Journal of Genetics and Genomics

The Role of MicroRNAs in Neural Stem Cells and Neurogenesis

Fen Ji, Xiaohui Lv, Jianwei Jiao

2013, 40(2): 61-66. doi: 10.1016/j.jgg.2012.12.008

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Abstract:
Neural stem cells give rise to neurons through the process of neurogenesis, which includes neural stem cell proliferation, fate determination of new neurons, as well as the new neuron's migration, maturation and integration. Currently, neurogenesis is divided into two phases: embryonic and adult phases. Embryonic neurogenesis occurs at high levels to form the central nervous system. Adult neurogenesis has been consistently identified only in restricted regions and occurs at low levels. As the basic process for embryonic neurodevelopment and adult brain maintenance, neurogenesis is tightly regulated by many factors and pathways. MicroRNA, short non-coding RNA that regulates gene expression at the post-transcriptional level, appears to be involved in multiple steps of neurogenesis. This review summarizes the emerging role of microRNAs in regulating embryonic and adult neurogenesis, with a particular emphasis on the proliferation and differentiation of neural stem cells.

Genetically Modified Pig Models for Human Diseases

Nana Fan, Liangxue Lai

2013, 40(2): 67-73. doi: 10.1016/j.jgg.2012.07.014

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Abstract:
Genetically modified animal models are important for understanding the pathogenesis of human disease and developing therapeutic strategies. Although genetically modified mice have been widely used to model human diseases, some of these mouse models do not replicate important disease symptoms or pathology. Pigs are more similar to humans than mice in anatomy, physiology, and genome. Thus, pigs are considered to be better animal models to mimic some human diseases. This review describes genetically modified pigs that have been used to model various diseases including neurological, cardiovascular, and diabetic disorders. We also discuss the development in gene modification technology that can facilitate the generation of transgenic pig models for human diseases.

Identification of the RNAs for Transcription Factor Mitf as a Component of the Balbiani Body

Mingyou Li, Yongming Yuan, Yunhan Hong

2013, 40(2): 75-81. doi: 10.1016/j.jgg.2012.12.006

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Abstract:
Balbiani body (BB) is a large distinctive organelle aggregate uniquely present in developing oocytes of diverse animal species. BB is thought as a stage-specific structure that resembles germ plasm, the cytoplasmic organelle of germ cells. The role and function of BB have remained speculative because of a highly dynamic structure and a lack of genetic and molecular data. BB has been found to contain proteins and RNAs, none of them – except the zebrafish foxH1 RNA, is or encodes a transcription factor. Here we report in the fish medaka (Oryzias latipes) that RNAs encoding microphthalmia-associated transcription factor (Mitf) are prominent components of the BB. By fluorescence in situ hybridization on ovarian section, we revealed that the transcripts of both mitf1 and mitf2 genes concentrated in the BB, in which they co-localized with the dazl RNA, a definitive BB marker highly conserved in vertebrates. Therefore, the mitf product may play dual roles in germ gene transcription and BB formation and/or function in this organism. Our data provide the second evidence that the RNA of a transcription factor can be a prominent component of the BB in a vertebrate.

Dual Effects of IL-1 Overactivity on the Immune System in a Mouse Model of Arthritis due to Deficiency of IL-1 Receptor Antagonist

Jian Yan, Yan Jiao, Hong Chen, Feng Jiao, Karen A. Hasty, John M. Stuart, Weikuan Gu

2013, 40(2): 83-91. doi: 10.1016/j.jgg.2013.01.001

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Abstract:
Previous studies have revealed the significance of cytokine interleukin 1 (IL-1) in the onset and progression of rheumatoid arthritis (RA). The precise molecular mechanisms related to IL-1 underlying RA is still elusive. We conducted a whole genome-wide transcriptomal comparison of wild-type (WT) and arthritis-prone IL-1 receptor antagonist (IL-1rn) deficient BALB/c mice to address this issue. To refine our search efforts, gene expression profiling was also performed on paired wild-type and arthritis-resistant IL-1rn deficient DBA/1 mice as internal controls when identifying causative arthritis candidate genes. Two hundred and fifteen transcripts were found to be dysregulated greater than or equal to 2-fold in the diseased mice. The altered transcriptome in BALB/c mice revealed increased myeloid cell activities and impaired lymphocyte functionality, suggesting dual regulatory effects of IL-1 hyperactivity on immunological changes associated with arthritis development. Phase-specific gene expression changes were identified, such as early increase and late decrease of heat shock protein coding genes. Moreover, common gene expression changes were also observed, especially the upregulation of paired Ig-like receptor A (Pira) in both early and late phases of arthritis. Real-time PCR was performed to validate the expression of Pira and an intervention experiment with a major histocompatibility complex (MHC) class I inhibitor (brefeldin A) was carried out to investigate the role of suppressing Pira activity. We conclude that global pattern changes of common and distinct gene expressions may represent novel opportunities for better control of RA through early diagnosis and development of alternative therapeutic strategies.

Cloning of Ln Gene Through Combined Approach of Map-based Cloning and Association Study in Soybean

Chao Fang, Weiyu Li, Guiquan Li, Zheng Wang, Zhengkui Zhou, Yanming Ma, Yanting Shen, Congcong Li, Yunshuai Wu, Baoge Zhu, Weicai Yang, Zhixi Tian

2013, 40(2): 93-96. doi: 10.1016/j.jgg.2013.01.002

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Abstract:

2013 Vol. 40, No. 2