Brief Note New Mastadon Finds from Southwestern Ohio

Author Institution: Department of Geology, University of Kentuck

The Pre-Illinoian Lake Clays of the Cincinnati Region

Author Institution: Department of Geology, University of CincinnatiPre-Illinoian clays have been known in Ohio since 1903 when W. G. Tight described their occurrence in the abandoned Teays River valley in south-central Ohio. Not until 1919 were similar clays noted in the Cincinnati region. These early occurrences were described from the unglaciated portions of northern Kentucky just south of Cincinnati, and their significance was not made clear. Because the clays occurred beyond what was then considered the Illinoian glacial boundary, the clays were called pre-Illinoian

Alx1, a member of the Cart1/Alx3/Alx4 subfamily of Paired-class homeodomain proteins, is an essential component of the gene network controlling skeletogenic fate specification in the sea urchin embryo

In the sea urchin embryo, the large micromeres and their progeny function as a critical signaling center and execute a complex morphogenetic program. We have identified a new and essential component of the gene network that controls large micromere specification, the homeodomain protein Alx1. Alx1 is expressed exclusively by cells of the large micromere lineage beginning in the first interphase after the large micromeres are born. Morpholino studies demonstrate that Alx1 is essential at an early stage of specification and controls downstream genes required for epithelial-mesenchymal transition and biomineralization. Expression of Alx1 is cell autonomous and regulated maternally through ß-catenin and its downstream effector, Pmar1. Alx1 expression can be activated in other cell lineages at much later stages of development, however, through a regulative pathway of skeletogenesis that is responsive to cell signaling. The Alx1 protein is highly conserved among euechinoid sea urchins and is closely related to the Cart1/Alx3/Alx4 family of vertebrate homeodomain proteins. In vertebrates, these proteins regulate the formation of skeletal elements of the limbs, face and neck. Our findings suggest that the ancestral deuterostome had a population of biomineral-forming mesenchyme cells that expressed an Alx1-like protein

The Dynamics and Regulation of Mesenchymal Cell Fusion in the Sea Urchin Embryo

AbstractCell–cell fusion occurs in a wide variety of developmental contexts, yet the mechanisms involved are just beginning to be elucidated. In the sea urchin embryo, primary mesenchyme cells (PMCs) fuse to form syncytial filopodial cables within which skeletal spicules are deposited. Taking advantage of the optical transparency and ease of micromanipulation of sea urchin embryos, we have developed methods for directly observing the dynamics of PMC fusionin vivo.A fraction of the PMCs was labeled with fluorescent dextran and transfer of the dye to unlabeled PMCs was followed by time-lapse, fluorescence microscopy. Fusion was first detected about 2 h after PMCs began to migrate within the blastocoel. Fusion proceeded in parallel with the assembly of the PMC ring pattern and was complete by the early gastrula stage. The formation of a single, extensive PMC syncytium was confirmed by DiI labeling of fixed embryos. When single micromeres were isolated and cultured in unsupplemented seawater, they divided and their progeny underwent fusion. This shows that the capacity to fuse is autonomously programmed in the micromere–PMC lineage by the 16-cell stage. PMC transplantations at late embryonic stages revealed that these cells remain fusion-competent long after their fusion is complete. At late stages, other mesenchyme cells (blastocoelar cells) are also present within the blastocoel and are migrating and fusing with one another. Fusion-competent blastocoelar cells and PMCs come into contact but do not fuse with one another, indicating that these two cell types fuse by distinct mechanisms. When secondary mesenchyme cells convert to a skeletogenic fate they alter their fusogenic properties and join the PMC syncytium, as shown by transfer of fluorescent dextran. Our analysis has provided a detailed picture of the cellular basis and regulation of mesodermal cell fusion and has important implications regarding molecular mechanisms that underlie fusion

Mississippian-Devonian Black Shales of Kentucky: East-West Transect in Five Cores from the Appalachian Basin to the Illinois Basin

