Nature and distribution of copper in green lagoon crab Scylla serrata (Forskal)

In Scylla serrata (Forskal), copper is present in detectable quantities in all tissues except the central nervous system. 75% of animal's total copper is found in the haemolymph, hepatopancreas, and cuticle. Both the haemolymph and the hepatopancreas share equally ≈ 60% of the animal's total copper. Copper is found in the TCA-soluble and insoluble fractions of water-soluble tissue extracts and in the chloroform : methanol-soluble and insoluble fractions of water-insoluble residue from the hepatopancreas. No other tissue has all the fractions of copper. In haemolymph copper is present only in the TCA-insoluble fraction. The TCA-soluble fraction is also absent in muscles. The absence of any lipid-bound copper in other tissues and the presence of copper in all fractions from the hepatopancreas indicates that this tissue may play a major role in the mobilization, conservation and detoxication of copper.     

Deoxyribonucleic acid hybridization among strains of lactobacilli

Hybridization of deoxyribonucleic acid (DNA) from Lactobacillus bulgaricus (ATCC 11842) with DNA of L. lactis (ATCC 12315), L. helveticus (ATCC 15009), and L. jugurt (ATCC 521) showed 86.0% reassociation with L. lactis, 4.8% with L. helveticus, and none with L. jugurt.     

Preparation, properties and metabolism of 5,6-monoepoxyretinoic acid

1. Methyl retinoate has been converted into methyl 5,6-monoepoxyretinoate by reaction with monoperphthalic acid. The epoxy acid ester on alkaline hydrolysis gave 5,6-monoepoxyretinoic acid. 2. Treatment of the 5,6-monoepoxy compounds with ethanolic hydrochloric acid gave the corresponding 5,8-epoxy (furanoid) compounds. 3. With lithium aluminium hydride, the acid and the ester groups were selectively reduced to primary alcohols. 4. Administration of methyl 5,6-monoepoxyretinoate intraperitoneally and subcutaneously had good growth response in vitamin A-deficient rats. 5. 5,6-Monoepoxyretinoic acid, when given intraperitoneally as the sodium salt, was 157% as active as all-trans-retinyl acetate. 6. Methyl 5,6-monoepoxyretinoate was hydrolysed to the epoxy acid by rat-liver homogenate. It had 35% of the biological activity of all-trans-retinyl acetate in the rat when given orally.     

Exercise and blood lymphocyte subset responses: intensity, duration, and subject fitness effects

This study examined the effect of exercise intensity and duration on the percent blood lymphocytes in men of low [LF; maximal O2 uptake (VO2max) less than 50 ml.kg-1.min-1 and sedentary], moderate (MF; VO2max = 50-60 ml.kg-1.min-1 and recreationally active), and high (HF; VO2max greater than 60 ml.kg-1.min-1 and recent training history) fitness. Thirty healthy adult men (aged 20-31 yr) participated in four randomly ordered cycle ergometer rides: ride 1 (65% VO2max, 30 min), ride 2 (30% VO2max, 60 min), ride 3 (75% VO2max, 60 min), and ride 4 (65% VO2max, 120 min). Blood samples were drawn at various times before and after the exercise sessions. Lymphocyte subsets were determined by flow cytometry using monoclonal antibodies for total T (CD3+), T-helper (CD4+), and T-suppressor (CD8+) lymphocytes and for a subset of cells expressing a natural killer (NK) cell antigen (Leu7+). Plasma catecholamines were assayed to determine exercise stress. There were sharp reductions (P less than 0.01) in the percentage of pan-T and T-helper lymphocytes immediately after exercise across all fitness levels; the magnitude of this reduction was greatest after the highest intensity (ride 3) or longest duration (ride 4) work. In contrast, the absolute number of T and T-helper cells tended to increase after exercise and significantly so in the HF subjects (P less than 0.005). There was no significant effect of exercise or subject fitness category on the percentage of T-suppressor lymphocytes, although the absolute numbers of this subset increased significantly after exercise in LF subjects. Marked increases (P less than 0.01) in the percentage of NK cells occurred immediately after exercise at all intensities and durations tested; numerical increases in total NK cells were significant in all fitness groups after the highest intensity work (ride 3; P less than 0.005). Irrespective of whether the changes were expressed as percentage or total numbers, recovery to base line occurred at 30 min after exercise. The results suggest that the exercise effect on blood lymphocyte subset percentages in men is transient and occurs across all fitness levels. Concomitant changes in plasma catecholamine concentrations are only weakly associated with these lymphocyte subset percentage responses to exercise. Furthermore, this study shows that the exercise-induced changes in lymphocyte percentages do not consistently reflect changes in the absolute numbers of cells.     

Transfer of Brassica tournefartii (TT) genes to allotetraploid oilseed Brassica species (B. juncea AABB, B. napus AACC, B. carinata BBCC): homoeologous pairing is more pronounced in the three-genome hybrids (TACC, TBAA, TCAA, TCBB) as compared to allodiploids (TA, TB, TC)

