Comparative genomics of brain size evolution

Enard, Wolfgang

doi:10.3389/fnhum.2014.00345

Cited by 13 publications

(11 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with pheno-are constrained, and how changes at a cellular level contribute to broad-scale anatomical evolution [Rausher and Delph, 2015]. The potential to dissect the biological basis of brain and behavioural evolution motivates many genomic comparisons across primates [Enard, 2014]. These have identified numerous genes associated with brain development with high rates of evolution [Enard et al, 2002a;Pollard et al, 2006;Montgomery et al, 2011;Montgomery and Mundy, 2012a, b;Kamm et al, 2013;Boyd et al, 2015;Boddy et al, 2017], divergent expression profiles [Enard et al, 2002b;Khaitovich et al, 2004;Brawand et al, 2011;Bauernfeind et al, 2015] or duplicated sequences [Burki and Kaessmann, 2004;Keeney et al, 2014;Florio et al, 2015;Zimmer and Montgomery, 2015] either across primates or during recent human evolution.…”

Section: Introductionmentioning

confidence: 61%

Genetics of Cerebellar and Neocortical Expansion in Anthropoid Primates: A Comparative Approach

Harrison

Montgomery

2017

Brain Behav Evol

View full text Add to dashboard Cite

What adaptive changes in brain structure and function underpin the evolution of increased cognitive performance in humans and our close relatives? Identifying the genetic basis of brain evolution has become a major tool in answering this question. Numerous cases of positive selection, altered gene expression or gene duplication have been identified that may contribute to the evolution of the neocortex, which is widely assumed to play a predominant role in cognitive evolution. However, the components of the neocortex co-evolve with other functionally interdependent regions of the brain, most notably in the cerebellum. The cerebellum is linked to a range of cognitive tasks and expanded rapidly during hominoid evolution. Here we present data that suggest that, across anthropoid primates, protein-coding genes with known roles in cerebellum development were just as likely to be targeted by selection as genes linked to cortical development. Indeed, based on currently available gene ontology data, protein-coding genes with known roles in cerebellum development are more likely to have evolved adaptively during hominoid evolution. This is consistent with phenotypic data suggesting an accelerated rate of cerebellar expansion in apes that is beyond that predicted from scaling with the neocortex in other primates. Finally, we present evidence that the strength of selection on specific genes is associated with variation in the volume of either the neocortex or the cerebellum, but not both. This result provides preliminary evidence that co-variation between these brain components during anthropoid evolution may be at least partly regulated by selection on independent loci, a conclusion that is consistent with recent intraspecific genetic analyses and a mosaic model of brain evolution that predicts adaptive evolution of brain structure.

show abstract

Section: Introductionmentioning

confidence: 61%

Genetics of Cerebellar and Neocortical Expansion in Anthropoid Primates: A Comparative Approach

Harrison

Montgomery

2017

Brain Behav Evol

View full text Add to dashboard Cite

show abstract

“…2 B ) may suggest gene–phenotype associations are maintained in parallel across independent anthropoid lineages. A common problem in large scale comparative analyses is a lack of power due to the large number of genes and small number of species (Enard 2014). Indeed, our estimates of the “global” false-positive rate in our data set are high, but variable, across the three phenotypes; 14.4%, 2.4%, and 27.6% for brain mass, body mass, and EQ, respectively.…”

Section: Resultsmentioning

confidence: 99%

Evidence of a Conserved Molecular Response to Selection for Increased Brain Size in Primates

