Cytoplasmic bodies are derived from the germinal vesicle

Parthenogenesis refers to the ability of embryos to develop without being fertilized.  Parthenogenesis is typically a derived trait and has independently evolved numerous times from non-parthenogenetic ancestors.  For example it is estimated that parthenogenetic haplo-dipoid insects have independently evolved at least 17 times.  In another striking example, the New Zealand water snail has independently evolved parthenogenesis over 100 times in lakes less than 100,000 years old.  These findings are astonishing when one considers the dramatic alterations that must occur at the cellular level for an egg to successfully develop in the absence of a sperm.  The sperm provides the paternal chromosome complement and a basal body, which immediately transforms into a centrosome upon fertilization.  Therefore evolution of parthenogenesis required an ability to compensate for the lack of a paternal genome and an ability to generate centrosomes solely from maternally supplied products.  We discovered that hundreds of centrosomes form de novo in specialized lamin-based organelles derived from the nucleus of the female oocyte.  For highlights of the progress we have made in this area over the past five years press here.

Relevant publications:

Ferree, P.M., McDonald, K., Fasulo, B., Sullivan, W.2006 The origin of Centrosomes in Parthenogenetic Hymenopteran Insects.  Current Biol. 16: 801-807.

Tram, U., and Sullivan W., 2000.  Reciprocal inheritance of centrosomes in the parthenogenetic hymenoptera Nasonia vitripennis.  Current Biol.  10: 1413-1419.