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The agglutinating effects of Concanavalin A (Con A) on protoplasts isolated from cell suspensions of Daucus carota were studied. Con A was shown to agglutinate the plants proto-plants in a manner similar to the way some animal cells are agglutinated. The agglutination process is dependent on the Concanavalin A concentration, protoplast density, treatment time, the temperature, and the membrane condition. α-D-Methylgluco-pyranosid completely inhibited Con A induced agglutination. The results are discussed in relation to membrane structure and morphology. [ABSTRACT FROM AUTHOR]

The article reports on the currents trends in dental research policy. Research has become one of the most important sources of innovations in modern society. The armament race has brought with it an enormous technological expansion, and the explosion in education has resulted in a state of affairs in Scandinavia in which studying at a university has become more common than admitted to grammar school. The concept "Research Policy" is usually understood as the basis on which communities decide the extent of research.

Recently there has been an increasing awareness of the need to study the genus Drosophila in the wild, to assess the various ecological and behavioral parameters determining its distribution. It must be stressed that the classic work of Dobzhansky and his collaborators has over the years provided much information especially in D. pseudoobscura and closely related species such as D. persimilis. It is one of the curiosities of this sort of scientific endeavor, that the species D. melanogaster, perhaps best known genetically of all species in the genus, has been studied extensively under laboratory conditions for over 60 years, with little thought given to the situation in the wild. In this review, some environmental stresses, natural and artificial, for which genetic variability has been found within and between species of Drosophila will be examined, as they are important in determining the distribution of species of the genus in the wild. Stresses to be considered are temperature extremes, desiccation, anoxia as assessed by resistance to long-term exposure to CO2, 60Co γ-radiation, various chemical stresses (some of importance in nature because of the activities of man), and ethyl alcohol. [ABSTRACT FROM AUTHOR]

This review is concerned mainly with the period January 1, 1970 to January 1, 1973. Because of limitation of space, it is more restricted in its coverage than the review of the previous three years, 1967-1970. The fourth International Congress of Human Genetics convened in Paris in September 1971. The published proceedings constitute a useful record of the state of the field as of that date. The reader is referred to it for review of some areas not covered here, e.g. radiation genetics. [ABSTRACT FROM AUTHOR]

The aim of developmental biology is to discover how the genetic instructions for development are implemented by the epigenetic processes of development. In recent years Drosophila has been increasingly used to answer many questions concerned with development, and the imaginal discs have received special attention. These small nests of cells are set aside early in development for the formation of the adult integument. The entire surface of the adult fly is formed from imaginal discs so that any mutation that affects the cuticle of a adult fly directly or indirectly alters the development of imaginal discs. Many such mutations have been detected, described, and analyzed. This review examines the genetic basis of the development of the imaginal discs of Drosophila. Other aspects of Drosophila developmental genetics such as chromosomes puffing, behavioral genetics, genetics of embryogenesis, spermatogenesis, oogenesis, and biochemical genetics have recently been reviewed. [ABSTRACT FROM AUTHOR]

Focuses on the development of a model of genetic replication in the map of the T4 DNA population. Role of circularly permutted terminal redundancy in genetic recombination; Experimental foundation for the creation of the rolling circle model; Observations deemed incompatible with the developed model; Related literature and experiments on the subject.

This article is a critique of the meaning and importance of some of the recently published work in the field whose development as a special area began with papers by Zuckerkandl & Pauling and Pauling & Zuckerkandl entitled Chemical Paleogenetics, Molecular Restoration Studies of Extinct Forms of Life and the paper by Margoliash on the evolution of cytochrome c. The primary emphasis is on conclusions and inferences derivable from amino acid sequences, followed bya section on nucleotide sequences. These are preceded by a brief indication of some of the literature that antedates the origin of the genetic code as it now stands. This will not treat immunoglobulin evolution, reviewed by Gally & Edelma and Smith, Hood & Fitch or related material on the evolution of enzymes and proteins reviewed by Smith and Arnheim. The functional interpretation of these changes has made significant progress [Dickerson and Takano et al]. For the evolution of metabolic pathways, see brew, Vogel, and Lejohn. [ABSTRACT FROM AUTHOR]

