Isoenzymes related to flight activity in Tetragonisca angustula (Hymenoptera:Apidae:Meliponinae): evidence of postranslational modification of the hexokinase and detection of new glycerol-3-phosphate dehydrogenase variants.

To detect genetic markers, electrophoretic analyses were carried out on Tetragonisca angustula, a stingless bee well adapted to its wide area of occurrence, which is becoming economically important because of the quality of its honey. Polymorphism of the enzyme hexokinase was detected and it was demonstrated that, although it presents two bands in meliponines, this enzyme is under the control of a single locus whose product probably undergoes postranslational modification. The more common allele occurs in the two Tetragonisca subspecies studied here, but the other seems to be characteristic of only one subspecies. Four variants involving the two glycerol-3-phosphate dehydrogenase loci are also described. These two enzymes share the property of presenting two electrophoretic bands, one of which is characteristic of actively flying adult thoraces.

Tolerance induction and immunological priming initiated by mucosal contacts with protein antigens in inbred strains of mice.

1. We show that mouse strains differ widely in susceptibility to tolerance induction and/or immunization (priming) following contact of protein antigens (ovalbumin, human or bovine gamma globulins) with different mucosal surfaces. 2. When compared to a control group pretreated with saline, mice pretreated by the oral (intragastric) route with antigen became significantly less responsive to subsequent parenteral immunization (i.e., tolerant). This was observed in most, but not all, antigen/strain combinations. 3. Similar, although less prominent changes were induced by pretreatments with antigen by the ocular (conjunctival) route. 4. No significant effects were observed following pretreatments by the nasal, vaginal or rectal routes. 5. Genes present in strains selected for multispecific "high" or "low" responsiveness are included among those involved in tolerance induction following mucosal contacts with protein antigens.

Genetics of susceptibility to oral tolerance to ovalbumin.

Inbred mouse strains vary widely in their susceptibility to the induction of tolerance following oral (intragastric) administration of ovalbumin. Marked differences were found between strains that form a congenic pair differing at the H-2 complex: C3H/HeJ (H-2k) and C3H.SW (H-2b)-which were very susceptible and resistant to tolerance induction, respectively. In contrast, no significant differences were found between A/J (H-2a) and A.BY (H-2b) congenics, which were both susceptible, nor among C57BL/10J congenics, which were uniformly resistant to tolerance induction. We conclude that H-2-linked genes determine tolerance susceptibility in conjunction with background genes.

Genetics of susceptibility to oral tolerance to ovalbumin

Inbred mouse strains vary widely in their susceptibility to the induction of tolerance following oral (intragastric) adminsitation of ovalbumin. Marked differences were found berween strains that form a congenic pair differing at the H-2 complex: C3H/HeJ (H-2K) and C3H.SW(H2b) - which were very susceptible and resitant to tolerance induction, respectively. In comtrast, no significant differences were found betwwwn a/J(H-2a) and A.BY (H-2b) congenics, which were both susceptible, nor among C57BL/10J congenics, which were uniformly resitant to tolerance induction. We conclude that H-2-linked genes determine tolerance susceptibility in conjunction with background genes