DISTRIBUTION OF PARTHENOGENETIC CELLS IN THE MOUSE-BRAIN AND THEIR INFLUENCE ON BRAIN-DEVELOPMENT AND BEHAVIOR

A systematic analysis of parthenogenetic (PG) cell fate within the cen tral nervous system (CNS) was made throughout fetal development and ne onatal and adult life, Chimeras were made between PG embryos carrying a ubiquitously expressed lacZ transgene and normal fertilized embryos. After detailed histological analysis, we find that the developmental potential of PG cells is spatially restricted to certain parts of the brain, PG cells are prevalent in telencephalic structures and are larg ely excluded from diencephalic structures, especially the hypothalamus , These spatial restrictions are established early in development. Beh avioral studies with chimeras identified an increase in male aggressio n when the proportion of PG cells in the brain was high, These studies demonstrate that imprinted genes play key roles in development of the CNS and may be involved in behavior.