Assignment of a human serum glycoprotein SP-40,40 gene (CLI) to chromosome 8.

SP-40,40 is a serum glycoprotein consisting of two different subunits (alpha and beta) assembled into a dimer by disulfide bonds. Northern blot hybridization, using total RNA from several cell lines, showed that SP-40,40 is expressed in glioblastoma and testicular tumor cells, as well as hepatoma cells. Spot blot hybridization of flow-sorted human chromosomes, using a SP-40,40 cDNA fragment as a probe, localized the gene for SP-40,40 to human chromosome 8. This gene has been given the designation CLI, for complement lysis inhibitor, by the Human Gene Nomenclature Committee.     

NMR study of isoleucine transfer RNA from Thermus thermophilus

An NMR and nuclear Overhauser effect (NOE) analysis of Thermus thermophilus tRNAIle1a is presented. This species contains modifications including s2T54 and s4U8 [Horie, N., Hara-Yokoyama, M., Yokoyama, S., Watanabe, K., Kuchino, Y., Nishimura, S., & Miyazawa, T. (1985) Biochemistry 24, 5711-5715]. All the expected secondary and reverse Hoogsteen AU pairs were identified, with one possible exception. The general geometry of the T psi C loop is the same as the Escherichia coli species, and there is NOE evidence for an A9-UA12 triple. Preliminary measurements of solvent exchange rates of internally hydrogen-bonded bases suggest that this tRNA is more stable than previously studied E. coli and yeast tRNAs.     

Genetics and Mechanism of Resistance to Meloidogyne arenaria in Peanut Germplasm

Segregation of resistance to Meloidogyne arenaria in six BC₅F₂ peanut breeding populations was examined in greenhouse tests. Chi-square analysis indicated that segregation of resistance was consistent with resistance being conditioned by a single gene in three breeding populations (TP259-3, TP262-3, and TP271-2), whereas two resistance genes may be present in the breeding populations TP259-2, TP263-2, and TP268-3. Nematode development in clonally propagated lines of resistant individuals of TP262-3 and TP263-2 was compared to that of the susceptible cultivar Florunner. Juvenile nematodes readily penetrated roots of all peanut genotypes, but rate of development was slower (P = 0.05) in the resistant genotypes than in Florunner. Host cell necrosis indicative of a hypersensitive response was not consistently observed in resistant genotypes of either population. Three RFLP loci linked to resistance at distances of 4.2 to 11.0 centiMorgans were identified. Resistant and susceptible alleles for RFLP loci R2430E and R2545E were quite distinct and are useful for identifying individuals homozygous for resistance in segregating populations.     

Evidence for an adrenergic mechanism in the control of body asymmetry

The effect of phenylephrine, an alpha-1 adrenergic agonist, on development of body asymmetry was studied using a rat whole embryo culture system. Embryos were explanted at the presomite stage, cultured in 100% rat serum containing various concentrations of phenylephrine, and examined at the 20-25 somite stage for sidedness of asymmetric body structures, namely, bulboventricular loop, allantoic placenta, and tail. Phenylephrine treatment resulted in a dose-dependent increase of situs inversus with a maximum incidence of 52%. Coadministration of prazosin, an alpha-1 adrenergic antagonist, almost completely prevented this effect. Our results suggest that receptor-mediated stimulation of the alpha-1 adrenergic pathway is involved in the control of normal body asymmetry in developing rat embryos.