摘要:

AbstractThe chromocenter ofDrosophilapolytene chromosomes, which consists of two major chromatin types, has long been a troublesome region in molecular terms. The recent microcloning of part of this region, the isolation of a monoclonal antibody to abeta‐heterochromatin binding protein, and newin situstudies now shed a little more light on this chromosomal regio

ISSN:0265-9247    

DOI:10.1002/bies.950120102

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe contribution of roots to the biology of the whole plant is being reevaluated in the light of classical and recent findings. In addition to their role in water and nutrient uptake and in symbiotic associations, plant roots also synthesize a remarkable variety of secondary metabolites. These chemicals, many of which are used as pharmaceuticals, agrichemicals, flavors, dyes, or fragrances, may help the plant cope with biotic and abiotic stress. Root cultures are being used as experimental systems to explore both root‐specific secondary metabolites and their biological significance. They may also provide future systems for commercial production of plant specialty chemical

ISSN:0265-9247    

DOI:10.1002/bies.950120103

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

年代:1990

数据来源: WILEY

摘要:

AbstractNucleoli are the sites of ribosome biogenesis. Transcription of the ribosomal RNA genes as well as processing and initial packaging of their transcripts with ribosomal and non‐ribosomal proteins all occur within the nucleolus in an ordered manner and under defined topological conditions. Components of the nucleolus have been localized by immunocytochemistry and their functional aspects investigated by microinjection of antibodies directed against the enzyme responsible for rDNA transcription, RNA polymerase I. The role of nascent transcripts in postmitotic formation of nucleoli will be discusse

ISSN:0265-9247    

DOI:10.1002/bies.950120104

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

年代:1990

数据来源: WILEY

摘要:

AbstractProto‐oncogene products may be multi‐functional proteins with various roles in cell differentiation as well as cell proliferation. The molecular biology of the gene products of three well characterized proto‐oncogenes (c‐fos, c‐mycandc‐src) are described, and the roles of three other proto‐oncogene products, involved in hormone and growth factor reception,

ISSN:0265-9247    

DOI:10.1002/bies.950120105

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

年代:1990

数据来源: WILEY

摘要:

AbstractThree multifunctional protein kinases, cyclic AMP‐dependent protein kinase, protein kinase C, and calmodulin‐dependent protein kinase II, are involved in signal transduction in response to their respective second messengers, cyclic AMP, diacylglycerol, and Ca2+. This review will summarize the key findings on calmodulin‐dependent protein kina

ISSN:0265-9247    

DOI:10.1002/bies.950120106

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

年代:1990

数据来源: WILEY

摘要:

AbstractAmine acetylation is a diverse topic with importance to the regulation of several physiological processes as well as the metabolism of drugs and environmental chemicals. ArylalkylamineN‐acetyltransferase is widely distributed in several species, where this enzyme plays an important role in the seasonal regulation of reproduction and photoperiodism in vertebrates through the pathway of melatonin formation. In insects, this enzyme is involved in monoamine neurotransmitter inactivation and the formation of catecholamine intermediates necessary for sclerotization of the insect cuticl

ISSN:0265-9247    

DOI:10.1002/bies.950120107

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

年代:1990

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950120108

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

年代:1990

数据来源: WILEY

摘要:

AbstractClonal studies of adult chimaeric mouse epithelium have demonstrated the monoclonal composition of crypts of Lieberkühn(1). In neonatal life, however, polyclonal crypts have been found, indicating that crypts are of polyclonal origin(2). We here relate these findings to studies of mosaic tissues which have addressed the question whether solid tumours are of monoclonal or polyclonal origin (ref. 3 for review, 4). The issues has so far remained unresolved because the expected frequencies of polyclonal tumours, given polyclonal origins, have not previously been estimated. A general approach for the calculation of such expected values is suggested. The consistent reports of tumours with polyclonal components suggest that autocrine or paracrine mechanisms play an important role during tumorigenesis

ISSN:0265-9247    

DOI:10.1002/bies.950120109

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

年代:1990

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950120110

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

年代:1990

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950120111

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

年代:1990

数据来源: WILEY