Abstract

Fagr Kh. Ali , Saber A. El-Shafai, Farag A. Samhan and Wagdy K.B. Khalil

This research was aimed to study quality of water in Lake Qarun and effects of pollution on expression of immune genes in Egyptian sole (Solea aegyptiaca) fish. The study was carried out from August 2006 to the end of April 2007. The water samples were collected from different locations of Lake Qarun at Al-Oberge within an area of 200 to 1500 meter from the shore. The samples were subjected to different physical and chemical analyses. The concentration of total dissolved solids (TDS) recorded an average value of 37.8 g/l while the chloride content was 14.3 g/l on average. The corresponding value of salinity was 25.9 g/l. For the chemical oxygen demand and biochemical oxygen demand the results revealed that the average values were 98 �?� 22 mg O2/l and 8.0 �?� 2.1 mg O2/l for the chemical oxygen demand (COD) and biochemical oxygen demand (BOD), respectively. Analyses of nitrogen group indicated presence of low concentrations of all. For total pesticides which might be one of the most potential pollutants in the lake, the results showed an average value of 0.62 mg/l. Furthermore, the total viable bacterial count (TVBC) ranged from 103 colony forming unit (CFU) in the middle of the Lake to 107 (CFU) near the shore. Stressed total coliform group (STC), stressed faecal coliform group (SFC) and stressed faecal streptococci group (SFS) increased from the middle of the Lake to the shore. The differential expression of the immune genes, that is, GARP and SIMP genes, as a result of pollution influence was further confirmed by RT-PCR, with the up-regulation of these genes in the liver of the collected fish. The application of the expression of the immune genes of fish might be time safe and cost effective in case there are different source of pollution.