Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world’s vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species

We have compiled and analyzed 263 promoters with known transcriptional start points for E. coli genes. Promoter elements (-35 hexamer, -10 hexamer, and spacing between these regions) were aligned by a program which selects the arrangement consistent with the start point and statistically most homologous to a reference list of promoters. The initial reference list was that of Hawley and McClure (Nucl. Acids Res. 11, 2237-2255, 1983). Alignment of the complete list was used for reference until successive analyses did not alter the structure of the list. In the final compilation, all bases in the -35 (TTGACA) and -10 (TATAAT) hexamers were highly conserved, 92% of promoters had inter-region spacing of 17 +/- 1 bp, and 75% of the uniquely defined start points initiated 7 +/- 1 bases downstream of the -10 region. The consensus sequence of promoters with inter-region spacing of 16, 17 or 18 bp did not differ. This compilation and analysis should be useful for studies of promoter structure and function and for programs which identify potential promoter sequences.

2016-12-23T18:52:10

The phylogenetic relationships among 36 validly described species or subspecies within the genus Staphylococcus were investigated by cloning and sequencing their 60 kDa heat-shock protein (HSP6O) genes using a set of universal degenerate HSP6O PCR primers. The cloned partial HSP60 DNA sequences f rom nine Staphylococcus aureus strains were highly conserved (97-100% DNA sequence similarity; mean 98O/0), indicating that the HSP60 gene of multiple isolates within the same species have little microheterogeneity. A t the subspecies level, DNA sequence similarity among members of 5. aureus, Staphylococcus schleiferi, Staphylococcus cohnii and Staphylococcus capitis ranged from 91 to 98%. A t the interspecies level, sequence similarity among 23 distinct species of staphylococci ranged from 74 to 93 O/ O (mean 82 YO). By comparison, the highest sequence similarity of Bacillus subtilis and Escherichia coli with members within the genus Staphylococcus was only 70 and 59 %, respectively. Importantly, phylogenetic analysis based on the neighbour-joining distance method revealed remarkable concordance between the tree derived from partial HSP60 gene sequences and that based on genomic DNA-DNA hybridization, while 165 rRNA gene sequences correlated less well. The results demonstrate that DNA sequences from the highly conserved and ubiquitous HSP6O gene offer a convenient and accurate tool for species-specif ic identification and phylogenetic analysis of staphylococci.