Search In this Thesis
   Search In this Thesis  
العنوان
GENOTYPING OF PLANKTON USEFUL FOR
FEEDING COMMON EGYPTIAN MARINE
FISHES AND THEIR FRIES /
المؤلف
ELSAYED, HANY TOLBA ABU-TALEB.
هيئة الاعداد
باحث / HANY TOLBA ABU-TALEB ELSAYED
مشرف / Mohamed Abdel-Salam Rashed
مشرف / Mahmuod Ahmed Abd Elhafiez Sallam
مناقش / Hussein Mohamed Attia Elghobashy
تاريخ النشر
2018.
عدد الصفحات
211 P. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
الزراعية والعلوم البيولوجية (المتنوعة)
تاريخ الإجازة
1/1/2018
مكان الإجازة
جامعة عين شمس - كلية الزراعة - قسم الوراثة
الفهرس
Only 14 pages are availabe for public view

from 211

from 211

Abstract

This study was carried out in the Department of Genetics, Faculty of Agriculture, Ain Shams University, Shoubra El Kheima, Cairo, Egypt and laboratories of the Department of Genetics and Genetic Engineering, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt during the period from 2013 to 2018.
This study presented a complete profile for phylogenetic diversity of gut microbiome of two life stages, adult and fingerlings, of M. cephalus, at a Mediterranean estuary. The present investigation is carried out with three main parts as follow:
A- Sampling was assembling of Ashtum El-Gamil estuary that is the main entrance of estuarine water between the Mediterranean and Manzala Lake.
B- The study was based on two culture-independent rRNA gene analyse approaches, PCR/Cloning and PCR/DGGE approach.
C- Exploring the diversity of gut microbiome in mullet fishes was an important for understanding fish feeding metabolism and health.
M. cephalus, inhabiting El-Gamil estuary, Manzala Lake, Egypt, was studied, based on PCR/Cloning and PCR/DGGE sequencing approach of rRNA genes for the three domains, eukaryotes, bacteria and archaea as follow:
1- The PCR/Cloning approach recorded 21 phylotypes of eukaryote 18S rRNA gene, 18 phylotypes of bacterial 16S rRNA gene and 17 archaeal 16S rRNA gene phylotypes, in the guts of adults. The guts of fingerlings harbored 7 and 13 eukaryote 18S rRNA gene phylotypes and bacterial 16S rRNA gene phylotypes, respectively, based on PCR/Cloning approach.
2- The DGGE profiles displayed 10 and 4 phylotypes of 18S rRNA gene in gut contents of adults and fingerlings, respectively, with respect to 4 phylotypes, which shared gut contents of adults and fingerlings. Six specific DGGE phylotypes of bacterial 16S rRNA gene were recorded in gut contents of each of adult and fingerling stages with respect to 3 phylotypes, which shared gut contents of adults and fingerlings.
3- Both of two approaches, PCR/Clonining and PCR/DGGE confirmed the excistence of archaeal-like phylotypes in guts of only adults.
Phylogenetic analyses uncover zooplankton-like phylotypes as a dominant eukaryote fraction in the guts of both adults and fingerlings. Proteobacteria and cyanobacteria-like 16S rRNA gene phylotypes were dominated in the guts of adults. The bacteroidetes-like phylotypes characterized the guts of fingerlings. The PCR cloning approach indicated showed the guts of adult’s harboured archaeal-like phylotypes in the branch of thaumarchaeota, a phenomenon that has not been recorded before and gave us an evidence for the dissemination of this phylum in the guts of fishes. The studied fish guts may considered as a reservoir for geographic distant species, including Lessepsian species, with respect to some core gut microbiota. Also, the pollution in the estuary could shape a fraction of the studied fish gut microbiota. PCR/DGGE approach could uncover phylotypes belonging to Adelina dimidiate and Enterobacter agglomerans in guts of fingerlings, implicating existence of pathogens.
CONCLUSION
Both of PCR/Cloning and PCR/DGGE approaches could reveal almost the total composition of rRNA gene phylotypes in guts of adults and fingerlings of current mullet species, M. cepahlus. The used molecular approaches could illustrate the ability of mullet guts to harbor diverse communities, including unique species, from the three domians, eukaryotes, bacteria and archaea. Also, the current molecular approaches were useful in screening benefecial and harmful mullet gut microflora. Finally, the study could introduced complete profiles for uncultured mullet gut microbiome and open a new window towards understanding the impact of gut flora on health of mullet living in Egyptian Estuaries.
Advanced molecular studies based on Next Generation Sequencing, NGS is needed to expand the exploration of the diversity of gut microbiome and uncover new microbial phylotypes that may affect the growth and health of different life stages of mullet species. Also, future studies are needed to understand the biological significance of all recorded gut microbiota, especially those of belonging to thaumarchaeotes.