The anatomy of tissue cultured red raspberry prior to and after transfer to soil

The leaf, petiole, stem and root anatomy of an aseptically cultured red raspberry clone (Rubus idaeus L.) was studied before and 5 weeks after transfer to soil under controlled environmental conditions. Tissues persistent from culture showed little or no change with time in soil; they grew minimally and slight secondary wall deposition occurred. New organs formed in successive weeks after transplantation showed a graded increase in potential size and development. Some features, such as collenchyma formation, rapidly returned to control levels; this was seen in new leaves expanding in the first week after transplantation. Other features, such as sclerenchyma formation, did not occur in leaves expanding during the first 2 weeks after transplantation, even when these were a month or more in age. Some sclerenchyma was seen in leaves expanding in the third week after transplantation, increasing in later-formed leaves. Increasing the light intensity of transplant accelerated the return to control-type organ size and appearance. During acclimatization transitional forms of leaves, petioles, stems and roots develop that ranged anatomically from culture-to control-type. This trend is analagous to the normal developmental sequence of organ formation as it affects the potential for development of successily formed organs.     

The disease resistance response in pea is associated with increased levels of specific mRNAs

A cDNA library was constructed using poly(A)⁺RNA fromPisum sativum which had been treated for 8 h with the fungusFusarium solani f. sp.phaseoli. Two thousand four hundred recombinant colonies were screened by differential colony hybridization using³²P-labelled cDNAs prepared from RNA extracted from either noninoculated or inoculated pea tissue. cDNA clones were then selected, which showed greater hybridization with cDNA prepared from pea RNA 8 h post-inoculation than with a cDNA probe from 0 h. Seven distinct hybridization classes were chosen for further study. Northern blot analyses of total cellular RNAs inoculated for 16 h with eitherF. solani phaseoli or water demonstrated that each cDNA clone selected represents an mRNA species which increases substantially in abundance during infection. Results of³H-uridine pulse-labelling experiments suggested that enhanced synthesis is at least partially responsible for the accumulation of the fungus-inducible mRNAs which hybridized with the clones.     

The regulation of''early'' enzymes during the development and dedifferentiation of Dictyostelium discoideum

The specific activities of the enzymes alpha-mannosidase and N-acetylglucosaminidase increase immediately after the initiation of the development of bacterially grown cell cultures of Dictyostelium discoideum. The regulation of these two enzymes was found to be dissociable in the developmental timer mutant, FM-1, which aggregates 4.5 h earlier than wild-type cells due to the absence of the first rate-limiting component of the preaggregative period. The increase in alpha-mannosidase activity occurs in the absence of the first rate-limiting component, but the increase in N-acetylglucosaminidase activity does not. These results indicate the following: (1) the increase in the specific activity of alpha-mannosidase is not related to the timing of subsequent developmental stages; (2) the increase in the specific activity of N-acetylglucosaminidase is not necessary for the subsequent developmental program; and (3) either the increase in the specific activity of N-acetylglucosaminidase is dependent upon progress through the first rate-limiting component, or the increase in this enzyme activity and the first rate-limiting component are both dependent upon an early event for which FM-1 is defective. In addition to early development, we monitored the two enzyme activities during dedifferentiation. The results demonstrate that there is no difference between dedifferentiating wild-type cells and dedifferentiation-defective mutant HI-4 cells. Changes in enzyme specific activity accompanying dedifferentiation are dependent upon the composition of the dedifferentiation-inducing media and are consistent with the levels of these enzymes observed in cells growing in the different nutrient media.     

Combined immunostaining of neurofilaments, neuron specific enolase, GFAP and S-100. A possible means for assessing the morphological and functional status of the enteric nervous system

Neurofilaments, part of the cytoskeletal network, and neuron specific enolase, a major enzyme in glycolysis, are both present in central and peripheral neurons. Glial fibrillary acidic protein and S-100, on the other hand, are soluble proteins which are found exclusively in the supportive cells of the nervous system, i.e. the glial cells. Examination was made, using immunocytochemistry, of all main areas of the gastrointestinal tract of three mammalian species, rat, pig and man. By applying serial tissue sectioning, it was possible to study the relative occurrences of the two neuronal markers in the same cell bodies and to examine the relationships of the neurons with the glial cells as revealed by the antibodies to glial fibrillary acidic protein and S-100. Both neurofilaments and neuron specific enolase were localised to an extensive system of enteric nerves, with the level of neuron specific enolase-immunoreactivity showing greater variability than that observed using antibodies to neurofilaments. Comparison of the occurrence of neuron specific enolase and neurofilament immunoreactivity in serially sectioned neuronal cell bodies revealed that a minor population stained only with antibodies to neurofilaments. The equivocal or absent neuron specific enolase-immunoreactivity in some perikarya may reflect variations in functional status within the nervous system. Glial fibrillary acidic protein- and S-100-immunoreactivities were confined to glial cells which, in this normal tissue, were always in close association with the neurons.(ABSTRACT TRUNCATED AT 250 WORDS)     

