Zygotic regulation of maternal cyclin A1 and B2 mRNAs

At the midblastula transition, the Xenopus laevis embryonic cell cycle is remodeled from rapid alternations between S and M phases to become the complex adult cell cycle. Cell cycle remodeling occurs after zygotic transcription initiates and is accompanied by terminal downregulation of maternal cyclins A1 and B2. We report here that the disappearance of both cyclin A1 and B2 proteins is preceded by the rapid deadenylation of their mRNAs. A specific mechanism triggers this deadenylation. This mechanism depends upon discrete regions of the 3' untranslated regions and requires zygotic transcription. Together, these results strongly suggest that zygote-dependent deadenylation of cyclin A1 and cyclin B2 mRNAs is responsible for the downregulation of these proteins. These studies also raise the possibility that zygotic control of maternal cyclins plays a role in establishing the adult cell cycle.

Mothers' fear of child death due to acute diarrhoea: a study in urban and rural communities in northern Punjab, Pakistan

The investigation of cultural models of diarrhoeal illness which are employed by mothers and their emotional responses to children's illnesses is presented in a study of 595 households in urban and rural communities in Punjab, Pakistan. The household survey of mothers of children 0-36 months was complemented with in-depth interviews of a subsample of 70 mothers. Findings indicate that diarrhoea must be regarded not only as a disease but as a symptom belonging to several popular illness categories. Mothers' emotional responses to symptoms are in part shaped by the illness categories to which they assign a child's diarrhoea episode, and maternal fears that symptoms of diarrhoea may be life threatening are associated with previous experiences with death of children, with treatment choices and help-seeking. A significantly higher proportion of mothers who fear diarrhoea to be life threatening to their children than mothers with other concerns choose to use NIMKOL, the Pakistan ORS. The necessity of recognizing the complexity of interpretive and emotional processes which shape the care of children and the home treatment of childhood disease is emphasized.