Bio 580, Developmental Biology.  Wednesday, April 23, 1997

Gametogenesis: Male and Female

Common features:
A. Meiosis
        2N ->  4N  ->  2N  ->  1N  gamete

B. Maternal/Paternal effects
    1. both can contribute to the gamete during the 4N stage of meiosis.

    2. male and female DNA has different methylation patterns

    3. distinct genes donate maternal vs paternal effects
        a. paternal effect genes
            1) spe-11 in C. elegans.   - affects the orientation of the mitotic spindle in embros
                            - perhaps acts on the microtubule organizing center such as centiole.
                            - example of cytoplasmic inheritance?
                            - a donation by the male of a geneticly regulated trait formed in the male state
 
        b. maternal effect genes
            1) genes of the germ line
                a) oocyte
                    - early acting for oocyte determination and A/P-axis
                    - early acting for D/V-axis
                    - posterior group genes
                    - anterior system genes
                    - cytoskeleton genes

                b) nurse cells
                    - suppressor of Hairy wing
                    - Cyclin E

            2) genes of the soma
                a) ovarian cells: e.g.
                       - follicle cells
                            * early acting genes of Dorsal group
                       - oviduct
                b) fat body (liver)

    4. Other donations of interest
        a.  Ribosomes
                Diving beetles, Dytiscus, Giardina's ring (1901)
                Xenopus Oxford mutant story

        b.  Calmodulin
                Sea urchin
                African clawed toad, Xenopus laevis
                Cockroach, Blattella germanica

        c.  Yolk protein (vitellin or lipovitellin)