Book Review of Kenneth F. McCallion, Shoreham and the Rise and Fall of the Nuclear Power Industry

Review of Kenneth F. McCallion, Shoreham and the Rise and Fall of the Nuclear Power Industry (Praeger 1995). About the author, acknowledgements, foreword by Irving Like, index, preface, prologue, selected bibliography. LC 94- 32930; ISBN 0-275-94299-6 [221 pp. Cloth $55.00. 88 Post Road West, Westport CT 06881.

Marsupials and monotremes sort genome treasures from junk

A recent landmark paper demonstrates the unique contribution of marsupials and monotremes to comparative genome analysis, filling an evolutionary gap between the eutherian mammals (including humans) and more distant vertebrate species

Does gene dosage really matter?

Mechanisms to compensate for dosage differences of genes on sex chromosomes are widespread in animals and have been thought to be critical for viability. However, in birds, compensation is inefficient, implying that for many genes dosage compensation is not critical, and for some genes, dosage differences have even been selected for

Economic Impact of Hospitals: the Case of Baylor Regional Medical Center at Grapevine.

This report analyzes the economic impacts of the Baylor Regional Medical Center at Grapevine, Texas. The economic impacts are analyzed using the IMPLAN impact modeling system developed by the Minnesota IMPLAN Group. The analysis evaluates construction activities by Baylor-Grapevine as well as procurement spending and employment. Additionally, the impact of ancillary facilities surrounding Baylor-Grapevine and the impact of patient visitor spending is also reviewed. Total recurring impacts of procurement spending at Baylor-Grapevine, employment at Baylor-Grapevine and its ancillary facilities, and visitor spending will generate over $227 million in economic activity for the Dallas/Fort Worth Metroplex. This activity will support more than 3,300 direct, indirect, and induced jobs paying over$138 million in annual earnings

An Initial Assessment of the Potential of Genomic Analysis to Help Inform Bighorn Sheep Management

Genetic research may be a useful approach for understanding factors that could impact productivity and restoration of bighorn sheep (Ovis canadensis) herds.  For example, genetic consequences of inbreeding in small populations can impact recruitment and local adaptations can influence translocation success.  This modest pilot study quantified genetic attributes of bighorn sheep populations with a range of different herd histories in Montana and Wyoming to investigate genetic similarity and differences, genetic heterogeneity and genetic distance.  Employing an Ovine array containing about 700,000 single nucleotide polymorphisms (SNPs) with approximately 24,000 markers that are informative for Rocky Mountain bighorn sheep, we used whole genome genotyping to analyze genetic material.  This technique represents a significant advancement in genetic analysis of bighorn sheep, as most previous studies have used microsatellites and less than 200 genetic markers.  We analyzed approximately fifteen individuals from each of four different populations that we predicted would differ in genetic characteristics, due to population dissimilarities that potentially impacted their genetics, including origin (native/reintroduced), population size, bottleneck history, degree of connectivity, and augmentation history.  We selected four populations that provided a spectrum of these herd attributes, including the Tendoys, Stillwater and Glacier National Park in Montana and the northeastern Greater Yellowstone Area in Wyoming.  We present the results of this effort and examine expected and observed heterogeneity and genetic distance estimates to evaluate the potential for links between genetics and herd demography.  We discuss the utility of genetic analyses in improving knowledge of bighorn sheep populations and potential implications for bighorn sheep management

Independent Evolution of Transcriptional Inactivation on Sex Chromosomes in Birds and Mammals

X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination). We used RNA-fluorescent in situ hybridization (RNA-FISH) to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains) on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial) silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes.This project was supported by an Australian Research Fellowship to PDW (DP0987091) and an Australian Research Council discovery project grant to PDW, JED and JAMG (DP1094868) (http://www.arc.gov.au/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Construction of a highly enriched marsupial Y chromosome-specific BAC sub-library using isolated Y chromosomes

The Y chromosome is perhaps the most interesting element of the mammalian genome but comparative analysis of the Y chromosome has been impeded by the difficulty of assembling a shotgun sequence of the Y. B AC-based sequencing has been successful for the human and chimpanzee Y but is difficult to do efficiently for an atypical mammalian model species (Skaletsky et al. 2003, Kuroki et al. 2006). We show how Y-specific sub-libraries can be efficiently constructed using DNA amplified from microdissected or flow-sorted Y chromosomes. A Bacterial Artificial Chromosome (BAC) library was constructed from the model marsupial, the tammar wallaby (Macropus eugenii). We screened this library for Y chromosome-derived BAC clones using DNA from both a microdissected Y chromosome and a flow-sorted Y chromosome in order to create a Y chromosome-specific sub-library. We expected that the tammar wallaby Y chromosome should detect ∼100 clones from the 2.2 times redundant library. The microdissected Y DNA detected 85 clones, 82% of which mapped to the Y chromosome and the flow-sorted Y DNA detected 71 clones, 48% of which mapped to the Y chromosome. Overall, this represented a ∼330-fold enrichment for Y chromosome clones. This presents an ideal method for the creation of highly enriched chromosome-specific sub-libraries suitable for BAC-based sequencing of the Y chromosome of any mammalian species