M. A. Sleigh

Evolutionary relationships among protozoa: an introduction. The molecular phylogeny of protozoa: solid facts and uncertainties. Evolutionary relationships between protist phyla constructed from large subunit ribosomal RNAs accounting for unequal rates of substitution among sites. Evolutionary relationships in microsporidia. Phylogenetics of protozoan tubulin. Enzymes and compartmentation of core energy metabolism of anaerobic protists: a special case in eukaryotic evolution? Molecular phylogeny of Trichomonas and Naegleria: implications for the relative timing of the mitochondrion emdosymbiosis. Hydrogenosomes and plastid-like organelles in amoeboflagellates, chytrids, and apicoplexan parasites. Molecular systematics of the intestinal amoebae. Relationships between amoeboflagellates. Molecular phylogeny of kinetoplastids. Evolutionary relationships among the African trypanosomes: implications for the epidemiology and generation of human sleeping sickness epidemics. Organelle and enzyme evolution in trypanosomatids. The phylum Apicomplexa: an update on the molecular phylogeny. Origin of plastids. Plastid-like DNA in apicomplexans. The karyorelictids, a unique and enigmatic assemblage of marine, interstitial ciliates: a review emphasizing ciliary patterns and evolution. Molecular and cellular evolution of ciliates: a phylogenetic perspective. Phylogenetic relationships of myxozoans. Relationships between lower fungi and protozoa. Neomonada and the origin of animals and fungi. Classification of protozoa and protists: the current status.

The beat pattern of rabbit tracheal cilia has been investigated using high-speed cine photography and scanning electron microscopy, on cultured epithelia of known orientation. The cilia normally rest in the position reached at the end of the effective stroke, the ciliary tips pointing towards the oropharynx. Each beat begins with a recovery (or preparative) stroke in which a bend is propagated up the cilium causing the cilium to rotate backwards in a clockwise sweep, as viewed from above. At the end of its recovery stroke the cilium progresses immediately into the effective (or power) stroke, which is almost planar and in a cephalad direction. The active cilium describes an arc of almost 110 degrees before reaching the rest stage. This beat pattern is not significantly altered over an increase in frequency from 13-29 Hz; the relative duration of the 2 active phases of the beat remain similar over this range. Metachronal waves exist in the form of short erratic areas of coordinated beating which travel only short distances. Within each area, the non-planar recovery strokes initiate an antilaeoplectic wave of activity which recruits inactive cilia to extent the wave. As cilia perform their effective strokes, adjacent cilia in the plane of beating move in an antiplectic sequence. This pattern of coordination is related to the pattern of beat of the cilia and their distribution on the epithelium.