排序方式: 共有121条查询结果,搜索用时 15 毫秒
91.
Krystelle Nganou-Makamdop Aarthi Talla Ashish Arunkumar Sharma Sam Darko Amy Ransier Farida Laboune Jeffrey G. Chipman Gregory J. Beilman Torfi Hoskuldsson Slim Fourati Thomas E. Schmidt Sahaana Arumugam Noemia S. Lima Damee Moon Samuel Callisto Jordan Schoephoerster Jeffery Tomalka Peter Mugyenyi Daniel C. Douek 《Cell》2021,184(15):3899-3914.e16
92.
The objective of this work was to produce doubled haploid plants from durum wheat through gynogenesis using unpollinated ovary
culture of three local Tunisian genotypes (Jenah Khotifa, Hmira, Azizi) and three improved cultivars (Karim, Khiar, Razzek).
A total of 12,000 unpollinated ovaries were cultured in this study. Spikes were either pretreated at 4°C for 14 days or at
4°C in a mannitol solution (0.3 M) for 7 days. Induction was performed using two media. We showed that ovary development,
callus and plantlet regeneration was influenced significantly by genotype and growth conditions. The highest regeneration
frequency was obtained when the microspore population was in the late mononucleate to binucleate stage. Our results suggested
that the cold pretreatment for 14 days was more efficient than the cold treatment in a mannitol solution. Furthermore, the
addition of 2,4-D, vitamins and glutamine, and the use of maltose as sugar source in media improved the ovary culture. When
the unpollinated ovaries were cultured under the conditions found to be optimal in the present study, a total of 84 plants
were produced, all green and haploid. The best levels for regenerated plants were obtained with the cultivars Khiar (3.5%),
Hmira (3.1%) and Karim (1.5%). Fertile doubled haploid plants were obtained by colchicine treatment. This result represents
a modern tool for breeders to produce durum wheat homozygous lines in a few months. 相似文献
93.
Ayed IB Chamkha I Mkaouar-Rebai E Kammoun T Mezghani N Chabchoub I Aloulou H Hachicha M Fakhfakh F 《Biochemical and biophysical research communications》2011,(2):381-386
Pearson syndrome (PS) is a multisystem disease including refractory anemia, vacuolization of marrow precursors and pancreatic fibrosis. The disease starts during infancy and affects various tissues and organs, and most affected children die before the age of 3 years. Pearson syndrome is caused by de novo large-scale deletions or, more rarely, duplications in the mitochondrial genome. In the present report, we described a Pearson syndrome patient harboring multiple mitochondrial deletions which is, in our knowledge, the first case described and studied in Tunisia. In fact, we reported the common 4.977 kb deletion and two novel heteroplasmic deletions (5.030 and 5.234 kb) of the mtDNA. These deletions affect several protein-coding and tRNAs genes and could strongly lead to defects in mitochondrial polypeptides synthesis, and impair oxidative phosphorylation and energy metabolism in the respiratory chain in the studied patient. 相似文献
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95.
Emna Mkaouar-Rebai Imen Chamkha Thouraya Kammoun Olfa Alila-Fersi Hajer Aloulou Mongia Hachicha Faiza Fakhfakh 《Biochemical and biophysical research communications》2013,430(2):585-591
Mitochondrial diseases are a clinically heterogeneous group of disorders that arise as a result of dysfunction of the mitochondrial respiratory chain. Sensorineural hearing loss (SNHL) has been described in association to different mitochondrial multisystem syndromes, often involving the central nervous system, neuromuscular, or endocrine organs. In this study, we described a Tunisian young girl with hearing impairment, congenital visual loss and maternally inherited diabetes. No mutation was found in the mitochondrial tRNALeu(UUR) and the 12S rRNA genes. However, we detected the m.7444G>A mutation in the mitochondrial COI/tRNASer(UCN) genes. This mutation eliminates the termination codon of the MT-CO1 gene and extends the COI polypeptide by three amino acids (Lys–Gln–Lys) to the C-terminal. The whole mitochondrial genome screening revealed the presence of a novel mutation m.6498C>A (L199I) in the mitochondrial DNA-encoded subunit I of the cytochrome c oxidase (COX). This “probably damaging” transversion affects a highly conserved domain and it was absent in 200 Tunisian controls. The studied patient was classified under the haplogroup H2a. 相似文献
96.
Jihène Rejeb Asma Omezzine Lamia Rebhi Imen Boumaiza Hajer Mabrouk Hamida Rhif Nabila Ben Rejeb Naoufel Nabli Wahiba Douki Ahmed Ben Abdelaziz Essia Boughzala Ali Bouslama 《Biochemical genetics》2013,51(1-2):76-91
PON1 and PON2 have attracted considerable attention as candidate genes for coronary heart disease because their enzymes function as key factors in lipoprotein catabolism pathways. We studied the distribution of PON1 and PON2 polymorphisms, including genotyping, lipid profile, and PON1 activity, and their association with PON1 activity and significant coronary stenosis (SCS) in a Tunisian population. PON1 activity was lower in patients with SCS than in controls. It increased with the R allele (QQ < QR < RR) in PON1-192 genotypes and with the L allele (MM < ML < LL) in PON1-55 genotypes. In the presence of metabolic syndrome and diabetes, PON1-192RR and PON2-311CC were associated with an increased risk of SCS and PON1-55MM seems to have lower risk. This association was evident among nonsmokers for PON1-55MM and among smokers for PON1-192RR and PON2-311CC. The GTGC haplotype seemed to increase the risk of SCS compared with the wild haplotype in a Tunisian population. 相似文献
97.
