The development of PCR-based markers for the selection of eyespot resistance genes Pch1 and Pch2

Two eyespot resistance genes (Pch1 and Pch2) have been characterised in wheat. The potent resistance gene Pch1, transferred from Aegilops ventricosa, is located on the distal end of the long arm of chromosome 7D (7DL). Pch2 derives from the variety Cappelle Desprez and is located at the distal end of chromosome 7AL. The RFLP marker Xpsr121 and the endopeptidase isozyme allele Ep-D1b, are very closely linked to Pch1, probably due to reduced recombination in the region of the introgressed A. ventricosa segment. Pch2 is less closely linked to these markers but is thought to be closer to Xpsr121 than to Ep-A1b. In the present study simple sequence repeat (SSR) markers were integrated into the genetic map of a single chromosome (7D) recombinant (RVPM) population segregating for Pch1. Sequence-tagged-site (STS)-based assays were developed for Xpsp121 and a 7DL wheat EST containing a SSR. SSR markers Xwmc14 and Xbarc97 and the Xpsr121-derived marker co-segregated with Pch1 in the RVPM population. A single chromosome (7A) recombinant population segregating for Pch2 was screened for eyespot resistance and mapped using SSRs. QTL interval mapping closely associated Pch2 with the SSR marker Xwmc525.     

B chromosomes and genome size in flowering plants.

B chromosomes are extra chromosomes found in some, but not all, individuals within a species, often maintained by giving themselves an advantage in transmission, i.e. they drive. Here we show that the presence of B chromosomes correlates to and varies strongly and positively with total genome size (excluding the Bs and corrected for ploidy) both at a global level and via a comparison of independent taxonomic contrasts. B chromosomes are largely absent from species with small genomes; however, species with large genomes are studied more frequently than species with small genomes and Bs are more likely to be reported in well-studied species. We controlled for intensity of study using logistic regression. This regression analysis also included effects of degree of outbreeding, which is positively associated with Bs and genome size, and chromosome number, which is negatively associated with Bs and genome size, as well as variable ploidy (more than one ploidy level in a species). Genome size, breeding system and chromosome number all contribute independently to the distribution of B chromosomes, while variable ploidy does not have a significant effect. The genome size correlates are consistent with reduced selection against extra DNA in species with large genomes and with increased generation of B sequences from large A genomes.     

Facial symmetry and judgements of apparent health: Support for a “good genes” explanation of the attractiveness–symmetry relationship

The “good genes” explanation of attractiveness posits that mate preferences favour healthy individuals due to direct and indirect benefits associated with the selection of a healthy mate. Consequently, attractiveness judgements are likely to reflect judgements of apparent health. One physical characteristic that may inform health judgements is fluctuating asymmetry as it may act as a visual marker for genetic quality and developmental stability. Consistent with these suggestions, a number of studies have found relationships between facial symmetry and facial attractiveness. In Study 1, the interplay between facial symmetry, attractiveness, and judgements of apparent health was explored within a partial correlation design. Findings suggest that the attractiveness–symmetry relationship is mediated by a link between judgements of apparent health and facial symmetry. In Study 2, an opposite-sex bias in sensitivity to facial symmetry was observed when judging health. Thus, perceptual analysis of symmetry may be an adaptation facilitating discrimination between potential mates on the basis of apparent health. The findings of both studies are consistent with a “good genes” explanation of the attractiveness–symmetry relationship and problematic for the claim that symmetry is attractive as a by-product of the ease with which the visual recognition system processes symmetric stimuli.     

The head and foot of Pelmatohydra oligactis,pall., as unipotent systems

Summary The head and foot ofPelmatohydra oligactis function in regeneration as unipotent systems. The exact extent of the unipotent tissue immediately posterior to the tentacles and anterior to the foot is not determined in these experiments. The intermediate tissue is pluripotent.The potentiality for head formation is stronger at the oral end and decreases towards the aboral end as the potentiality for foot formation increases.In these grafting experiments the stock has no influence over the graft which retains its individuality.Preliminary account im Akademischen Anzeiger, Wien, No. 24. 22. November 1923: Mitteilungen aus der Biologischen Versuchsanstalt der Akademie der Wissenschaften in Wien, Zoologische Abteilung, Vorstand:H. Przibram. Nr. 113. Kopf und Fuß des Süßwasserpolypen,Pelmatohydra oligactis Pall., als unipotente Systeme vonD. R. R. Burt.     

The relative influence of urban climates on outdoor human energy budgets and skin temperature I. Modeling considerations

An attempt is made to provide a tool for systematically analyzing variations of outdoor human energy budgets and skin temperatures as a result of different urban street canyon geometries and vegetative properties. To this end, three previously developed numerical models were combined. The interaction of the models and the derivation of the necessary human-urban view-factors is discussed. Some sample results are given for non-urban macadam and park plains, to be used later as standards in the comparison of the impact of urban morphology on human comfort.     

Can interaction coefficients be determined from cencus data?

