Molecular organization and chromosomal localization of 5S rDNA in Amazonian Engystomops (Anura, Leiuperidae).
Molecular organization and chromosomal localization of 5S rDNA in Amazonian Engystomops (Anura, Leiuperidae).
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DOI：
10.1186/1471-2156-13-17
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发表时间：
2012-03-20
期刊：
影响因子：
2.9
通讯作者：
Lourenço LB
中科院分区：
文献类型：
--
作者：
Rodrigues DS;Rivera M;Lourenço LB
对于无尾两栖类，5S rDNA的知识是稀缺的。对于Engystomops物种，由于种间和种内细胞遗传学变异的高水平，染色体同源性难以识别。为了更好地比较亚马逊物种Engystomops freibergi和Engystomops petersi的核型，并扩展无尾类5S rDNA组织的知识，亚马逊Engystomops物种的5S rDNA序列被分离，表征和映射。从大肠杆菌中分离到两种5SrDNA，它们的大小和组成很容易区分。freibergi和E.来自厄瓜多尔两个地区（Puyo和Yasuní）的petersi。在急诊在freibergi核型中，整个I型5S rDNA重复单元与3p的近着丝粒区域杂交，而整个II型5S rDNA重复单元定位于6q的远端区域，表明这些序列的差异定位。I型NTS探针在E. freibergi和E. petersi和E. petersi从Yasuní，但没有远端或间质信号观察。有趣的是，该探针还在三种核型中检测到许多着丝粒区域，表明存在来自5S rDNA的卫星DNA家族。Ⅱ型NTS探针在3种核型中仅检测到远侧6q区域，证实了两种类型的5S rDNA的差异分布。由于在Engystomops中发现的5S rDNA类型与酸浆属的核苷酸序列和染色体位置相关，因此它们的起源可能早于这些属的进化分歧。此外，我们的数据表明，E. petersi和E. freibergi和E.来自Puyo的Petersi。此外，Ⅱ型5SrDNA的染色体定位证实了E. petersi和E.尽管亚苏尼标本的核型与其他标本的核型有很大差异，但freibergi是同源的。
For anurans, knowledge of 5S rDNA is scarce. For Engystomops species, chromosomal homeologies are difficult to recognize due to the high level of inter- and intraspecific cytogenetic variation. In an attempt to better compare the karyotypes of the Amazonian species Engystomops freibergi and Engystomops petersi, and to extend the knowledge of 5S rDNA organization in anurans, the 5S rDNA sequences of Amazonian Engystomops species were isolated, characterized, and mapped. Two types of 5S rDNA, which were readily differentiated by their NTS (non-transcribed spacer) sizes and compositions, were isolated from specimens of E. freibergi from Brazil and E. petersi from two Ecuadorian localities (Puyo and Yasuní). In the E. freibergi karyotypes, the entire type I 5S rDNA repeating unit hybridized to the pericentromeric region of 3p, whereas the entire type II 5S rDNA repeating unit mapped to the distal region of 6q, suggesting a differential localization of these sequences. The type I NTS probe clearly detected the 3p pericentromeric region in the karyotypes of E. freibergi and E. petersi from Puyo and the 5p pericentromeric region in the karyotype of E. petersi from Yasuní, but no distal or interstitial signals were observed. Interestingly, this probe also detected many centromeric regions in the three karyotypes, suggesting the presence of a satellite DNA family derived from 5S rDNA. The type II NTS probe detected only distal 6q regions in the three karyotypes, corroborating the differential distribution of the two types of 5S rDNA. Because the 5S rDNA types found in Engystomops are related to those of Physalaemus with respect to their nucleotide sequences and chromosomal locations, their origin likely preceded the evolutionary divergence of these genera. In addition, our data indicated homeology between Chromosome 5 in E. petersi from Yasuní and Chromosomes 3 in E. freibergi and E. petersi from Puyo. In addition, the chromosomal location of the type II 5S rDNA corroborates the hypothesis that the Chromosomes 6 of E. petersi and E. freibergi are homeologous despite the great differences observed between the karyotypes of the Yasuní specimens and the others.
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影响因子：
6.1
作者：
Fernandez-Tajes, Juan;Mendez, Josefina
通讯作者：
Mendez, Josefina
影响因子：
2.6
作者：
Daniels, LM;Delany, ME
通讯作者：
Delany, ME
影响因子：
1.5
作者：
Ferreira, Irani A.;Oliveira, Claudio;Martins, Cesar
通讯作者：
Martins, Cesar
影响因子：
2.4
作者：
Guerra, Monica A.;Ron, Santiago R.
通讯作者：
Ron, Santiago R.
DOI：
10.1016/s0167-4781(01)00264-0
发表时间：
2001-08-30
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION
影响因子：
--
作者：
Hallenberg, C;Frederiksen, S
通讯作者：
Frederiksen, S