A nematode having null mutations in hop 1 and sel 12, said nematode having a combined maternal effect embryonic lethality and egg laying {TAIL ~ defective phenotype}, at least one of said mutations being introduced by artifice, wherein said {HEAD ~ nematode} is a C. elegans nematode 
A nematode having null mutations in hop 1 and sel 12 , said nematode having a combined maternal effect embryonic lethality and egg laying { TAIL ~ defective phenotype } , at least one of said mutations being introduced by artifice , wherein said { HEAD ~ nematode } is a C. elegans nematode
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH