TY - JOUR
T1 - Neocortex expansion is linked to size variations in gene families with chemotaxis, cell-cell signalling and immune response functions in mammals
AU - Castillo-Morales, Atahualpa
AU - Monzón-Sandoval, Jimena
AU - de Sousa, Alexandra A
AU - Urrutia, Araxi O.
AU - Gutierrez, Humberto
PY - 2016
Y1 - 2016
N2 - Increased brain size is thought to have played an important role in the evolution of mammals and is a highly variable trait across lineages. Variations in brain size are closely linked to corresponding variations in the size of the neocortex, a distinct mammalian evolutionary innovation. The genomic features that explain and/or accompany variations in the relative size of the neocortex remain unknown. By comparing the genomes of 28 mammalian species, we show that neocortical expansion relative to the rest of the brain is associated with variations in gene family size (GFS) of gene families that are significantly enriched in biological functions associated with chemotaxis, cell-cell signalling and immune response. Importantly, we find that previously reported GFS variations associated with increased brain size are largely accounted for by the stronger link between neocortex expansion and variations in the size of gene families. Moreover, genes within these families are more prominently expressed in the human neocortex during early compared with adult development. These results suggest that changes in GFS underlie morphological adaptations during brain evolution in mammalian lineages.
AB - Increased brain size is thought to have played an important role in the evolution of mammals and is a highly variable trait across lineages. Variations in brain size are closely linked to corresponding variations in the size of the neocortex, a distinct mammalian evolutionary innovation. The genomic features that explain and/or accompany variations in the relative size of the neocortex remain unknown. By comparing the genomes of 28 mammalian species, we show that neocortical expansion relative to the rest of the brain is associated with variations in gene family size (GFS) of gene families that are significantly enriched in biological functions associated with chemotaxis, cell-cell signalling and immune response. Importantly, we find that previously reported GFS variations associated with increased brain size are largely accounted for by the stronger link between neocortex expansion and variations in the size of gene families. Moreover, genes within these families are more prominently expressed in the human neocortex during early compared with adult development. These results suggest that changes in GFS underlie morphological adaptations during brain evolution in mammalian lineages.
KW - Brain size
KW - Encephalization
KW - Gene family size
KW - Neocortex
UR - http://www.scopus.com/inward/record.url?scp=85032127821&partnerID=8YFLogxK
UR - http://dx.doi.org/10.6084/m9.figshare.c.3489039
U2 - 10.6084/m9.figshare.c.3489039
DO - 10.6084/m9.figshare.c.3489039
M3 - Article
AN - SCOPUS:85032127821
SN - 2046-2441
VL - 6
JO - Open Biology
JF - Open Biology
IS - 10
M1 - 3489039
ER -