本文選題：編碼基因　切入點：間隔區(qū)　出處：《中國水產(chǎn)科學(xué)》2017年04期

【摘要】：核糖體基因為串聯(lián)重復(fù)多拷貝的基因,包括3個編碼基因(18S,5.8S,28S)和兩個間隔區(qū)ITS1(internal transcribed spacer 1)和ITS2(internal transcribed spacer 2)。目前,對核糖體基因的相關(guān)報道主要集中在個體內(nèi)不同拷貝間的多態(tài)特征,以及其作為分子標(biāo)記在系統(tǒng)演化關(guān)系中的應(yīng)用,GC含量作為一項非常重要的核苷酸序列指標(biāo),而鮮有報道。為了探討魚類的核糖體基因GC含量特征以及間隔區(qū)是否也存在GC平衡現(xiàn)象,本研究選擇了鱸形目(Perciformes)5科11種魚類5個片段的核糖體基因進行研究,包括尖吻鱸科(Latidae)、射水魚科(Toxotidae)、軍曹魚科(Rachycentridae)、劍魚科(Xiphiidae)、湽科(Carangidae)。獲得了1651個單克隆序列,通過分析并比較已有的其他硬骨魚序列片段的GC含量變化特征,結(jié)果發(fā)現(xiàn):本研究魚類的18S的GC含量為52.6%~57.1%(平均54.6%),5.8S為55.6%~58.9%(平均57.4%),28S為64.2%~65.8%(平均64.6%),ITS1為56.5%~73.0%(平均65.0%),ITS2為62.3%~77.5%(平均69.1%)。編碼區(qū)的GC含量相對較保守,變異范圍較小,18S和5.8S變化范圍明顯小于間隔區(qū),28S則位于間隔區(qū)的最低值和最高值之間。因此,我們發(fā)現(xiàn)硬骨魚核糖體ITS高于60%的GC含量是該類群的一個特征,并且高GC含量的ITS1和ITS2序列中不存在明顯的高GC富集區(qū),其含量高低的變化與序列長度也沒有相關(guān)性。本研究11種魚類的ITS1和ITS2的GC含量在種內(nèi)的相似性既有大于也有小于種間相同片段的相似性,因此GC平衡現(xiàn)象只存在部分種類中。本研究結(jié)果可為魚類核糖體基因序列特征的進一步研究及利用提供科學(xué)依據(jù)。
[Abstract]:Ribosomal gene is due to multiple copies of tandem repeat genes, including three coding genes 18 S5. 8 S5 / 28S) and two spacers, ITS1(internal transcribed spacer 1) and ITS2(internal transcribed spacer 2. At present, the related reports of ribosomal genes mainly focus on the polymorphic characteristics of different copies in individuals. And its application as molecular marker in phylogenetic relationships GC content is a very important index of nucleotide sequence. In order to study the characteristics of ribosomal gene GC content and the existence of GC equilibrium in the spacer region, the ribosomal genes of 5 fragments from 11 fishes belonging to 5 families of Perciformesus perciformes were studied in this study. Including Latidaeidae, Toxotidaeae, Rachycentridaeae, Xiphiidaeae, Carangida dae. 1651 monoclonal sequences were obtained, and the GC content characteristics of other bone fish sequences were analyzed and compared. The results showed that the GC content of 18s in the fish in this study was 52.67.1. (the average value of 54.66.8S was 55.68.9S (57.40.28s was 64.25.8S). The average value of ITS1 was 56.53.0 (the average 65.0ITS2 was 62.37.57.5.) the GC content in the coding area was relatively conservative. The variation ranges of 18s and 5.8s were significantly smaller than those of the spacer, which were between the lowest and highest values of the spacer region. Therefore, we found that the GC content of the ribosome above 60% is a characteristic of this group. Moreover, there is no obvious high GC rich region in ITS1 and ITS2 sequences with high GC content. There was no correlation between the variation of ITS1 content and sequence length. In this study, the similarity of GC content of ITS1 and ITS2 in 11 species of fish was greater than that of the same fragment in different species. Therefore, GC equilibrium exists only in some species. The results of this study can provide scientific basis for further study and utilization of ribosomal gene sequence characteristics in fish.
【作者單位】： 中國科學(xué)院熱帶海洋生物資源與生態(tài)重點實驗室;中國科學(xué)院大學(xué);
【基金】：國家自然科學(xué)基金項目(31272273;41276166)
【分類號】：S917.4

【相似文獻】

相關(guān)期刊論文 前2條

1 張爭;張楊;徐進;許景升;何禮遠;馮潔;;高GC含量青枯菌aac基因PCR擴增體系的建立與優(yōu)化[J];植物保護;2008年02期

2 ;[J];;年期

，

本文編號：1679825