الفهرس 
Geographical description
Tilapia gut microbiotaOnly 14 pages are availabe for public view
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Abstract
Mai Abdel Monem Mohamed Wassel: Molecular Identification of
Planktonic Meals for Tilapia Species based on rRNA Gene Analyses.
Unpublished M.Sc. Thesis, Department of Genetics, Faculty of
Agriculture, Ain Shams University, 2016.
The diversity of Oreochromis niloticus gut microbiome domains,
eukaryotes, bacteria and archaea, was studied in order to understand the
contribution of these microbiotas to the health of the fish in four different
Khors, Kalabsha, Wadi Abyad, Tushka and Korosko, Lake Nasser, Egypt.
The approach of this study based on culture-independent PCR/DGGE and
sequence of small subunit of rRNA genes, eukaryotic 18S rRNA gene and
prokaryotic, bacterial and archaeal, 16S rRNA genes. The DGGE
patterns displayed 5, 12 and 5 band groups, phylotypes, for eukaryotic
18S rRNA gene, bacterial and archaeal 16S rRNA genes, respectively, in
fish gut contents from all studied khors. DGGE showed rRNA gene
bands, which were common and specific for each site and could be used
as barcodes to certify the origin of the fish. Statistical analyses, using
binary matrix, showed that numbers of DGGE bands, 1, 2 and 2, for
eukaryotes, bacteria and archaea, respectively, were commonly occurred
in all studied khors. The DGGE phylotype, 3.Euk.Kr characterized
eukaryotes in Khor Korosko. Phylogenetic analyses showed that two of
eukaryotic phylotypes, 1.Euk.Kl.Kr and 2.Euk.Common, were belonged
to crustacean, Ostracoda, of the genera Darwinula and Vestalenula. Some
helminths, of the genera Neoechinorhynchus and Catenula, -like rRNA
gene phylotypes were recorded in guts from Kalabsha, Tushka and
Korosko, suggesting common gut parasitic worms. Cyanobacteria-like
phylotypes were recorded in gut contents from all studied khors. Most
bacteria-like phylotypes constituted unique phylogenetic lineages within
the branch of uncultured environmental bacteria. All archaeal phylotypes
were located in the branch of methanogenic uncultured Euryarchaeota.
The similarity index analysis of the DGGE gel patterns indicated that the
eukaryotic composition in Kalabsha and Tushka had similarity, 75% with
Jaccard and 86% with Dice. Also, the eukaryotic phylotype compositions
of guts from Korosko and Tushka showed similarity, 20% with Jaccard
and 33.3% with Dice. The bacterial phylotype compositions of Wadi
Abyad and Tushka were the most similar to each other among studied
khors with similarity percentage of 90% with Jaccard and 94% with Dice,
while Wadi Abyad and Korosko showed low similarity 27.3% with
Jaccard and 42.9% with Dice. Archaeal phylotype compositions were
similar in all studied khors. The DGGE patterns and sequence analyses
showed some similarities of eukaryote, bacteria and archaea rRNA gene
phylotype compositions in fish guts from distant khors, implicating
existence of core gut microbiome. This is the first phylogenetic survey of
all microbiome domains in tilapia guts at Lake Nasser.
Keywords: Lake Nasser; Oreochromis niloticus; DGGE; rRNA;
Phylogenetic analyses