RESUMEN
Lysozyme degrades the bacterial cell walls and gives rise to degradation product that stimulates and activates the immune system. Several gram positive and gram negative bacteria were found to be susceptible to different degree of purified lysozyme. Variation in promoter region may regulate the expression of a particular gene. Hence, considering lysozyme gene a potential marker for general immune response, expression pattern of various genotypes on the basis of variations in promoter region is investigated in Muzaffarnagri sheep. A 268 bp fragment spanning partial promoter, exon 1 and partial intron 1 of serum lysozyme gene were amplified and sequenced. Sequencing revealed five genotypes AA, AB, AC, BB and CC and consequently three alleles A, B and C in Muzaffarnagri sheep. Differential expression study of various genotypes by real time pcr revealed significant difference (P≤0.05) in the serum lysozyme expression in animals having different genotypes. Animals having AA genotype showed higher expression of serum lysozyme than the animals having AB, AC and BB genotype.