Paternal Relationships With Sons and Daughters

This chapter examines paternal relationships with sons and daughters. Identity drives investment (and parental investment in particular), because people invest in that which aligns with their identity. And biological sex drives identity. These two ideas combined imply that a parent-offspring match in biological sex can influence parental favoritism in a systematic manner, an idea supported by recent empirical studies. This parental bias of concordant-sex favoritism can have broad implications, outside the context of the traditional family structure. In single parent or same-sex parent households, the consequences of this bias can be even stronger, because there would not be an opposite-direction bias from the other parent to even things out. This favoritism could have even broader ramifications, entirely outside the context of the family. On the one hand, whenever social norms dictate that men should control a family’s financial decisions, then sons may systematically receive more resources than daughters. This asymmetry in investment would then result in ever-increasing advantages that persist over time. On the other hand, if women are a family’s primary shoppers, this can manifest in subtle but chronic favoritism for daughters.

Factors Affecting Compliance to a Gluten-Free Diet in Pediatric Populations with Celiac Disease

Celiac disease (CD) is a multisystemic autoimmune disorder triggered by gluten, and the only known remedy available for this malady is a gluten-free diet (GFD). Therefore, we performed a systematic review to correlate the influence of different factors in compliance to a GFD. We searched PubMed database, from inception to April 2019. As inclusion criteria we considered population under 18 years, confirmed diagnosis of CD without related comorbidities and the study objective being the factors affecting compliance to a GFD. The variables compared were age, parent's education level, parental knowledge about CD, family type, celiac association membership, quality of life, and perception of difficulties in maintaining a GFD. We identified 1,414 articles, 35 articles were eligible for full text assessment and 12 were included in the study since they studied similar variables. Our work has found some limitations namely a variety of methods to assess GFD compliance, a limiting definition of compliance, a parental bias in data, an absence of standardization in age categories, and a majority of studies being observational in their nature. Age as well as parental knowledge of CD and family type are key factors in pediatric GFD compliance. Nevertheless environmental, social, and family factors were also related with compliance. Further studies are needed to fully disclose the causality relation between these factors and compliance.

Single nucleus analysis of Arabidopsis seeds reveals new cell types and imprinting dynamics

Seeds are the basis of agriculture, yet their full transcriptional complexity has remained unknown. Here, we employ single-nucleus RNA-sequencing to characterize developing Arabidopsis thaliana seeds, with a focus on endosperm. Endosperm, the site of gene imprinting in plants, mediates the relationship between the maternal parent and embryo. We identify new cell types in the chalazal endosperm region, which interfaces with maternal tissue for nutrient unloading. We further demonstrate that the extent of parental bias of maternally expressed imprinted genes varies with cell cycle phase, and that imprinting of paternally expressed imprinted genes is strongest in chalazal endosperm. These data indicate imprinting in endosperm is heterogeneous and suggest that parental conflict, which is proposed to drive the evolution of imprinting, is fiercest at the boundary between filial and maternal tissues.

The germline mutational process in rhesus macaque and its implications for phylogenetic dating

Understanding the rate and pattern of germline mutations is of fundamental importance for understanding evolutionary processes. Here we analyzed 19 parent-offspring trios of rhesus macaques (Macaca mulatta) at high sequencing coverage of ca. 76X per individual, and estimated an average rate of 0.77 × 10−8de novo mutations per site per generation (95 % CI: 0.69 × 10−8 - 0.85 × 10−8). By phasing 50 % of the mutations to parental origins, we found that the mutation rate is positively correlated with the paternal age. The paternal lineage contributed an average of 81 % of the de novo mutations, with a trend of an increasing male contribution for older fathers. About 3.5 % of de novo mutations were shared between siblings, with no parental bias, suggesting that they arose from early development (postzygotic) stages. Finally, the divergence times between closely related primates calculated based on the yearly mutation rate of rhesus macaque generally reconcile with divergence estimated with molecular clock methods, except for the Cercopithecidae/Hominoidea molecular divergence dated at 52 Mya using our new estimate of the yearly mutation rate.

Quantitative and functional interrogation of parent-of-origin allelic expression biases in the brain

The maternal and paternal genomes play different roles in mammalian brains as a result of genomic imprinting, an epigenetic regulation leading to differential expression of the parental alleles of some genes. Here we investigate genomic imprinting in the cerebellum using a newly developed Bayesian statistical model that provides unprecedented transcript-level resolution. We uncover 160 imprinted transcripts, including 41 novel and independently validated imprinted genes. Strikingly, many genes exhibit parentally biased—rather than monoallelic—expression, with different magnitudes according to age, organ, and brain region. Developmental changes in parental bias and overall gene expression are strongly correlated, suggesting combined roles in regulating gene dosage. Finally, brain-specific deletion of the paternal, but not maternal, allele of the paternally-biased Bcl-x, (Bcl2l1) results in loss of specific neuron types, supporting the functional significance of parental biases. These findings reveal the remarkable complexity of genomic imprinting, with important implications for understanding the normal and diseased brain.