A number of cophylogenetic relationships between two organisms namely a host and a symbiont or parasite have been studied to date; however, organismal interactions in nature usually involve multiple members. Here, we investigated the cospeciation of a triplex symbiotic system comprising a hierarchy of three organisms -- termites of the family Rhinotermitidae, cellulolytic protists of the genus Pseudotrichonympha in the guts of these termites, and intracellular bacterial symbionts of the protists. The molecular phylogeny was inferred based on two mitochondrial genes for the termites and nuclear small-subunit rRNA genes for the protists and their endosymbionts, and these were compared. Although intestinal microorganisms are generally considered to have looser associations with the host than intracellular symbionts, the Pseudotrichonympha protists showed almost complete codivergence with the host termites, probably due to strict transmissions by proctodeal trophallaxis or coprophagy based on the social behaviour of the termites. Except for one case, the endosymbiotic bacteria of the protists formed a monophyletic lineage in the order Bacteroidales, and the branching pattern was almost identical to those of the protists and the termites. However, some non-codivergent evolutionary events were evident. The members of this triplex symbiotic system appear to have cospeciated during their evolution with minor exceptions; the evolutionary relationships were probably established by termite sociality and the complex microbial community in the gut.

Bacterial attachments to nearly the entire surface of flagellated protists in the guts of termites and the wood-feeding cockroach Cryptocercus are often observed. Based on the polymerase chain reaction-amplified 16S rRNA gene sequences, we investigated the phylogenetic relationships of the rod-shaped, attached bacteria (ectosymbionts) of several protist species from five host taxa and confirmed their identity by fluorescence in situ hybridizations. These ectosymbionts are affiliated with the order Bacteroidales but formed three distinct lineages, each of which may represent novel bacterial genera. One lineage consisted of the closely related ectosymbionts of two species of the protist genus Devescovina (Cristamonadida). The second lineage comprised three phylotypes identified from the protist Streblomastix sp. (Oxymonadida). The third lineage included ectosymbionts of the three protist genera Hoplonympha, Barbulanympha and Urinympha in the family Hoplonymphidae (Trichonymphida). The ultrastructural observations indicated that these rod-shaped ectosymbionts share morphological similarities of their cell walls and their point of attachment with the protist but differ in shape. Elongated forms of the ectosymbionts appeared in all the three lineages. The protist cells Streblomastix sp. and Hoplonympha sp. display deep furrows and vane-like structures, but these impressive structures are probably evolutionarily convergent because both the host protists and their ectosymbionts are distantly related.

In this cross-cultural comparison 36 Japanese and 36 American 3-month-old infant-mother dyads were videotaped in a standardized laboratory setting in their own countries. Mothers in both countries responded contingently to these infant behaviors, but there were differences in the type and timing of maternal behavior vis-a-vis infant behavior. Japanese mothers were more likely than American mothers to punctuate their facial expressions and vocalizations with looming upper-body movements and with touches and they were less likely to respond selectively to infant vocalizations. American mothers held their faces closer to the infants' and provided primarily facial and vocal displays for the infant. Japanese infants tended to display longer average durations of smiling and vocalizing with a lower rate of onsets compared with American infants. The results have implications for understanding the role of the face-to-face period in human development and the way in which cultural differences in interpersonal communicative style may guide the development of infant affective expression, Between 2 and 3 months of age infants begin to look into adult's eyes and to express recognition and enjoyment by responsive smiling and disappointment by crying. Because reaching, grasping, and object interest have not yet developed, adult and infant engage in face-to-face play in which the topic of conversation is the mutual exchange of looks, smiles, touches, and sounds (Stern, 1974).The function-infant regulation of positive attention and affect-and the developmental course of infant behavior during this period is similar across a variety of cultures, with only minor variations in the age of onset and peak time for gazing at mother and for social smiling (Super & Harkness, 1982). At 3 months the primary responsibility for the sequencing of faceto-face interaction is with the mother, who provides a repeated series of exaggerated vocalizations, facial expressions, and body movements, all organized in a theme and variation format (Stern, 1974). Moreover, these maternal displays are usually timed to be responsive to changes in the infant's facial expression, vocalization, and gaze direction (Fogel, 1977). It is not

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