ISSN:0265-9247    

DOI:10.1002/bies.950020602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractChi sites are examples of special sites enhancing homologous recombination in their region of the chromosome. Chi, 5′ G‐C‐T‐G‐G‐T‐G‐G3′, is a recognition site for the RecBC enzyme, which nicks DNA near Chi as it unwinds DNA. A molecular model of genetic recombination incorporating these fea

ISSN:0265-9247    

DOI:10.1002/bies.950020603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractTo further comprehend how synthesis and assembly of myofibrillar components is regulated, several laboratories have undertaken genetic studies of muscle development in Drosophila melanogaster. This small fly lends itself well to classical and molecular genetic approaches, and possesses a set of muscle fibers, termed indirect flight muscles (IFM), which is particularly advantageous for such investigations. Structural and functional analyses of cloned Drosophila contractile protein genes have revealed that protein isoforms can be specified either by multigene families or by differentially splicing primary transcripts of a single gene. Characterization of mutations which disrupt flight muscle development has so far revealed that profound abnormalities are caused by defective alleles of actin, tropomyosin, and myosin heavy‐chain genes. Muscle defects associated with particular alleles can be alleviated by integration of corresponding wild‐type gene copies into germ‐line chromosomes. Strategies for further applying genetic techniques to investigations of Drosophila muscle development are disc

ISSN:0265-9247    

DOI:10.1002/bies.950020604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractDNA transfer directly from cell to cell (conjugation) is common among prokaryotes, particularly Gram‐negative bacteria like Escherichia coli. The phenomenon invariably requires a set of plasmid genes in the DNA donor cell. In addition, E. coli itself makes limited and specific contributions to the donor activity of strains carrying the conjugative plasmid F. These contributions have yet to be defined biochemically, but it is already clear that the cell envelope is an importan nexus between plasmid‐ and chromosome‐encoded proteins required for the establishment and maintenance of DNA donor act

ISSN:0265-9247    

DOI:10.1002/bies.950020605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe mechanism(s) by which lentiviruses and related non‐oncogenic retroviruses (e.g. HTLV‐III, the etiologic agent of AIDS) escape immune surveillance, and thereby create long term progressive disease conditions, has been unknown until recently. Studies with two lentiviruses have begun to illuminate the mechanisms. In one, antigenic drift in the virus appears to be the primary mechanism of escape from immune surveillance; in the second, selective masking of the viral envelope glycoprotein epitope, which normally elicits neutralizing anti‐body, appears to provide the means of e

ISSN:0265-9247    

DOI:10.1002/bies.950020606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe small, relatively constant size and conservative evolution of chloroplast DNA (cpDNA) make it an ideal molecule for tracing the evolutionary history of plant species. At lower taxonomic levels, cpDNA variation is easily and conveniently assayed by comparing restriction patterns and maps, while at higher taxonomic levels, DNA sequencing and inversion analysis are the methods of choice for comparing chloroplast genomes. The study of cpDNA variation has already yielded important new insights into the origin and evolution of many agriculturally important crop plants, and promises to significantly enhance our phylogenetic understanding of the major lines of descent among land plants and algae.

ISSN:0265-9247    

DOI:10.1002/bies.950020607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractCytokinesis in animal cells is accomplished by the active constriction of the equatorial regions of a cell by an actomyosin‐containing contractile ring. The mitotic apparatus specifies the position and orientation of the furrow such that the mitotic spindle is always bisected. Global cortical contractions occur in the cortex of a cell prior to cytokinesis that are independent of the presence of the mitotic apparatus. It was proposed some years ago that the asters of the mitotic apparatus could act to relax the preformed cortical tension in their vicinity. This would produce a differential in tension between the equatorial regions and the adjacent regions of the cortex so that the equatorial regions would contract, forming a cleavage furrow. It can be shown that, as it stands, this theory cannot explain cleavage. However, if cortical contractile elements are assumed to be laterally mobile in the plane of the cortex, then the astral relaxation theory can account for many of the aspects of cleavage, including the formation of the contractile ring. Similar schemes may account for the behaviour of the lamellapodia of motile cell

ISSN:0265-9247    

DOI:10.1002/bies.950020608

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950020609

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950020610

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950020611

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY