ABSTRACT
Objectives: Developmental theory and previous studies support the potential value of prodromal interventions for infants at elevated likelihood of developing autism. Past research has supported the efficacy of parent-mediated prodromal therapies with infants from as early as 7 months. We outline the rationale for implementing interventions following this model from even earlier in development and report on the feasibility of a novel intervention developed following this model of parent-mediated infant interventions. Methods: We report a feasibility study (n = 13) of a parent-mediated, video-aided intervention, beginning during pregnancy, focussed on parent-infant interactions. The study evaluated the feasibility of this intervention initially with a general population sample. Feasibility was assessed across four domains (acceptability, implementation, practicality and integration) using self-report questionnaire, semi-structured interviews with parents and therapists, attendance and assessment completion. Results: Feasibility assessment shows that the intervention was acceptable, with all participants reporting that they had benefited from the program, with perceived positive benefits to their understanding of and communication with their infant, and that they had integrated program teachings into everyday life. The intervention was implemented as planned with 100% attendance for the core sessions. Changes to minimise the number of antenatal sessions was suggested to improve practicality. Conclusions: This study found initial feasibility for this intervention in a general population sample. This suggests parent-mediated video feedback interventions are a promising format to be implemented within the perinatal developmental time period.
ABSTRACT
The importance of regulatory incompatibilities to the early stages of speciation remains unclear. Hybrid mammals often show extreme parent-of-origin growth effects that are thought to be a consequence of disrupted genetic imprinting (parent-specific epigenetic gene silencing) during early development. Here, we test the long-standing hypothesis that abnormal hybrid growth reflects disrupted gene expression due to loss of imprinting (LOI) in hybrid placentas, resulting in dosage imbalances between paternal growth factors and maternal growth repressors. We analyzed placental gene expression in reciprocal dwarf hamster hybrids that show extreme parent-of-origin growth effects relative to their parental species. In massively enlarged hybrid placentas, we observed both extensive transgressive expression of growth-related genes and biallelic expression of many genes that were paternally silenced in normal sized hybrids. However, the apparent widespread disruption of paternal silencing was coupled with reduced gene expression levels overall. These patterns are contrary to the predictions of the LOI model and indicate that hybrid misexpression of dosage-sensitive genes is caused by other regulatory mechanisms in this system. Collectively, our results support a central role for disrupted gene expression and imprinting in the evolution of mammalian hybrid inviability, but call into question the generality of the widely invoked LOI model.