A newly established human acute lymphoblastic leukemia cell line with characteristics of the earliest B-cell maturation

A new human acute lymphoblastic leukemia (ALL) cell line, designated HBL-3, was established from the bone marrow of a patient with non-T-ALL. The HBL-3 cell line expressed B4 (CD 19), BA-1 (CD 24) and HLA-DR antigens, but not surface immunoglobulin (SIg) or cytoplasmic immunoglobulin (CIg). The cell line lacked the common acute lymphoblastic leukemia antigen (CALLA) and antigenic markers characteristic of T-cell and myeloid cell lineages. The HBL-3 cells had structural rearrangements of both the homologous chromosome 9s, including a translocation with chromosome 1 which has been reported in a patient with common ALL. The cell line had rearranged immunoglobulin heavy chain genes but retained germ-line κ light chain genes and germ-line T-cell receptorβ- and γ-chain genes. The HBL-3 cell line was strongly positive for terminal deoxynucleotidyl transferase (TdT). These findings indicate that the HBL-3 cell line is derived from the earliest B-cell committed to B-cell lineage.     

New Data on Therangospodus oncalensis from the Berriasian Fuentesalvo Tracksite (Villar del Río,Soria, Spain): An Example of Gregarious Behaviour in Theropod Dinosaurs

Therangospodus oncalensis is a Berriasian theropod ichnotaxon from the Cameros Basin (Soria Province, Spain). We discovered new trackways assigned to this ichnotaxon during cleaning and conservation works at the type locality (Fuentesalvo), enabling us to describe it more precisely. Therangospodus oncalensis was made by a medium-sized theropod dinosaur and is characterized by a single tapering pad on each toe, a rounded heel impression and a narrow trackway. In addition to having similar morphometric characteristics, most of the trackways at the Fuentesalvo site show comparable size and biometric features. This indicates that, in terms of size and age, a homogeneous population of a single theropod species could have produced these tracks. Moreover, the similar orientation (lying within a range of only 15°) and estimated speed suggested by most of the trackways, lend weight to the hypothesis that the trackmaker of Therangospodus oncalensis was able, at least at times, to move in structured packs displaying gregarious behaviour. Furthermore, this is the first structured pack of theropods to be described.     

The Oldowan site Aïn al Fil (El Kowm,Syria) and the first humans of the Syrian Desert

At present, the oldest traces of human cultures are found in Eastern Africa. New discoveries set anew the questions about human and animal dispersal into Eurasia. For over 1.8 million years, humans have been present in the Levant. An extensive program of surveys and excavations in the Syrian Desert showed that this part of the world was a very ancient land of settlement. In Central Syria, the oldest site, Aïn al Fil in the region of El Kowm, was excavated in 2008 and 2010. The lithic industry in the lowest layer can be characterized by numerous unretouched flakes, pebble-tools and core-like artefacts. This assemblage is typical in a broad sense of archaic Palaeolithic the debitage of which corresponds to mode 1. From a techno-typological point of view, this industry tallies quite well with the so-called Oldowan stage. It shows remarkable similarities with the oldest African assemblages. From a chronologic point of view, these levels occur before three positive events in the Matuyama paleomagnetic sequence. It seems consistent to place the Oldowan sequence around 1.8 Ma BP within the Olduvai subchron or just before Olduvai/Matuyama reversal limit. Together with those of the neighbouring site Hummal, these levels would be the oldest traces of human presence ever found in Syria. In the Levant, the first humans not only occupied favourable zones but regularly ventured deep into less welcoming environments suggesting an astonishing flexibility in their behavioural and survival skills.     

Chronology of the Middle to Upper Palaeolithic transition at Abric Romaní, Catalunya

This paper presents new data from Abric Romaní, a key site in the region of Catalunya, northeastern Iberia, which is central to discussions of the transition between the Middle and Upper Palaeolithic in Europe. Until now, the Mid-Upper Paleolithic transition had been dated at the site through samples from the remaining baulk sections of levels A and B (typologically classified as ‘earliest Aurignacian’ and Mousterian, respectively) at the rear of the rockshelter, which were left from excavations in the late 1900s and early 1910s. We dated samples of bone and charcoal from these remnant sections with accelerator mass spectrometry (AMS) methods. We also analysed several humanly-modified artefacts (bone points and perforated shells) excavated from other areas of the same layers. From the initial series, we obtained ages of c. 20 ka BP (thousands of years before present); much younger than expected if they indeed dated to the early Upper Palaeolithic. We sampled additional material to test the robustness of these initial ages, and older determinations that were more comparable with the chronology outlined by [Bischoff et?al., 1988] and [Bischoff et?al., 1994] resulted. All of the old and new results have been compared in a Bayesian model using the new INTCAL09 ¹⁴C calibration dataset. The results appear to confirm the suggestion of some researchers (e.g., Zilhão and d’Errico, 1999) that there was no Aurignacian in the north of Iberia until c. 36,500 BP. The chronometric model shows a good level of agreement between the radiocarbon and U-series chronologies previously obtained, and the new results published in this paper.     

