
of Sus mRNA was clearly shown in several tissues, such as the suspensor and embryo, but also in the transfer cells and endothelium.
The results highlight the diverse roles that Sus might play during seed development in common bean. 相似文献
134.
Development of a measles vaccine production process in MRC-5 cells grown on Cytodex1 microcarriers and in a stirred bioreactor 总被引:1,自引:0,他引:1
Measles vaccination remains the most efficient way to control the spread of the virus. This work focuses on the production
of a measles vaccine using stirred conditions as an advanced option for process scale up. Non-porous Cytodex 1 microcarriers
were used to support MRC-5 cell growth in suspension cultures. Virus replication was first optimized in spinner flasks, and
the effects of various operational parameters were investigated. Cell infection with AIK-C measles strain at an MOI (multiplicity
of infection) of 0.005, without glucose regulation and in M199 medium, resulted in a virus titer of 106.25 TCID50 (median tissue culture infective dose)/ml. To optimize the production process in a 7-l bioreactor, we carried out various
perfused cultures using minimum essential medium (MEM) + 5% FCS diluted with phosphate-buffered saline (PBS). We achieved
a high cell density level (4.1 × 106 cells/ml) with an efficient use of the medium when MEM + 5% FCS diluted with PBS at 25% was used during the cell amplification
step. Optimization of measles production in MRC-5 cells grown on Cytodex 1 beads in a 7-l bioreactor showed that perfusion
was the most efficient when compared to repeated-batch culture. Perfusion at a rate of 0.25 V (reactor volume)/day showed
the highest specific productivity (1.6 IVP [infectious virus particle] cell−1 day−1). Testing of several stabilizers containing pharmaceutically improved components such as sugars, amino acids, and charged
ions showed that the formulation composed of sucrose and MgCl2, led to the maintenance of the infectivity of the AIK-C measles virus strain to a significant level, when stored at +28 °C,
+4 °C and −60 °C. 相似文献
135.
Guo-Shu Wang Hartmut Grammel Khaled Abou-Aisha Rudolf S?gesser Robin Ghosh 《Applied and environmental microbiology》2012,78(20):7205-7215
The biosynthesis of the major carotenoid spirilloxanthin by the purple nonsulfur bacterium Rhodospirillum rubrum is thought to occur via a linear pathway proceeding through phytoene and, later, lycopene as intermediates. This assumption is based solely on early chemical evidence (B. H. Davies, Biochem. J. 116:93–99, 1970). In most purple bacteria, the desaturation of phytoene, catalyzed by the enzyme phytoene desaturase (CrtI), leads to neurosporene, involving only three dehydrogenation steps and not four as in the case of lycopene. We show here that the chromosomal insertion of a kanamycin resistance cassette into the crtC-crtD region of the partial carotenoid gene cluster, whose gene products are responsible for the downstream processing of lycopene, leads to the accumulation of the latter as the major carotenoid. We provide spectroscopic and biochemical evidence that in vivo, lycopene is incorporated into the light-harvesting complex 1 as efficiently as the methoxylated carotenoids spirilloxanthin (in the wild type) and 3,4,3′,4′-tetrahydrospirilloxanthin (in a crtD mutant), both under semiaerobic, chemoheterotrophic, and photosynthetic, anaerobic conditions. Quantitative growth experiments conducted in dark, semiaerobic conditions, using a growth medium for high cell density and high intracellular membrane levels, which are suitable for the conventional industrial production in the absence of light, yielded lycopene at up to 2 mg/g (dry weight) of cells or up to 15 mg/liter of culture. These values are comparable to those of many previously described Escherichia coli strains engineered for lycopene production. This study provides the first genetic proof that the R. rubrum CrtI produces lycopene exclusively as an end product. 相似文献
136.
Belghith KS Dahech I Hamden K Feki A Mejdoub H Belghith H 《International journal of biological macromolecules》2012,50(4):1070-1074
Levan polysaccharide, a type of fructan, has been shown to have industrial applications as a new industrial gum in the fields of cosmetics, foods like dietary fiber and pharmaceutical goods. The objective of this current study was to investigate the possible hypolipidemic and antioxidative effects of levan in rats fed with a high-cholesterol diet. Animals were allocated into four groups of six rats each: a normal diet group (Control), normal rats received levan (L), a high-cholesterol diet group (Chol) and a high-cholesterol diet with a daily dose of levan equivalent to 5%. Treated hypercholesterolemic rats were administrated with levan in drinking water through oral gavage for 60 days. After the treatment period, the plasma antioxidant enzymes and lipid profiles were determined. Our results show that treatment with levan polysaccharide positively changed plasma antioxidant enzyme activities and lipid profiles (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides) in cholesterol-rats, and thus may have potential hypolipidemic and antioxidant effects. Levan could protect against oxidative stress linked atherosclerosis and decrease the atherogenic index. 相似文献
137.
