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Expression Profiling of Cotton Fiber Genes and Evaluation of Some Regulatory Sequences for Gene Expression in Dicots

Thesis Info

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Author

Iqbal, Nadia

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2017

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/9059/1/Nadia_iqbal_Biotechnology_HSR_QAU_2017_16.06.2017.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726173061

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Cotton fiber is the most important raw material used in textile industry throughout the world. Due to demand of good quality fiber for manufacture of fabrics, there is need to develop cotton varieties with improved fiber characteristics. Through conventional breeding, a number of cotton varieties have been developed. However, this technique has disadvantage of narrow germplasm and requirement of longer time period for selection of best lines. Using genetic engineering techniques, fiber genes may be directly introduced in cotton which may express under the control of certain promoters. Through gene expression profiles, tissue and developmental stage specific expression level of genes can be determined. Gene those have been expressed specifically in fibers or other tissues may be transformed to alter various characters. Upstream regulatory regions of theses gene may also be evaluated as promoter. Fully characterized promoters can be used as component of expression cassette for crop improvement through molecular breeding. Cotton fibers are unicellular seed trichomes and the largest known plant cells. Fiber development in cotton is a complex process involving a large number of genes expressed during each fiber development stage. The objective of the study was to determine expression level of fiber related genes in cotton. The expression level of eight fiber related genes (EXPANSIN, tubulins, LTP1, LTP3, LTP7, E6, SPS, and susy) was determined in cotton tissues using reverse transcriptase real time PCR. Three cotton (Gossypium hirsutum) lines of varying fiber length were used to study the effect of genotypes on gene expression. The results revealed that transcription level of most of genes elevated from 5 to 20 DPA fibers. All genes showed similar expression pattern in all three genotypes. However, EXPANSIN was found to be highly expressed in long fiber variety during rapid elongation period than in medium and short fiber length. Sucrose synthase showed high expression in 15-20 DPA fibers and roots. Expression data may help also to explore the role of particular gene in fiber development. On the basis of expression profiles, two genes (SPS and LTP7) were selected. Upstream sequences of both genes were retrieved through high through put genomic sequences (HTGS) and analyzed using bioinformatics tool. About 2 kb region upstream of SPS and 1.8 kb upstream of LTP7 gene were selected for promoter isolation. Patent BLAST results of SPS and LTP7 promoter sequences confirmed that both were novel regulatory regions. Analysis of both promoter sequences using plantCARE revealed basal promoter elements including TATA box and CAAT box. There were various light regulated motifs, MYB binding sites and stress related motifs. Various motifs related to transcription activation and tissue specific expression were also identified in both promoters. Analysis of promoter sequences using plantPAN identified binding sites for transcription factors including MYBS, ERELEE4, GAREAT, ABRELATERD1 and WBOXNTERF3. Both SPS and LTP7 promoters along with their deletion fragments were isolated from genomic DNA of cotton leaves. A 1.5 kb deletion fragment for SPS promoter was cloned in expression vector. Two 5′ deletion fragments for LTP7 promoter (1 kb and 1.5 kb) were also cloned. Transient GUS expression assay revealed that full length SPS and LTP7 promoters were active in fiber tissues. Deletion derivatives (1.5 kb) of both promoters showed relatively weak GUS expression in fiber tissues. However, 1 kb LTP7 promoter was highly active in fiber tissues. No GUS expression was detected in root, shoot and leaf tissues. Agrobacterium mediated transformation in tobacco revealed that SPS promoter exhibited GUS stain in tobacco leaves in the form of patches while its 1.5 kb deletion fragment showed much low expression. Full length LTP7 promoter along with 1 kb LTP7 showed high vascular tissues specific expression in tobacco leaves. The novel promoters may be used to derive fiber specific expression in cotton and vascular tissues specific expression in heterologous system. The indigenous promoters can be used for specific expression of transgenes without IPR issues.
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حدیقۃ العجائب

حدیقۃ العجائب

التحریر چوک کے ایک حصے میں ایک بڑی اور عالی شان عمارت ایستادہ تھی میں نے  دکتور محمود سے پوچھا یہ کیا ہے بولے ھذاٰ حدیقۃ العجائب ۔عجائب گھر پر نگاہ ڈالی تو مسافر کے دل میں تحریر چوک کی قدرو منزلت سوا ہو گئی جہاں عصرِ حاضر کے مصری نوجوان بہتر مستقبل کے لیے عصری فرعونوں سے نبرد آزما ہوتے ہیں اور ماضی کے فرعونوں کو بہ طور عبرت اپنی آغوش میں جگہ دی ہے ۔ عجائب گھر میں داخلے کے لیے ٹکٹ لینا ضروری تھا ۔مسافر کو اہلِ فراعنہ کی لاشوں اور لکی ایرانی سرکس کے جانوروں میںکوئی فرق محسوس نہ ہوا سچ کہا میرے رب نے ’’اب تو ہم صرف تیر ی لاش بچائیں گے تاکہ تو بعد کی نسلوںکے لیے نشانِ عبرت بنے ‘‘۔

