Maternal age effects on offspring lifespan and reproduction vary within a species.

Across diverse taxa, offspring from older mothers have decreased lifespan and fitness. Little is known about the extent to which maternal age effects vary among genotypes for a given species, however, except for studies of a few arthropod species. To investigate the presence and degree of intraspecific variability in maternal age effects, we compared lifespan, reproductive schedule, and lifetime reproductive output of offspring produced by young, middle-aged, and old mothers in four strains of rotifers in the Brachionus plicatilis species complex. We found significant variability among strains in the magnitude and direction of maternal age effects on offspring life history traits. In one strain, offspring of young mothers lived 20% longer than offspring of old mothers, whereas there were no significant effects of maternal age on lifespan for other strains. Depending on strain, advanced maternal age had positive effects, negative effects, or no effect on lifetime reproductive output. Across strains, older mothers produced offspring that had higher maximum daily reproduction early in life. The effects of maternal age on offspring vital rates could not be explained by changes in trade-offs between lifespan and reproduction. This study documents intraspecific variability in maternal age effects in an additional clade. Investigating intraspecific variability is critical for understanding the ubiquity of maternal age effects and their role in the evolution of life history and aging.

Children of trauma survivors: Influences of parental posttraumatic stress and child-perceived parenting.

BACKGROUND: Research has established a negative association between parental posttraumatic stress symptoms (PTSS), including subthreshold symptoms, and child physical and behavioral health outcomes. Such intergenerational transmission of risk has multiple possible mechanisms, including lack of positive parenting, increased negative parenting, shared environmental and contextual risks, and potential biological components such as shared genetics or even transmission of epigenetic risk. METHOD: This study examined 93 parent-child dyads (n = 171 participants total) from a mixed Urban-Suburban US metropolitan area to investigate the relations between parental PTSS and child-perceived parenting and child PTSS. We sought to examine interactions between parental PTSS and parenting on child PTSS. RESULTS: We found an association between parent and child PTSS, consistent with prior literature showing increased risk for children of trauma survivors. Interestingly, we found effects of positive parenting on diminished child PTSS symptoms only in parents without PTSS, whereas the effect of positive parenting on buffering child symptoms was absent in parents with PTSS. LIMITATIONS: The present findings are tempered by the use of self-report data to assess parent and child PTSS, which is not as reliable as clinician assessment of symptoms. Further, the use of survey data limits what is known about the extent of trauma exposure in parents and children, and different measures were used to assess PTSS in parents and kids, which limits comparability of these reported symptoms. DISCUSSION: Limitations notwithstanding, findings suggest joint attention paid to parenting practices and to a parent's recovery, even from subthreshold symptoms of PTSS, as two different but important ways to support trauma survivor parents in their efforts to most optimally parent and protect their children from intergenerational risk.

Maternal age effects on offspring lifespan and reproduction vary within a species.

Across diverse taxa, offspring from older mothers have decreased lifespan and fitness. Little is known about whether such maternal age effects vary among genotypes for a given species, however. We compared maternal age effects among four strains of rotifers in the Brachionus plicatilis species complex. For each strain, we measured lifespan, reproductive schedule, and lifetime reproductive output of offspring produced by young, middle-aged, and old mothers. We found unexpected variability among strains in the magnitude and direction of maternal age effects on offspring life history traits. In one strain, offspring of young mothers lived 20% longer than offspring of old mothers, whereas there were no significant effects of maternal age on lifespan for the other strains. Across strains, advanced maternal age had positive effects, negative effects, or no effect on lifetime reproductive output. For all but one strain, older mothers produced offspring that had higher maximum daily reproduction early in life. Maternal age effects appear to be genetically determined traits, not features of life history strategy or due to accumulation of age-related damage in the germline. Investigating intraspecific variability is critical for understanding the ubiquity of maternal age effects and their role in the evolution of life history and aging.