Morphological and molecular identification of Nematodirus species (Nematoda, Molineidae) from domestic ruminants in Uzbekistan

Abstract

The species composition and distribution of the genus Nematodirus ha ve not been studied in Uzbekistan for a long time , even though nematodes are widespread in the digestive tract of domestic and wild ruminants and are one of the main components of the Molineidae fauna . The article presents the results of a study on the morphometric and molecular analysis of the genus Nematodirus Ransom, 1907 , nematode s of the digestive system of ruminant ungulates living in the territory of Uzbeki s tan. In the study, the species of Nematodirus identified from domestic sheep and goats can mainly be distinguished by the shape of the male spicules and the structure of the bursa. Nematodirus abnormalis can be distinguished from other species because the tip of the spicule is slightly curved and covered with an asymmetrical lanceolate membrane, N. oiratianus has a fused tip and a thin tube-like shape, and N. spathiger has a slightly curved distal tip of the spicule. Furthermore, based on the nucleotide sequence results of the rDNA ITS-2 region, the N. abnormalis samples studied were found to match Nematodirus sp. in the GenBank database, while the N. oiratianus and N. spathiger samples were 98 – 99% similar to the respective species. Phylogenetic analysis using ITS-2 nucleotide sequences revealed that N. oiratianus and N. abnormalis are closely related and sister species and N. spathiger and N. helvetianus are also phylogenetically close. The species N. abnormalis w as deposited for the first time in the GenBank database