In the part of the Loire River recently colonized by Eurasian beavers, we compared habitat characteristics among sites with lodges, sites with cut trees and sites without beaver. The absence of sandbank and canopy cover (by 10-15-m tall trees, by tall Salicaceae, and by bushy Salicaceae) appeared as good predictors for lodge settling. Based on this model, the number of proper lodge sites was es...

Difference electron density maps, using as few as four 1/2 degrees oscillation photographs, have been computed for tomato bushy stunt virus crystals soaked in EDTA. GdCl3 and silicotungstate. The maps define a double divalent cation site, responsible for regulating expansion of the virus particle, as well as sites for binding tungstate anions.

Tomato bushy stunt virus (TBSV) was detected in tomato crop (Lycopersicon esculentum) in Egypt with characteristic mosaic leaf deformation, stunting, and bushy growth symptoms. TBSV infection was confirmed serologically by ELISA and calculated incidence was 25.5%. Basic physicochemical properties of a purified TBSV Egh isolate were identical to known properties of tombusviruses of isometric 30-...

On January 10 and 11, 1997, a two-day symposium titled Quasi-Equivalence: Motion and Adaptability in Living Molecules was held at Florida State University on the occasion of the 70th birthday of Dr. Donald L. D. Caspar. This issue of the Biophysical Journal contains articles presented at that symposium in recognition of the contributions that Dr. Caspar has made to our understanding of the stru...

A soilborne disease of lettuce, associated with necrosis and dieback, has been found with increasing frequency in California and Arizona over the last 10 years. An isometric virus, serologically related to Tomato bushy stunt virus (TBSV), was consistently isolated from lettuce plants with these disease symptoms. Back-inoculation to healthy lettuce plants and subsequent reisolation of the virus ...

We have analyzed atypical tomato bushy stunt virus defective interfering (DI) RNA species which accumulated during a passage series in protoplasts. We present a rationale for the order of appearance of these molecules and show, using competition assays, that either segment duplication or single nucleotide insertion can enhance DI RNA competitiveness. Possible mechanisms for the introduction of ...

SUMMARY This study identified a role for the Tomato bushy stunt virus (TBSV) p19 protein (P19) in local lesion expansion on cowpea (Vigna unguiculata), and cell-to-cell movement in pepper (Capsicum annuum). The contribution to short distance spread in both hosts was strongly influenced by a cluster of charged amino acids between positions 72 and 78 on the 172 amino acid P19. Charged amino acids...

Tomato bushy stunt virus (TBSV) is probably the most suitable of the simple viruses for atomic resolution structure analysis. It is built from 180 copies of a coat protein subunit (Mw 41,000) and a single piece of RNA (MW 1.5 X 106) (1-3). There may also be a single copy of a large internal protein (MW 87,000) (a). The coat subunits form a T=3 icosahedral surface lattice. The symmetry of this l...