Hajer Ben Hlima Samir Bejar Jonas Riguet Richard Haser Nushin Aghajari 《Applied microbiology and biotechnology》2013,97(22):9715-9726
The role of residue 219 in the physicochemical properties of d-glucose isomerase from Streptomyces sp. SK strain (SKGI) was investigated by site-directed mutagenesis and structural studies. Mutants G219A, G219N, and G219F were generated and characterized. Comparative studies of their physicochemical properties with those of the wild-type enzyme highlighted that mutant G219A displayed increased specific activity and thermal stability compared to that of the wild-type enzyme, while for G219N and G219F, these properties were considerably decreased. A double mutant, SKGI F53L/G219A, displayed a higher optimal temperature and a higher catalytic efficiency than both the G219A mutant and the wild-type enzyme and showed a half-life time of about 150 min at 85 °C as compared to 50 min for wild-type SKGI. Crystal structures of SKGI wild-type and G219A enzymes were solved to 1.73 and 2.15 Å, respectively, and showed that the polypeptide chain folds into two structural domains. The larger domain consists of a (β/α)8 unit, and the smaller domain forms a loop of α helices. Detailed analyses of the three-dimensional structures highlighted minor but important changes in the active site region as compared to that of the wild-type enzyme leading to a displacement of both metal ions, and in particular that in site M2. The structural analyses moreover revealed how the substitution of G219 by an alanine plays a crucial role in improving the thermostability of the mutant enzyme. 相似文献
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99.
Hajer Khemaissia Raja Jelassi Catherine Souty‐Grosset Karima Nasri‐Ammar 《African Journal of Ecology》2018,56(1):38-50
In Tunisia, while wetlands are considered as remarkable habitats for their faunal and floral diversity, few studies on the biogeography and the diversity of terrestrial isopods were performed. To fill this gap, we carried out a field study in the supralittoral zone of 146 Tunisian wetlands belonging to eight types (lagoon, river, lake, sebkha, dam, hill reservoir, beach and chott) and to five bioclimatic zones (humid, subhumid, semi‐arid, arid and Saharan). Field work was carried out in spring 2010. Terrestrial isopods were collected in the morning by hand search each time with the same sampling effort. During the study, 22 species of terrestrial isopods belonging to nine families were collected. Porcellio variabilis, Porcellio laevis, Chaetophiloscia elongata and Armadillidium pelagicum are the most common species identified. From the northern to the southern regions, a gradual decrease in species richness has been shown. The identified species belonged to different biogeographical categories: Mediterranean, Mediterranean‐Atlantic, North Africa with circum‐Sicilian islands, semi‐arid and Saharan species. Some of these species are endemic to Tunisia (Porcellio dominici) or to North Africa (Armadillidium sulcatum, Armadillidium tunisiense, Porcellio marginenotatus and P. variabilis). Terrestrial isopod species differ according to wetland type and bioclimatic zone. 相似文献
100.
Imen Jaballi Hajer Ben Saad Intidhar Bkhairia Boutheina Cherif Choumous Kallel Ons Boudawara Michael Droguet Christian Magné Ahmed Hakim Ibtissem Ben Amara 《Biological trace element research》2018,184(1):99-113
The current study aimed at evaluating the ability of a mineral and antioxidant-rich extract from Chondrus canaliculatus to improve maneb (MB)-induced toxicity in adult rat. The animals were divided into four groups: group 1 used as a control group, group 2 received MB, group 3 received MB + C. canaliculatus extract, and group 4 received only the algal extract. MB, a Mn-containing ethylene-bis-dithiocarbamate fungicide, induced oxidative stress damages, mineral perturbations in the plasma, urine, and bone, and genotoxicity in rats. Hematological analysis revealed in the MB-treated group a disruption in the number of red blood cells, platelets, and white blood cells associated with a striking genotoxicity. Interestingly, a significant increase in malondialdehyde and advanced oxidation protein product levels in erythrocytes and bones were found. On the other hand, an impairment of the antioxidant status in both tissues was occurred. Along, our results revealed that MB injection caused a striking drop and disruption in bone’s mineral rates, especially calcium and phosphorus. These biochemical results were in accordance with the histological and molecular changes. However, co-treatment with C. canaliculatus extract showed, for the first time, that this alga was effective against MB-induced hematotoxicity, genotoxicity, and oxidative stress in the blood and bone and maintained osteomineral metabolism and bone histo-architecture. Such observations might be explained by the strong in vitro antioxidant and antibacterial activities exhibited by the alga, as well as by its high levels in several minerals: calcium, phosphorus, sodium, potassium, magnesium, iron, and zinc. 相似文献