Spin-Labeled Nucleotide Mobility in the Boundary of the EcoRI Endonuclease Binding Site

Abstract

A complex consisting of the EcoRI endonuclease site-specifically bound to spin-labeled DNA 26mers was prepared to provide a model system for studying possible conformational changes resulting from protein binding. EPR was used to monitor the mobility of the spin labels that were strategically placed in position 6, 9, or 11 with respect to the dyad axis of the 26mer. These positions are located within the flanking region on either side of the EcoRI hexamer binding site. This allows the monitoring of potential distal structural changes in the DNA helix caused by protein binding. The spectral line shapes indicate that the spin label closest to the EcoRI endonuclease binding site, i.e., in position 6, is most influenced by the binding event. The EPR data are analyzed according to a model that distinguishes between spectral effects due to a change in the hydrodynamic shape of the complex and those resulting from local variations in the spin-label mobility as characterized by a local order parameter S. S reflecting the motional restriction of the spin-labeled base is 0.20 ± 0.01 for all three oligomers as well as for the two complexes with the label in position 9 or 11, while the position 6 labeled complex yields S=0.25. To further evaluate the origin of the slightly larger EPR effect observed with position 6 labeled material, molecular dynamics (MD) simulations were used to explore the space accessible to the probes in positions 6, 9, and 11. MD results gave similar nitroxide trajectories for all three labeled 26mers in the absence or presence of EcoRI. Thus, the small position 6 effect is attributed to a structural distortion in the major groove of the DNA at this location possibly corresponding to a bend induced by protein binding. The observation that the spectral changes are small indicates the absence of any significant structural disruption being propagated along the helix as a result of protein binding. Also, the fact that the line shape of the 26mers did not change as expected from hydrodynamic theory in view of the significant increase in molecular volume upon protein binding suggests that there are additional relaxation processes involving the protein and nucleic acid.     

Palaeobiology and evolution of the earliest agglutinated Foraminifera: Platysolenites, Spirosolenites and related forms

Tubular agglutinated fossils of Platysolenites antiquissimus Eichwald, 1860, P. cooperi n.sp. and Spirosolenites spiralis Glaessner, 1979 are examined from selected lower Cambrian successions in Avalonia (England; Wales; Newfoundland) and Baltica (Russia and Estonia). Platysolenites cooperi n.sp. is shown to extend below the first appearance of P. antiquissimus in the Neoproterozoic-Cambrian boundary stratotype region, SE Newfoundland, and to occur at higher stratigraphic levels in Wales and Finnmark. Taphonomic, teleological and ultrastructural studies on well-preserved material are consistent with a similar grade of organization and mode of life for P. antiquissimus and the living astrorhizacean foraminiferid Bathysiphon. However, agglutinated proloculi are here described from both rectilinear P. antiquissimus and coiled S. spiralis, which suggests that neither were typical astrorhizaceans.     

Honghea xui gen. et sp. nov., the second Earliest Jurassic damsel-dragonfly (Odonata: Campterophlebiidae) from the Junggar Basin,NW China

A new campterophlebiid damsel-dragonfly, Honghea xui gen. et sp. nov., is described from the Lower Jurassic Badaowan Formation of the Junggar Basin, NW China. This is the second Chinese Campterophlebiidae recorded for the earliest Jurassic, reflecting the quick diversification and radiation of the damsel-dragonflies during this period. H. nouveau onghea gen. nov. is closely related to Chinese genera Zygokaratawia and Ctenogampsophlebia, both from the Middle Jurassic of the Daohugou Biota; but differs from these genera in having a larger wing size, RP2 slightly distal of Sn, and a narrower area between IR2 and RP3/4.     

长江三峡东部早奥陶世早期的几丁虫

该文介绍了国内外关于早奥陶世早期的几丁虫研究现状,描述了峡东地区早奥陶世早期分乡组的几丁虫3属6种:Conochitina symmetrica,Conochitina cf.pomoti,Conochitina sp.A,Conochitina sp.B,Lagenochitina cf.combazi,Cyathochitina sp.。根据共生的笔石和牙形石以及这些几丁虫在世界其它地区的地质分布,讨论了其时代与对比问题。指出了长江三峡东部早奥陶世早期的几丁虫面貌与世界各地同期几丁虫生物古地理的亲缘关系。     

Conserved Sequences of Prokaryotic Proteomes and Their Compositional Age

A full repertoire of octapeptides which are present in at least 30 bacterial proteomes of total 131 currently available is computationally derived and filtered. An original search technique is used that, in terms of computational time and memory, is similar to the Suffix tree method. The presence of a given sequence in a large number of proteomes qualifies it as a conserved sequence. The larger the number of proteomes where it is found, the higher is the conservation. The concept of compositional age of the amino acid sequences (“compositional clock”) is introduced for the first time. The compositional age is calculated on the basis of the consensus temporal order of appearance of amino acids in early evolution. The correlation between the compositional age and the sequence conservation is established. [Reviewing Editor: Martin Kreitman]