GRB10 Imprinting Is Eutherian Mammal Specific
MOLECULAR BIOLOGY AND EVOLUTION
Authors: Stringer, Jessica M.; Suzuki, Shunsuke; Pask, Andrew J.; Shaw, Geoff; Renfree, Marilyn B.
Abstract
GRB10 is an imprinted gene differently expressed from two promoters in mouse and human. Mouse Grb10 is maternally expressed from the major promoter in most tissues and paternally expressed from the brain-specific promoter within specific regions of the fetal and adult central nervous system. Human GRB10 is biallelically expressed from the major promoter in most tissues except in the placental villus trophoblast where it is maternally expressed, whereas the brain-specific promoter is paternally expressed in the fetal brain. This study characterized the ortholog of GRB10 in a marsupial, the tammar wallaby (Macropus eugenii) to investigate the origin and evolution of imprinting at this locus. The protein coding exons and predicted amino acid sequence of tammar GRB10 were highly conserved with eutherian GRB10. The putative first exon, which is located in the orthologous region to the eutherian major promoter, was found in the tammar, but no exon was found in the downstream region corresponding to the eutherian brain-specific promoter, suggesting that marsupials only have a single promoter. Tammar GRB10 was widely expressed in various tissues including the brain but was not imprinted in any of the tissues examined. Thus, it is likely that GRB10 imprinting evolved in eutherians after the eutherian-marsupial divergence approximately 160 million years ago, subsequent to the acquisition of a brain-specific promoter, which resides within the imprinting control region in eutherians.
GIGYF2 Asn56Ser and Asn457Thr mutations in Parkinson disease patients
NEUROSCIENCE LETTERS
Authors: Guo, Yi; Jankovic, Joseph; Zhu, Shaihong; Le, Weidong; Song, Zhi; Xie, Wenjie; Liao, Daoguang; Yang, Huarong; Deng, Hao
Abstract
Parkinson disease (PD) is one of the most common neurodegenerative disorders with major clinical features of bradykinesia, rigidity, resting tremor, and postural instability. At least thirteen gene loci responsible for PD or parkinsonism have been found and nine causative genes have been identified. Recently, Asn56Ser or Asn457Thr mutations in the Grb10-Interacting GYF Protein-2 gene (GIGYF2) were found to occur in about 2.4% familial PD Italian and French patients. We conducted genetic examination of Asn56Ser or Asn457Thr mutations, but none was found in 310 PD patients from North America. We did identify a non-disease-associated polymorphism Pro460Thr. Our results suggest that the GIGYF2 Asn56Ser and Asn457Thr mutations are a rare cause of PD in North American Caucasian population. (C) 2009 Elsevier Ireland Ltd. All rights reserved.