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排序方式: 共有139条查询结果,搜索用时 406 毫秒
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Maryam Moradi Hadi Hajarian Hamed Karamishabankareh Leila Soltani Bijan Soleymani 《Reproduction in domestic animals》2021,56(2):263-269
Pre-conceptual sex selection is still a highly debatable process whereby X and Y chromosome bearing spermatozoa are isolated before oocyte fertilization. Recently, magnetic nanoparticles (MNP) have been used to determine X and Y chromosomes bearing spermatozoa as a result of searching for a cheap, highly efficient method using non-toxic materials. This study aimed to recover the sperm bearing X chromosomes in ram with different concentrations of MNP and then evaluate the success of this method using polymerase chain reaction (PCR). Ram sperms were divided into four groups, treated with 0 (control), 50, 100 and 200 μg/ml MNP, respectively. MNP was used to restore sperm cells bearing X chromosomes. Upon recovery, the PCR was performed to identify the X and Y sperms, Methyl ThiazoleTetrazolium (MTT), to assess MNP toxicity and sperm viability and acridine orange (AO) to evaluate sperm DNA integrity. The results of PCR revealed that the treatment of spermatozoa- bearing X chromosomes with 50 μg/ml MNP had the highest effects on the recovery of X sperm rather than the other concentrations of MNP. However, the concentrations of MNP did not have any toxic effects on spermatozoa, sperm viability and, DNA integrity, but the high concentration of MNP (200 μg/ml) significantly reduced DNA integrity. According to MTT and AO results, the concentrations of MNP used in this study had no toxic effects on spermatozoa and did not reduce the sperm viability and DNA integrity, except that 200 μg/ml MNP significantly reduced DNA integrity. 相似文献
4.
El-Hassan A El-Sayed M Hamed AI Rhee IK Ahmed AA Zeller KP Verpoorte R 《Fitoterapia》2003,74(1-2):184-187
The aerial part of Leptadenia arborea has been shown to contain pinoresinol (1), syringaresinol (2), leucanthemitol (3) and E-ferulaldehyde (4). These known compounds are being reported for the first time from this plant. Among them, syringaresinol has shown an inhibitory effect against acetylcholinesterase. The IC(50) (the concentration of 50% enzyme inhibition) value of this compound was 200 microg/ml. 相似文献
5.
Glutathione and its Related Enzymes in the Nile Fish 总被引:2,自引:0,他引:2
Ragaa R. Hamed Tahany M. Maharem Rasha A. M. Guinidi 《Fish physiology and biochemistry》2004,30(3-4):189-199
Glutathione (GSH) and related enzymes, glutathione transferase (GST), glutathione peroxidase (GPx) and glutathione reductase
(GR) form an important phase 2 biotransformation enzymes system. The objective of this study was to compare this enzymes system
in three fish species from the river Nile, Oreochromis niloticus, Claris lazera and Cyprinus carpio in order to establish the main differences and to purify and characterize GST from the liver of O. niloticus.The level of GSH and the activity of GST, GPx and GR in the liver, kidney and gills of the three fish species were examined.
A simple reproducible procedure for the purification of GST from the liver of O. niloticus to homogeneity, which includes chromatography on DEAE- cellulose followed by affinity chromatography on GSH-sepharose was
established. The molecular mass was found to be 25,460 Da by SDS-PAGE. The Michaelis-Meneten constants (Km) of the enzyme for GSH and CDNB were 0.35 mM and 0.42 mM, respectively. The affinity purified enzyme exhibited maximum pH
at pH 8.0 and increasing pH above 8.0 did not affect the observed maximum. The purified enzyme acts readily on CDNB, less
readily on some standard transferase substrates (1,2-dichloro-4-nitrobenzene and p-nitrophenethyl bromide) and not at all on others (bromosulphophthalein and p-nitrobenzyl chloride). Bromosulfophthalein, cibacron blue and hematin inhibited CDNB-conjugating activity of the purified
enzyme with IC50 0.079, 3.98 and 0.126 μM, respectively. 相似文献
6.
