Heterozygotes are WT with GFP+ (pharynx) and segregate Dpy with GFP+ (pharynx) and slow growing GFP- animals which are generally sterile (with germline tumor at 25C). pro-1(na48) is a weak, recessive, loss-of-function allele that behaves as a stronger loss-of-function at lower temperatures. At 25C, 85% of na48 animals will develop a proximal germline tumorr. Although tumors are less common at lower temperatures, the animals are generally sterile due to low proliferation and somatic gonad defects. na48 animals are slow growing at all temperatures.