IMMUNE RESPONSES TO BRUCELLA VACCINE AND GENETIC DIVERSITY OF SUDANESE CAMELS BREEDS

Abstract

Immunological and genetic studies were performed in Sudanese camels. The aims of the former were to determine the optimum concentration of Ficoll for separation of camel lymphocytes, and to measure the cellular immune response of Sudanese camels which were vaccinated with Brucella vaccine. The genetic studies were performed to analyze the genetic diversity and relationships between a five Sudanese camels breeds i.e. Anaffi, Arabi, Rashidi, Bishari, and Kenanni. The immunological results revealed that 10 % Ficoll concentration was efficient for separation of camel lymphocytes. The colorimetric assay which was used for measuring the degree of the proliferative response of lymphocytes to various stimulations revealed the mitogenic effect of the PHA on the camel lymphocytes. Also low stimulation indices were calculated from lymphocytes isolated from non vaccinated camels, whereas lymphocytes isolated from vaccinated camels showed high values of stimulation indices, indicating the high magnititute of cellular immunity produced in camel followed vaccination with Brucella vaccine. The genetic studies were performed in the above mentioned five Sudanese camel breeds. Genomic DNA was extracted from 128 individuals representing the five breeds. Two types of polymorphic DNAThe first type was Random Amplified Polymorphic DNA (RAPD) marker. RAPD analysis was performed by using Polymerase Chain Reaction (PCR) with one random primer to amplify the genomic DNA of different camel breeds. The primer resulted in amplification of 18 polymorphic bands in the five breeds ranged in size from 150 – 1700bp. The mean number of bands that were produced in the five breeds ranged from 5.3 – 6.9 in Anaffi and Kenanni breeds respectively. The average value of bands sharing within a breed ranged from 0.54 – 0.87 between Kenanni and Bishari individuals respectively. The values of average bands sharing between breeds ranged from 0.212 – 0.359 between Anaffi- Kenanni, and Arabi – Rashidi, respectively. The studies with eight labeled microastellite primers indicated that seven of these primers were found to be polymorphic in the five camel breeds. The eighth primer was polymorphic in four breed and monomorphic in Kenanni breed. The number of alleles generated by the eight primers in the five camel breeds ranged from 1 – 19 alleles per locus. The observed hetrozygosity ranged from 45 % - 53 % in Bishari and Anaffi respectively. Four of the microsatellite loci were found to show significant deviation from HWE in some breeds. When F statistics test was done to measure the genetic diversity among breeds, it was found that the value FIS, which measures inbreeding in subpopulation, was found to be 17.4 % . The value of FIT, which measures inbreeding in the total population, was 20.2 % , while the value of FST, which is an indication of differentiation between breeds, indicated that the five breeds were poorly differentiated with FST value of only 3.3 % .