摘要:

AbstractTraditionally, plant viruses are viewed as harmful, undesirable pathogens. However, their genomes can provide several useful ‘designer functions’ or ‘sequence modules’ with which to tailor future gene vectors for plant or general biotechnology.The majority (77 %) of known plant viruses have single‐stranded RNA of the messenger (protein coding) sense as their genetic material. Over the past 4 years, improvedin vitrotranscription systems and the construction of partial of fulllength DNA copies of several plant RNA viruses have enhanced our ability to manipulate and study their genomes, particularly in the context of their pathogenic interactions with host plants.Recently, two forms of genetically engineered protection against plant virus infections have been reported. In both, a virus‐related ‘interfering’ molecule was stably introduced into plants via the DNA‐transfer mechanism ofAgro‐bacterium tumefaciens. To date, the choice of ‘interfering’ molecule has been guided by empirical field‐observations and each is effective against only a narrow range of closely‐related viruses. As yet, we do not fully understand the molecular mechanism(s) responsible for the observed protection.The ability to manipulate the plant–pathogen relationship is a powerful tool to increase our knowledge and improve future strategies for uncoventional cropprotection by g

ISSN:0265-9247    

DOI:10.1002/bies.950100602

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

年代:1989

数据来源: WILEY

摘要:

AbstractNow, some 55 years after its discovery in bovine red cells, carbonic anhydrase (CA), in all its varied forms, continues to challenge and intrigue physiologists, biochemists and molecular geneticists. This is so because of an increasing awareness of the many apparently diverse functions of the different CA isozymes encoded by this large multigene family, the continuing discovery of new CA, or CA‐related, genes, and the extensive variation in their hormonal control, cellular expression and subcellular localizatio

ISSN:0265-9247    

DOI:10.1002/bies.950100603

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

年代:1989

数据来源: WILEY

摘要:

AbstractMast cells are a unique class of blood cell. Unlike most blood cells, undifferentiated precursors of mast cells migrate in the bloodstream, invade tissues, proliferate there and then differentiate. Even after differentiation, some mast cells may proliferate extensively. Differentiation of mast cells is regulated by both diffusible growth factors and direct contact with fibroblasts.

ISSN:0265-9247    

DOI:10.1002/bies.950100604

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

年代:1989

数据来源: WILEY

摘要:

AbstractWe describe here recent work on the molecular genetics of mitosis in the filamentous fungusAspergillus nidulans. Aspergillusis one of three simple eukaryotes with powerful genetic systems that have been used to analyze mitosis. The modern molecular biological techniques available with this organism have made it possible to use mutations to identify genes and proteins that play an important role in mitosis. ThreeAspergillusgenes that affect mitosis are described. One gene,nimA, is specifically expressed late in the cell cycle and codes for a putative protein kinase that induces mitosis, even in cells blocked in S‐phase. The second gene,bimG, codes for a putative phosphatase that interacts functionally with thenimA kinase. The third gene,bimE, codes for a protein that suppresses mitosis during interphase, apparently by keepingnimA turned off. None of these genes appear to be similar to any of the genes affecting mitosis that have been characterized in other eukaryotes, but rather appear to be elements of a system that prevents mitosis from occurring during interphas

ISSN:0265-9247    

DOI:10.1002/bies.950100605

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe alcohol‐soluble (prolamin) storage proteins of barley, wheat and rye vary in their structures, but all have two features in common: the presence of distinct structural domains differing in amino acid compositions, and of repeats within one of these domains. Detailed comparisons of amino acid sequences show that all appear to have evolved from a single ancestral gene consisting of three short related regions (called A, B and C). Regions related to A, B and C are also present in the minor prolamins of maize and in three other groups of seed proteins: inhibitors of α‐amylase and /or trypsin from cereals. 2S storage globulins from several dicotyledonous species and a 2S albumin from sunflower. It is suggested that these proteins together constitute a protein superfamily with limited sequence homo

ISSN:0265-9247    

DOI:10.1002/bies.950100606

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

年代:1989

数据来源: WILEY

摘要:

AbstractTeichoic acids are major wall components of most Gram‐positive bacteria. Their discovery followed that of their nucleotide precursors. Lipoteichoic acids associated with the cell membrane were discovered at the same time. Events leading to these discoveries and the probable function of teichoic acids in cation control are describe

ISSN:0265-9247    

DOI:10.1002/bies.950100607

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe classical estrogen receptor model does not sufficiently account for the tumor‐promoting activity of extrogens or for the antiproliferative effect of antiestrogens in estrogen‐dependent tumors. Particular difficulties not readily accommodated within the model are that hormonal autonomy can supervene without loss of the estrogen receptor and that antiestrogen effects are highly context‐dependent, without apparent differences in the estrogen receptor itself or in metabolic transformation of antiestrogens. Recent studies suggest that estrogens may promote cell proliferation, in part, through the mediation of growth factors and that antiestrogens may exert some of their effects by mechanisms unrelated to the estrogen rec

ISSN:0265-9247    

DOI:10.1002/bies.950100608

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

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950100610

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

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950100611

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

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950100601

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

年代:1989

数据来源: WILEY