Fleas (Siphonaptera: Ceratophyllidae, Ctenophthalmidae) from rodents in five southwestern states

Nine species of fleas were collected incidental to a survey of rodents for molecular studies in Arizona, Colorado, New Mexico, Texas, and Utah, south of latitude 38° N. Three species were parasites of woodrats, Neotoma spp.: Orchopeas neotomae Augustson was confirmed for Texas, and the distribution patterns of O. agilis (Rothschild) and O. schisintus (Jordan) were more clearly defined. Four species were parasites of mice, Peromyscus spp.: Aetheca wagneri (Baker) was a new flea for P. gratus Merriam, the distribution of O. leucopus (Baker) was extended to far west Texas, Plusaetis sibynus (Jordan) was new for Utah and N. lepida , and the range of Stenoponia americana (Baker) was extended west of the Continental Divide in New Mexico. Other species included Foxella ignota (Baker) and Meringis dipodomys Kohls.     

Sequence and analysis of chromosome 1 of the plant Arabidopsis thaliana

The genome of the flowering plant Arabidopsis thaliana has five chromosomes. Here we report the sequence of the largest, chromosome 1, in two contigs of around 14.2 and 14.6 megabases. The contigs extend from the telomeres to the centromeric borders, regions rich in transposons, retrotransposons and repetitive elements such as the 180-base-pair repeat. The chromosome represents 25% of the genome and contains about 6,850 open reading frames, 236 transfer RNAs (tRNAs) and 12 small nuclear RNAs. There are two clusters of tRNA genes at different places on the chromosome. One consists of 27 tRNA(Pro) genes and the other contains 27 tandem repeats of tRNA(Tyr)-tRNA(Tyr)-tRNA(Ser) genes. Chromosome 1 contains about 300 gene families with clustered duplications. There are also many repeat elements, representing 8% of the sequence.     

Effects of histamine,histidine and imidazole acetic acid on neurones of the medulla oblongata of the cat

Zusammenfassung Mikroelektrophoretisch verabreichtes Histamin, Histidin und Imidazolessigsäure hemmen die Aktivität von Neuronen der Medulla oblongata der Katze. Strychnin, welches in reversibler Weise die hemmende Wirkung von Glycin blockiert, zeigt keinen Antagonismus zu Imidazolessigsäure.