Sequence variation and detection of a functional promoter polymorphism in the lysozyme c-type gene from Ragusano and Grigio Siciliano donkeys

Lysozyme is an antimicrobial agent in milk and inhibits growth of pathogenic bacteria.1,2 The vertebrate lysozyme gene family includes at leat three groups of genes: lactalbumin alpha (LALBA), lysozyme-like (LYZL*) and lysozyme (LYZ).3 The latter is the most studied in human, camel, ruminants and equine milk.4 Donkey milk contains 1.0 mg/ml OF lysozyme c, a higher concentration than in milk from ruminants (traces) and humans (0.12 mg/ml).5 Although genetic variants have been already reported in donkey LYZL*, 6 so far no information is available on the molecular variation for the LYZ locus in this species. In the present study, we report molecular variation of the donkey LYZ gene and the detection of functional polymorphisms. Blood samples were collected from 27 donkeys of two breeds (15 Ragusano and 12 Grigio Siciliano), and DNA was extracted. Using primers designed on donkey genome sequence (GeneBank NW_014638180.1, complement 1781536...1786728),