A nonsense allele at rs1343879 in human MAGEE2 on chromosome X has previously been reported as a strong candidate for positive selection in East Asia. This premature stop codon causing ∼80% protein truncation is characterized by a striking geographical pattern of high population differentiation: common in Asia and the Americas (up to 84% in the 1000 Genomes Project East Asians) but rare elsewhere. Here, we generated a Magee2 mouse knockout mimicking the human loss-of-function mutation to study its functional consequences. The Magee2 null mice did not exhibit gross abnormalities apart from enlarged brain structures (13% increased total brain area, P = 0.0022) in hemizygous males. The area of the granular retrosplenial cortex responsible for memory, navigation, and spatial information processing was the most severely affected, exhibiting an enlargement of 34% (P = 3.4×10-6). The brain size in homozygous females showed the opposite trend of reduced brain size, although this did not reach statistical significance. With these insights, we performed human association analyses between brain size measurements and rs1343879 genotypes in 141 Chinese volunteers with brain MRI scans, replicating the sexual dimorphism seen in the knockout mouse model. The derived stop gain allele was significantly associated with a larger volume of gray matter in males (P = 0.00094), and smaller volumes of gray (P = 0.00021) and white (P = 0.0015) matter in females. It is unclear whether or not the observed neuroanatomical phenotypes affect behavior or cognition, but it might have been the driving force underlying the positive selection in humans.
Conference abstracts: Malaysia in affiliation
(1). PO-211. AGE-SPECIFIC STRESS-MODULATED
CHANGES OF SPLENIC IMMUNOARCHITECTURE
IN THE GROWING BODY. Marina Yurievna Kapitonova, Syed Baharom Syed Ahmad Fuad, Flossie Jayakaran; Faculty of Medicine, Universiti Teknologi MARA, Shah Alam, Malaysia
syedbaharom@salam.uitm.edu.my
(2). PO-213. A DETAILED OSTEOLOGICAL STUDY OF THE ANOMALOUS GROOVES NEAR THE
MASTOID NOTCH OF THE SKULL. ISrijit Das, 2Normadiah Kassim, lAzian Latiff, IFarihah Suhaimi, INorzana Ghafar, lKhin Pa Pa Hlaing, lIsraa Maatoq, IFaizah Othman; I Department of Anatomy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia; 2 Department of Anatomy, Universiti Malaya, Kuala Lumpur, Malaysia. das_sri jit23@rediffmail.com
(3). PO-21S. FIRST LUMBRICAL MUSCLE OF THE
PALM: A DETAILED ANATOMICAL STUDY WITH
CLINICAL IMPLICATIONS. Srijit Das, Azian Latiff, Parihah Suhaimi, Norzana Ghafar, Khin Pa Pa Hlaing, Israa Maatoq, Paizah Othman; Department of Anatomy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia. das_srijit23@rediffmail.com
(4). PO-336. IMPROVEMENT IN EXPERIMENTALLY
INDUCED INFRACTED CARDIAC FUNCTION
FOLLOWING TRANSPLANTATION OF HUMAN
UMBILICAL CORD MATRIX-DERIVED
MESENCHYMAL CELLS. lSeyed Noureddin Nematollahi-Mahani, lMastafa Latifpour, 2Masood Deilami, 3Behzad Soroure-Azimzadeh, lSeyed
Hasan Eftekharvaghefi, 4Fatemeh Nabipour, 5Hamid
Najafipour, 6Nouzar Nakhaee, 7Mohammad Yaghoobi, 8Rana Eftekharvaghefi, 9Parvin Salehinejad, IOHasan Azizi; 1 Department of Anatomy, Kerman University of Medical Sciences, Kerman, Iran; 2 Department of Cardiosurgery, Hazrat-e Zahra Hospital, Kerman, Iran; 3 Department of Cardiology, Kerman University of Medical Sciences, Kerman, Iran; 4 Department of Pathology, Kerman University of Medical Sciences, Kerman, Iran; 5 Department of Physiology, Kerman University of Medical Sciences, Kerman, Iran; 6 Department of Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran; 7 Department
of Biotechnology, Research Institute of Environmental Science, International Center for Science, High Technology & Environmental Science, Kerman, Iran; 8 Students Research Center, Kerman University of Medical Sciences, Kerman, Iran; 9 Institute of Bioscience, University Putra Malaysia,
Kuala Lumpur, Malaysia; 10 Department of Stem Cell, Cell Science Research Center, Royan Institute, ACECR, Tehran, Iran. nnematollahi@kmu.ac.ir
(5).