Devonian-Mississippian black shales are widespread across North America and underlie nearly 70 percent of Kentucky (Kepferle and Roen, 1981; Ettensohn and others, 1988). These black-shale units are among the most thoroughly investigated format ions in the commonwealth, because t hey have sourced most of t he conventional hydrocarbons (Gooding and Ettensohn, 2008; Gooding, 2013), have been major producers of gas in both the Illinois and Appalachian Basins, and have major potential as unconventional producers in both basins. In fact, maturation indicators such as vitrinite reflectance and total organic carbon, from both basins, show that the shales are most ly mature and had a high potent ial to generate hydrocarbons (East and ot hers, 2012; Gooding, 2013; Ryder and others, 2013). In Kentucky, however, temporal and stratigraphic relationships between basins differ, and the units in each basin are known by different names, making cross-basin correlations difficult (Ettensohn and others, 1988). Thus, the purpose of this chart is to provide preliminary interbasinal correlations based on five cores (A-E) available at the Kentucky Geological Survey Earth Analysis Research Library. This chart correlates organic-rich shales across the Cincinnati Arch via radioactive stratigraphy and supplemental biostratigraphic control. Where available, commercial gamma-ray logs were used for correlation, but where unavailable, artificial gamma-ray logs, or radioactivity profiles, were produced using a hand held scintillometer (Ettensohn and others, 1979)

A large-scale analysis of mRNAs expressed by primary mesenchyme cells of the sea urchin embryo

The primary mesenchyme cells (PMCs) of the sea urchin embryo have been an important model system for the analysis of cell behavior during gastrulation. To gain an improved understanding of the molecular basis of PMC behavior, a set of 8293 expressed sequenced tags (ESTs) was derived from an enriched population of mid-gastrula stage PMCs. These ESTs represented approximately 1200 distinct proteins, or about 15% of the mRNAs expressed by the gastrula stage embryo. 655 proteins were similar (P<10-7 by BLAST comparisons) to other proteins in GenBank, for which some information is available concerning expression and/or function. Another 116 were similar to ESTs identified in other organisms, but not further characterized. We conservatively estimate that sequences encoding at least 435 additional proteins were included in the pool of ESTs that did not yield matches by BLAST analysis. The collection of newly identified proteins includes many candidate regulators of primary mesenchyme morphogenesis, including PMC-specific extracellular matrix proteins, cell surface proteins, spicule matrix proteins and transcription factors. This work provides a basis for linking specific molecular changes to specific cell behaviors during gastrulation. Our analysis has also led to the cloning of several key components of signaling pathways that play crucial roles in early sea urchin development

Subsurface Relationships between the Sebree Trough and Carbonate-Siliciclastic Mixing in the Upper Ordovician Lexington-Trenton and Point Pleasant-Utica Intervals in Ohio, USA, using Multivariate Statistical Well Log Analysis

The Upper Ordovician (lower Katian; upper Chatfieldian-lower Edenian) Lexington-Trenton limestone and Point Pleasant-Utica shale intervals are important subsurface stratigraphic units across Ohio as they are the sources of significant conventional and unconventional hydrocarbon resources. However, both units exhibit anomalous distributions across the state and heterogeneous relationships, especially in areas where they intertongue. The limestone units show a peculiar SW-NE thinning trend across Ohio, whereas the overlying shale units show an anomalous thickening along the same trend—a trend associated with the poorly understood Sebree Trough, a supposed Late Ordovician paleobathymetric low related to the coeval Taconic Orogeny. To explore relationships amon Lexington-Trenton carbonates, Point Pleasant-Utica shales, and the presumed Sebree Trough, multivariate statistical analysis was used to compare geophysical well logs across the state with well logs referenced to the mineral content of 4 Lexington-Trenton-Point Pleasant-Utica cores. Comparing well-log responses with the mineral content of the reference cores allowed the discernment of 10 electrofacies, keyed to lithofacies in the cores. Software analysis of many other well logs across the state then made electrofacies assignments by comparing well-log responses from the other wells with well-log responses from the reference cores preset into the software. Electrofacies responses were color-coded, mapped in wells at 0.6 m (2 ft) resolution, and used to make section lines and isopach maps of similar electrofacies. Isopach maps and cross sections confirm the presence of the Sebree Trough across Ohio, with trends that parallel existing and projected basement structures. This suggests that the Sebree Trough in Ohio was a bathymetric low, which was, at least in part, controlled by reactivation of basement structures due to far-field Taconic stresses

