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
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 189 (1994), S. 531-537 
    ISSN: 1432-0568
    Keywords: Embryonic chick gonad ; Sertoli cell ; Differentiation ; In vitro feminization ; Sex-specific antigen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male and female gonads from 7- to 9-day-old chick embryos were cultured for 6 days in Sertoli cell-conditioned medium or in serum-free medium to investigate the possible effect of substances secreted by rat Sertoli cells on chick gonad development. Histological analysis showed that whereas all female gonads proceed through normal ovarian development in both culture media, most of male gonads showed clear feminization only when cultured in Sertoli cell-conditioned medium; male gonads cultured in serum-free medium developed as normal testes. Because the only substance detected in our conditioned medium with the potential to cause these effects was sex-specific antigen (Sxs), our results provide further evidence that Sxs antigen may play a role in sexual differentiation in birds, and probably in mammals.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-6849
    Keywords: B-chromosomes ; black rat ; NORs ; rDNA ; supernumerary chromosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In-situ hybridization with a rDNA probe has demonstrated the presence of non-transcribed ribosomal genes in the B chromosomes of the black rat Rattus rattus. To test whether methylation of ribosomal DNA present in the B chromosomes could account for their inactivation, we performed in-situ digestions and Southern analyses of DNA digested with the isoschizomers MspI and HpaII. Our results suggest that the accessory chromosomes of this species have originated from one of the smaller NOR-carrying chromosome pairs. In the course of evolution, repetitive sequences invaded this supernumerary element and its ribosomal DNA content was dispersed throughout the chromosome and inactivated by heterochromatinization and methylation.
    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...