J. A. W. M. van der Donk

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Quiescent gonocytes were isolated from fetal testes of rat 18-day post coitum and cultured alone or on monolayers of somatic cells from different origins. The gonocytes specifically adhered to Sertoli cells, isolated from 21 to 23-day-old rat testes; this adherence was necessary for their survival in vitro. Addition of follicle-stimulating hormone and(More)
The influence of proteins and RNA from unpollinated, inter-and intraspecifically pollinated styles and from pollen on pollen tube growth in vivo was tested by their application to the stigma prior to pollination. No RNA sample nor proteins from unpollinated styles were effective, whereas pollen tubes were shortened if the S-genotypes of the pollen matched(More)
Regulation of pollen germination of Petunia was investigated by determining RNA content and composition in an in vitro system in the presence and absence of the transcription inhibitor actinomycin D and by labelling with C14-orotic acid. At the beginning of the progamic phase 2 stages can be distinguished: First (up to 15 minutes) no essential RNA synthesis(More)
Styles of Petunia hybrida were pollinated (selfed or crossed) and pollentubes were allowed to grow in the presence of 3H-orotic acid. After 24 h RNA was extracted using the cold phenol method and separated on a tandem polyacrylamide gel. Results show that: 1. the synthesis of RNA is more enhanced after cross- than after selfpollination and 2. a restricted(More)
Acute irradiation of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) pollen by X-rays enhances pollen tube elongation. To determine whether this effect was due to physical damage of the pollen membranes or to metabolic processes, irradiated and control pollen were grown under conditions of anoxia. Thus, it was determined that physical damage only could(More)
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