The regular occurrence of a univalent sex chromosome in male meiosis but not in female meiosis was confirmed by light (orcein staining of squash preparations) and electron microscopical (3-D-reconstruction of serial sections) techniques. Therefore, male heterogamety, most probably of the X0-XX type, is present in Dinophilus. This seems to be in conflict with the obvious occurrence of two types of eggs, large ones and small ones, that normally give rise to females and males, respectively. The review of available data shows that the control of egg ratio and therefore of sex ratio in Dinophilus gyrociliatus is progamic and influenced by environmental as well as genetic conditions. Sex determination eventually is Syngamic and brought about by selective fertilization of large eggs by female determining sperms and of small eggs by male determining sperms.
|Journal||International Journal of Invertebrate Reproduction and Development|
|Number of pages||21|
|Publication status||Published - 03.1987|
Research Areas and Centers
- Academic Focus: Center for Infection and Inflammation Research (ZIEL)