I shall review the field of cell-free protein synthesis for both the RNA- and DNA-dependent systems with particular emphasis on the latter and the uses to which these systems can be put. This is a young field and it is more important to point the way than to review past accomplishments. [ABSTRACT FROM AUTHOR]

The purpose of the present review is to retrace as succinctly as possible the historical development of the concept of dosage compensation in Drosophila, to review new experimental evidence accumulated over the past dozen years, and to discuss various hypotheses and models that have been proposed to account for the compensation. Since most of the analysis has been performed with D. melanogaster, all statements made during the course of this review will, therefore, refer to this species unless otherwise indicated. The survey of the literature for this review was concluded in February, 1973. [ABSTRACT FROM AUTHOR]

Cytogenetic methods are traditionally used to estimate the location of genes on chromosomes. By using cytogenetic procedures in some favorable cases, the control of, or the appearance of, a specific protein or RNA can be ascribed to a distinct chromosome region. Recently a very powerful method, which circumvents traditional genetic procedures, has become available for locating specific genes. The development of in situ RNA-DNA hybridization techniques has made it possible to observe the sites of production of specific classes of RNA on cytological preparations. In this methodology particular species of radioactive RNA or DNA are hybridized to denatured DNA in the chromosomes of standard cytological preparations. As complementary nucleic acid sequences anneal specifically to each other, autoradiographs of these cytological hybridizations reveal a radioactive site on the chromosome, which presumably marks the location of the DNA coding for the RNA species. In theory, the site of production on any RNA species sufficiently different from other forms can be located on chromosomes. In the last few years these methods have revealed the sites of production in certain organisms of 18 and 28S ribosomal RNA, transfer RNAs, histone message, and possibly hemoglobin message. In addition, in situ annealing methods have shown the location of a number of different satellite or reiterated DNAs on chromosomes. This review will deal mainly with in situ hybridization, practice, theory, results, and future potential. [ABSTRACT FROM AUTHOR]

Explains the methods for the longitudinal differentiation of metaphase chromosomes. Treatment of live tissues and cells with a variety of chemicals by cytologists in an attempt to differentiate chromosomes longitudinally; Administration of differential fluorescence and constitutive heterochromatin; Description of the nature of the C-bands and giemsa bands.

Explains the process of paramutation in the study of genetics. Survey of literature on the abnormal manifestation of chromosome components that control developmental and metabolic reactions; Early investigations on the paramutation in maize and analysis of the paramutant phenotype; Genetic fine structure of R-stippled allele.

Explains the mechanism of intragenic recombination. Examination of marker effects in fission yeast and in Ascobulus where two alleles were virtually at the same site of the sample under tetrad analyses; Theory on the distortion of the maps of genetic fine structure of a specific marker; Repair of heteroduplexes and the general marker effects.

This is a selective review of five major topics intensively investigated during the last several years. They are the polygeny of immune responsiveness, immune responses to infectious agents, genetic regulation of immune responses in man, specific immune response genes in mice and guinea pigs, and mechanisms of Ir (immune response) gene action. Some 70 key references are cited to enable the (immune response) gene action. Some 70 key references are cited to enable the reader to pursue any of these topics in greater depth. To save space, more recent or definitive articles are listed. Hopefully, none of the now numerous workers in this field will feel slighted by the selective emphasis inherent in this overview. [ABSTRACT FROM AUTHOR]

Presents a historical background on the study of population genetics. Natural selection and the theory of population genetics; Appearance of the first rough estimates of genic variation in small biological samples; Challenges in the direct testing of the theory of natural selection and the discovery of vast amounts of genetic polymorphism in a wide diversity of organisms.

