A fundamental tenet of classical mendelian genetics is that allelic information is stably inherited from one generation to the next, resulting in predictable segregation patterns of differing alleles. Although several exceptions to this principle are known, all represent specialized cases that are mechanistically restricted to either a limited set of specific genes (for example mating type conversion in yeast) or specific types of alleles (for example alleles containing transposons or repeated sequences). Here we show that Arabidopsis plants homozygous for recessive mutant alleles of the organ fusion gene HOTHEAD (HTH) can inherit allele-specific DNA sequence information that was not present in the chromosomal genome of their parents but was present in previous generations. This previously undescribed process is shown to occur at all DNA sequence polymorphisms examined and therefore seems to be a general mechanism for extra-genomic inheritance of DNA sequence information. We postulate that these genetic restoration events are the result of a template-directed process that makes use of an ancestral RNA-sequence cache.

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This study examined mother-child interaction as a predictor of mastery motivation (i.e., persistence on a problem-posing task) in 3-year-old children who were born premature and had either motor impairment or developmental delay (n = 34). Two aspects of mother-child interaction were hypothesized to predict for mastery motivation: response to child's distress and cognitive growth-fostering behaviors. Hierarchical regression analyses revealed that maternal response to distress, but not cognitive growth promotion, added significant unique variance (15.3%) beyond child cognitive performance in the prediction of mastery motivation. Results suggest that interventions focused on emotional aspects of the mother-child dyad provide important benefits to young children with disabilities who are born preterm.

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