The secondary cytotoxic responses to the male specific antigen (H-Y) in in mice show H-2 restrictions so that cytotoxic female cells must share K and/or D end antigen with the male target cells. The production of cytotoxic cells is under the control of Ir genes, thus offering the possibility of studying the function of Ir genes in H-2-restricted cytotoxic responses. There are two kinds of Ir ge...

Hybrids were prepared between Y79 retinoblastoma (RB) and nonmalignant NIH3T3 cells and studied to confirm the presumed recessiveness of RB. Twenty hybrids containing both of the dominant gene markers, pSV2neo and pSV2GPT, initially transfected into the parent cells were isolated. All of the hybrids showed a fibroblastic morphology and anchorage-dependent growth. None of the tested hybrids or t...

Genotypes of burley (cultivars B-21 and B-49), flue-cured (line VA-81 and cultivar PD-4), and Connecticut broadleaf (cultivar C9) tobacco (Nicotiana tabacum) resistant (R) or susceptible (S) to the tobacco cyst nematode Globodera tabacum tabacum were crossed. F1 progeny of burley and susceptible broadleaf were selfed and backcrossed to produce additional progeny for evaluation of resistance in ...

Cells of Paramecium caudatum, syngen 3 usually become sexually mature about 50 fissions after conjugation. In order to study the genetic mechanisms that control fission-department expression of maturity, an attempt was made to obtain early mature mutants by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. A new cytoplasmic marker, erythromycin resistance, was used to eliminate nonconjugant ...

Immune responsiveness of inbred mice to low doses of ovalbumin or ovomucoid is under control of single dominant genes closely linked to alleles of the H-2 locus. High responsiveness to ovomucoid is linked with the H-2(a) and H-2(k) alleles, and to ovalbumin with the H-2(b), H-2(d), and H-2(q) alleles.