This review is addressed to the biochemical events that underlie the early phases of the meiotic cycle. Late activities such as chromosomes disjunction and special processes involved in gametogenesis are excluded from this article. Of primary concern are the prophase stages of meiosis during which homologous chromosomes pair and presumably undergo crossing-over. These two events are fundamental to genetic recombination and constitute a major and universal feature of meiosis. In reviewing the field from the standpoint of biochemical mechanisms we have one general concern which is best to state at the outset. The sources of evidence on biochemical activities during meiosis are few. Biochemical analyses of meiosis in yeast are just beginning and will not be reviewed here. The bulk of our information comes from analyses of liliaceous plants, but their study has been pursued in very few laboratories. The credibility of the conclusions drawn from biochemical studies depends to a large extent upon the degree to which they are consistent with the information provided by genetics and cytology. Genetic approaches to intragenic recombination in yeast were surveyed two years ago. The cytology and fine structure of meiotic cells from various sources have been fully reviewed in the previous volume and genetic aspects of meiosis will be discussed in the succeeding one. No incontrovertible evidence yet exists for the occurrence of crossing-over during the pachytene stage and no demonstration is yet available that zygotene synapsis is an essential condition for crossing-over. The controversies surrounding the relationship of synapsis to crossing-over and/or disjunction are rather lively and have been competently presented elsewhere. No attempt will be made in this review directly to challenge the substance of these controversies. Instead, the reader will be put in company with appreciable circumstantial evidence which supports the simple tie between synapsies and crossing-over. In writing this artile, we have favored the view that crossing-over between homologous chromosomes follows and is dependent upon chromosome synapsis. The data presented may indeed have considerable bearing on the correctness of the underlying proposition. [ABSTRACT FROM AUTHOR]

The article discusses a few ideas about the control of cutaneous biology by topical medication. It states that there are two rather distinct groups of researchers in the field of percutaneous absorption. They are probably best classified as theoreticians and practitioners. Theoreticians are primarily physical chemists who establish strict mathematical relationships of penetration based on general theory and observations of simple membrane structures. In general, they try to avoid working with human or animal skin because these perverse models generally fail to substantiate their predictions based on simpler systems and theoretical models.

The importance of the stratum corneum as the rate-limiting barrier to perceutaneous penetration has been well documented in the literature. Data have also been reported which suggest that the barrier function of this zone varies among different regions of the body. However, little attention has been given to regional variation of two morphologic parameters know to affect permeability--thickness and number of cell layers. In the present study, significant regional variation in both the mean thickness and the mean number of cell layers has been documented for four selected , sample regions of the body of a population of six adult volunteers, and for two more homogeneous subgroups separated by sex and age. While the pooled data from the total population and the pooled data from the male and female subgroups are in general agreement. It has been shown that there is also marked individual variation within a region that is characteristic and specific for each individual. The number of cell layers appears to account for the variation in thickness. [ABSTRACT FROM AUTHOR]

Primary epidermal cell cultures and fibroblasts (1st or 2nd subculture), both isolated from embryonic or newborn mouse skin, were tested for differences in membrane antigens by use of rabbit antimouse sera, developed against mouse lymphatic cells or against epidermal material scraped from adult mouse skin. The antisera against mouse tissues were highly reactive in the mixed hemadsorption technique when tested against epidermal or fibroblastic cells from three mouse inbred strains (C57BL/6, B10LP, C3H). Absorption in vivo of these sera by injecting 0.1 ml serum per 25 mg mouse body weight i.p. into a mouse of the appropriate strain reduced all activity from the sera when tested against fibroblasts. The absorbed serum against lymphatic tissue was also negative when applied to epidermal cells. The absorbed antiepidermal serum, however, remained highly reactive against epidermal cells from all three strains. This reaction was observed immediately after outgrowth and remained detectable for the following 6-8 days. The epidermal antigen may be used for testing the purity of the isolated cell fractions and might further serve to control the epidermal nature of permanent cell lines of epidermal origin. [ABSTRACT FROM AUTHOR]