The Silurian of central Kentucky, U.S.A.: Stratigraphy, palaeoenvironments and palaeoecology

Silurian rocks in Kentucky are exposed on the eastern and western flanks of the Cincinnati Arch, a large-wavelength cratonic structure separating the Appalachian foreland basin from the intracratonic Illinois Basin. The Cincinnati Arch area experienced uplift during latest Ordovician-early Silurian time, so that the exposed Silurian section is relatively thin due to onlap and post-Silurian erosional truncation on the arch. On both flanks of the arch, dolomitic carbonates predominate, but the section on the eastern side reflects a more shale-rich ramp that faced eastern Appalachian source areas. In the Silurian section on the western side of the arch, which apparently developed across a platform-like isolation-accommodation zone, shales are rare except during some highstand episodes, and rocks in the area reflect deposition across a broad, low-gradient shelf area, interrupted by structurally controlled topographic breaks. Using the progression of interpreted depositional environments and nearshore faunal communities, a relative sea-level curve, which parallels those of previous workers, was generated for the section in Kentucky. While the curve clearly shows the influence of glacial eustasy, distinct indications of the far-field, flexural influence of Taconian and Salinic tectonism are also present. In fact, at times, regional tectonic subsidence seems to have overwhelmed the effects of glacio-eustasy. Regional angular truncations in the section, as well as overlying bentonitic shales and a dysaerobic fauna in the deepest-water part of the section (Estill Shale), are best explained in terms of far-field tectonic subsidence accompanying the first tectophase of the Salinic Orogeny in the Appalachian area

Tectonic, foreland-basin origins of Upper Ordovician black gas shales in the Appalachian Basin of eastern United States

Black gas shales are major parts of many foreland-basin sequences and comprise important components of unconformity-bound tectophase cycles, which reflect sedimentary/stratigraphic, flexural responses to deformational loading and relaxation in an orogen. Using as examples Upper Ordovician black gas shales, deposited during the Taconian orogeny in the Appalachian Basin of the eastern United States, black-shale origins and their importance in understanding the tectonic framework are discussed. Foreland-basin black shales are clearly the product of distinctive tectonic frameworks and histories, and aside from economic value, may provide important controls on the timing and location of tectonic events

A nomenclature for echinoderm genes.

Echinoderm embryos and larvae are prominent experimental model systems for studying developmental mechanisms. High-quality, assembled, annotated genome sequences are now available for several echinoderm species, including representatives from most classes. The increased availability of these data necessitates the development of a nomenclature that assigns universally interpretable gene symbols to echinoderm genes to facilitate cross-species comparisons of gene functions, both within echinoderms and across other phyla. This paper describes the implementation of an improved set of echinoderm gene nomenclature guidelines that both communicates meaningful orthology information in protein-coding gene symbols and names and establishes continuity with nomenclatures developed for major vertebrate model organisms, including humans. Differences between the echinoderm gene nomenclature guidelines and vertebrate guidelines are examined and explained. This nomenclature incorporates novel solutions to allow for several types of orthologous relationships, including the single echinoderm genes with multiple vertebrate co-orthologs that result from whole-genome-duplication events. The current version of the Echinoderm Gene Nomenclature Guidelines can be found at https://www.echinobase.org/gene/static/geneNomenclature.jsp Database URL https://www.echinobase.org/