Effects of both varietal and ecotypic traits e. g. l/b ratio of seeds, plant stature, days to maturation, growth habitat, indices of germinability and vigour of seedlings on in vitro development of seed derived-callus-system were studied in thirteen cultivars of indica rice (O. sativa L.). Variations in germination capacity and vigour index vis-a-vis callus mass production per seed were observed in varieties of different grain types. Studies indicated that long slender grains were superior to medium slender and long bold sized seeds in terms of callus induction frequencies and callus mass production. Maturation period and growth pattern, i.e., early to medium duration varieties with medium to dwarf stature, were more responsive in culture than long duration and tall varieties excepting scented rice. In general, higher rate of germination showed greater callus induction frequency whereas seedling vigour manifested ecotypic dependent response viz, very high vigour promoted gain in seedling growth or seed weight with low culturing potential as evidenced by seedling length (SL) and seedling weight ratio (SWR). Also, scent and colour provided an extra basis linked with l/b ratio to culturing potential of seeds wherein light black and red colour with medium slender seeds were inferior to cream to white colour, long slender seeds. In most of these varieties, 2,4-D at 2 mg/l was a potent level to give maximum callus production except in deep water varieties for discriminating the culture of responsive (CR) and non-responsive (NR) cultivars. Pattern of seed orygenins provided a supporting feature in grouping of cultivars differing in callusing potential in vitro. It seems that interdependence of seed vigour, germinability, seedling growth and seed proteins determine the genotype-dependent response in rice tissue culture.
Until recently the classification and the understanding of the malignant diseases in haematology were based on cell morphology. After the initial finding of Philadelphia chromosome in leukemia and translocation t(8,14) in Burkitt lymphoma, several chromosomal abnormalities were identified. These analysis in conjunction with the use of membrane markers, led to new classifications of these cancers. Thereafter with cloning and sequencing procedures it was possible to define the diseases at the DNA level. In this paper we present the evolution of ideas in that field during the last 20 years. After a period based purely on morphological description, haematologic cancers are now interpreted in terms of deregulation of various cell functions.
The question of the origin of the elements of the Mendelian hereditarian knowledge in other sciences and their implications for the early Mendelian discourse are discussed in two aspects: how statistics and the science of probability allowes to signify empirical data and to give rise to a general order of heredity; how the idea of constant units like the always identical A, which descends from atomistic chemistry, constituted a decisive boundary of the early Mendelian discourse. Finally the paper focusses on how the Mendelian discourse defended the identical hereditarian elements against opponents and contradictory experimental data by shifting the elements from the visible traits to the invisible genes.
The discussion about the risk assessment of environmental hazards and the environmental impact assessment is overburdened with speculative options. The classification of patterns, modes and extents of biological invasions by terrestrial plants and vertebrates ist one way to understand these trends.
Three human and six animal herpesviruses were shown to produce virus-related growth factors. All these factors similary to previously described pseudorabies virus growth factor (PRGF) induced a transformed phenotype in normal MK-2 cells and repressed the transformed phenotype of Hep-2 and T 24 tumor cells. By the use of gel filtration chromatography on the FPLC Superose -12 column, seven growth factors could be resolved into, two and three factors were resolved in three small active components (Mr < 1000). Each of two components of the factors belonging to the first group possessed only transforming activity, the transformed phenotype repressing activity could be reconstituted by simultaneous application of both components. The middle component of three-component factors possessed only transformation repressed activity, whereas other two components were transforming only. The middle transformation repressing components, devoid of transforming activity are discussed as possible anticancerogenic substances.
The effect of cut wing mutation (a sex-linked recessive mutation) on mating propensity was studied by using wild type and mutant stocks of Drosophila bipectinata. Mating success was observed directly in an Elens-Wattiaux mating chamber and multiple-, female-, male- and no-choice techniques were used. The results show that two types of flies mate randomly and isolation estimate remains close to one in all the crosses and thus there is no evidence for selective mating between females and males of the same type. The comparison of sexual activity of mutant and wild type flies clearly indicates that both types of flies are equally successful in mating in all the experiments. Thus cut wing mutation does not affect mating propensity in D. bipectinata.
On March 29, 1995 the German poet and thinker ERNST JUNGER was 100 years old. His extensive oeuvre - novels, stories, essays, aphorisms, and above all the diaries - reveal his intensive involvement with nature - a relationship unmatched by any other writer in the German language. JUNGER was fascinated his whole life long by "things which vary, even though they maintain their form", most notably beetles. He observed them, as someone trained to see the whole while bearing the knowledge of the researcher he kept the sense of the revelation of the amateur. A central interest of his was and is entomology and what in German is called Gestaltlehre. He brought to his observations a deeper sense of meaning, elevating physical to metaphysical and real to surreal, thereby creating something poetical. JUNGER studied zoology in Heidelberg and Leipzig, and briefly at the Marine Biological Station in Naples. The influence of OTTO BUTSCHLI and HANS DRIESCH On his work is unmistakable.
Eight Indian geographical populations of D. melanogaster and Z. indianus collected along 20 degrees N latitudinal range, revealed significant Adh clinal variation, i.e., 3% and 1% for 1 degrees latitude in D. melanogaster and Z. indianus, respectively. D. melanogaster populations could utilize 9.5 to 15.0 percent ethanol while Z. indianus populations utilized 3.75 to 8.5 percent ethanol. The parallel patterns of interspecific divergence of ethanol tolerance level are compatible with their natural habitats, i.e., Z. indianus mainly utilized fermented organic matter and fruits in the wild while D. melanogaster exploits man made highly ethanol rich sources indoors. The present observations suggest that Z. indianus revealed an adaptive characteristic for ethanol utilization mainly while D. melanogaster populations have depicted both ethanol utilization as well as ethanol detoxification. The observed latitudinal variation of Adh(F) frequency and ethanol tolerance in these two drosophilids could be maintained by balancing natural selection varying spatially along the north-south axis of the Indian sub-continent.
