الفهرس 
المقدمةيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
In the present study, a total of twelve species of family Cyprinidae namely Labeo niloticus, Labeobarbus bynni, Enteromius prince, Labeobarbus werneri (Cyprininae), Raiamas senegalensis, Leptocypris niloticus, Lobeo annectens, Chelaethiops bibie, Garra dembeensis, Ctenopharyngodon Idella, Hypophthalmichthys molitrix and Cyprinus Carpio(Cyprininae).were collected from River Nile at Assiut city, Egypt, and transported into the laboratory to investigate:
1- The morphological diversity and taxonomic status among the tested species.
2- The genetic diversity among the tested species using SCoT and ISSR markers.
3- The differences between males and females of two economically valuable species namely L. niloticus and L. bynni at molecular levels using SCoT and ISSR markers.
The collected live specimens were subjected to morphological and molecular genetic analyses as following.
1. Morphological analysis:
A total of three morphometric measurements viz, stander length (SL), total length (TL), and body depth (BD) as well as seven meristic measurements viz, number of dorsal-fin rays, number of pectoral-fin rays, number of pelvic-fin rays, number of anal-fin rays, number of caudal-fin rays, number of barbels, and number of scales on the lateral line (LL) were taken on the left said of the collected specimens. The data were then analyzed using ANOVA and multivariate analysis.
2. Genetic diversity analyses:
The DNA was isolated from the dorsal fin tissues from ten individuals (five males and five females) from each species to prepare the bulked genomic DNA samples to be used for genetic diversity study among the tested species. However, to investigating molecular sex differences between males and females of L. niloticus and L.bynni, the DNA was isolated from the dorsal fin tissues from five males and five females from each species to prepare the bulked genomic DNA sample for each gender in the tested species, respectively.
Both markers tested were useful and effective to generate enough number of bands to discriminate among the tested species, and it is recommended to be used in fish genetic diversities studies in the future
The morphological traits analysis based-dendrogram separated the tested species into two main clusters. The first cluster contains of (L. niloticus, L. bynni, C. carpio, C. Idella and H. molitrix). While, the second cluster contains the other tested species (Lobeo annectens, C. bibie, L*. niloticus, R.senegalensis, G. dembeensis L. werneri and E. prince). The SCoT marker analysis based-dendrogram separated the tested species into three main clusters. the first main cluster consisted of L. niloticus, L. bynni and L*. niloticus. The second main cluster included most of the species in this study, (i.e., E. prince, L. werneri, L. annectens, C. idella, C. carpio, H. molitrix, C. bibie and G. dembeensis). While, R.senegalensis was placed solely in the third main cluster. On the other hand, the ISSR marker analysis based-dendrogram separated the tested species into three main clusters. The first cluster contains L. niloticus and L. bynni while, the second cluster included most of the species tested in this study (i.e., E. prince, L. werneri, L. annectens, C. bibie, G. dembeensis, H. molitrix, C. carpio and C.idella). The third main cluster consisted of R. senegalensis and L*. niloticus. The combined SCoT and ISSR markers analysis based-dendrogram separated the tested species into two main clusters. The first cluster contains (L. niloticus, L. bynni and L*. niloticus). While, the second cluster contains the other tested species. The combined molecular markers and morphological traits analysis based-dendrogram separated the tested species into two main clusters. The first cluster contains (L. niloticus, L. bynni, C. carpio, C. Idella and H. molitrix), while the second cluster contains the other tested species. In general, the large size fish species grouped together, while the small size fish species grouped together. Both of L niloticus and L. bynni, L. werneri and E. prince, and the carp species grouped together. Moreover, considering all the tested species, the SCoT marker analysis-based dendrogram separated the tested species in a pattern was more similar to that generated from the morphological traits analysis compared to the ISSR marker analysis-based dendrogram.
Regarding molecular sex differences between males and females of L. niloticus and L. bynni, both markers tested successfully generated number of possible specific bands for males and/ or females with the bulked DNA samples of the tested species. However, SCoT marker was more efficient than ISSR marker by showing higher number of possible sex-specific bands in the two tested species. SCoT primers were able to generate 7 and 4 possible male-specific bands, along with 2 and 5 possible female-specific bands for L. bynni and L. niloticus, respectively. Whereas, ISSR primers generated 4 and 2 possible male-specific bands, also it generated 2 and 3 possible female-specific bands for L. bynni and L. niloticus, respectively. Interestingly, SCoT-01 primer generated unique common female specific band (690bp) which appeared only in the females of L. bynni and L. niloticus.
Finally, to the best of our knowledge, this is the first time to investigate the genetic diversity and taxonomic relationship among the tested species. The results obtained from molecular and morphological analysis in the present study will add a new insight regarding to the taxonomy issue in family Cyprinidae. Also, it is recommended to use and combined molecular and morphological analysis in fish genetic diversity studies in the future. Also, it is the first time to study the molecular sex differences using molecular markers between L. niloticus and L. bynni. Herein, both SCoT and ISSR markers were useful and effective to generate enough number of bands to discriminate among the tested species, and it is recommended to be used in fish genetic diversities studies in the future. Also, markers were able to generate possible sex specific bands in the tested species using bulked DNA samples and they can be used with other fishes. However, the possible specific bands resulted from the bulked DNA samples must be confirmed using individual samples from large number of specimens.