GENES INDUCED IN PROGRAMMED CELL-DEATH OF NEURONAL PC12 CELLS AND DEVELOPING SYMPATHETIC NEURONS IN-VIVO

To identify primary response genes induced during early stages of neur onal programmed cell death (PCD), we screened by differential hybridiz ation a subtracted cDNA library prepared from neuronal PC12 cells depr ived of NGF for 6 hr in the presence of cycloheximide. Eight induced c DNA sequences were identified and designated message up-regulated duri ng death (mud)-1-8. To determine which cloned sequences might be invol ved in neuronal PCD in vivo, expression of mud genes was analyzed in d eveloping rat superior cervical ganglia (SCG) undergoing programmed ce ll death, using a combination of reverse Southern, reverse transcripti on polymerase chain reaction (RT-PCR), and in situ hybridization. Five sequences (mud-1, -3, -5/8, -6, and -7) are induced in SCG undergoing cell death in vivo, and induction of at least three of these (mud-3, -6, and -7) occurs in neurons. Partial sequence analysis reveals that mud-1: corresponds to annexin VI; mud-3 corresponds to rat PC3, mouse TIS21; mud-4 appears to be the rat homolog of human TAFII70; mud-5 and -8 are >85% identical members of the rodent gene family of B2-transcr ibed repeats; and mud-6 appears to be the rat homolog of human Ring 3 and Drosophila female sterile homeotic (fsh). Mud-2 and mud-7 encode n ovel sequences. These new candidate genes provide markers for early st ages of neuronal PCD, are potentially involved in the cell death proce ss, and serve to expand our view of cell death control in the developi ng nervous system. (C) 1997 Academic Press.