Temporal expression of neurospora crassa tyrosinase gene under the control of glucose-repressible gene-1 (GRG-1)‎ promoter

العناوين الأخرى

التعبير الزمني لموروثة التايروسنيز في عفن Neurospora crassa تحت مراقبة محفز الموروثة المعطلة بالجلوكوز (Grg-1)‎

مقدم أطروحة جامعية

Ulaywi, Nadiyah Bin al-Din

مشرف أطروحة جامعية

al-Tarawinah, Khalid Ahmad

أعضاء اللجنة

Khulayfat, Khalid Muhammad
Umar, Sharaf Sharif
al-Mustafa, Ahmad Husayn Husayn

الجامعة

جامعة مؤتة

الكلية

كلية العلوم

القسم الأكاديمي

قسم الأحياء

دولة الجامعة

الأردن

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2008

الملخص الإنجليزي

n this study a chimeric glucose- repressible gene-1/tyrosinase gene (Grg-1/tyrosinase) was used.

This chimeric gene contains 1.558kb fragment of Neurospora crassa Grg-1 regulatory region upstream of the tyrosinase coding region.

This 1.558 kb fragment of Neurospora crassa Grg-1 5' region controls the expression of Neurospora tyrosinase in a glucose-repressible manner.

The level of the tyrosinase enzyme increases about 5 fold in absence of glucose in the extra-cellular medium compared to that in the presence of glucose.

This highest level is reached within 2 hours after the shift from medium containing glucose to medium without glucose.

The level of tyrosinase enzyme returns to the basal level of expression with less than 10 minutes following the shift of fungus mycelia from medium without glucose to medium with glucose.

High ratio of the expression of the tyrosinase in absence of glucose to that in presence of glucose is obtained with 3% and 4% glucose concentration in the extracellular media.

The glucose repression is obtained with a minimum glucose concentration as much as 1% in the growth media.

The level of the expression of the endogenous tyrosinase gene is very low and does not respond to the glucose repression effect.

The repression of tyrosinase expression under grg-1 regulatory region was not obtained with other carbon sources such as arabinose, sorbitol, xylose, glycerol, starch, maltose, ribose, manitol, sucrose, lactose and fructose.

In the developmental stages: conidia and mycelia the expression of the tyrosinase gene is repressed by glucose in both stages.

The level of the expression of the tyrosinase enzyme in presence of glucose in the conidia is higher than that in the mycelia.

However, in the absence of glucose the level is higher in the mycelia than that in conidia.

The Grg-1/ tyrosinase gene is regulated by biological clock with a period length close to 20 hours.

التخصصات الرئيسية

الأحياء

الموضوعات

• علم الوراثة
• الأمراض
• الاضطرابات الوراثية

عدد الصفحات

60

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-298483