The effects of serum immunoglobulins on the metachronal coordination of the lateral cilia of Mytilus edulis

Abstract

Human IgM and a bovine, IgM-enriched serum fraction isolated from normal adult serum at concentrations of 0.25-1 mg/ml protein induced a pronounced increase in the metachronal wavelength of the lateral (L) cilia of the sea mussel Mytilus edulis without altering their beat frequency. This change in activity was indistinguishable from that induced by 50% adult human or bovine serum. At protein concentrations ranging from 1-9 mg/ml, human IgG or a bovine, IgG-enriched serum fraction had no or little effect on the activity of the L cilia. Similarly, neither monomeric (8S) human IgM (0.25 mg/ml) nor monospecific pentameric IgM (1 mg/ml) isolated from Waldenström's macroglobulinemia patients altered the metachrony of the L cilia. Indirect immunofluorescence demonstrated that both bovine and human IgM became attached almost exclusively to the L cilia, while very little bovine or human IgG was found to associate with these cilia. The results of this study suggest that serum IgM specifically binds to the L cilia of Mytilus in an antigen-antibody manner and agglutinates adjacent cilia into blocks or bundles, thereby increasing the coupling between cilia. As a result, the wavelength of the metachronal coordination is increased. The origin of these ciliary antibodies and their significance to ciliary bioassays used to monitor serum for the detection of cystic fibrosis are discussed.

Characterization of metachronal wave of beating cilia on frog's palate epithelium in tissue culture.

“…It has been observed previously that cilia create a metachronal wave on the epithelium (Sleigh, 1974; Aiello & Sleigh, 1977;Sanderson & Sleigh, 1981;Marino & Aiello, 1982;Sanderson & Sleigh, 1984).…”

“…There is, nevertheless, the possibility of utilizing two methods, each of which is capable of demonstrating (among other things) the existence of the metachronal wave and of estimating its wave-length: (a) high-speed cinematography -which, in addition to estimating the wave-length, provides in-formation on the frequency and shape of the beating cilia. This technique has greatly contributed to the study of ciliary motion (Aiello & Sleigh, 1977;Sanderson & Sleigh, 1981;Marino & Aiello, 1982;Sanderson & Sleigh, 1984); (b) electron microscopy which has made it possible to both estimate the wave-length and to study the detailed inner structure of cilium and suggests a molecular mechanism for ciliary movement (Warner, 1974;Sanderson & Sleigh, 1981).…”