Characterization of DNA sequences that confer complement resistance in Leishmania chagasi.
Serial passage of axenically cultured Leishmania chagasi promastigotes results in a progressive diminution in resistance to complement-mediated lysis (CML), whereas high CML resistance is seen in infectious metacyclic promastigotes from the sandfly vector as well as metacyclic-like promastigotes within low-passage cultures at stationary growth phase. As we previously reported, in a screen seeking to identify novel genes involved in CML resistance: (1) a genomic cosmid library derived from DNA of CML-resistant L. chagasi promastigotes was transfected into high-passage (constitutively CML-sensitive) L. chagasi promastigotes; (2) transformants were screened for acquisition of CML-resistance; (3) multiple cosmid-transfectants exhibited partial CML resistance; and (4) the sequence for one of the cosmids (Cosmid 51) was determined. This report extends the analysis of Cosmid 51, and identifies by deletion analysis a subregion of the cosmid insert that is critical to the CML-resistance phenotype of Cosmid 51 transformants. We also report the sequence determination and initial CML-resistance activity of another cosmid that also confers partial resistance to CML.
Dahlin-Laborde
Rebecca R
RR
Department of Veterinary Pathology, Iowa State University, Ames, Iowa, USA.
Scolaro
Eric J
EJ
Romine
Nathan M
NM
Ramer-Tait
Amanda E
AE
Lei
Soi Meng
SM
Beetham
Jeffrey K
JK
D000818:Animals; D003165:Complement System Proteins / Q000502:physiology*; D003360:Cosmids; D016054:DNA, Protozoan / Q000235:genetics*; D007891:Leishmania / Q000235:genetics*
D016054:DNA, Protozoan; D003165:Complement System Proteins