Hybridomas: a new dimension in biological analyses

Since the first report of hybridomas producing monoclonal antibodies by Kohler and Milstein in 1975, this technique has spread to nearly all areas of biological, biochemical, and biomedical research. Watching the use of these methods spread from immunologists to cell biologists, developmental biologists, biochemists and to other biological disciplines and observing the nearly logarithmic increase in publications using these reagents has been in itself fascinating and informative. An overview of the development of this technology and its applications is presented including the use of monoclonal antibodies to study cell surface molecules, differentiation antigens, receptors, and histocompatibility antigens. The use of these antibodies to analyze microorganisms and parasitic antigens as well as their use in the genetic analysis of human cell surface antigens and the detection of polymorphic variation in enzymes and other proteins is discussed. Examples of the application of monoclonal reagents to the study of tumor cell biology including the labeling of metastatic tumor cells and the detection of cell surface molecules implicated in the regulation of growth control and cell division are provided.     

The potential of morphometrically based phylo-zonation: Application of a Late Cenozoic planktonic foraminiferal lineage

Phylo-zonations (or lineage-zonations) are based upon morphological changes within individual evolutionary lineages. These zonations, although potentially of use for stratigraphic subdivision and correlation, often suffer from a lack of quantitative exactness in the definitions of chronospecies. Thus exact reproducibility is hindered for stratigraphic determinations.The potential of morphometrically defined phylo-zonations is demonstrated on a temperate South Pacific Late Cenozoic lineage of planktonic foraminifera (Globorotalia conoidea through intermediate forms to Globorotalia inflata in DSDP Site 284) exhibiting phyletic gradualism. Our sampling interval is about 0.1 m.y. during the last 8 m.y. Changes in the number of chambers in the final whorl, test conicalness, percentage of keeled forms, and test roundness or inflatedness, are used to quantitatively define the following five chronospecies: G. conoidea (Late Miocene; 6.1–>8.3 m.y.), G. conomiozea (latest Miocene; 5.3–6.1 m.y.), G. puncticulata sphericomiozea (earliest Pliocene; 4.5–5.3 m.y.), G. puncticulata puncticulata (Early-Middle Pliocene; 2.9–4.5 m.y.), and G. inflata (Late Pliocene-Quaternary; 0–2.9 m.y.). This phylo-zonation is directly applicable to temperate cool subtropical Southern Hemisphere areas where the evolution took place (Kennett, 1967, 1973; Scott, 1979). It is still not known if the lineage occurs elsewhere; thus the applicability of the phylo-zonation over broader areas is still uncertain. Trends in general size and aperture shape seem to be climatically controlled, and thus may be only of local stratigraphic utility.The practical applications of morphometric phylo-zonation for stratigraphy is to a large extent dependent upon the amount of time and effort required to statistically define the trends. Experiments with large numbers of subsamples from this lineage demonstrate that accurate stratigraphic determinations are possible from measurements on only 15 specimens per sample, except for those very close to chronospecies boundaries.     

Late Quaternary paleoceanography as recorded by benthonic foraminifera in Strait of Sicily sediment sequences

At specific times during the late Quaternary, a widespread low-salinity surface water layer was produced over the eastern Mediterranean which created stagnant conditions and associated deposition of sapropelic muds in the deep basins. The Strait of Sicily has been positioned above the anoxic deeper water masses and is therefore devoid of sapropel deposits. Sediment sequences in the region contain a valuable record of upper bathyal (200–1000 m) benthonic foraminiferal change during times of deep-basin stagnation.Quantitative examiniation of benthonic foraminiferal assemblages in Strait of Sicily Quaternary cores generally reveals changes coeval with sapropels S1, S2, S4, S5, and S6. The benthonic foraminiferal expression is seen as increases in frequency ofGlobobulimina affinis, Globobulimina pseudospinescens, Chilostomella mediterranensis, Bolivina dilatata, and otherBolivina species during intervals corresponding to the episodic abyssal stagnation events. Some cores also display a decrease inCassidulina carinata and an increase inArticulina tubulosa.Similar assemblage changes have been previously documented to be closely associated with the sapropel layers in the deep basins of the eastern Mediterranean (the actual sapropel layers usually do not contain benthonic foraminifera). However, in the Strait of Sicily area, the species exhibit less drastic changes than in the deep eastern basins because of the less severe anoxic conditions. In the deep eastern basins, benthonic foraminifera almost totally disappeared in sapropel layers; at the same time, there was a general reduction in foraminiferal numbers in the shallower Strait area.     

