Anti-mu induces lymphoma in germfree congenitally athymic (nude) but not in heterozygous (nu/+) mice

To further our understanding of the role of host immunity in the development of lymphoid neoplasia, groups of germfree BALB/c nude and nu/+ mice were either followed unmanipulated or were treated, beginning at birth, with anti-mu, normal goat IgG or with lipopolysaccharide (LPS). The survival and development of neoplasia of all groups of animals were monitored up to 2 yr. Nude mice, under germfree and specific pathogen-free (spf) conditions, had a higher incidence of lymphoid neoplasia and reduced survival when compared to nu/+ littermates. The incidence of lymphoid tumors in nude mice under spf or germfree conditions was 7.2 and 8.7%, respectively, in comparison to 0% in nu/+ animals. Treatment of germfree nude mice with anti-mu, but not with goat IgG, increased the incidence of lymphoid tumors to 39%. Anti-mu did not significantly change the incidence of lymphoid neoplasia in nu/+ animals. Treatment of nu/nu and nu/+ mice with LPS, however, led to a several-fold increase in the appearance of neoplasia, to values of 25.4% in nude and 10% in nu/+ mice. Lymphoid neoplasia found in either unmanipulated, anti-mu, or IgG-treated germfree or spf mice included Thy-1.2+, surface IgM+, and IgG+ tumors. In contrast, all the lymphomas found in LPS-treated mice were surface IgM+. Thus, whereas LPS may have generated a relatively homogeneous group of tumors, anti-mu may have randomly increased the normal incidence of spontaneous tumors. Moreover, although there was significant variation in the histologic appearance of tumors, both within treatment groups as well as in different areas of the same animal, only LPS-treated mice were regularly noted to have distant nonlymphoid involvement, with lesions found in liver, lung, and kidney. In contrast, the incidence of nonlymphoid neoplasia was similar and was less than 2.5% in all groups.     

Control of the Expression of AV-1 Protein, a Position-Specific Antigen, by ZPA (Zone of Polarizing Activity) Factor in the Chick Limb Bud

AV-1 protein is a molecule which shows position-specific expression during chick limb development, and is expected to have some important roles in limb pattern formation. In this study, to examine whether the ZPA (Zone of polarizing activity) effects the expression of the AV-1 protein, we have removed or grafted the ZPA in chick limb buds and observed AV-1 expression. Anterior halves of the limb buds which lack a ZPA were used as hosts. In such anterior halves, AV-1 expression was initially observed in distal mesodermal cells including the cut surface. These anterior halves were combined with ZPA fragments, anterior fragments, posterior half limb buds, or left to develop alone, and the distribution of AV-1 expression was examined. The results of these experiments show that AV-1 expression requires the ZPA, and that expression occurs in the distal mesodermal cells certain distance from the ZPA.     

Expression patterns of genes encoding carbohydrate-metabolizing enzymes and their relationship to grain filling in rice (Oryza sativa L.): comparison of caryopses located at different positions in a panicle

In rice, caryopses located at the base of the panicle have a lower growth rate than those at the tip of the panicle. The former and latter types of caryopses are called inferior and superior caryopses, respectively. Taking the different growth rate into consideration, sugar status and the expression of genes encoding carbohydrate-metabolizing enzymes in inferior caryopses were compared with those in superior caryopses. During the first 5 d after flowering, superior caryopses elongated rapidly, but inferior caryopses did not. At this phase, inferior caryopses had a low ratio of hexose to sucrose, high activity of acid invertase and the absence of the expression of the genes encoding the above enzymes except for two isoforms of cell wall invertase, OsCIN4 and INV1, in comparison with superior caryopses. At the start of caryopsis elongation in both superior and inferior caryopses, the hexose/sucrose ratio increased accompanied by gene expression of vacuolar invertase (INV3), sucrose synthase (RSus1) and ADP-glucose pyrophosphorylase (AGP-L2: D50317). Furthermore, the genes related to endospermal starch accumulation were expressed highly with the decrease in the hexose/sucrose ratio after its peak. Based on the comparison of superior and inferior caryopses, the possible mechanism of grain filling in rice is discussed.     

Biosynthesis of Biotin-vitamers from Pelargonic Acid by Pseudomonas sp.

Influence of positional and stereoisomers of methylproline on the biosynthesis of neoviridogrisein (NVG) by Streptomyces griseoviridus P8648 was investigated. 3-(dl-cis + trans)- and 5-(d-cis + l-trans)-Methylprolines inhibited NVG synthesis, but they did not affect the cell growth. When these imino acids were added to cultures of S. griseoviridus P8648, there occurred no production of NVG homologues. In the presence of 4-methylproline (d-cis + l-trans), the organism synthesized a new NVG, designated NVG-MP, in which the imino acid moiety was replaced by 4-methylproline (d-cis). The antimicrobial activity of NVG-MP was compared with those of NVG II and viridogrisein (VG).     

Biosynthesis of Biotin-vitamers from Pelargonie Acid by Pseudomonas sp. Strain 393

The biosynthesis of biotin-vitamers from pelargonic acid by Pseudomonas sp. strain 393 was investigated. The main product of biotin-vitamers from pelargonic acid was desthiobiotin. The addition of streptomycin or l-alanine enhanced accumulation of desthiobiotin in culture fluid. Propionic, pimelic and azelaic acids were identified as main metabolites from pelargonic acid. When propionic acid was incubated with resting cells, pelargonic and azelaic acids were formed. The biosynthetic pathway of pelargonic acid to pimelic acid was also studied.     

Are contents of Rubisco, soluble protein and nitrogen in flag leaves of rice controlled by the same genetics?

Genetic relations among the contents of Rubisco, soluble protein and total leaf nitrogen (N) in leaves of rice (Oryza sativa L.) were studied by quantitative trait loci (QTL) analysis with a population of backcross inbred lines (BILs) of japonica Nipponbarexindica Kasalath. The ratio of Rubisco to total leaf N in leaves is the main target in improving photosynthetic N-use efficiency in plants. QTLs controlling Rubisco content were not detected near QTLs for total leaf N content. These results indicate that contents of Rubisco and total leaf N are controlled by different genetics. QTLs that controlled the ratio of Rubisco to total leaf N (CORNs) were detected. These results suggest that some mechanism(s) may be involved in determining this ratio, while the contents of Rubisco and total leaf N are controlled in other ways. In elite BILs, the ratios of Rubisco to total leaf N were higher than those of both parents. These results suggest a good possibility of improving N-use efficiency by CORNs in cultivated rice. A QTL controlling Rubisco content was mapped near a QTL for soluble protein content on chromosome 8 at 5 d after heading and on chromosome 9 at 25 d. In each chromosome region, the peaks of both QTLs overlapped accurately, giving a high possibility of pleiotropic effects by the same genes. Different QTLs controlling soluble protein or Rubisco were detected from those detected at 5 d or 25 d after heading. This suggests that these traits are genetically controlled depending on the growth stages of leaves.