Two more independent selectable markers for stable transfection of Leishmania

Mol Biochem Parasitol. 1993 Nov;62(1):37-44. doi: 10.1016/0166-6851(93)90175-w.

Abstract

Genetic transformation of Leishmania has relied upon two exogenous selectable markers, neo and hyg, encoding resistance to G418 and hygromycin B respectively. There is a need for multiple independent selectable markers, since Leishmania is diploid and experimental sexual crosses are not currently feasible. Here we report on the development of two additional markers: pac, conferring resistance to the glycopeptide antibiotic puromycin, and phleo, conferring resistance to the DNA-binding drug phleomycin. We constructed a set of four analogous shuttle vectors with these four markers, using DNA segments flanking the Leishmania major H region hmtxr gene to provide information required for expression. These constructs (pHM-NEO, pHM-HYG, pHM-PAC and pHM-PHLEO) were successfully transfected into L. major, mostly with efficiencies comparable to those observed with previous DHFR-TS-based neo and hyg-containing constructs. The exception was pHM-PHLEO, which transfected 30-fold less efficiently; this may be related to the nonenzymatic mechanism of resistance encoded by phleo. All four constructs were shown to replicate extra-chromosomally. Stable transfectants bearing all paired combinations of pHM constructs were obtained by a second round of transfection. These data show that the four markers are functionally independent and in conjunction with the Leishmania N-acetylglucosaminyl transferase gene, brings the number of selectable markers available in Leishmania to five.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • DNA, Protozoan / genetics
  • Drug Resistance / genetics
  • Genes, Protozoan
  • Genetic Markers
  • Genetic Vectors
  • Gentamicins / pharmacology
  • Hygromycin B / pharmacology
  • Leishmania major / drug effects
  • Leishmania major / genetics*
  • Molecular Sequence Data
  • Phleomycins / pharmacology
  • Puromycin / pharmacology
  • Transfection*

Substances

  • DNA, Protozoan
  • Genetic Markers
  • Gentamicins
  • Phleomycins
  • Hygromycin B
  • Puromycin
  • antibiotic G 418