( Melanocytes ( ( are ( ( ( the melanin ) - ) ( ( ( producing cells ) and ) ( they ( are ( scattered ( along ( ( the bottom ) ( of ( the epidermis ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Melanocytes)) (VP (VBP are) (NP (NP (DT the) (NN melanin)) (: -) (S (S (VP (VBG producing) (NP (NNS cells)))) (CC and) (S (NP (PRP they)) (VP (VBP are) (VP (VBN scattered) (PP (IN along) (NP (NP (DT the) (NN bottom)) (PP (IN of) (NP (DT the) (NNS epidermis))))))))))) (. .)))
Melanocytes are the melanin -producing cells and  they are scattered along the bottom of the epidermis.
(ROOT (S (NP (NNS Melanocytes)) (VP (VBP are) (VP (VBN located) (PP (IN in) (NP (NP (DT the) (JJ bottom) (NN layer)) (PP (IN of) (NP (DT the) (NNS epidermis))))))) (. .)))