Sources of Parent-Child Transmission of Drug Abuse: Path Analyses of Not-Lived-With Parental, Stepparental, Triparental, and Adoptive Families

To clarify the origins of parent-child resemblance for drug abuse (DA), using national Swedish data, we fit path models to information on DA in parents and children from six informative family types: i) not-lived-with father, ii) not-lived-with mother, iii) stepfather, iv) stepmother, v) triparental, and vi) adoptive. From these families, we estimated parent-offspring resemblance reflecting the effects of genes + rearing, genes only, and rearing only. The estimates of parent-offspring correlations were statistically homogenous across family types. The weighted estimate of the father-offspring correlation for DA for genes + rearing, genes-only, and rearing-only relationships were, respectively, +0.26, +0.19, and +0.06. Parallel figures for mother-offspring relationships were +0.19, +0.13, and +0.09. In both genes + rearing and genes-only parent-offspring relationships, DA correlations were stronger for fathers than for mothers. Both genetic and environmental factors contribute substantially to parent-offspring resemblance for DA and seem to be additive.

Synchrony in parent-offspring social interactions across development: A cross-species review of rodents and humans

In humans, parent-child neural synchrony has been shown to support early communication, social attunement and learning. Further, some animal species (including rodents and bats) are now known to share neural synchrony during certain forms of social behaviour. However, very little is known about the developmental origins and sequelae of neural synchrony, and whether this neural mechanism might play a causal role in the control of social and communicative behaviour across species. Rodent models are optimal for exploring such questions of causality, with a plethora of tools available for both disruption/induction (optogenetics) and even mechanistic dissection of synchrony-induction pathways (in vivo electrical or optical recording of neural activity). However, before the benefits of rodent models for advancing research on parent-infant synchrony can be realised, it is first important to address a gap in understanding the forms of parent-pup synchrony that occur during rodent development, and how these social relationships evolve over time. Accordingly, this review seeks to identify parent-pup social behaviours that could potentially drive or facilitate synchrony and to discuss key differences or limitations when comparing mouse to human models of parent-infant synchrony. Uniquely, our review will focus on parent-pup dyadic social behaviours that have particular analogies to the human context, including instrumental, social interactive and vocal communicative behaviours. This review is intended to serve as a primer on the study of neurobehavioral synchrony across human and rodent dyadic developmental models.

Familial type 1 diabetes mellitus - gender distribution and age at onset of diabetes distinguish between parent-offspring and sib-pair subgroups

BACKGROUND

Familial type 1 diabetes mellitus (T1D) comprises parent-offspring and sib-pair subgroups.

OBJECTIVE

To compare the demographic and clinical characteristics in the two subgroups at diagnosis and evaluate the differences between index cases and second affected family members.

METHODS

Retrieved from our institutional registry of new T1D cases for the years 1979-2008 were a cohort of 194 familial cases (87 parent-offspring, 107 sib-pairs); 133 sporadic cases matched by age, gender, and year of diagnosis were selected as controls. Extracted from their medical files were demographic data, family background, clinical and laboratory findings.

RESULTS

The parent-offspring subgroup was characterized by male preponderance (p = 0.009). At diagnosis parents were significantly older than their offspring (p < 0.001) and probands were significantly younger than their affected siblings (p = 0.03). Clinical symptoms and metabolic decompensation were similar in the familial subgroups. Diabetic ketoacidosis (DKA) rate and hemoglobin A1c (HbA1c) levels were lower in second affected family members in both parent-offspring (p = 0.05 and p < 0.001) and sib-pair subgroups (p < 0.001, for both parameters). Consanguinity and T1D were more frequent in the extended family of familial than sporadic cases (p < 0.001 and p = 0.012, respectively) with no difference between the two subgroups.

CONCLUSIONS

The genetic background for T1D would appear to differ not only between familial and sporadic cases but also between parent-offspring and sib-pair subgroups. Whereas differences in age of onset are attributable to both genetic and environmental factors, the less severe clinical manifestations in second affected family members may result from increased awareness or a less aggressive disease process.

Gene expression underlying parenting and being parented shows limited plasticity in response to different ambient temperatures

Flexible interactions between parents and offspring are essential for buffering families against variable, unpredictable, and challenging environmental conditions. In the subsocial carrion beetle, Nicrophorus orbicollis, mid-summer temperatures impose steep fitness costs on parents and offspring but do not elicit behavioural plasticity in parents. Here, we ask if plasticity of gene expression underpins this behavioural stability or facilitates independent compensation by larvae. To test this, we characterized gene expression of parents and offspring before and during active parenting under benign (20°C) and stressful (24°C) temperatures to identify genes of parents and offspring associated with thermal response, parenting/being parented, and gene expression plasticity associated with behavioural stability of parental care. The main effects of thermal and social condition each shaped patterns of gene expression in females, males, and larvae. In addition, we implicated 79 genes in females as "buffering" parental behaviour across environments. The majority of these underwent significant changes in expression in actively parenting mothers at the benign temperature, but not at the stressful temperature. Our results suggest that neither genetic programmes for parenting nor their effects on offspring gene expression are fundamentally different under stressful conditions, and that behavioural stability is associated primarily with the maintenance of existing genetic programmes rather than replacement or supplementation. Thus, while selection for compensatory gene expression could expand the range of thermal conditions parents will tolerate, without expanding the toolkit of genes involved selection is unlikely to lead to adaptive changes of function.