The AVERY-group and the explanation of the GRIFFITH experiment: The breakthrough to the acceptance of deoxyribonucleic acid as genetic substance. Even after the foundation of chromosome theory about 1900 the nature of the genetic substance could not be cleared. In 1944 a paper of the AVERY-group demonstrated the central role of deoxyribonucleic acid using a pneumococci model. It lasted until 1952 before this theory was generally accepted as a milestone in genetics, which marks the beginning of molecular biology.
Seed storage at 50% or 20% water content subsequent to MH treatment of Vicia faba root tip meristem cells leads to a decrease or increase, respectively, of the frequency of CAs. Deeper insight into the distribution patterns of chromatid aberrations observed in these experiments and available from the use of the reconstructed ACB-karyotype of Vicia faba show that significant changes during storage as to the frequency of induced chromatid aberrations have no significant influence on the percentage of chromatid aberrations located in the particular chromosome segments. It can be stated that, although at 50% water content storage the frequency of damaged cells decreases, the distribution pattern of the chromatid aberrations remains basically uninfluenced. The same is true in the case of 20% water content storage when the frequency of damaged cells increases. Since the distribution pattern of the chromatid aberrations was in both cases (decrease vs. increase) non-random, a possible explanation is that while the DNA damage is selective and some segments are preferentially involved, the repair of this DNA damage is not selective for a particular chromosome or segment of the chromosome.
GOTTLIEB HABERLANDT, the co-founder and main representative of the physiological plant anatomy, died 50 years ago. His integral program of studying the structural-functional relations of plant tissues reformed the contemporary general botany. HABERLANDT'S way to botany, the emergence and effects of functionally and evolutionary physiological plant anatomy and its theoretical and methodological fundamentals are traced giving a vivid impression of the outstanding personality of this thorough scientist and teacher.
Genotoxic effects of griseofulvin, a mycotoxin with wide application in the therapy of dermatophytoses, were studied in the somatic and germ line cells of Drosophila melanogaster. Third and second instar larvae carrying genetic markers mwh and flr(3) on chromosome 3 were used to study the genotoxic effects in the wing primordial cells and the standard Base technique was followed to study the genotoxic effects in the germ line cells. On the basis of the results obtained, it is concluded that griseofulvin is genotoxic both in the somatic and germ line cells of Drosophila following chronic larval feeding.
The history of civilization in China shows a special relationship of Chinese to insects and their application in agriculture with the most famous example of producing silk from the silkworm. Another over 1000 year old Chinese tradition is the performance of cricket fights, which created an abundant amount of technical literature and developed many tricks in handling and rearing these animals. Although the theoretical background of cricket aggression is quite different - the chinese concept is very anthropomorphic in contrast to the modern ethological and neurobiological terminology - a comparison of the results shows interesting analogies. Some old chinese findings may help to extend the current neuroethological study of aggression in crickets, e.g. the method of resetting the fighting readiness in a loser by "punishing". This example leads to the more general suggestion for an experimental history of science, comparative in culture and time, which may help to solve some problems of modern biology, e.g. the spontaneous generation of behaviour patterns or the psychophysical basis of gestalt perception.
In his organismic approach BERTALANFFY postulates two biological principles: 1. the maintenance of the organism in a steady state, 2. the hierarchic order of the structured system (grade of organization). Bertalanffy defines an organism [bio-theoretical term for substance] as an open system organized in a hierarchic process order in steady state (autonomous metabolism). Because of the system lawfulness Life is characterized by gestalt (shape), i. e. it is bound on structure or on organization functionally characterized by equifinality.
Experiments were conducted to test the effect of stabilizing selection on sternopleural bristle number in Drosophila ananassae. Selection for intermediate bristle phenotypes was carried out through 15 generations. Two replicates of selection line and a control line without selection were maintained. The results show that mean number of bristles remained close to the base population mean but fluctuation in bristle number was more in the control line than in both replicates of selection line. The phenotypic variance and coefficient of variaton decreased in both replicates of selection line as compared to the control line. These results indicate that stabilizing selection for sternopleural bristle number was effective in D. ananassae.
Chromosomal aberrations (CA) and sister chromatid exchanges (SCE) were estimated as end points for chromosome damage in lymphocytes of 25 untreated and 10 radiologically treated patients including 3 patients with mosaic deletion of 13q14 with retinoblastoma. There was a significant statistical increase in CA and SCE in both patient groups when compared with age and sex matched controls. No difference was seen between the patient groups and in patients with normal and mosaic karyotype. However the effects of the tumor treatment in these patients with these parameters was not seen. The presence of the tumor might still be the cause for chromosome damage in these patients.
Fluorescent in situ hybridization revealed (5'-TTTAGGG-3')(n)-motifs at the chromosome termini of Selaginella martensii, thus showing that this sequence represents the basic telomere-specific repeat in all plant phyla from algae up to the angiosperms.
During the 1920s and 1930s a widespread fascination with cultural pessimism was on the upsurge in the German speaking countries. Scientists from various disciplines reacted to this state of mind by discussing the actual or presumed problems of the time and by developing suggestions for a possible solution. In this situation geneticists conceived of the crisis as a genetic crisis and, accordingly, suggested genetic, i.e. eugenic, measures. In the decades after 1945 eugenic ideas were considered obsolete for both scientific and political reasons. Latest developments, however, seem to suggest that a revival of eugenic views is currently in progress.
