2052. Read that back to me! What do these characters have in common? 主 温 妊 息 愚

They all have a reading that is the same backwards.  

主  SHU, nushi, omo - lord, main

温  ON, atata(kai), atata(meru) - warm

妊  NIN - pregnancy

息  SOKU, iki, musu - breath, son

愚  GU , oro(ka) - foolish, stupid