Hybridomas: A new dimension in biological analyses

Summary Since the first report of hybridomas producing monoclonal antibodies by Kohler and Milstein in 1975, this technique has spread to nearly all areas of biological, biochemical, and biomedical research. Watching the use of these methods spread from immunologists to cell biologists, developmental biologists, biochemists and to other biological disciplines and observing the nearly logarithmic increase in publications using these reagents has been in itself fascinating and informative. An overview of the development of this technology and its applications is presented including the use of monoclonal antibodies to study cell surface molecules, differentiation antigens, receptors, and histocompatibility antigens. The use of these antibodies to analyze microorganisms and parasitic antigens as well as their use in the genetic analysis of human cell surface antigens and the detection of polymorphic variation in enzymes and other proteins is discussed. Examples of the application of monoclonal reagents to the study of tumor cell biology including the labeling of metastatic tumor cells and the detection of cell surface molecules implicated in the regulation of growth control and cell division are provided. Presented in the symposium on The Biology of Hybridomas at the 32nd Annual Meeting of the Tissue Culture Association. Washington, D.C., June 7–11. 1981. This symposium was supported in part by the following organizations: Bethesda Research Laboratories, Cetus Corporation, Hybritech Incorporated, MAB-Monoclonal Antibodies, Inc., National Capital Area Branch of the Tissue Culture Association, New England Nuclear Corporation, and Ortho Pharmaceutical Corporation.     

Cloning, Analysis, and Chromosomal Localization of Myoxin (MYH12), the Human Homologue to the Mouse dilute Gene

The mouse dilute gene encodes a novel type of nonmuscle myosin that structurally combines elements from both nonmuscle myosin type I and nonmuscle myosin type II. Phenotypically, mutations in the mouse dilute gene result not only in the lightening of coat color, but also in the onset of severe neurological defects shortly after birth. This may indicate that the mouse dilute gene is important in maintaining the normal neuronal function in the mouse. We report the isolation and sequencing of "myoxin" (MYH12), the human homologue of the mouse dilute gene, and its assignment to human chromosome 15.     

Environmental and management factors controlling the potentially invasive native species Violet Kunzea (Kunzea parvifolia)

Violet Kunzea (Kunzea parvifolia), a native shrub of eastern Australia, is reputed to form dense thickets in areas that have undergone significant landscape modification, and has been listed as an invasive native species for which clearing is permitted under the Native Vegetation Act 2003 (NSW). We quantified factors controlling its abundance in 81 sites within the Braidwood region of NSW, on the basis of 36 strata reflecting soil landscape, topographic position, aspect and canopy cover. Within each study site 34 variables describing environmental, disturbance, management and vegetation attributes were measured using a transect sampling technique and landowner surveys. An analysis of these data indicated that, in the sites we surveyed, Violet Kunzea is a common shrub present at relatively high mean levels of cover (44%), with no preferred topographic position or aspect. There were no significant associations between management activities such as slashing or grazing, and the cover of Violet Kunzea. Multiple regression modelling indicated that overstorey cover was the key variable explaining variation in the cover of Violet Kunzea, with an increase in cover of the shrub as overstorey cover declined. We conclude that a reduction in overstorey cover results in an increase in Violet Kunzea abundance as competition is removed, and the subsequent suppression of overstorey regeneration sets up a feedback loop facilitating the further expansion of Violet Kunzea and the contraction of overstorey cover. Approaches to the management of this species will therefore require long‐term commitments to conserve and restore overstorey cover.