ELIMINATED CHROMATIN OF ASCARIS CONTAINS A GENE THAT ENCODES A PUTATIVE RIBOSOMAL-PROTEIN

Chromatin diminution in the nematodes Parascaris equorum and Ascaris lumbricoides leads to the formation of somatic cells that contain less DNA than the germ-line cells. We present molecular evidence for the coding potential of germ-line-specific DNA. We report on a cDNA clone that codes for a putative ribosomal protein (ALEP-1, for A. lumbricoides eliminated protein 1). That the corresponding gene is located in the eliminated portion of the genome indicates a difference in germ-line and somatic ribosomes of A. lumbricoides and P. equorum. Elimination of the ALEP-1 gene from all somatic cells in its fully active state may represent an alternative way to gene regulation.