The neurohypophysial hormones of a chondrostean, the sturgeon (Acipenser sp.), have been purified by adsorption onto neurophysin, dissociation of the complex hormone-protein by trichloroacetic acid precipitation and isolation of active peptides, from the supernatant solution, by paper chromatoelectrophoresis. Arginine vasotocin has been characterized by amino acid composition, chromatographic and electrophoretic migrations and pharmacological properties as well. The amount of arginine vasotocin (about 50 nmol per g pituitary powder) is intermediary between those found for bony fishes about 1000 nmo]/g) and cartilaginous fishes (about 5 nmol/g). A second hormone, which can be classified in the oxytocin-likc type by its electrophoretic nigration and its pharmacological properties, has been disclosed. The very weak amount did not allow chemical identification. However the chromatographic behaviour and the pharmacological ‘profile’ indicate that this hormone differs from the six known oxytocin-like peptides. [ABSTRACT FROM AUTHOR]

The population variation of leaf and inflorescence characters of Stachys palustris L., S. sylvatica L. and the hybrid S. x ambigua Sm. in Britain has been studied and shows S. palustris and S. x ambigua to intergrade. S. palustris varies extensively both within and between populations and, from studies of the variation of leaf and rhizome characters in wet and dry soil, the 'dry-ground' form is shown to be an ecotype. S. sylvatica is less variable, both within and between the populations sampled. S. palustris outbreeds more readily than S. sylvatica and this difference in breeding system may be responsible for the patterns of variation exhibited by the parents. Attempts to backcross S. x ambigua to either S. palustris or S. sylvatica have been totally unsuccessful. The intergradation between S. palustris and S. x ambigua is unlikely to be the result of introgressive hybridization but is principally produced since first, S. palustris exhibits a much greater range of variation than S. sylratica and secondly, the F1 is not intermediate but closer to S. palustris. [ABSTRACT FROM AUTHOR]

Heteranthelium is a monotypic genus in the tribe Triticeae represented by an annual diploid species, H. piliferum. The spike of this species is quite different from other members of the tribe. In an attempt to elucidate the genetic relationships to other genera of the tribe, H. piliferum was crossed with various species of Aegilops, Agropyron, Eremopyrum, Henrardia and Hordeum. From these crosses F1 hybrids of (1) Heteranthelium piliferum (2x) × Eremopyrum bonaepartis (2x) and (2) Heteranthelium piliferum × Hordeum depressum (4x) were produced. At the same time F1 hybrids of (3) Eremopyrum bonaepartis × Hordeum depressum was also obtained. The hybrid under (1) showed subnormal growth and the shape of the spikes was of Eremopyrum-type, while the spikelets were intermediate. Growth of the hybrid under (2) was vigorous and the spike morphology was intermediate between the parents. A solitary spikelet with two glumes and a single spikelet at each rachis node like the Heteranthelium parent was observed but no rudimental spikelets which are the characteristic of Heteranthelium were found. Growth of the hybrid under (3) was very vigorous and the shape of the spikes was of Hordeum type. However, floral construction at each rachis node was very complicated. Rachis nodes with three glumes and a single spikelet were the most common. Sterility of all three combinations was complete. Average chromosome pairing per cell of the F1 hybrids was in (1) 0.04 bivalents and 13.93 univalents, in (2) 0.00 trivalents, 5.06 bivalents and 10.88 univalents, and in (3) 0.00 quadrivalents, 0.01 trivalents, 5.50 bivalents and 9.97 univalents. Judging from the chromosome pairing in (1), (2) and (3), a high bivalent formation in (2) and (3) is attributable to autosynthesis of chromosomes derived from the Hordeum parent. It is concluded that there is no homology among the genomes of those three species. Considering morphological features, geographical distribution, intergeneric cross-ability and genetic relationships of Heteranthelium piliferum, it is concluded that the monotypic genus Heteranthelium is a distinct entity in the tribe Triticeae. This taxon has evolved as an annual during the process of adaptation to rather dry habitats of the Mediterranean climatic regions in the course of generic differentiation of the tribe. [ABSTRACT FROM AUTHOR]