TDP-1, a toxic component causing tibial dyschondroplasia in broiler chickens, and trichothecenes from Fusarium roseum 'Graminearum'

Fusarium roseum 'Graminearum' was isolated from overwintered oats in Alaska and was tested for its ability to cause tibial dyschondroplasia (TDP) in broiler chickens. The water-soluble fraction was tested and found to cause TDP. In addition, diacetoxyscirpenol and 7-hydroxydiacetoxyscirpenol were identified in the acetonitrile fraction of the extracts and caused mild mouth lesions in chickens. Six major water-soluble components were purified by thin-layer chromatography and tested for toxicity to chick embryos. One of the six components, called TDP-1, was found to be lethal to chick embryos. There was a 100% incidence of TDP in chickens fed a diet containing 75 ppm (wt/wt) of pure TDP-1, thus establishing the cause and effect relationship between TDP and TDP-1. Analyses by thin-layer chromatography and mass spectrometry revealed that TDP-1 is polar and ninhydrin positive, exhibits fluorescence with UV irradiation, and is a nitrogen-containing component with an empirical formula of C15H20N2O4.     

Pilot-scale production of l-phenylalanine from d-glucose

Effects of inoculum size and total sugar content on both l-phenylalanine productivity and titre have been investigated using a tyrosine auxotrophic regulatory mutant of Escherichia coli. Fermentations were carried out in a 500 litre pilot fermenter with intermittent feeding of d-glucose plus phosphate. It was found that the productivity was not greatly affected by inoculum size. However, the l-phenylalanine titre was significantly affected by total sugar content. Relatively high productivities of up to 0.35–0.40 g l-phenylalanine l^?1 h^?1 have been achieved at l-phenylalanine titres of 14–15 g l^?1.     

Correlation between limitation of growth ofPachysolen tannophilus on D-xylose with the formation of ethanol and other products

The formation of ethanol, xylitol, ribitol, arabitol and acetic acid from D-xylose byPachysolen tannophilus correlated with the limitation of growth. The correlation was consistent with these products being secondary metabolites.Issued as NRCC Publication Number 24259.     

The effects of ACTH1-24 or cortisol on pulmonary maturation in the adrenalectomized ovine fetus

Pulmonary maturation in 8 ovine fetuses bilaterally adrenalectomized at 98-101 days and infused at term with either ACTH1-24 or cortisol was compared with that in 4 untreated sham-operated controls. Four of the adrenalectomized fetuses were infused intravascularly with ACTH1-24 5 micrograms/h for 84 h before delivery and the other four were infused with cortisol 1 mg/h for 72 h. The high plasma concentrations of immunoreactive ACTH in the adrenalectomized fetuses (2762 +/- 1339 ng/l, mean +/- SD) were not significantly elevated by infusion of ACTH1-24 but were markedly depressed by infusion of cortisol. Distensibility (V40) of the lungs was less than that of controls in both the ACTH1-24-infused and cortisol-infused fetuses (1.86 +/- 0.31 ml/g vs 0.62 +/- 0.13 ml/g and 1.27 +/- 0.34 ml/g respectively) but it was significantly greater in the cortisol-infused fetuses compared to those infused with ACTH1-24. The volume of air retained at 5 cm H2O pressure (V5) during deflation was markedly reduced in adrenalectomized fetuses (controls 1.14 +/- 0.52 ml/g vs 0.25 +/- 0.25 ml/g and 0.12 +/- 0.6 ml/g). The wet weight of the lungs and the concentrations of saturated phosphatylcholine in lung tissue and lavage fluid were lower in the adrenalectomized fetuses than in controls but the differences were not significant. It is concluded that infusion of ACTH1-24 at term in adrenalectomized fetuses is probably without effect whereas cortisol enhances distensibility.     

Developmental expression of rat transforming growth factor-alpha mRNA.

Expression of the gene encoding transforming growth factor-alpha (TGF alpha) was examined in developing rat embryos by using a cloned TGF alpha cDNA as a hybridization probe. Northern blot analysis of RNA isolated from whole fetuses revealed that TGF alpha mRNA was present at relatively high levels in 8- through 10-day-old embryos and then declined to the low or undetectable level, which is characteristic of adult tissues before birth. The level of TGF alpha mRNA present during early gestation was similar to that present in retrovirus-transformed cells in culture, suggesting that TGF alpha expression is not highly localized in the embryo. These observations are consistent with the hypothesis that TGF alpha plays a role in development, possibly as a fetal growth factor.