Three new phenotypes of human erythrocyte acid phosphatase (ACP1) have been detected and found to be unique by direct comparison with previously identified ACP1 variants. One of these new electrophoretic variants, labeled as ACP1FA, has been detected in the Hispanic population of California. The electrophoretic variants identified as ACP1GA and ACP1GB have been detected in a black family in North Carolina. A family study has shown that ACP1G is transmitted as an allele of ACP1.

Chicken Lines 63 and 72 were inbred during selection for resistance or susceptibility to viral-induced tumors. A sandwich ELISA assay was adapted to define the milligrams per milliliter of Ig-gamma (IgG) in plasma from chickens of Lines 63 and 72, as well as 19 recombinant congenic strains (RCS). Each RCS resulted from a 7(2) x 6(3) F(1) and two backcross matings using 63 as the recurrent female line. The IgG levels in the RCS were evaluated after four to seven generations of sib-matings, when each RCS was becoming inbred and fixed for a different 12.5% of the 72 genome. In three generations approximately 24-wk-old chickens of Line 72 had higher levels of plasma IgG than chickens of Line 63 (P < 0.05). None of the RCS had repeatable IgG levels comparable to Line 7(2). However, in the last two generations, two of the 18 RCS had higher IgG levels than nine with low IgG levels (P < 0.05). There was no correlation between an IgG level of a RCS and resistance to Marek's disease. It was concluded that selected RCS may be useful for identifying genes that determine differences in IgG levels, as well as for understanding the relationship between genes, IgG levels, and other traits that differ between Lines 63 and 72.

Aims:  To determine whether conversion of lactocepin substrate binding regions by gene replacement can alter lactocepin specificity in Lactococcus lactis starter bacteria without affecting other important strain properties. Methods and Results:  We utilized two‐step gene replacement to convert substrate‐binding determinants in the L. lactis prtP genes encoding group h (bitter) lactocepin in two industrial strains into the corresponding group b (nonbitter) variant. Analysis of lactocepin activity toward αs1‐casein (f 1–23) by reversed‐phase high‐pressure liquid chromatography demonstrated enzyme specificity among isogenic derivatives had been altered in a manner that was consistent with predicted amino acid substitutions in substrate binding regions. Milk acidification properties of some mutants were not statistically different (P > 0·05) from wild‐type parent strains, and strain propensity for autolysis was also not significantly (P > 0·05) changed. Conclusions:  Conversion of lactocepin substrate binding regions by allele exchange can effectively alter lactocepin specificity in industrial strains of L. lactis without significantly affecting other important strain properties. Significance and Impact of the Study:  Methodology outlined in this study can be used to alter lactocepin specificity in commercial starter cultures with a propensity for bitter flavour defect, and prtP derivatives developed by this approach should be suitable for commercial application.