Nucleotide sequence of the human polyomavirus AS virus, an antigenic variant of BK virus.

The complete DNA sequence of the human polyomavirus AS virus (ASV) is presented. Although ASV can be differentiated antigenically from the other human polyomaviruses (BK and JC viruses), it shares 94.9% homology at the nucleotide level with the Dunlop strain of BK virus. Differences found in ASV relative to BK virus include the absence of tandem repeats in its regulatory region, the deletion of 32 nucleotides in the late mRNA leader region (altering the initiation codon for the agnoprotein), the presence of a cluster of base pair substitutions within the coding region of the major capsid protein, VP1, and the absence of 4 amino acids in the carboxy-terminal region of the early protein, T antigen. The 43 nucleotides deleted in the Dunlop strain of BK virus relative to the Gardner prototype strain of BK virus are present in ASV. Possible reasons for the distinct antigenicity of the ASV capsid, given the high degree of nucleotide homology with BK virus, are discussed. To reflect the high degree of sequence homology between ASV and BK virus, we suggest ASV be renamed BKV(AS).     

Normal Bias in the Direction of Fetal Rotation Depends on Blastomere Composition during Early Cleavage in the Mouse

Interest in establishing the basis of left/right asymmetry during embryogenesis has burgeoned in recent years. Relevant studies in mammals, focused largely on the mouse, have revealed involvement of a variety of genes that are common to the process in other animals. In the mouse, lateral differences in gene expression are first evident late in gastrulation when directional rotation of nodal cilia has been implicated in effecting the normally very strong bias in handedness. Reconstructing cleavage stages with correspondingly positioned blastomeres from appropriate numbers of conceptuses with similar division planes provides a way of testing whether they differ in potency without the confounding effects of reduced cell number. In a study using this strategy, 4-cell stage conceptuses reconstructed from blastomeres produced by equatorial as opposed to meridional second cleavage were found to be compromised in their ability to support normal development. Here, in more refined reconstructions undertaken at both the 4- and 8-cell stage, no significant impairment of development to the 9^th or 12^th day of gestation was found for products of equatorial second cleavage or their 8-cell stage progeny. Most surprisingly, however, a significant increase in reversal of the direction of axial rotation was found specifically among fetuses developing from conceptuses reconstructed from 8-cell stage progeny of products of equatorial second cleavage. Hence, manipulations during early cleavage some 6 days before fetal asymmetries are first evident can perturb the normally very strong bias in specification of a facet of left-right asymmetry.     

Ethological study of early language

Sign language studies of cross-fostered chimpanzees measure the effect of special rearing conditions on the development of very young chimpanzees. Cross-fostered chimpanzees, like human children, develop gradually in a process that takes many years. Here we discuss details of the procedure, the overlap between human and chimpanzee infants in the contents of the first 50-item vocabularies, and the ways in which the signs of the chimpanzees exhibit the fuzziness of natural language categories. We also compare the cross-fostering approach with more traditional modular approaches to the study of language-like behavior in nonhuman animals. Project Washoe was originally supported by grants MH-12154 from the National Institute of Mental Health and GB-7432 from the National Science Foundation. We gratefully acknowledge this support and the support that later sign language studies of chimpanzees have received since then from NIH, NSF, the National Geographic Society, the Grant Foundation, the Spencer Foundation, the University of Nevada, and the UNR Foundation.     

Mapping and analysis of protein sulfhydryl groups by modification with 2-bromoacetamido-4-nitrophenol

A method for identifying cysteine-containing peptides in proteins is presented using 2-bromoacetamido-4-nitrophenol (BNP) to introduce an easily detectable probe. The formation of a covalent bond between the protein sulfhydryl group and the acetamido moiety of BNP introduces a chromophore with an absorbance maximum at 410 nm. The modified protein can then be cleaved with appropriate proteases and the resulting peptides separated by chromatographic methods. Monitoring the effluent at a single wavelength (405 nm) provides a rapid and simple method of detecting and isolating only those peptides which contain cysteine residue(s). The nitrophenol derivative is stable under conditions required for protease cleavage. The reagent is therefore useful for locating cysteine-containing peptides in protein digests and can be used to explore the accessibility of different cysteines under a variety of conditions. The ease of modification, specificity of reaction, product stability, and simple detection of modified peptides make BNP ideal for investigation of cysteine residues.     

A small one-band paracentric inversion inv (4) (p15.3p16.3).

A neonate with aniridia was found to have a one band paracentric inversion of the short arm of chromosome 4. This was initially difficult to interpret on high resolution banding. The inversion was present in three generations of the family.