Organelle Alteration as a Mechanism for Maternal Inheritance

Abstract

An ultrastructural study of pollen-derived plants and normal microspore development indicates that chloroplasts and mitochondria are physically altered during microsporogenesis. These changes appear to debilitate the organelle so that only chloroplasts and mitochondria of the female parent are contributed to the offspring.

The Egg Cell: Development and Role in Fertilization and Early Embryogenesis

“…The male cytoplasm is clearly transmitted in some plants (Russell, 1983) but not in others (Jensen and Fisher, 1968;Mogensen, 1988). A number of mechanisms that would reduce the likelihood of male cytoplasmic transmission prior to sperm cell deposition have been proposed: (1) organellar diminution through the pinching off of cellular processes (see Mogensen, 1992) or production of enucleated cytoplasmic bodies ; (2) alteration of organelles (Vaughn et al, 1980); (3) modification of organellar DNA through molecular means (Day and Ellis, 1984), including specific nucleases (e.g., nuclease C; Nakamura et al, 1992); or (4) low ratios of paternal to maternal organelles (Russell, 1987), resulting in a high probability of paternal organelle extinction (Birky, 1983) or in levels of expression that are below the threshold for detection (Milligan, 1992). Just prior to fusion, the sperm cells may shed their cytoplasm outside the egg and central cells, as in cotton (Jensen and Fisher, 1968), or just outside of the egg cell, as in barley (Mogensen, 1988).…”

The Egg Cell: Development and Role in Fertilization and Early Embryogenesis.

“…The male cytoplasm is clearly transmitted in some plants (Russell, 1983) but not in others (Jensen and Fisher, 1968;Mogensen, 1988). A number of mechanisms that would reduce the likelihood of male cytoplasmic transmission prior to sperm cell deposition have been proposed: (1) organellar diminution through the pinching off of cellular processes (see Mogensen, 1992) or production of enucleated cytoplasmic bodies ; (2) alteration of organelles (Vaughn et al, 1980); (3) modification of organellar DNA through molecular means (Day and Ellis, 1984), including specific nucleases (e.g., nuclease C; Nakamura et al, 1992); or (4) low ratios of paternal to maternal organelles (Russell, 1987), resulting in a high probability of paternal organelle extinction (Birky, 1983) or in levels of expression that are below the threshold for detection (Milligan, 1992). Just prior to fusion, the sperm cells may shed their cytoplasm outside the egg and central cells, as in cotton (Jensen and Fisher, 1968), or just outside of the egg cell, as in barley (Mogensen, 1988).…”

Ribulose Bisphosphate Carboxylase Activity in Anther-Derived Plants of Saintpaulia ionantha Wendl. Shag

“…Alternatively, the possibility that plastid DNA changes have occurred exists. Vaughn et al (21) have established morphological changes in plastids during microsporogenesis.…”