For the transfer of genes from B. tournefortii (TT) to the allotetraploid oilseed brassicas, B. juncea AABB, B. carinata BBCC and B. napus AACC, B. tournefortii was first crossed with the three basic diploid species, B. campestris (AA), B. nigra (BE) and B. oleracea (CC), to produce the allodiploids TA, TB and TC. These were tetraploidized by colchicine treatment to produce the allotetraploids TTAA, TTBB and TTCC, which were further crossed with B. juncea and B. napus to produce three-genome hybrids with substitution-type genomic configurations: TACC, TBAA and TCAA. These hybrids along with another hybrid TCBB produced earlier, the three allodiploids, their allotetraploids and the four diploid parent species were studied for their male meiotic behaviour. The diploid parent and the allotetraploids (TTAA, TTBB and TTCC) showed regular meiosis although the pollen viability was generally low in the allotetraploids. In the allodiploids (TA, TB and TC) only some end-to-end associations were observed without any clearly discernible chiasmata or exchange points. Chromosomes involved in end-to-end associations were randomly distributed at the metaphase/anaphase-I stages. In contrast, the three-genome hybrids (TACC, TBAA, TCAA and TCBB) showed normal bivalents whose number exceeded the expected bivalent values. Bivalents arising out of homoeologous pairing were indistinguishable from normal pairs by their disjunction pattern but could be distinguished on the basis of the heteromorphy of the homoeologous chromosomes. The three-genome hybrids could be backcrossed to allotetraploid oilseed brassicas as they had some fertility. In contrast, the allodiploids could neither be selfed nor back-crossed. On the basis of their meiotic stability, in terms of more pronounced homoeologous pairing and fertility for backcrossing, the three-genome configurations provide the best possible situation for the introgression of alien genes from the secondary gene pool to the allotetraploid oilseed crops B. juncea, B. napus and B. carinata.     

Synthesis of hexaploid (AABBCC) somatic hybrids: a bridging material for transfer of ‘tour’ cytoplasmic male sterility to different Brassica species

Most of the alloplasmic cytoplasmic male sterility (CMS) systems are known to be associated with a number of floral abnormalities that result from nuclear-cytoplasmic incompatibilities. One such system, tour, which is derived from Brassica tournefortii, induces additional floral abnormalities and causes chlorosis in Brassica spp. While the restorer for this CMS has been reported to be present in B. napus, in B. juncea, where the abnormalities are more pronounced, no restorer has yet been identified. Rectification of these floral abnormalities through mitochondrial recombinations and chloroplast replacement might result in the improvement of this CMS system. As organelle recombinations can possibly be achieved only by somatic cell hybridization, fusion experiments were carried out between hygromycin-resistant B. juncea AABB carrying tour cytoplasm and phosphinotricin-resistant, normal B. oleracea CC to generate AABBCC hexaploid somatic hybrids. The presence of selectable marker genes facilitated the selection of hybrids in large numbers. The resulting hybrids showed wide variation in floral morphology and organelle composition. Regenerants with normal, male-sterile flowers having recombinant tour-or oleracea-type mitochondria and oleracea-type chloroplasts were obtained. Hybrids with male-fertile flowers were also obtained that had recombined tour mitochondria. The AABBCC hexaploid hybrids synthesized in the present study were successfully utilized as a bridging material for transferring variability in the organelle genome simultaneously to all the digenomic Brassica species, and all of these hybrids are now being stabilized through repeated backcrosses to the allopolyploid crop brassicas.     

Somatic hybrids with substitution type genomic configuration TCBB for the transfer of nuclear and organelle genes from Brassica tournefortii TT to allotetraploid oilseed crop B. carinata BBCC

Oilseed crop Brassica carinata BBCC is a natural allotetraploid of diploid species B. nigra BB and B. oleracea CC. To transfer the nuclear and organelle genes in a concerted manner from an alien species, B. tournefortii TT, to B. carinata, we produced somatic hybrids with genomic configuration TCBB using B. nigra and B. oleracea stocks that carried selectable marker genes. B. tournefortii TT was sexually crossed with hygromycin-resistant B. oleracea CC. Protoplasts isolated from shoot cultures of hygromycin-resistant F₁ hybrids of B. tournefortiixB. oleracea TC were fused with protoplasts of kanamycin-resistant B. nigra BB. In two different fusion experiments 80 colonies were obtained through selection on media containing both hygromycin and kanamycin. Of these, 39 colonies regenerated into plants. Analysis of 15 regenerants by random amplified polymorphic DNA (RAPD) markers showed the presence of all three genomes, thereby confirming these to be true hybrids. Restriction fragment length polymorphism (RFLP) analysis of organelle genomes with heterologous chloroplast (cp)and mitochondrial (mt) DNA probes showed that the chloroplast genome was inherited from either of the two parents while mitochondrial genomes predominantly showed novel configurations due to either rearrangements or intergenomic recombinations. We anticipate that the TCBB genomic configuration will provide a more conducive situation for recombination between the T and C genomes during meiosis than the TTCCBB or TCCBB type configurations that are usually produced for alien gene transfer. The agronomic aim of producing TCBB hybrids is to transfer mitochondrial genes conferring cytoplasmic male sterility and nuclear genes for fertility restoration from B. tournefortii to B. carinata.     

Growth Stimulation by Conditioned Medium and Spermidine in Low-Density Suspension Cultures of Rice

Suspension cultures of Oryza sativa L. var IR 20 grew in Murashigeand Skoog medium (MS) supplemented with 2,4-D and kinetin ina density-dependant manner with a critical minimum inoculation-densityof 10,000 cells ml^–1. Conditioned medium obtained fromthese cultures and added to MS+2,4-D+kinetin induced the growthof cultures at 1,000 cells ml^–1. Growth stimulation byconditioned medium was mimicked by spermidine but not by otherpolyamines viz. putrescine and spermine. This is the first reportof a polyamine substituting for conditioned medium in cultures. ² Present address: Vice-Chancellor, Pondicherry University,Pondicherry 605 014, India.