Schistosoma mansoni and S. japonicum Worm Numbers in 129/J Mice of Two Types and Dominance of Susceptibility in F 1 Hybrids

Abstract

In a study on the genetics of resistance to schistosomiasis in WEHI 129/J mice, susceptibility to either Schistosoma mansoni or Schistosoma japonicum was shown to be unequivocally dominant in F1 hybrid crosses between genetically resistant WEHI 129/J and susceptible BALB/c mice. The operation of only 1 or 2 genes in the expression of resistance to S. mansoni was suggested by backcross analysis. Thus, approximately 25% of (BALB/c x WEHI 129/J) F1 x WEHI 129/J mice were resistant to S. mansoni infection, whereas resistance was manifest in approximately 50% of WEHI 129/J mice. The data are consistent with resistance being controlled by 1 recessive gene having 50% penetrance. We also report that 129/J mice obtained directly from the Jackson Laboratories (Bar Harbor, Maine) (designated JAX 129/J), differ from locally bred WEHI 129/J in being entirely susceptible to S. mansoni infection. However, both WEHI 129/J and JAX 129/J are relatively resistant to S. japonicum infection.

Further studies on variable resistance of 129/J and C57BL/6 mice to infection with Schistosoma japonicum and Schistosoma mansoni

“…However, their offspring bred at WEHI resemble WEHI 129/J mice in that many demonstrate a shunting of microbeads. Whether all mice bred in the Jackson Laboratory and maintained for some time at WEHI remain permissive with an intact hepato-portal system is doubtful as in a previous study (Wright et al 1988b) evidence of resistance in some mice was obtained. What is entirely clear, however, is that 129/J mice purchased from the Jackson Laboratory resemble other mouse strains and show no hepato-portal system defects, no immunological disturbances and no resistance to schistosome infection (Fanning & Kazura 1984;van Snick & Masson 1980;D.Bout, E.Skamene and G.F.Mitchell, unpublished observations).…”

“…In contrast, a proportion of C57BL/6 mice (2/7) (group 2, Table 2) failed to trap the beads in the liver, the injected beads being found in the lungs. 129/J mice obtained from the Jackson Laboratories are of interest (Fanning & Kazura 1984, Wright et al 1988b). 129/J mice when injected with beads soon after arrival in this laboratory quantitatively trap the beads in the liver (1 1 mice, group 4 in Table 2).…”

“…The maintenance of S . japonicum (Sorsogon, Philippines) and S. mansoni (Puerto Rico) in Oncomelania hupensis quadrasi and Biomphalaria glabrata snails, respectively, has been described (Wright et al 1988b). Anaesthetized mice were exposed percutaneously to either 15 or 20 S. japonicum cercariae or 100 S. mansoni cercariae per mouse.…”

Attempts to induce resistance in mice to Schistosoma japonicum and Schistosoma mansoni by exposure to crude schistosome antigens plus cloned glutathione‐S‐transferases

“…The maintenance of the lifecycles of S. Japonicum (Philippines) (Sorsogon isolate) in Oncomelania hupensis quadrasi and S. mansoni (Puerto Rico) in Biomphalaria glabrata have been described in detail (6). For routine exposure, anaesthetized mice in dorsal recumbency were given 20 cercariae per mouse (dm) of 5. japonicum or 100 c/m of S. mansoni applied to the shaved abdomen.…”

“…For routine exposure, anaesthetized mice in dorsal recumbency were given 20 cercariae per mouse (dm) of 5. japonicum or 100 c/m of S. mansoni applied to the shaved abdomen. Worm burdens were determined 40-60 days after challenge using standard perfusion procedures (6) and expressed as the arithmetic mean ± standard error of the mean. Cercariae in water, shed from B. glabraia or following crushing of O. h. quadrasi, were irradiated in an Eldorado 6 teletherapy unit (Atomic Energy of Canada, Commercial Products) charged with 5000 Ci of ^^Co at a dose rate of about 8 Gy/min for a total dose of 300 Gy (i.e.…”