Preparation of a cDNA library from the hagfish slime gland

The slime glands of hagfish have two major cell types, gland thread cells (GTCs) and gland mucous cells (GMCs), both of which upon contact with water contribute to an abundant viscous mucus. GTCs are unique specialized cells in which 60-80% of the mature GTC volume is occupied by a single tapered thread about 60 cm long formed by bundling keratin intermediate filaments (IFs). Each IF is composed of three 63.5 kD protein subunits (α, β, γ). Poly (A+) mRNA was isolated from GTCs and translated by the rabbit reticulocyte system with [35S] Met. Analysis of the translation products showed a major labeled protein at 65 kD. A cDNA library prepared from the poly (A+) mRNAs was screened with 32P-labeled IF probes from human epidermis. Several clones containing cross-hybridizing inserts were identified