The choline binding proteins (CBPs) are a family of surface proteins noncovalently bound to the phosphorylcholine moiety of the cell wall of Streptococcus pneumoniae by a conserved choline binding domain. Six new members of this family were identified, and these six plus two recently described cell wall hydrolases, LytB and LytC, were characterized for their roles in virulence. CBP-deficient mutants were constructed and tested for adherence to eukaryotic cells, colonization of the rat nasopharynx, and ability to cause sepsis. Five CBP mutants, CbpD, CbpE, CbpG, LytB, and LytC, showed significantly reduced colonization of the nasopharynx. For CbpE and -G this was attributable to a decreased ability to adhere to human cells. CbpG, a putative serine protease, also played a role in sepsis, the first observation of a pneumococcal virulence determinant strongly operative both on the mucosal surface and in the bloodstream.

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Body composition analysis confirmed that egg development and reproductive senescence were delayed in silver female kokanee Oncorhynchus nerka (a small proportion of female kokanee exhibit extreme prespawning waiting and are called 'silvers' because of their colouration) relative to that of red female kokanee (most female kokanee exhibit this 'normal' phenology and are called 'reds'). Silver females were also smaller and younger than red females. A simple life-history model with two size thresholds is proposed to account for the observed body size and age differences. Adoption of the silver tactic by small females is proposed as a means to minimize intrasexual competition.

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