Boddy

Harrison

Montgomery

et al. 2017

Genome Biology and Evolution

View full text Add to dashboard Cite

The adaptive significance of human brain evolution has been frequently studied through comparisons with other primates. However, the evolution of increased brain size is not restricted to the human lineage but is a general characteristic of primate evolution. Whether or not these independent episodes of increased brain size share a common genetic basis is unclear. We sequenced and de novo assembled the transcriptome from the neocortical tissue of the most highly encephalized nonhuman primate, the tufted capuchin monkey (Cebus apella). Using this novel data set, we conducted a genome-wide analysis of orthologous brain-expressed protein coding genes to identify evidence of conserved gene–phenotype associations and species-specific adaptations during three independent episodes of brain size increase. We identify a greater number of genes associated with either total brain mass or relative brain size across these six species than show species-specific accelerated rates of evolution in individual large-brained lineages. We test the robustness of these associations in an expanded data set of 13 species, through permutation tests and by analyzing how genome-wide patterns of substitution co-vary with brain size. Many of the genes targeted by selection during brain expansion have glutamatergic functions or roles in cell cycle dynamics. We also identify accelerated evolution in a number of individual capuchin genes whose human orthologs are associated with human neuropsychiatric disorders. These findings demonstrate the value of phenotypically informed genome analyses, and suggest at least some aspects of human brain evolution have occurred through conserved gene–phenotype associations. Understanding these commonalities is essential for distinguishing human-specific selection events from general trends in brain evolution.

show abstract

“…This suggests the existence of a specific cross-talk between DNA repair pathways and primary cell cycle functions in these progenitors, which might have become more critical during evolution. Integrating these molecular findings with genetics and evolutionary biology will be a powerful approach in investigating brain size evolution (Enard, 2014 ).…”

Section: Mcph1 and Brain Evolutionmentioning

confidence: 99%

“…These studies go beyond correlating genetic changes with brain size, and attempt to experimentally test the hypothesis that MCPH1 is an important gene in brain size evolution. Futher approaches may be to generate humanized and primatized mice expressing human and other primate MCPH1 (Pulvers et al, 2010 ), or the use of cerebral organoids (Lancaster et al, 2013 ), an in vitro model of human cortical development, where microcephaly-causing mutations in humans and primate-specific variants in MCPH1 can be investigated in detail in a system amenable to experimentation (Enard, 2014 ). Gene expression profiling studies aimed at identifying pathways dependent on MCPH1 in mouse and human, as well as the characterization of molecular partners for both the mouse and human proteins, will provide major clues on the molecular mechanisms involving MCPH1 and its role in the evolution of brain size.…”

Section: Mcph1 and Brain Evolutionmentioning

confidence: 99%

MCPH1: a window into brain development and evolution

Pulvers

Journiac

Arai

et al. 2015

Front. Cell. Neurosci.

View full text Add to dashboard Cite

The development of the mammalian cerebral cortex involves a series of mechanisms: from patterning, progenitor cell proliferation and differentiation, to neuronal migration. Many factors influence the development of the cerebral cortex to its normal size and neuronal composition. Of these, the mechanisms that influence the proliferation and differentiation of neural progenitor cells are of particular interest, as they may have the greatest consequence on brain size, not only during development but also in evolution. In this context, causative genes of human autosomal recessive primary microcephaly, such as ASPM and MCPH1, are attractive candidates, as many of them show positive selection during primate evolution. MCPH1 causes microcephaly in mice and humans and is involved in a diverse array of molecular functions beyond brain development, including DNA repair and chromosome condensation. Positive selection of MCPH1 in the primate lineage has led to much insight and discussion of its role in brain size evolution. In this review, we will present an overview of MCPH1 from these multiple angles, and whilst its specific role in brain size regulation during development and evolution remain elusive, the pieces of the puzzle will be discussed with the aim of putting together the full picture of this fascinating gene.

show abstract

Comparative genomics of brain size evolution

Cited by 13 publications

References 62 publications

Genetics of Cerebellar and Neocortical Expansion in Anthropoid Primates: A Comparative Approach

Genetics of Cerebellar and Neocortical Expansion in Anthropoid Primates: A Comparative Approach

Evidence of a Conserved Molecular Response to Selection for Increased Brain Size in Primates

MCPH1: a window into brain development and evolution

Contact Info

Product

Resources

About