Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1985-1989  (2)
  • Xenopus laevis  (2)
  • 1
    ISSN: 1432-1432
    Keywords: Xenopus laevis ; Xenopus tropicalis ; Adult α-globin genes ; Gene organization ; Conserved upstream sequences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To investigate the evolution of globin genes in the genusXenopus, we have determined the primary structure of the related adult α1- and αII genes ofX. laevis and of the adult α-globin gene ofX. tropicalis, including their 5′-flanking regions. All three genes are comprised of three exons and two introns at homologous positions. The exons are highly conserved and code for 141 amino acids. By contrast, the corresponding introns vary in length and show considerable divergence. Comparison of 900 bp of the 5′-flanking region revealed that theX. tropicalis gene contains a conserved proximal 310-bp promoter sequence, comprised of the canonical TATA and CCAAT motifs at homologous positions, and five conserved elements in the same order and at similar positions as previously shown for the corresponding genes ofX. laevis. We therefore conclude that these conserved upstream elements may represent regulatory sequences for cell-specific regulation of the adultXenopus globin genes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-041X
    Keywords: Hemoglobin transition ; Erythrocytes ; Indirect immunofluorescence ; Metamorphosis ; Xenopus laevis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To elucidate the cellular basis of hemoglobin transition inXenopus laevis the distribution of larval and adult hemoglobins was analyzed by indirect immunofluorescence in the circulating erythrocytes during metamorphosis. In addition, the morphological characteristics as well as the capacity for synthesis of DNA and hemoglobin in the erythrocytes were followed during the same developmental period. Our quantitative analysis on the distribution of larval and adult hemoglobins suggests that they are localized in different cells. Hemoglobin transition, therefore, most likely reflects replacement of the larval erythrocyte population by new cells which are committed to adult globin synthesis. Since hemoglobin transition is not accompanied by an increase in the abundance of immature erythroid cells with active DNA synthesis, we assume that the presumptive adult erythroid cells are released into circulation at a relatively advanced stage of maturation. The decline in the synthesis of DNA and larval hemoglobin further indicates that cessation of cell renewal in the larval erythrocyte population may represent a decisive step in hemoglobin transition.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...