Corriveau JL et al. 1991
- Authors:
Corriveau JL. Coleman AW.
- Title:
Monitoring by epifluorescence microscopy of organelle DNA fate during
pollen development in five angiosperm species.
- Reference location:
Developmental Biology. 147(1):271-80, 1991 Sep.
- Abstract:
The fates of mitochondrial and plastid nucleoids during pollen development
in six angiosperm species (Antirrhinum majus, Glycine max, Medicago
sativa, Nicotiana tabacum, Pisum sativum, and Trifolium pratense) were
examined using epifluorescence microscopy after double staining with
4',6-diamidino-2- phenylindole (DAPI) to stain DNA and with a
potentiometric dye (either DiOC7 or rhodamine 123) for visualization of
metabolically active mitochondria. From the pollen mother cell stage to
the microspore stage of pollen development, mitochondria and plastids both
contained DNA detectable by DAPI staining. However, during the further
maturation preceding anthesis, mitochondrial DNA became undetectable
cytologically in either the generative or the vegetative cell of mature
pollen; even in germinated pollen tubes containing hundreds of
metabolically active mitochondria undergoing cytoplasmic streaming, vital
staining with DAPI failed to reveal mitochondrial DNA. By the mature
pollen stage, plastid DNA also became undetectable by DAPI staining in the
vegetative cell. However, in the generative cell of mature pollen the
timing of plastid DNA disappearance as detected by DAPI varied with the
species. Plastid DNA remained detectable only in the generative cells of
pollen grains from species known or suspected to have biparental
transmission of plastids. The apparent absence of cytologically detectable
organelle genomes in living pollen was further examined using molecular
methods by hybridizing organelle DNA-specific probes to digests of total
DNA from mature pollen and from other organs of A. majus and N. tabacum,
both known to be maternal for organelle inheritance. Mitochondrial DNA was
detected in pollen of both species; thus the cytological alteration of
mitochondrial genomes during pollen development does not correspond with
total mtDNA loss from the pollen. Plastid DNA was detectable with
molecular probes in N. tabacum pollen but not in A. majus pollen. Since
the organelle DNA detected by molecular methods in mature pollen may lie
solely in the vegetative cell, further study of the basis of maternal
inheritance of mitochondria and plastids will require molecular methods
which distinguish vegetative cell from reproductive cell organelle
genomes. The biological effect of the striking morphological alteration of
organelle genomes during later stages of pollen development, which leaves
them detectable by molecular methods but not by DAPI staining, is as yet
unknown.
This page is part of the
Snapdragon Home Page.
The URL of the Snapdragon Home Page is
http://www.mpiz-koeln.mpg.de/snapdragon/snapdragon.html
If you have any comments, additions or corrections to this page of general
interest you are invited to use the
Snapdragon Guest Book.
For personal comments please write to the author(s) of this page or to
Kurt Stueber.
This page has last been modified on May 26, 1997.