Loutfy N El-Tayeb MA Hassanen AM Moustafa MF Sakuma Y Inouhe M 《Journal of plant research》2012,125(1):173-184
Salicylic acid (SA) controls growth and stress responses in plants. It also induces drought tolerance in plants. In this paper,
four wheat (Triticum aestivum L.) cultivars with different drought responses were treated with SA in three levels of drain (90, 60, 30% of maximum field
capacity) to examine its interactive effects on drought responses and contents of osmotic solutes that may be involved in
growth and osmotic adjustment. Under drought condition, the cultivars Geza 164 and Sakha 69 had the plant biomass and leaf
relative water content (LRWC) greater than the cultivars Gemaza 1 and Gemaza 3. In all cultivars, drought stress decreased
the biomass, LRWC, and the contents of inorganic solutes (Ca, K, Mg) and largely increased the contents of organic solutes
(soluble sugars and proline). By contrast, SA increased the biomass, LRWC and the inorganic and organic solute contents, except
proline. Correlation analysis revealed that the LRWC correlated positively with the inorganic solute contents but negatively
with proline in all cultivars. SA caused maximum accumulations of soluble sugars in roots under drought. These results indicated
that SA-enhanced tolerance might involve solute accumulations but independently of proline biosynthesis. Drought-sensitive
cultivars had a trait lowering Ca and K levels especially in shoots. Possible functions of the ions and different traits of
cultivars were discussed. 相似文献
138.
Santosh S. Chobe Bhaskar S. Dawane Khaled M. Tumbi Prajwal P. Nandekar Abhay T. Sangamwar 《Bioorganic & medicinal chemistry letters》2012,22(24):7566-7572
The DNA molecule is a target for plethora of anticancer and antiviral drugs that forms covalent and non-covalent adducts with major or minor groove of DNA. In present study we synthesized series of novel Pyrazolo [1,5-a]pyrimidine derivatives. The newly synthesized compounds were characterized by elemental analysis, IR, 1H NMR, and mass spectral data. The selected compounds were studied for interaction with Calf thymus DNA (CT-DNA) using electronic spectra, viscosity measurement and thermal denaturation studies. Further, molecular interactions were revealed for compound IIIa and IVa by computational methodologies. The preferred mode of ligand binding with double helical DNA as well as preferable DNA groove were explored by molecular docking in different DNA models. 相似文献
139.
Shirley Haun Lu Sun Satanay Hubrack David Yule Khaled Machaca 《Channels (Austin, Tex.)》2012,6(5):379-384
The Ins(1,4,5)P3 receptor acts as a central hub for Ca2+ signaling by integrating multiple signaling modalities into Ca2+ release from intracellular stores downstream of G-protein and tyrosine kinase-coupled receptor stimulation. As such, the Ins(1,4,5)P3 receptor plays fundamental roles in cellular physiology. The regulation of the Ins(1,4,5)P3 receptor is complex and involves protein-protein interactions, post-translational modifications, allosteric modulation, and regulation of its sub-cellular distribution. Phosphorylation has been implicated in the sensitization of Ins(1,4,5)P3-dependent Ca2+ release observed during oocyte maturation. Here we investigate the role of phosphorylation at T-930, a residue phosphorylated specifically during meiosis. We show that a phosphomimetic mutation at T-930 of the rat Ins(1,4,5)P3 receptor results in decreased Ins(1,4,5)P3-dependent Ca2+ release and lowers the Ins(1,4,5)P3 binding affinity of the receptor. These data, coupled to the sensitization of Ins(1,4,5)P3-dependent Ca2+ release during meiosis, argue that phosphorylation within the coupling domain of the Ins(1,4,5)P3 receptor acts in a combinatorial fashion to regulate Ins(1,4,5)P3 receptor function. 相似文献
140.
The prefrontal cortex (PFC) develops from birth through late adolescence. This extended developmental trajectory provides many opportunities for experience to shape the structure and function of the PFC. To date, a few studies have reported links between parental socioeconomic status (SES) and prefrontal function in childhood, raising the possibility that aspects of environment associated with SES impact prefrontal function. Considering that behavioral measures of prefrontal function are associated with learning across multiple domains, this is an important area of investigation. In this study, we used fMRI to replicate previous findings, demonstrating an association between parental SES and PFC function during childhood. In addition, we present two hypothetical mechanisms by which SES could come to affect PFC function of this association: language environment and stress reactivity. We measured language use in the home environment and change in salivary cortisol before and after fMRI scanning. Complexity of family language, but not the child's own language use, was associated with both parental SES and PFC activation. Change in salivary cortisol was also associated with both SES and PFC activation. These observed associations emphasize the importance of both enrichment and adversity-reduction interventions in creating good developmental environments for all children. 相似文献