Maternal genes

Kubiak Indeed, but given that it is a checkpoint which is activated at that time, there must be a reason to activate this checkpoint delay in the first mitosis and not in the second one. Whatever the mechanism is, it is maternally determined and it is specific for this particular mitosis. This is the only mitosis that depends entirely on maternal genes in the mouse embryos, so we must look for a mechanism triggering a checkpoint delay. 

FIG. 3. (A) Screening scheme for maternal genes that can modulate apoptosis when expressed... 

FIGURE 28-36 Distribution of a maternal gene product in a Drosophila egg. (a) Micrograph of an immunologically stained egg, showing distribution of the bicoid (bed) gene product. The graph measures stain intensity. This distribution is essential for normal develop-... 

Establishment of the D-V axis in Drosophila requires the participation of several genes. As mentioned above, gurken affecfs follicle cells. These cells cooperate with the ovum to set up a concentration gradient of the maternal gene Dorsal, the protein encoded by the dorsal Dorsal is a transcription factor... 

There are several possible causes which could affect the differential phenotypic expression of enzymes in early development- the maternal effect. Among these are (1) the stability of enzyme accumulated during oocyte maturation (2) the stability of mRNA s which code for the maternal subunits of enzyme (3) the comparatively early activation of maternal genes as opposed to paternal genes. 

It should be noticed that in this case the differential inactivation is specifically restricted to the nucleolar organizer region, because many enzymes which are controlled by paternal as well as maternal genes were active (Wall and Blackler,... 

Lehmann R. and Nusslein-VoUiard C. 1986. Abdominal segmentation, pole ceU formation, and embryonic polarity require the localized activity of oskar, a maternal gene in Drosophila. Cell 47 141-152. 

The maternal gene nanos has a central role in posterior pattern formation of the Drosophila... 

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