56 Folia Zool. – 58 (Suppl. 1): 56–64 (2009) Urinary lipocalins in Mastomys coucha Kristina DANISZOVÁ 1 , Kateina jANOtOVÁ 1 , Petr L. jEDELSKÝ 2 and Pavel StOPKA 1 * 1 Department of Zoology, Faculty of Science, Charles University in Prague, Viničná 7, Prague, 128 44, The Czech Republic; e-mail: pstopka@natur.cuni.cz 2 Department of Cell Biology, Faculty of Science, Charles University in Prague, Viničná 7, Prague, 128 44, The Czech Republic Received 1 December 2008; Accepted 1 April 2009 Abstract. the presence of large amounts of proteins in mammal urine is usually associated with a pathological condition and indicates serious renal lesions. However, there are few species with obligate proteinuria indicating that they must derive some benefit from this condition. Urinary proteins have been most extensively studied in the house mouse and the rat, and findings to date indicate that their function in intraspecific communication is complex and not yet fully understood. Other proteins of the same protein family as MUPs have been also found in urine of some other rodent species, and still less is known about these. In this study we demonstrate the existence of urinary lipocalins in Mastomys coucha for the first time. Our results support the hypothesis that urinary proteins may play an important role in chemical communication in species other than mice and rats. Information about the presence, concentration, and level of polymorphism of these proteins in different rodents may help us to understand their specific function. Key words: Major Urinary Protein, chemical communication Introduction Mouse major urinary proteins (MUPs) were discovered in 1932 by Parfentjev who noticed a high normal proteinuria in laboratory mice. Urinary MUPs originate in the liver, from which they are released to the plasma and promptly excreted in the urine (Finlayson et al. 1965). the concentration of these proteins has been shown to reach several milligrams per millilitre of urine in male mice, although females often excrete MUPs in substantially lower concentrations. thus MUP expression is sexually dimorphic as a consequence of the regulation by androgens especially testosterone (W i c k s 1941, t h u n g 1956). MUP expression has also been detected in several glandular tissues (S h a w 1983, S h a h a n et al. 1984, S h a h a n et al. 1987 a,b, U t s u m i 1999), although we focus here mainly on those excreted in the urine. Major urinary proteins belong to the lipocalin protein superfamily. Members of this class are characterised by an eight-stranded β-barrel which incorporates a central hydrophobic cavity (B o c s k e i et al. 1992, Flower 1996, Z i d e k et al. 1999). this cavity allows binding and transport of different ligands, which is the general function of the lipocalins including MUPs (F l o w e r 1996). Ligands associated with urinary MUPs are hydrophobic endogenous semiochemicals, a number of which is known to have pheromonal effects (j e m i o l o et al. 1985, 1986, B a c c h i n i et al. 1992, R o b e r t s o n et al. 1993, N o v o t n y et al. 1999 a,b). For a long time, MUPs were considered a metabolic curiosity (H o f f m a n 1970) and it took several decades from their discovery to proposing their possible function. * Corresponding author