Summary The method of estimating interactions proposed independently by Pimm and Schoener is studied using field data from the community of rodents which lives in the arid, rocky habitats of Israel. One important problem the method addresses is how to remove the effects of habitat heterogeneity on the estimate. We tried six different variations of the analysis scheme outlined by Crowell and Pimm, and found their results qualitatively inconsistent. This was especially true when we compared the results produced from separate habitat variables with those produced from the principal components of the habitat variation.Another problem, this one not previously addressed, is great variation in the average abundance of the different species. We discovered that the ratio of the average abundances of two species is the best predictor of the value of their coefficients of interaction. Common species appear to have weak influence on rare ones; rare ones appear to have strong influence on common ones. The statistical mechanism which produces this relationship is clear, indicating that the relationship is an artifact.     

Reviews

The Family Album. A film by Alan Berliner. 16mm, 55min, b/w. Distributed by Filmmakers Library, Inc.

Beyond Words—Images from America's Concentration Camps. By Deborah Gesensway and Mindy Roseman. 1987, 176 pages, illustrated. Ithaca: Cornell University Press. Price: cloth $24.95.

The Lau (Granada Television “Disappearing World” Series). A film by Leslie Woodhead, producer‐director; Jon Woods, camera; Ray French, sound; Kimball Horton, editor; David Wasson, researcher; and Pierre Maranda, anthropological consultant. 1987, video, color, 52 minutes. Dialogues: Lau. Subtitles: English. Narration: English. Distributed by Granada TV International, Suite 3468, 1221 Avenue of the Americas, New York, NY 10020, tele. 212–242–2363. Price: on application.

Men's Lives: The Surfmen and Baymen of the South Fork. By Peter Matthiessen. 1986, New York: Random House. Price: hardcover $29.95; softcover $7.95 (Vintage Press); limited edition $200 (University of Washington Press, Seattle).

In Her Own Time. A film by Lynne Littman with Barbara Myerhoff. 1986, 16mm, color, 60 minutes. Distributed by Direct Cinema, Ltd., P.O. Box 69589, Los Angeles, CA 90060, tele. 213–652–8000. Price: 16mm—purchase $895, rental $100; video—purchase $350, rental $50 (prices quoted are for educational institutions only).

The Miracle of Intervale Avenue. A film by Irving Rappaport, producer; Ken Howard, director; and Jack Kugelmaas, associate producer. 1983, 16mm, color, 65 minutes. Catalog #430. Distributed by Ergo Media, Inc., P.O. Box 2037, Teaneck, NJ 07666, tele. 201–692–0404.

Some Babies Die. A film by Martyn Landon Down. Australia, 16mm, color, 54 minutes. Distributed by The University of California Extension Media Center, 2176 Shattuck Avenue, Berkeley, CA 94704, tele. 415–642–1340. Price: 16mm—purchase $850, rental $60; video—purchase $450, rental $60.

El Sebou’: The Egyptian Birth Ritual. A film by Fadwa El Guindi; produced by El Nil Research Project; co‐sponsored by the Office of Folklife, Smithsonian Institution. 1986, 16mm, color, 27 minutes. Distributed by El Nil Research Project, 1157 Beverwil Drive, Los Angeles, CA 90035, tele. 213–553–5645. Price: 16mm—purchase $570, rental $70; video—purchase $370. Screenings: Society for Visual Anthropology (1987 Award for Excellence); 1987 Margaret Mead Film Festival; Royal Anthropological Institute (1988 Commendation).

The Making of El Sebou‘

Classified People. Yolande Zauberman, director; produced by OBSESSION/INA/CNC/ FR3‐TOULOUSE; Dewald Aukema, camera; Tony Bensusan, sound; Jean‐François Naudon, editor. 1987, 16mm, color, 53 minutes. Distributed by TELEMONDIS, 15, rue Mesnil, 75016, Paris, tele. 47–27–03–84, telex: 649 078 TELMOND. In U.S., distributed by Filmmaker's Library, 124 E. 40th Street, New York, NY 10016, tele. 212–355–6545. Price: 16mm—rental only $150; video (½″ or ¾″)—purchase $75, rental $75. Screenings: Festival of Women's Films at Créteil (Prix de Jury); Festival of Young Directors at Belfort (Prix de Publique); Bilan du Film Ethnographique 1988 (Prix Nanook/Grand Prix); 1988 Cinéma du Réel; 1987 Margaret Mead Film Festival; U.S. Public Television.

To Cross the Border: An interview with Filmmaker Yolande Zauberman, Paris, May 1988.     

Muscarinic receptors in pineal

The presence of muscarinic receptors in sheep and rat pineals was detected by binding of [³H]quinuclidinyl benzilate ([³H]QNB), a potent and specific muscarinic antagonist. [³H]QNB binding to sheep pineal membrane resuspensions was saturable and reversible, with a rate constant for association at 37°C of 6×10⁸M^?1min^?1 and a rate constant for dissociation of 1×10^?2min^?1. Kinetic and saturation experiments yielded an equilibrium dissociation constant of 13–18 pM and a concentration of binding sites equivalent to 1.1 pmol/g of original wet weight. This is only about 5% of the level of β-adrenergic receptors. Competition by a variety of cholinergic drugs confirmed the muscarinic nature of the binding sites. Experiments in rats failed to detect a significant decrease in pineal [³H]QNB binding following bilateral superior cervical ganglionectomy, suggesting that the binding sites are not localized exclusively on sympathetic terminals.