rDNA subtypes and their transcriptional expression in zebrafish at different developmental stages
rDNA subtypes and their transcriptional expression in zebrafish at different developmental stages
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斑马鱼不同发育阶段的rDNA亚型及其转录表达
DOI：
10.1016/j.bbrc.2020.05.196
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发表时间：
2020
影响因子：
3.1
通讯作者：
He Jin
中科院分区：
文献类型：
--
作者：
Tao Boxiang;Lo Li Jan;Peng Jinrong;He Jin
真核生物的18 S、5.8S和28 S rRNA是由45 S rDNA基因转录的单个转录物加工而成，45 S rDNA基因通常在基因组中串联排列超过100个拷贝。最近，在斑马鱼中鉴定了rDNA的母体（M）亚型和体细胞（S）亚型，其中M亚型位于4号染色体上，S亚型位于5号染色体上。似乎M-亚型仅在卵中表达，而S-亚型的表达与合子基因表达的起始偶联。在这份报告中，我们发现了三个新的，但转录活性的18 S变异体在斑马鱼基因组中的染色体位置不同的M-和S-亚型，建议在斑马鱼进化过程中的18 S rDNA片段易位。此外，我们证实，未受精卵只有M亚型的转录本，而大脑，心脏和肝脏只有S亚型的转录本。在雌性生殖腺中检测到M和S亚型转录本。我们的研究结果支持不同亚型的rDNA的表达差异调节，以满足在不同的发育阶段的“专门的核糖体”的要求。
Eukaryotic 18S, 5.8S and 28S rRNAs are processed from a single transcript transcribed from the 45S rDNA gene, which is normally tandemly arrayed over hundred copies in a genome. Recently, a maternal (M) subtype and a somatic (S) subtype of rDNA were identified in zebrafish, with M-subtype on chromosome 4 and S-subtype on chromosome 5. It appears that the M-subtype is only expressed in eggs whilst the expression of the S-subtype is coupled with the initiation of zygotic gene expression. In this report, we identified three novel but transcriptionally inactive 18S variants in zebrafish genome with chromosome location different from the M- and S-subtype, suggesting translocation of 18S rDNA fragment during zebrafish evolution. Furthermore, we confirmed that the unfertilized eggs only have the M-subtype transcripts while brain, heart and liver have only the S-subtype transcripts. Both the M- and S-subtype transcripts were detected in female gonad. Our results support that the expression of different subtypes of rDNA is differentially regulated to meet the requirement for ‘specialized ribosomes’ during different developmental stages.