摘要:

AbstractTheDrosophila melanogastermutantfs(1)1304is an ovary autonomous female sterile mutant that causes abnormal morphology of the egg. Vitellogenesis proceeds at an abnormally slow rate in homozygous females. We have used pole cell transplantation to construct germ line mosaics in order to determine whether the 1304 defect depends upon the genotype of the germ line cells (oocyte or nurse cells) or the somatic line (follicle cells). We have found that the germ line is the primary target tissue where the mutant gene is expressed.

ISSN:0192-253X    

DOI:10.1002/dvg.1020060402

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

年代:1985

数据来源: WILEY

摘要:

AbstractTriploid intersexes homozygous for a mutant (msl‐2) known to impede the hyperactivation of the X chromosome in diploid males differentiate into adults, sexually indistinguishable from their heterozygous sibs. A shift toward female sexual differentiation mediated by manipulating the rearing temperature is accompanied by an apparent increase in the level of an X‐linked gene product. This unexpected result is rationalized in terms of differential lethality of individuals at the two extremities of the distribution of X‐activity levels in intersexes raised at a particular temperature. No evidence of a mosaicism comparable to the sexual mosaicism exhibited could be found with respect to an X‐linked gene product in triploid int

ISSN:0192-253X    

DOI:10.1002/dvg.1020060403

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

年代:1985

数据来源: WILEY

摘要:

AbstractCell death and its effect on wing size have been described in some wing mutants ofDrosophila hydei. Dead cells in the imaginal discs were localized by Nile‐bule and acridine‐orange staining. VariousNotch (N)alleles, the mutationCostal‐nick(Cnk) and the compoundN/Cnkshow characteristic patterns of cell death in the imaginal wing disc. Some but not all of the structural features of the adult wing can be related to the site of cell death during larval stages. InNAxtypes, extensive cell death is followed by regenerative growth, invalidating a simple relation between size of the disk and size of the wing. InNts/Cnkcell death and wing morphology depend on the breeding temperature. From temperature experiments we conclude that cell death starts between day 4 and 5 after egg laying and can be induced by a shift to the restrictive temperature during the critical phase. Patterns of wing incisions and cell death inNts/Cnkgenotypes seem not to be delimited by any of the known compartment bound

ISSN:0192-253X    

DOI:10.1002/dvg.1020060404

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe response ofVolvoxto ultraviolet irradiation was analyzed. Young individuals isolated from a synchronous culture were exposed to UV light (120 J/m2) and subjected to variable lenght periods of dark following irradiation. The major effect of the UV treatment was the inability of the gonidia present in the colonies at the time of irradiation to continue and complete the developmental program. Individuals show a heightened sensitivity to UV for a limited period immediately following inversion and are insensitive at other stages of development. The cytotoxic effect of UV during this interval is completely reversed by the immediate exposure to white light and is increased with longer periods of dark treatment prior to exposure to white light. The temporal profile of the sensitivity defines a smooth curve in which the maximal sensitivity occurs three hours after inversion. The response to higher doses of UV (up to 500 J/m2) is a nonlinear increase in cytotoxicity and is disproportionanately greater in those individuals just prior to the period of maximal sensitivity than those later in development. The results suggest thatVolvoxhas at least two pathways for the repair of UV damage and that one of these, the principal dark repair pathway, is temporarily deficient in the gonidia of young individuals.

ISSN:0192-253X    

DOI:10.1002/dvg.1020060405

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

年代:1985

数据来源: WILEY

摘要:

AbstractA spontaneouswhitemutation recovered inDrosophila mauritianais unstable and reverts to normal eye color at a frequency greater than 4 per 1,000 ×‐chromosomes. Germ line reversion occurs at a high rate inD. mauritianamales and in interspecific hybrid females, while the rate is depressed inD. mauritianafemales. These events are not restricted to the germ line, as cases of variegated patterns of eye pigmentation, indicating somatic reversion, are recovered at a frequency comparable to that of the male germ line reversion rate. Germ line reversion events are genetically stable, while the somatic variegation patterns are not heritable. The patterns of eye pigment variegation produced suggests that reversion events are occurring throughout development. Whole genome DNA digests blotted and probed with the clonedD. melanogaster whitegene indicate that this unstablewhitemutation inD. mauritianais associated with an insertion of DNA that is lost upon reversion to wild type, indicating that this DNA insert is in fact a transposable eleme

ISSN:0192-253X    

DOI:10.1002/dvg.1020060406

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

年代:1985

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020060407

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

年代:1985

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020060408

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

年代:1985

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020060409

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

年代:1985

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020060401

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

年代:1985

数据来源: WILEY