摘要:

AbstractWe examined a temporal series of embryos from 14 full‐sib families of rainbow trout with starch gel electrophoresis to determine the time of initial detection of enzyme produced by ldh‐3. Maternal enzyme was detected in unfertilized eggs, whereas paternal alleles showed evidence of initial expression after gastrulation and epiboly. Two alleles, 40 and 71, were expressed synchronously several days before the 114 allele. Measurement of enzyme activity by spectrophotometric analysis and serial dilution supported these observations. The degree of delay of expression of the 114 allele between families was coupled with other estimates of developmental rate. These data suggest the existence of allelic variation at a cis‐acting genetic element controlling the pattern of ontogenetic expression of structural alleles at

ISSN:0192-253X    

DOI:10.1002/dvg.1020050302

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

年代:1984

数据来源: WILEY

摘要:

AbstractMonoclonal and polyclonal antibodies were used to examine the expression of three erythroid developmental antigen systems in the chicken, Japanese quail, and quail‐chicken hybrid. Chicken fetal antigen (CFA), quail fetal antigen (QFA), and chicken adult antigen (CAA) each represent a series of cell‐surface glycorproteins associated with the development of avian hematopoietic cells. Monoclonal anti‐CFA antibodies from clones 190‐4 and 288‐1.1.1.2 supernatants were shown to react against epitopes associated with CFA determinants 8 and 2, respectively. Using complement‐mediated microcytotoxicity, these reagents permitted the identification of different erythroid subpopulations in the neonatal chicken and hybrid; therefore, heterogeneity in cell surface CFA determinants among mature peripheral erythrocytes should serve as a useful tool for analyzing erythroid development. In the case of CAA, erythrocytes from adult hybrids were found to express the same complement of CAA determinants identified in the chicken, and CAA appeared much earlier in the hybrid than in either of the parental species. Similarly, two species‐restricted fetal antigens associated with similar glycoproteins, CFA8 and QFA, had similar developmental profiles in their respective species, the chicken and quail. In contrast, these antigens were dominantly expressed but exhibited different developmental profiles on erythrocytes from the hybrids. While quail‐chicken hybrids exhibited apparent genomic interactions in the expression of these developmental antigens, no evidence for the existence of hybrid‐specific fetal anti

ISSN:0192-253X    

DOI:10.1002/dvg.1020050303

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

年代:1984

数据来源: WILEY

摘要:

AbstractMating type determination in Tetrahymena thermophila involves developmentally programmed, heritable alterations of the macronucleus, localized to themtdlocus. This determination can be predictably controlled by the environmental conditions during macronuclear development, eg, temperature and time of refeeding. In this article we have further characterized the effects of delayed refeeding on mating type determination, as revealed by the frequency of mating types among the progeny of a cross. Our results show that 1) the magnitude of this starvation effect decreases with temperature of conjugation and becomes undetectable at 18°C; 2) starvation during the interval 14 to 22 hr (after conjugation is induced at 30°C) is a necessary and sufficient condition for the induction of starvation effects; 3) relative mating type frequencies vary monotonically with nutrient concentration present during this critical period; and 4) sister macronuclei, developing under starvation conditions in the same cytoplasm, differentiate majority mating types characteristic of early or late refeeding; sister macronuclei show no apparent correlation with each other. On the basis of our observations on early and late refed cells, we propose that the composition of the newly developed macronucleus is the outcome of two key events: 1) mating type determination at themtdlocus and 2) differential molecular cloning of generally one or two autonomously replicating fragments (ARFs) of the macronuclear DNA bearing themtdlocu

ISSN:0192-253X    

DOI:10.1002/dvg.1020050304

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe mode of the developmental expression of adenylate cyclase (AC) and phosphodiesterase (PDE) in D melanogaster indicates that PDE plays the major role in the maintenance of a certain level of cAMP in postembryonic development, while both enzymes function in concert in imago. The ts‐mutants ts155 and ts622, characterized upon their isolation as having an increased cAMP content and normal PDE activity, manifest high levels of AC activity from the third day of imago life. The levels of PDE activity characteristic for adult mutants with altered enzyme activity (low in ts66 and ts980, high in ts398) are manifested in ts980 from larval instar II, and from the larval instar III in ts398 and ts66. Data on the dependence of PDE activity in adults upon temperature of incubation, being in agreement with the expectations for a ts‐mutation in a gene coding for a form of PDE in case of ts66, suggest that ts398 affects not the enzyme‐coding gene but rather one for an activator protein. The fact that in ts398 (the polyphasic ts‐lethal mapping to 1‐38.9) 1) AC activity is somewhat higher than normal at 22°C and is readily activated at 29°C, 2) activity of PDE‐I assayed in heat‐pretreated homogenates is higher than normal, 3) that boiled extracts of ts398 are potent activators of the wild type and of its own PDE‐I indicates that it is a mutation affecting calmodulin, which is known to be stable at boiling and capable of activating both AC and PDE‐I. Data on Ca2+and EGTA effects suggest that the mutation presumably increases Ca2+‐binding activity of calmodulin, ts980 and ts622, in which ts‐lethality could be produced only by certain doses of haloperidol and triftazine, appear to be lethal in compounds with ts398, thus indicating that these mutations could affect the same calm

ISSN:0192-253X    

DOI:10.1002/dvg.1020050305

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

年代:1984

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020050306

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

年代:1984

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020050307

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

年代:1984

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020050308

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

年代:1984

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020050301

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

年代:1984

数据来源: WILEY