Observations on the biology of carrot fly (Psila rosae (F.)) were made in the important carrot-growing areas of eastern England in the period 1948-72. Adults of the spring generation usually emerged in May and peak numbers were usually swept during the third and fourth weeks of May. Eggs were found from the end of May and larval damage was evident from late June. Calculations of accumulated day-degrees of air temperature above 42°F (5.6°C) showed that peak emergence could generally be associated with a total of 422 day-degrees commencing on 1 April. Both separate and combined totals of accumulated day-degrees for February and March were markedly different in years of early and late fly emergence. Adults of the second generation appeared from late July onwards and oviposition occurred mainly during August and September, although in some years eggs were found much later. Resulting larval damage was present by October and increased in severity until the crop was harvested. [ABSTRACT FROM AUTHOR]

Antigen-induced migration inhibition of guinea-pig peritoneal cells was clearly detectable after in vitro irradiation with 5000 to 10,000 rads, but it was weaker than with non-irradiated cells. An attempt was made to quantify this effect by diluting immune cells with non-immune peritoneal cells. The titrations showed a drop of four two-fold dilution steps after 5000 rads and even 2000 rads caused a small drop to 50 per cent efficiency when compared to non-irradiated cells. [ABSTRACT FROM AUTHOR]

Delves into geography and botany. Discussion of the effects of the Darwin theory upon plant geography; Description of some of the current trends in plant geography; History of the development of geography.

Discusses the role of geographic variation in the biological nature of species and speciation. Application of multivariate techniques; Factor analysis; Geographic maps of variation; Causal analysis of geographic variation; Association of characters in phenetic distinctions; Variation in gene frequencies relative to environmental variation.

Presents a study on seed predation by animals. Involvement of all levels of animal-plant interaction from the internal energy budget of individuals to the entire community; Dependence of the successful development of a seedling on the seed's dispersal; Difference between predators and leaf eaters in the coevolution of seed predators and seeds.

Examines the theory of feeding strategies. Maximization of the performance of feeding as measured in net energy yield; Trisections the primary task of the theory; Four key aspects of feeding strategies.

Discusses the karyotype in plant systematics. Tenability of the idea of the karyotype as a characteristic applied to generic definitions; Association of a karyotype with a complex of characters circumscribing a family, tribe, genus, species or race; Implications of the correspondence of certain peculiarities to higher taxonomic subdivisions.

Discusses principles of clustering in taxonomy. Use of the term cluster to require the separation by some comparable negative relationship from all other elements that might be potential members of the cluster; Importance of the distinction between terminologies related to the clustering procedures; Role played by purely logical considerations in clustering theory.

Presents the second article of a two-part series that highlighted the importance of reproductive characteristics as major determinants of evolutionary trends in angiosperms. Exploratory review of the characteristics of seeds and seedlings; Interactions that take place between the termination of flowering; Reason for the rarity of comparative systematic ecological studies on seeds and seedlings.

Discusses the hypothesis of nonspecificity and taxonomic congruence. Condition for the acquisition of a broad representation of genomes; Association of the notion of taxonomic congruence to the nonspecificity congruence; Significance of the hypothesis in terms of the intellectual milieu at the time of its proposal.

Discusses the significance of intestinal microflora in herbivory. Formation of an organ by the expansion of the alimentary tract parts of herbivores; Utilization of the vitamins and proteins synthesized in the formed organ by the animals; Absorption of microbial fermentation products from the formed organ.

Focuses on analogies of language to life. Communication systems operating in life; Properties of symmetry, meaning, arbitrariness and style; Biological level at which information is transmitted.

Explains analytical psychology as a modern science. Psychic phenomena as properties of life; Interplay between the observed biological needs of man and his environment; Analogy between a theoretical entity in the universe and the theoretical entity in the psyche.

The article enumerates the plant species that occur in Surinam and compiles a key to these species. Of the seven species known up to the present date from Surinam, three are of recent collection and are not treated in the Flora of Surinam. The article also included three species of Strychnos that have not yet been collected in Surinam.

