الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Biodiversity provides the essential resources on which communities worldwide and future generations rely. To study biodiversity and propose a plan for conservation of marine ecosystem fundamentally demand accurate species inventories. Ascidians (Pphylum: Chordata, Class: Ascidiacea) are one of the most significant individuals of the benthic organisms. Their exaggerating recruitment all over the world via their attachments to several natural and artificial substrata has substantially being boosted the biodiversity of marine ecosystem. Morphological identification of ascidian demands highly specialized experience and a frequent misidentification is occurred. MT-COI gene sequence is being used as a suitable marker for the invertebrate distinctness. In this study, Phenol-chloroform method, PCR, and CO1 sequencing were selected to elucidate the molecular identification of selected ascidians from Egypt and to display their phylogenetic relationships with other CO1 of ascidian species in the world obtained from GenBank. Constructed phylogenetic trees show that COI has ability to identify the three species to the closest taxonomic rank and determine discrimination of each geographical distribution of species. Although class of Ascidiacea has almost three thousand described species that inhabit all marine environments, nearly 120 various COI of ascidian species only recorded in NCBI databases, with several replicates for each species COI. Hence, severe deficiency in molecular information of ascidians resulted in mis-knowing of the exact biodiversity in each ecosystem.
Discovering novel drugs for curing cancer and infectious diseases is the prime interest of several research areas now. Marine sessile invertebrates have produced secondary metabolites, a lot of which are utilized as novel pharmaceutical agents with diverse effects whether anti-cancer or anti-microbial. Ascidians are marine sessile animals. Various anti-cancer, anti-viral, and anti-bacterial components were extracted and purified from different bioactive compounds of ascidians species and are in different stages of clinical trials. In this study, samples of five different ascidian species were collected from three sites in Egypt. These specimens were utilized for preparing crude extracts with using organic and inorganic solutions. Cytotoxicity assay was performed for dried extracts, besides anti-microbial tests of twelve types of various microbes. The anti-microbial activity of crude extract of ascidians showed inhibitory activity against some of used bacteria and fungi species, and a significant cytotoxicity against breast carcinoma cells from all five ascidian species. Therefore, ascidian species are excellent species for further studies to discover new pharmaceutical agents.