Molecular characterization of a Litomosoides sigmodontis protein involved in the development of the microfilarial sheath during embryogenesis

A cDNA clone Ls110 was isolated from a female Litomosoides sigmodontis expr ession library using an antiserum raised against the microfilarial sheath. The complete cDNA encodes a protein (Ls110) of 382 amino acids. Southern an d PCR analyses revealed the presence of Ls110 in L. sigmodontis as a single copy gene. The transcription of the Ls110 gene was limited to female worms . In these worms the transcription was confined to the epithelial cells of the uterus. The protein Ls110 was detected not only in the epithelial layer of the uterus but also secreted in the lumen of the uterus. All the intra- uterine embryonic stages showed the protein bound to their egg shell:sheath , except the early multicellular embryonic stages and fully developed micro filariae. The transient occurrence of Ls110 on these structures of intra-ut erine stages besides the presence of a cysteine-rich N-terminal region (SXC -like domain) suggest that the protein may play a role in the formation of the microfilarial sheath during embryogenesis. (C) 2000 Elsevier Science B. V. All rights reserved.