Cloning and characterization of class 1 and class 2 insulin-like growth factor-I mRNA in Songliao black pig
Cloning and characterization of class 1 and class 2 insulin-like growth factor-I mRNA in Songliao black pig
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DOI：
10.1007/s11033-007-9195-y
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发表时间：
2009-02
影响因子：
2.8
通讯作者：
S. Xiao;Shuang Li;Jiabao Zhang;Shumin Zhang;L. Dai;Yonghua Bao;Ning Jiang;Yan Gao;Zhongli Zhao;Delin Mo;Yaosheng Chen;Zhihui Zhao
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文献类型：
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作者：
S. Xiao;Shuang Li;Jiabao Zhang;Shumin Zhang;L. Dai;Yonghua Bao;Ning Jiang;Yan Gao;Zhongli Zhao;Delin Mo;Yaosheng Chen;Zhihui Zhao
胰岛素样生长因子-I（IGF-I）在哺乳动物出生后的生长、发育和代谢中起着重要作用。哺乳动物IGF-I基因含有至少六个外显子，从其转录几种不同的mRNA。本研究采用RLM-RACE技术对松辽黑猪肝脏IGF-I mRNA进行了研究。采用3′-RACE技术，我们确定所有的mRNA转录本都缺少外显子5序列，只含有外显子6序列。使用5′-RACE技术，我们研究了1类和2类IGF-I mRNA的存在。在其他几个物种中，1类和2类IGF-I多肽分别由含有外显子1或外显子2的mRNA产生。在松辽黑猪肝脏中检测到IGF-I的1类和2类mRNA。转录起始于外显子1和2的上游多个分散的起始位点，产生两种不同的IGF-1 mRNA转录物类别，其不同之处在于从其各自的前导序列预测的前体肽。采用实时荧光定量RT-PCR技术，研究了松辽黑猪IGF-Ⅰ 1类和IGF-Ⅰ 2类mRNA的组织分布。两类IGF-I mRNA在多种组织中表达，然而，1类IGF-I mRNA在所有组织中比2类更丰富。
Insulin-like growth factor-I (IGF-I) plays a fundamental role in postnatal mammalian growth, development, and metabolism. The mammalian IGF-I gene contains at least six exons from which several different mRNAs are transcribed. In this study, IGF-I mRNA in Songliao black pig liver was investigated using RLM-RACE. Using a 3′-RACE technique, we determined that all mRNA transcripts lacked exon 5 sequence and contained only exon 6 sequence. Using a 5′-RACE technique, we investigated the presence of class 1 and class 2 IGF-I mRNAs. In several other species, the class 1 and class 2 IGF-I polypeptides are generated from mRNAs containing exon 1 or exon 2, respectively. Both class 1 and class 2 IGF-I mRNAs were identified in Songliao black pig liver. Transcription is initiatated upstream of exons 1 and 2 at multiple dispersed start sites to yield two distinct IGF-I mRNA transcript classes which differ in the precursor peptides predicted from their individual leader sequences. Tissue distribution of Songliao black pig class 1 and class 2 IGF-I mRNA was investigated by real-time RT-PCR. Both classes of IGF-I mRNA were expressed in a variety of tissues, however, class 1 IGF-I mRNA was more abundant than class 2 in all tissues.