Hagfish Slime Threads - The Functional Fold: Amyloid Structures in Nature - page 17

Figure 2.1 Slime production by a Pacific hagfish in a bucket of sea water. 5

Photo by Christine Ortlepp. See also Colour Insert.

The slime originates in numerous (generally 150-200) slime
glands that line both sides of the hagfish's body. The slime glands are
approximately 2 mm in diameter and are packed with two different
types of cells that make up the slime exudate. These are the gland
mucus cells (GMCs) and the gland thread cells (GTCs). GMCs are

large secretory cells that are filled with countless vesicles containing
condensed mucins. When a slime gland contracts, GMCs are ejected
from the gland through the slime gland duct. During ejection, the
GMC plasma membrane ruptures, releasing the mucin vesicles.
GTCs are large cells that manufacture a single protein thread
that in mature cells takes over the vast majority of the volume of
the cytoplasm. Like GMCs, GTCs undergo holocrine secretion from
the gland, and also lose their plasma membrane during their short
journey through the narrow slime gland duct. As it exits the slime
gland, the slime exudate is a thick suspension of mucin vesicles
and coiled thread cell polymers, also called “skeins” due to their
resemblance to balls of yarn (Fig. 2.2).

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