Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1982 Mar;191(2):112-118.
doi: 10.1007/BF00848448.

The morphogenetic significance of the first quartet micromeres for the development of the snailBithynia tentaculata

W I van Dam  1 , N H Verdonk  1
Affiliations

The morphogenetic significance of the first quartet micromeres for the development of the snailBithynia tentaculata

W I van Dam et al. Wilehm Roux Arch Dev Biol. 1982 Mar.

Abstract

The significance of the first quartet of micromeres for the morphogenesis ofBithynia - a polar lobe-forming gastropod-has been studied by deletion experiments. After removal of the whole first quartet at the 8-cell stage a dorsoventrally organized veliger larva is formed. Apparently, an interaction between the animal micromeres and a vegetal macromere, which is essential for the origin of a dorsoventral organization in equally cleaving gastropods, is not required in polar lobe forming eggs. It is concluded that in these eggs dorsoventrality is determined by segregation of the polar lobe. The embryos, in which the first quartet has been removed, never develop head structures. This indicates that the capacity to form head structures is restricted to the first quartet of micromeres. Deletion of a specific first quartet micromere (1a, 1b, 1c or 1d) showed, however, that the individual cells of this quartet are not strictly determined right from their origin. Frequently regulative development was observed after removal of individual first quartet cells.

Keywords: Determination; Mollusca; Mosaic development; Polar lobe; Regulation.

PubMed Disclaimer

References

    1. Dev Biol. 1979 Feb;68(2):462-71 - PubMed
    1. J Embryol Exp Morphol. 1974 Apr;31(2):415-22 - PubMed
    1. J Embryol Exp Morphol. 1970 Jun;23(3):667-92 - PubMed
    1. J Morphol. 1977 Oct;154(1):157-86 - PubMed
    1. Dev Biol. 1968 Feb;17(2):165-86 - PubMed