Asma Ali Abahussain Abdelhadi Abdelwahab Mohamed Ahmed Ali Salih Ahmad Al Safe Nader Abdul Hamed Mosa Yahya Othman 《农业科学与技术》2014,(2):112-122
Monitoring and assessment of agricultural land degradation is of vital importance for better land and water management planning and reclamation. It requires setting baseline information and basic analysis at specific time and space. About 33 geo-referenced soil sampling spots were selected in two agricultural production locations in the Kingdom of Bahrain to assess the status and preliminary causes of land degradation. Soil samples were taken from 13 sites in Diraz location while 19 samples were taken from Budayyi location. The samples were taken to 90 cm depth at 30 cm intervals. Standard procedures were followed to determine soil physiochemical properties. In addition, field observations on farm condition, distance from the sea, method of irrigation and irrigation water source were taken. Some of the soil samples were deliberately taken from outside the irrigated basins among trees compared with samples taken from inside the actively growing area for comparison. The results indicated that the salinity level was significantly (P 〈 0.001) higher at the 0-30 cm soil depth compared with 30-60 cm or 60-90 cm depths in both locations. The distance from the sea did not show clear correlation with surface soil salinity in Budayyi area compared with Diraz. Both locations showed significantly higher salinity levels on samples taken outside the actively growing areas compared with those taken from within. The effect is more prominent at the 0-30 cm depth. The observed variability on salinity levels may be attributed to farm management practices and deteriorating quality of ground water. Thus, agricultural land degradation in Bahrain cannot be attributed to ground water deterioration alone. The use of tertiary treated sewage water (TSE) may ease the pressure on ground water, but the pH of the TSE should be carefully monitored and managed with proper studies on leaching requirements to avoid further salinity complications. 相似文献
7.
Haitham Sayed Gunter Backes Hamed Kayyal Amor Yahyaoui Salvatore Ceccarelli Stefania Grando Ahmad Jahoor Michael Baum 《Euphytica》2004,135(2):225-228
A partial genetic linkage map was constructed on 71 doubled-haploid lines derived from a cross between the barley lines Tadmor
and WI2291 with 181 molecular markers. The segregating population was used to detect markers linked to the gene Mlg conferring resistance to powdery mildew (Erysiphe graminis f. sp. hordei) and to genes for quantitative resistance to scald (Rhynchosporium secalis). The gene Mlg on chromosome 4H was flanked by two AFLP markers at a distance of 2.0 and 2.4 cM, respectively. QTLs for resistance to scald
were detected on chromosomes 2H and 3H. This association of molecular markers with qualitative and quantitative disease resistance
loci represents a valuable starting-point for marker-assisted selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Haitham Sayed Hamed Kayyal Luke Ramsey Salvatore Ceccarelli Michael Baum 《Euphytica》2002,125(2):265-272
A total of 147 simple sequence repeat (SSR) markers (including86 barley and 61 wheat microsatellite markers) were tested for
their segregation in a doubled haploid (DH) and an F2 population of barley. The DH population consisted of 71 doubled haploid lines, developed from F1 plants of a cross between Tadmor and WI2291using isolated microspore culture technique. A genetic linkage map consisting
of 43 microsatellite markers was constructed using the DH population. Particularly on chromosome 4H microsatellite markers
showed distorted segregation ratios. Segregation of DH lines based on molecular markers were compared with segregation of
92 F2 lines from the same cross. The proportion of loci deviating from the expected monogenic segregation ratios in the DH population
was significantly higher (19/43loci, 44%) than in the F2 population (7/43 loci, 16%). The deviation was biased towards the WI2291 parent alleles. In line with this observation, WI2291
was found to perform better than Tadmor in regenerating green plantlets with the isolated microspore-culture technique.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
Mohammad Reza Naghavi Mohsen Mardi Seyed Mostafa Pirseyedi Mehrbanu Kazemi Payam Potki Mohammad Reza Ghaffari 《Genetic Resources and Crop Evolution》2007,54(2):237-240
Genetic diversity of 54 accessions of Aegilops tauschii from five countries was assessed using sequence-tagged microsatellites (or simple sequence repeats, SSRs) and amplified fragment
length polymorphisms (AFLPs). In the case of AFLP analysis, a total of 256 amplification products obtained, 234 of them were
polymorphic across all the 54 accessions. A total of 224 fragments were obtained from the 24 SSR primers and 219 of fragments
were polymorphic across all the genotypes screened. Based on both AFLP and SSR markers, the highest percentage of polymorphisms
were obtained in Iranian and accessions of unknown origin. The highest polymorphic information content (PIC) value was observed
for SSRs (0.82) while the highest marker index (MI) value was for AFLPs (8.5) reflecting the hyper-variability of the first
and the distinctive nature of the second system. Principal co-ordinate analysis (PCO) revealed congruent patterns of genetic
relationships for both data sets, but did not group accessions strictly according to their geographical origins. Poor correlation
was found between AFLP and SSR marker loci. This low association may be due to low number of AFLP and SSR markers. These results
show that molecular markers can help to organize the genetic variability and expose useful diversity for breeding purposes. 相似文献