غیر ملکیوںکے لیے یہ ٹکٹ تین سو مصری پائونڈ کا تھا مصریوں کے لیے ایک سو پچاس جبکہ مصری طالب علموں کے لیے ساٹھ مصری پائونڈ ۔ دکتور محمود نے کوئی جگاڑ لگایااورہم بغیر ٹکٹ کے اندر داخل ہو گئے عجائب گھر کی مرکزی عمارت کے سامنے ایک بہت بڑے دالان میں کچھ ٹوٹے ہوئے اور خراب مجسمے رکھے گئے تھے ،ان کے درمیان میں پیادہ روشیں بنائی گئی تھیں یہ تما م پیادہ روشیں عجائب گھر کی مرکزی عمارت تک جا کر ایک بڑے رستے کی شکل اختیار کر لیتی ہیں ۔یہاں سے ہم سیڑھیاں چڑھے تو ایک خود کار مشین کے ذریعے تلاشی بھی لی گئی ۔صدر دروازے سے گزر کر ہم ایک بڑے ہال میں داخل ہوئے۔ جہاں اہل فراعنہ کے کئی میٹر طویل مجسمے اس انداز میں رکھے گئے تھے جیسے ان کا دربار لگا ہو اور امورِ سلطنت پر اجلاس جاری ہو ۔میں نے ایک قوی ہیکل فرعونی مجسمے کے قریب جا کر دکتور محمود کوکہا...

روایاتِ اسباب النزول کے تفسیری ادب پر اثرات کا جائزہ

Sabab al-Nuzūl (cause of revelation) in Qur'anic studies means the time, context, cause, and the situation in which Allah has revealed verses. Cause of revelation has an important role in the interpretation of Qur’ān. Nevertheless, most of the verses and suras of Qur’ān are revealed independent of events, these verses are revealed to fulfill the general aim of Waḥī which is the guidance of people. Such knowledge is an invaluable tool for grasping the meaning of this type of Qur’ānic verse. Many Muslim scholars consider the studying of Asbāb alNuzūl and their related discussions as necessary. Some exegetes have written books studying the subject. The earliest and the most important work in this genre is undoubtedly Kitab Asbāb al-Nuzūl (Book of Occasions of Revelation) of ‘Alī bin Aḥmad al-Wāḥidī (d. 1075 CE). Another important work is by al-Suyūṭī (d. 1505 CE) which is a slight improvement of al-Wāḥidī’s book. In this paper descriptive method and comparative study are used to analysis traditions of revelation and their effects on Tafsīr literature. This paper proves the value of the causes of revelation in Qur’ānic Interptation and their effects on Tafsīr Literature, so that verification and authencity of traditions of causes of revelation are mandatory for Tafsīr.

Material and Design Optimization of Micro-Sensors

Measurements of three fluidic parameters i.e. velocity / flow rate / wall shear stress, pressure and temperature are crucial in many industrial applications including aerospace, automobile, bio-medical and process control etc. The key requirement is to measure these parameters at very fine spatial resolutions, which ultimately depends upon the size of measuring device. Size minimization is possible only through Micro-Electro-Mechanical Systems (MEMS) or mirco-fabrication technology. Therefore, using a novel SOI CMOS fabrication process, this thesis develops a multi-sensing platform that measures these three fluidic parameters, simultaneously.The developed chip has dimensions of just 1.6 mm × 1.6 mm as compared with the minimum chip size of 3.8 mm × 3.8 mm reported previously, thus improving the flow spatial resolution by 82.2%. The developed multi-sensing chip includes a thermal flow sensor, a piezoresistive pressure sensor and a Resistive Temperature Detector (RTD) based temperature sensor. Before integrating these sensors in a single chip, their material and design optimization have been carried out. Ashby‟s materials selection methodology has been used to select the optimum materials for these sensors. Since no MEMS compatible materials database having micro-scale material properties was readily available, therefore first a MEMS materials database has been developed and integrated with a material selection software. The developed materials database along with the derived performance indices for these sensors has then been used to select the candidate materials. Additionally, performance of these candidate materials and the variety of promising designs has also been evaluated experimentally in a two step iterative process using SOI CMOS fabrication technology. In a first iteration, eight thermal flow sensors (i.e. having square / circular membranes and four membrane to heater length ratios), six piezoresistive pressure sensors (i.e. having square membranes, three piezoresistor materials and two piezoresistor layout designs) and twelve RTDs temperature sensors(i.e. having five different materials and six layouts) have been fabricated andexperimental characterized. The best sensor of each type in the first iteration has been further improved when integrated in the final optimized multi sensing chip. The results showed that a thermal flow sensor with a silicon oxide square membrane having a membrane to heater length ratio of 3.35 has the highest sensitivity to area ratio. Similarly, a piezoresistor pressure sensor with a square membrane having p-doped silicon piezoresistors planted at the center of each membrane edges gives maximum sensitivity. The RTDs made of p-doped silicon and having higher L/W ratio exhibited the highest sensitivity and linearity. The optimized thermal, pressure and RTD sensors are much more sensitive than the previously reported such type of sensors. .It is worth highlighting that in addition to being highly sensitive, optimized sensors reported in this research are also CMOS compatible, which make them attractive considering their low cost and ease of integration with other CMOS devices, sensors and circuits.