Cultural conservatism and variability in the Acheulian sequence of Gesher Benot Ya‘aqov

The Acheulian Technocomplex exhibits two phenomena: variability and conservatism. Variability is expressed in the composition and frequencies of tool types, particularly in the varying frequencies of bifaces (handaxes and cleavers). Conservatism is expressed in the continuous presence of bifaces along an immense time trajectory. The site of Gesher Benot Ya‘aqov (GBY) offers a unique opportunity to study aspects of variability and conservatism as a result of its long cultural-stratigraphic sequence containing superimposed lithic assemblages. This study explores aspects of variability and conservatism within the Acheulian lithic assemblages of GBY, with emphasis placed on the bifacial tools. While variability has been studied through a comparison of typological frequencies in a series of assemblages from the site, evidence for conservatism was examined in the production modes expressed by the reduction sequence of the bifaces. We demonstrate that while pronounced typological variability is observed among the GBY assemblages, they were all manufactured by the same technology. The technology, size, and morphology of the bifaces throughout the entire stratigraphic sequence of GBY reflect the strong conservatism of their makers. We conclude that the biface frequency cannot be considered as a chrono/cultural marker that might otherwise allow us to distinguish between different phases within the Acheulian. The variability observed within the assemblages is explained as a result of different activities, tasks, and functions, which were carried out at specific localities along the shores of the paleo-Hula Lake in the early Middle Pleistocene.     

Quantitative determination of ferritin by electroimmunoassay

A method for the quantitative determination of tissue ferritin protein is described. It is based on the electroimmunoassay of Laurell [Laurell, C. B. (1966) Anal. Biochem.15, 45–52] and uses the iron content of ferritin for its identification. It measures as little as 0.1 μg of ferritin protein, requires only a few milligrams of tissue, and is rapidly performed.     

Landscape Alteration by Pre-Pottery Neolithic Communities in the Southern Levant – The Kaizer Hilltop Quarry,Israel

This study focuses on Kaizer Hill, a quarry site located in the vicinity of the city of Modiin where remains of a single prehistoric cultural entity assigned to the Pre-Pottery Neolithic A were discovered. A systematic survey revealed that large-scale quarrying activities have left damage markings on the bedrock of the Hilltop and its slopes. We aim to present here our findings from the Hilltop, which are concerned with the human impact on rock surfaces and the lithic artifacts retrieved during the survey. It is evident that the Pre-Pottery Neolithic A inhabitants of the area changed their landscape forever, “stripping” the caliche surface and penetrating it in search of flint bedded in the bedrock.     

Testing transgenic regulatory elements through live mouse imaging

To overcome positional and methylation effects on transgene expression, we developed a universal cloning cassette for in vivo assessment of regulatory elements using the luciferase reporter gene and the CCCD camera. Monitoring luciferase expression pattern in live mice enables screening of large numbers of transgenic founders quickly and inexpensively. We demonstrate that in the engineered transgenic mice, the chicken beta-globin 5'HS4 insulator did not always provide the desirable expression pattern, and the Island Element, responsible for the demethylation of the surrounding DNA region, was not beneficial. Both tested liver-specific and developmentally regulated promoters exhibited the expected expression pattern in most transgenic founders.     

Activin regulation of the follicle-stimulating hormone beta-subunit gene involves Smads and the TALE homeodomain proteins Pbx1 and Prep1

FSH is critical for normal reproductive function in both males and females. Activin, a member of the TGFbeta family of growth factors, is an important regulator of FSH expression, but little is known about the molecular mechanisms through which it acts. We used transient transfections into the immortalized gonadotrope cell line LbetaT2 to identify three regions (at -973/-962, -167, and -134) of the ovine FSH beta-subunit gene that are required for full activin response. All three regions contain homology to consensus binding sites for Smad proteins, the intracellular mediators of TGFbeta family signaling. Mutation of the distal site reduces activin responsiveness, whereas mutation of either proximal site profoundly disrupts activin regulation of the FSHbeta gene. These sites specifically bind LbetaT2 nuclear proteins in EMSAs, and the -973/-962 site binds Smad4 protein. Interestingly, the protein complex binding to the -134 site contains Smad4 in association with the homeodomain proteins Pbx1 and Prep1. Using glutathione S-transferase interaction assays, we demonstrate that Pbx1 and Prep1 interact with Smads 2 and 3 as well. The two proximal activin response elements are well conserved across species, and Pbx1 and Prep1 proteins bind to the mouse gene in vivo. Furthermore, mutation of either proximal site abrogates activin responsiveness of a mouse FSHbeta reporter gene as well, confirming their functional conservation. Our studies provide a basis for understanding activin regulation of FSHbeta gene expression and identify Pbx1 and Prep1 as Smad partners and novel mediators of activin action.     

Elucidating mechanisms underlying robustness of morphogen gradients

Morphogen gradients play a pivotal role in most phases of developmental patterning. To ensure proper patterning, reproducible gradients are established under diverse environmental conditions and genetic backgrounds. We refer to the capacity to buffer fluctuations in gene dosage or environmental conditions as 'robustness'. By theoretical analysis of mechanisms that facilitate robustness, it is possible to unravel the machinery responsible for generating the spatial distribution of morphogens.     

In silico screening of a saturated mutation library of tomato

A comprehensive mutant population is a basic resource for exploring gene function. We developed an isogenic tomato 'mutation library' in the genetic background of the inbred variety M82. A total of 13 000 M(2) families, derived from EMS (ethyl methane sulfonate) and fast-neutron mutagenesis, were visually phenotyped in the field and categorized into a morphological catalog that includes 15 primary and 48 secondary categories. Currently, 3417 mutations have been cataloged; among them are most of the previously described phenotypes from the monogenic mutant collection of The Tomato Genetics Resource Center, and over a thousand new mutants, with multiple alleles per locus. The phenotypic database indicates that most mutations fall into more than a single category (pleiotropic), with some organs such as leaves more prone to alterations than others. All data and images can be searched and accessed in the Solanaceae Genome Network (SGN) on a site called 'The Genes That Make Tomatoes' (http://zamir.sgn.cornell.edu/mutants/).