Duodenases are a small subfamily of ruminant intestinal serine proteases that have undergone a remarkable diversification in cleavage specificity

Ruminants have a very complex digestive system adapted for the digestion of cellulose rich food. Gene duplications have been central in the process of adapting their digestive system for this complex food source. One of the new loci involved in food digestion is the lysozyme c locus where cows have ten active such genes compared to a single gene in humans and where four of the bovine copies are expressed in the abomasum, the real stomach. The second locus that has become part of the ruminant digestive system is the chymase locus. The chymase locus encodes several of the major hematopoietic granule proteases. In ruminants, genes within the chymase locus have duplicated and some of them are expressed in the duodenum and are therefore called duodenases. To obtain information on their specificities and functions we produced six recombinant proteolytically active duodenases (three from cows, two from sheep and one from pigs). Two of the sheep duodenases were found to be highly specific tryptases and one of the bovine duodenases was a highly specific asp-ase. The remaining two bovine duodenases were dual enzymes with potent tryptase and chymase activities. In contrast, the pig enzyme was a chymase with no tryptase or asp-ase activity. These results point to a remarkable flexibility in both the primary and extended specificities within a single chromosomal locus that most likely has originated from one or a few genes by several rounds of local gene duplications. Interestingly, using the consensus cleavage site for the bovine asp-ase to screen the entire bovine proteome, it revealed Mucin-5B as one of the potential targets. Using the same strategy for one of the sheep tryptases, this enzyme was found to have potential cleavage sites in two chemokine receptors, CCR3 and 7, suggesting a role for this enzyme to suppress intestinal inflammation.

Assessment of Immunostimulatory Characteristics of Achyranthes aspera Seeds and Leaves Supplemented Diets in Labeo rohita Fingerlings

The effect of dietary supplementation of leaves and seeds of Achyranthes aspera on rohu, Labeo rohita fingerlings was evaluated. Three experimental diets containing 0.25 (D1) and 0.5% (D2) leaves and 0.5% (D3) seeds of A. aspera and control diet (D4) without plant ingredients were formulated. After 45 days of feeding, rohu were immunized with 20% chicken RBC. Tissue and blood samples were collected on days7, 14 and 21 after immunization. Dietary supplementation significantly (P<0.05) increased the average weight and specific growth rate of rohu. Serum lysozyme, myeloperoxidase, hemagglutination titer and nitric oxide synthase activities were significantly (P<0.05) higher in D3 compared to others. This group was followed by D2 and D1. Significantly (P<0.05) lower lipid and protein oxidations were found in D3 compared to others. This group was followed by D2 and D1. In hepatopancreas, lysozyme C, lysozyme G, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) expressions were up-regulated while interleukin-10 (IL-10) expression was downregulated. In anterior kidney, lysozyme C, lysozyme G and IL-10 expressions were upregulated while TNF-α and IL-1β expressions were down-regulated. The dietary inclusion of leaves and seeds of A. aspera enhanced the growth, improved immune system and reduced oxidative stress of rohu.