( ( The maps ) ( ( are ( ( composed largely ) ( of ( ( named genes ) ( identified ( by ( ( recombinant ( DNA probes ) ) ( in ( Southern ( blotting assays ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS maps)) (VP (VBP are) (VP (VBN composed) (ADVP (RB largely)) (PP (IN of) (NP (NP (VBN named) (NNS genes)) (VP (VBN identified) (PP (IN by) (NP (NP (JJ recombinant) (NN DNA) (NNS probes)) (PP (IN in) (NP (JJ Southern) (VBG blotting) (NNS assays)))))))))) (. .)))
The maps are composed largely of named genes identified by recombinant DNA probes in Southern blotting assays.
(ROOT (S (NP (NNS Genes)) (VP (VBP are) (VP (VBN composed) (PP (IN of) (NP (NN dna))))) (. .)))
Genes are composed of dna.