Electronic integrators are employed as analog editing devices to provide readings of the time integral of bioelectronic signals. Their advantage lies in the deletion of unnecessary aspects of the signal, and thereby in the use of less of the space of the recording medium initially, and later in the saving of work in the task of culling the desired data from extraneous information. The use of an integrator for a particular channel of psychophysiologic data presupposes that the investigator is primarily interested in the amplitude or activity aspect of the channel.

The effects on apparent photosynthesis in the green alga Scenedesmus quadricauda of four chelating substances, 8-hydroxyquinoline, (= oxine), β-isopropyltropoIone (= β-thujaplicin), sodium dimethyldithiocarbamate and 3-(β-hydroxyethyl)-C-pentamethylene-3-aza-dithiocarbamate have been investigated. The first three compounds mentioned had all an inhibitory effect on photosynthesis, measured as oxygen production with a manometric, a volumetric or a polarographic method. In combination with certain concentrations of CuSO4 bimodal dose response curves were observed, similar to those obtained on the growth of different microorganisms. Calculations of the amounts of different complexes that appeared in the nutrient solutions during the experiments are compared with the recorded degrees of inhibition. The results strongly Indicate that the 1 : 1-complexes between Cu2+ and the chelating substances are the most toxic agents at low concentrations of these compounds. [ABSTRACT FROM AUTHOR]

Discusses the integration of population genetics and ecology with other disciplines into a coherent evolutionary biology of populations. Selection of coefficients of genetics taken as given without worrying about their origin in the physiology; Integration of genetics with ecology.

Analyzes the genetic basis of behavior. Reasons why behavioral phenotypes were not different in principle from nonbehavioral ones; Claims that behavioral traits are uniquely more complex than nonbehavioral variables.

Explains the characteristics and stages in the developmental biology of Drosophila. Use of mutants for developmental studies; Analysis of the pre-embryonic and embryonic development; Growth of Drosophila cell sin cell and organ culture.

Comments on the progress of human genetics research from 1967 to 1970. Tendency of research directions to become sub-specialized into the areas of cytogenetics, biochemical genetics, immunogenetics, statistical and population genetics and clinical genetics; Explanation of the disadvantages of sub-specializations.

Describes certain lines of investigation of mutagenic mechanisms. Correlations between amino acid substitutions, tertiary structure and functional damage; Methods of analysis of mammalian mutation; Means of separating the direct effects of mutagens from those effects promoted or inhibited by organ-specific metabolism.

Presents a review of literature on bee genetics. Classification and geographical variation; Cytology and cytogenetics; Phenogenetics; Disease and pest resistance; Behavior genetics; Maintenance of genetic variability; Breeding for economic characteristics.

Explains various aspects of normal and abnormal cell surface genetics. Instances of variation from individual to individual as an example of genetic polymorphism; Categories of cell surface antigenetic disparity; Modification of the surfaces of tumor cells; Tumor antigens specified by cellular genes.

Emphasizes the progress made in the understanding of the phenomenon in developmental genetics that embryologists call "determination,". Mechanism of gene amplification; Role of nucleic acid and protein synthesis in eukaryotes; Distinction between cell determination and cell differentiation made by many investigators.

Examines the aspects of the competent state in genetic transformation. Characteristics of the adsorption and uptake in the early steps in genetic transformation; Properties of competent cells; Protein synthesis and cell wall modification during acquisition of competent state.

Examines the results of an experimental polyploidy in the animal kingdom. Role of polyploidization in the animal ontogenesis; Significance of animal polyploidy for animal phylogenesis; Importance of genome multiplication for the processes of genetic information for the phenotypical realization of the genotype.

Presents a review of literature on human population genetics. Models of population replacement and renewal; Population size; Patterns of reproduction; Patterns of migration; Interrelationships; Requirements of the future.

Presents a review of literature on transduction mechanisms. Formation of transducing particles; Generalized transduction; Specialized transduction using the hybrid formation model; Fates of transducing genetic elements in recipient bacteria.