The genetics of resistance of several rice cultivars (Oryza saliva L.) to the brown planthopper, Nilaparvata o lugens (Stal), and to the green leafhopper, Nephotettix impicticeps (Ishihara), was studied in the greenhouse. Two testing techniques were developed and employed. In one, 7-day-old seedlings were infested with insects and then classified on the basis of insect injury. In the other a known number of insects were caged on tillers of 6-weekold plants and insect survival was used as the criterion for classification. The resistance of 'Mudgo,' 'Manavari CO22,' and 'Dalwa Sannam MTU15' to the brown planthopper was controlled by single dominant genes that appeared to be allelomorphic. Another cultivar, 'Karsamba Red ASD7,' possessed a single recessive gene for planthopper resistance that was either allelic or closely linked to the locus that conditions resistance in the other three cultivars. The field reaction of F 4 lines of a cross between Mudgo and a susceptible cultivar was strongly correlated with the greenhouse reaction, and aparently the same gene controlled planthopper resistance at different stages of growth. Resistance to the green leafhopper in the cultivars 'Pankhari 203,' 'ASD7,' and 'IR8' also was controlled by single genes that were nonallelic and dominant. The planthopper resistance of Mudgo, and the leafhopper resistance of Pankhari 203 were independently inherited as was the resistance of ASD7 to the two insects.

No abstract

Antibody fragments can be expressed at a high level in microbial systems, but they may have limited therapeutic value because they are rapidly eliminated from the body. We demonstrate here that site-specific conjugation or binding of bacterially derived Fab' to the long-lived protein serum albumin allows full retention of the antibody's binding characteristics while imparting the albumin's longevity in vivo. In rats the area under the curve for Fab' conjugated to rat serum albumin was 17-fold greater than for the control of Fab' conjugated to cysteine. Again, a bispecific F(ab')(2) with specificity for rat serum albumin showed an area under the curve about 8-fold greater than did a F(ab')(2) without specificity to albumin. Genetic fusions of scFv to albumin were similarly long-lived and could be expressed in yeast to provide the basis of a cost-effective production system.

No abstract

The genetic variability and correlation coefficients involving five floral characters were investigated in a group of 29 cultivated and wild rices (Oryza Sp.). Wide variability existed in anther length, stigma length, and percent exserted stigma. The genetic variation constituted a high proportion of the total variation for these traits. Thus, selection for these characters is expected to be highly effective. The percent exserted stigma showed a high positive correlation with stigma length. Both traits also were correlated positively with spikelet length and anther length.One accession each of Oryza saliva f. spontanea and O. perennis subsp. balunga possessed anthers twice as long as those of cultivars. They also had a much higher proportion of exserted stigmas than most cultivated varieties.

This report describes the development and the biology of Sch 55700, a humanized monoclonal antibody to human IL-5 (hIL-5). Sch 55700 was synthesized using CDR (complementarity determining regions) grafting technology by incorporating the antigen recognition sites for hIL-5 onto consensus regions of a human IgG4 framework. In vitro, Sch 55700 displays high affinity (Kd = 20 pmol/l) binding to hIL-5, inhibits the binding of hIL-5 to Ba/F3 cells (IC50 = 0.5 nmol/l) and blocks IL-5 mediated proliferation of human erythroleukemic TF-1 cells. In allergic mice, Sch 55700 (0.1-10 mg/kg, i.p. or i.m.) inhibits the influx of eosinophils in the lungs, demonstrates long duration of activity and the anti-inflammatory activity of this compound is additive with oral prednisolone. In allergic guinea pigs, Sch 55700 (0.03-30 mg/kg i.p.) inhibits both the pulmonary eosinophilia and airway hyperresponsiveness and at 30 mg/kg, i.p. inhibited allergic, but not histamine-induced bronchoconstriction. In allergic rabbits, Sch 55700 blocks cutaneous eosinophilia. Sch 55700 (0.1-1 mg/kg i.p.) also blocks the pulmonary eosinophilia and neutrophilia caused by tracheal injection of hIL-5 in guinea pigs. In allergic cynomolgus monkeys, a single dose of Sch 55700 (0.3 mg/kg i.v.) blocks the pulmonary eosinophilia caused by antigen challenge for up to six months. Sch 55700 is, therefore, a potent antibody against IL-5 in vitro and in a variety of species in vivo that could be used to establish the role of IL-5 in human eosinophilic diseases such as asthma.

No abstract

Two new sources of cytoplasmic male‐sterility designated ‘L66A’ and ’L67A’ have been isolated. Genetic‐cytoplasmic interactions for restoration of fertility prove that these sources are different from ‘Tift 23A.’ The maintainers for these sources also maintain sterility in Tift 23A. ‘Tift 23B,’ maintainer for Tift 23A, is a good fertility restorer for L66A and L67A. Good fertility restorers for Tift 23A, such as ‘T239 and ‘L‐4,’ are excellent sterility maintainers for L66A and L67A. L66B, maintainer for L66A, restores fertility in L67A, while L67B is a partial fertility restorer for L66A. Genetic models suggesting the relationship between different sources are presented.