The genetic regulation of liver microsomal CYP2E1 activity among strains of the viviparous fish Poeciliopsis.
CYP2E1 expression was examined within, among, and in F(1) and backcross progeny of strains (P. monacha S68-5; P. viriosa M65-23) of the viviparous fish Poeciliopsis. CYP 2E1 activity varied dramatically in P. monacha, and P. viriosa (3.9+/-0.8 and 9.6+/-1.3 microg/min/mg) as well as the temperature which gave maximal activity (T(0)=25 degrees C and 31 degrees C). F(1) individuals from a crosses between P. monacha and P. viriosa, produced progeny whose CYP2E1 activity segregated into three different groups: (1) phenotypically the same as P. viriosa; (2) intermediate between the two parental strains; and (3) phenotypically the same as P. monacha. When a male P. monacha was crossed with a female P. viriosa 25% of the offspring had an intermediate phenotype and 65% the maternal P. viriosa phenotype. From the same cross, 85% of the females progeny had the maternal phenotype, while 80% of male progeny had the intermediate and paternal phenotype, suggesting an effect of the maternal genome on the F(1) phenotype. Among F(1) fish the T(0) was evenly distributed between parental values. In the backcross of a F(1) female to a male P. viriosa, CZX-6-hydroxylase activity segregated into the same three phenotypes with 60% of the progeny expressing the P. monacha phenotype. From the same cross, 70% of females and 40% of males expressed the P. monacha phenotype. The T(0) in the backcross were evenly distributed between the two parental values and the sex ratio among progeny was different than expected.
Department of Environmental Science, Teikyo Post University, Waterbury, CT, USA.
L A
LA
Kaplan
E
E
Fielding
J F
JF
Crivello
D000818:Animals; D003532:Cyprinodontiformes / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D013045:Species Specificity
D019392:Cytochrome P-450 CYP2E1