摘要:

AbstractNorthern blot analysis and in vitro nuclear transcription assays were performed in order to clarify conflicting reports on the expression of intracisternal A particle (IAP) genes in embryonal carcinoma (EC) cell lines. Results demonstrate that post‐transcriptional mechanisms control the final steady‐state levels of IAP RNA in EC cells. IAP genes were further found to be undermethylated in IAP‐expressing EC cell

ISSN:0192-253X    

DOI:10.1002/dvg.1020080302

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe murine “housekeeping” enzyme, cytosolic NADP‐isocitrate dehydrogenase (E.C. 1.1.1.42) (genetic locus:Idh‐1), exhibited a complex pattern of allele‐specific expression. Protein electrophoresis on cellulose‐acetate gels and determination of relative enzymatic activity by means of densitometry revealed that in heart tissue (but not liver tissue) of certain hybrid crosses the AA‐homodimer was underrepresented relative to total enzymatic activity, and the degree of underrepresentation changed during development. In mixtures of homozygous tissue extracts of heart tissue (but not liver tissue) the AA‐homodimer was underrepresented relative to the BB‐homodimer. Relative activity of allelic isozymes varied as a function of tissue (heart versus liver), age, and the parental source of theIdh‐1aallele, but did not vary as a function of sex.Allele‐specific expression was also exhibited in kidney tissue of the same animals. In adult male kidney tissue extracts from heterozygotes, the AA‐hornodimer was underrepresented relative to total enzymatic activity; in adult female kidney tissue extracts from heterozygotes, a more codominant phenotype was observed. Tissue extracts from immature hybrid animals exhibited a phenotype midway between the adult male and adult female phenotypes. Tissue extracts from castrated males exhibited a phenotype equivalent to that seen in females. Relative activity of allelic isozymes in kidney varied as a function of age and sex, but did not vary as a function of the parental source of theIdh‐1aallele.While cytosolic NADP‐IDH is a “housekeeping” enzyme, expressed in multiple tissues of the mouse, differences in the relative intensities of allelic isozyme bands provide evidence for tissue‐ and st

ISSN:0192-253X    

DOI:10.1002/dvg.1020080303

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe fourth chromosome mutant cubitus interruptus‐Wallace(ciW) produces leg, wing, and body bristle aberrations. The effect on the wing is similar to that produced by cubitus interruptus‐dominant (ciD) which also has an influence on larval segmentation indicating that it has a regulatory function. Leg morphology of haplo‐4,ciW, and mosaic haplo‐4:diplo‐4,ci/ci+flies was examined in an attempt to distinguish between a structural and a regulatory function byciW. Aberrations recovered include failure of segment elongation, intersegmental gaps, duplication of bristles, and segments that are shorter than normal and of greater than normal diameter. Many of these effects are localized, suggesting thatciWmay act to maintain cell positional reference. Increased local cell proliferation appears to be one manifestation of loss of the normal

ISSN:0192-253X    

DOI:10.1002/dvg.1020080304

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe 63‐kDa antigen recognized by the monoclonal antibody F7D6 is present in allDrosophilaembryonic cells and disappears from most tissues as each one reaches its final, differentiated state. Larval tissues lose the antigen around the time of hatching, imaginal tissues lose it during metamorphosis, and germ cells lose it during gametogenesis (Bedianet al: Devel Biol 115:105–118, 1986). The nervous system and spontaneously contracting musculature of the gut and gonads are exceptions and remain antigen positive at all stages. The F7D6 antigen appears to be associated with dividing, undifferentiated cells and electrogenic cells. This prompted us to test tumors for antigen presence. We tested four different recessive mutants that give rise to four different types of tumorous transformation: the embryonic tumorNotch, several larval melanotic tumors, the imaginal disc tumor1(2)gl, and three alleles of the ovarian tumorotu.In all cases, tumorous tissues in homozygotes contained the F7D6 antigen. The electrophoretic mobility of the antigen appeared to be unaltered in tumorous tissues compared to normal cells, but the antigen is expressed at higher levels. The antigen is found on the cytoplasmic surface of plasma membranes and appears to be a marker of undifferentiated normal and tumorous cells. Similarities and differences between the F7D6 antigen andDrosophila c‐srcprotein are disc

ISSN:0192-253X    

DOI:10.1002/dvg.1020080305

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

年代:1987

数据来源: WILEY

摘要:

AbstractAlbino mutation in animals blocks pigmentation owing to a deficiency in tyrosinase, although it does not affect the differentiation of colorless melanocytes from the neural crest. In the albino Japanese quail (al, sex‐linked), it was demonstrated that morphologically normal melanocytes differentiated from neural crest cells in culture and that these cells contained unmelanized melanosomes as expected for the mutant cells. The mutant melanocytes, however, were shown to exhibit tyrosinase activity in the Golgi‐endoplasmic reticulum‐lysosome region and in the Golgi vesicles. Our results seem to indicate that the mutation at theallocus affects the transport of tyrosinase from the Golgi area to melano

ISSN:0192-253X    

DOI:10.1002/dvg.1020080306

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

年代:1987

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020080307

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

年代:1987

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020080301

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

年代:1987

数据来源: WILEY