Genetic Determinism on Teachers’ Perceptions about Etiology of Mental Disorders

Mental disorders are disorders of the cognitive, emotional or behavioral condition of an individual. They can have several origins and are usually associated with expressive anguish and difficulty in various aspects of life, including school education. Mental disorders are accompanied by social stigmas which may be linked to the belief in genetic determinism, i.e., in the perception that mental disorders are unchanging. The objective of the present study was to understand the perception of Brazilian teachers of all levels about the etiology of mental disorders. The results showed that most of the teachers studied believe in the predominance or exclusivity of genes in mental disorders, and do not consider the environment as a potential influencer of their occurrence or mitigation. This perception approaches the belief in genetic determinism and can justify the labeling of students with mental disorders and the consequent perpetuation of social stigmas. It is therefore recommended to promote knowledge in this area, including knowledge of the dynamics of interaction between genes and the environment, helping educators to prepare and to be able to act according to the reality of each student without creating inappropriate stereotypes.

A Chance to Live

This chapter explores the role of randomness in genetics and evolution. We are each a blend of genetic determinism and chance. Through the process of meiosis, genetic material from father and mother are shuffled through recombination to provide the DNA for new individuals, each of whom is unique, but who nonetheless retain links to their genetic heritage. Some probabilistic aspects of evolution are explored: how does a process fuelled by chance nonetheless result in viable organisms? What are the chances of us being here, now?

Variable brain wiring through scalable and relative synapse formation in Drosophila

Variability of synapse numbers and partners despite identical genes reveals limits of genetic determinism. Non-genetic perturbation of brain wiring can therefore reveal to what extent synapse formation is precise and absolute, or promiscuous and relative. Here, we show the role of relative partner availability for synapse formation in the fly brain through perturbation of developmental temperature. Unexpectedly, slower development at lower temperatures substantially increases axo-dendritic branching, synapse numbers and non canonical synaptic partnerships of various neurons, while maintaining robust ratios of canonical synapses. Using R7 photoreceptors as a model, we further show that scalability of synapse numbers and ratios is preserved when relative availability of synaptic partners is changed in a DIPγ mutant that ablates R7's preferred synaptic partner. Behaviorally, movement activity scales inversely with synapse numbers, while movement precision and relative connectivity are congruently robust. Hence, the fly genome encodes scalable relative connectivity to develop functional, but not identical, brains.

Congenital cerebral palsy: genetic cause and nosological integrity

The review provides an analysis of 73 full-text articles, the source of which was the Medline, OMIM, NCBI, Pubmed, Scopus, eLibrary.ru databases. The data of studies of the main pathogenetic mechanisms of the formation of the cerebral palsy (CP) phenotype, such as chromosomal aberrations, copy number variations, single nucleotide polymorphisms, associated with the development of the CP phenotype, are reviewed and analyzed. Epigenetic effects on the genome, as well as the effects of the genome on the mechanisms of epigenomic regulation, are examined in detail. The data on the genetic determinism of concomitant pathology and reactivity to therapeutic tactics are presented. Based on the study of data from numerous studies, the authors draw the following conclusions:1) the pathogenesis of the phenotype of CP includes a large number of genes that determine violations of cellular metabolism, neuroontogenesis, brain resistance to hypoxia, etc;2) genes whose abnormalities form a syndromic pathology are involved in the pathogenesis of CP;3) the multidirectionality and breadth of the effects of the gene pool with the outcome in a syndrome-specific distinctive picture of the CP allows us to propose the concept of a neurotropic genome;4) the mechanisms of gene involvement can vary from aberrations to epigenetic imbalances;5) different groups of genes can differentially influence the formation of individual syndromes in the phenotype of CP;6) there are data indicating a genetic determinism of the tendency to contracture, pharmacoreactivity to drugs that reduce muscle tone, reactivity to habilitation effects;7) genomic-epigenomic interactions normally ensure the body’s adaptation to environmental conditions, and with pathology, they increase the likelihood of regulatory breakdowns that lead to the formation of a CP phenotype;8) the exclusion from the diagnosis of CP of genetically determined cases of phenotype development is incorrect.The authors present two anthropogenic reasons for the increase in the frequency of occurrence of de novo identified gene abnormalities:1) anthropogenic impact on the environment, increasing the number of anomalies of the genome de novo; 2) iatrogenic effects of technologies for preserving life, vitality and reproductive ability of carriers of genomic anomalies. This effect leads to the fixation of anomalies in the genome of the population.A paradox is formulated, according to which, in the presence of technologies capable of preserving the life of carriers of genomic anomalies, in vivo technologies for genome correction are only just beginning to be put into practice. Based on this, it is concluded that it is necessary to intensify the development of methods for prenatal diagnosis and gene therapy of CP.

Detection of unrecorded environmental challenges in high-frequency recorded traits, and genetic determinism of resilience to challenge, with an application on feed intake in lambs

Background Resilient animals can remain productive under different environmental conditions. Rearing in increasingly heterogeneous environmental conditions increases the need of selecting resilient animals. Detection of environmental challenges that affect an entire population can provide a unique opportunity to select animals that are more resilient to these events. The objective of this study was two-fold: (1) to present a simple and practical data-driven approach to estimate the probability that, at a given date, an unrecorded environmental challenge occurred; and (2) to evaluate the genetic determinism of resilience to such events. Methods Our method consists of inferring the existence of highly variable days (indicator of environmental challenges) via mixture models applied to frequently recorded phenotypic measures and then using the inferred probabilities of the occurrence of an environmental challenge in a reaction norm model to evaluate the genetic determinism of resilience to these events. These probabilities are estimated for each day (or other time frame). We illustrate the method by using an ovine dataset with daily feed intake (DFI) records. Results Using the proposed method, we estimated the probability of the occurrence of an unrecorded environmental challenge, which proved to be informative and useful for inclusion as a covariate in a reaction norm animal model. We estimated the breeding values for sensitivity of the genetic potential for DFI of animals to environmental challenges. The level and slope of the reaction norm were negatively correlated (− 0.46 ± 0.21). Conclusions Our method is promising and appears to be viable to identify unrecorded events of environmental challenges, which is useful when selecting resilient animals and only productive data are available. It can be generalized to a wide variety of phenotypic records from different species and used with large datasets. The negative correlation between level and slope indicates that a hypothetical selection for increased DFI may not be optimal depending on the presence or absence of stress. We observed a reranking of individuals along the environmental gradient and low genetic correlations between extreme environmental conditions. These results confirm the existence of a G $$\times$$ × E interaction and show that the best animals in one environmental condition are not the best in another one.

Genetics of reproduction in the rabbit.

This chapter describes the genetic determinism of all traits involved in male and female reproductive performances in rabbits. All traits related to the underlying biological processes leading to the mating outcome, as well as some of its general features, such as the homogeneity of the reproductive performances, are considered (semen and ejaculate characteristics, ovulation rate, fertility, embryo survival, fetal survival and litter size). Different parameters of fertility and litter size are discussed, including the contribution of both sexes to each phase of the reproductive cycle.