scholarly journals A CR1 element is embedded in a novel tandem repeat (HinfI repeat) within the chicken genome

Genome ◽  
2006 ◽  
Vol 49 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Juan Li ◽  
Frederick C Leung

Highly repetitive DNA sequences constitute a significant portion of most eukaryotic genomes, raising questions about their evolutionary origins and amplification dynamics. In this study, a novel chicken repetitive DNA family, the HinfI repeat, was characterized. The basic repeating unit of this family displays a uniform length of 770 bp, which was defined by the recognition site of HinfI. The HinfI repeat was specifically localized in the pericentric region of chromosome 4 by fluorescence in situ hybridization and constitutes 0.51% of the chicken genome. Interestingly, a chicken repeat 1 (CR1) element has been identified within this basic repeating unit. Like other CR1 elements, this CR1 element also displays typical retrotransposition characteristics, including a highly conserved 3′ region and a badly truncated 5′ end. This direct evidence from sequence analysis, together with our Southern blot results, suggests that the HinfI repeat may originate from a unique region containing a retrotransposed CR1 element.Key words: satellite DNA, CR1 retrotransposon, HinfI repeat, Gallus gallus.

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1061-1069 ◽  
Author(s):  
A. Cuadrado ◽  
N. Jouve ◽  
C. Ceoloni

The molecular characterization of heterochromatin in six lines of rye has been performed using fluorescence in situ hybridization (FISH). The highly repetitive rye DNA sequences pSc 119.2, pSc74, and pSc34, and the probes pTa71 and pSc794 containing the 25S–5.8S–18S rDNA (NOR) and the 5S rDNA multigene families, respectively, were used. This allowed the individual identification of all seven rye chromosomes and most chromosome arms in all lines. All varieties showed similar but not identical patterns. A standard in situ hybridization map was constructed following the nomenclature system recommended for C-bands. All FISH sites observed appeared to correspond well with C-band locations, but not all C-banding sites coincided with hybridization sites of the repetitive DNA probes used. Quantitative and qualitative differences between different varieties were found for in situ hybridization response at corresponding sites. Variation between plants and even between homologous chromosomes of the same plant was found in open-pollinated lines. In inbred lines, the in situ pattern of the homologues was practically identical and no variation between plants was detected. The observed quantitative and qualitative differences are consistent with a corresponding variation for C-bands detected both within and between cultivars.Key words: fluorescence in situ hybridization, repetitive DNA, rye, Secale cereale, polymorphism.


Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 293-306 ◽  
Author(s):  
Ekaterina D. Badaeva ◽  
Bernd Friebe ◽  
Bikram S. Gill

Genome differentiation in 12 diploid Aegilops species was analyzed using in situ hybridization with the highly repetitive DNA sequences pSc119 and pAs1 and C-banding. Chromosomes of all these diploid Aegilops species hybridized with the pSc119 probe; however, the level of hybridization and labeling patterns differed among genomes. Only four species (Ae. squarrosa, Ae. comosa, Ae. heldreichii, and Ae. uniaristata) showed distinct hybridization with pAs1. The labeling patterns were species-specific and chromosome-specific. Differences in in situ hybridization (ISH) patterns, also observed by C-banding, exist between the karyotypes of Ae. comosa and Ae. heldreichii, suggesting that they are separate, although closely related, subspecies. The S genome of Ae. spelioides was most similar to the B and G genomes of polyploid wheats on the basis of both C-banding and ISH patterns, but was different from other species of section Sitopsis. These species had different C-banding patterns but they were similar to each other and to Ae. mutica in the distribution of pSc119 hybridization sites. Two types of labeling were detected in Ae. squarrosa with the pAs1 probe. The first resembled that of the D-genome chromosomes of bread wheat, Triticum aestivum L. em. Thell., while the second was similar to the D genome of some of the polyploid Aegilops species. Relationships among diploid Aegilops species and the possible mechanisms of genome differentiation are discussed. Key words : wheat, Triticum, Aegilops, in situ hybridization, C-banding, evolution.


Genome ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Angeles Cuadrado ◽  
Nicolás Jouve

The presence and distribution of the most important highly repetitive DNA sequences of rye in cultivated and wild species of the genus Secale were investigated using fluorescence in situ hybridization. Accurate identification of individual chromosomes in the most commonly recognized species or subspecies of the genus Secale (S. cereale, S. ancestrale, S. segetale, S. afghanicum, S. dighoricum, S. montanum, S. montanum ssp. kuprijanovii, S. africanum, S. anatolicum, S. vavilovii, and S. silvestre) was achieved using three highly repetitive rye DNA sequences (probes pSc119.2, pSc74, and pSc34) and the 5S ribosomal DNA sequence pTa794. It is difficult to superimpose trends in the complexity of repetitive DNA during the evolution of the genus on conclusions from other cytogenetic and morphological assays. However, there are two clear groups. The first comprises the self-pollinated annuals S. silvestre and S. vavilovii that have few repeated nucleotide sequences of the main families of 120 and 480 bp. The second group presents amplification and interstitialization of the repeated nucleotide sequences and includes the perennials S. montanum, S. anatolicum, S. africanum, and S. kuprijanovii, as well as the annual and open-pollinated species S. cereale and its related weedy forms. The appearance of a new locus for 5S rRNA in S. cereale and S. ancestrale suggests that cultivated ryes evolved from this wild weedy species.Key words: rye, repeated nucleotide sequence, 5S rDNA, fluorescence in situ hybridization, FISH.


Genome ◽  
2008 ◽  
Vol 51 (8) ◽  
pp. 580-588 ◽  
Author(s):  
S. Marín ◽  
A. Martín ◽  
F. Barro

Hordeum chilense Roem. et Schult. (2n = 14) is an autogamous wild barley from Chile and Argentina included in the section Anisolepis Nevski. This species shows interesting agronomic traits that can be incorporated into crop plant species. Hordeum chilense has been successfully crossed with species of the genus Aegilops. Among the amphiploids obtained, the hexaploid tritordeum (2n = 6x = 42, AABBHchHch) is outstanding and shows good agronomic characteristics, suggesting its potential either as a new crop or as a bridge species to introgress interesting traits into cultivated cereals. The aim of the present work was to study the hybridization patterns of the two repetitive DNA probes pAs1 and pSc119.2 to evaluate their utility for the identification of H. chilense chromosomes. Fourteen lines of H. chilense were analyzed with fluorescent in situ hybridization using probes pSc119.2 and pAs1. The probe pAs1 was more widely dispersed than pSc119.2 over the H. chilense (Hch) genome. We found 89 different signals for pAs1, distributed evenly over the whole genome, and 10 for pSc119.2, located mainly over the telomeric regions. Five distinct hybridization signals were found for pAs1 and four distinct signals for pSc119.2. These signals allow the identification of different H. chilense lines. For example, centromeric signals for pAs1 on the short arms of chromosomes 1 and 7 identify line H46, and a telomeric signal for pSc119.2 on the short arm of chromosome 2 identifies line H1. A high degree of polymorphism in the hybridization patterns was found, confirming the extensive variability present in H. chilense. This work provides tools for the identification of H. chilense chromosomes in different genetic backgrounds.


2011 ◽  
Vol 30 (9) ◽  
pp. 1779-1786 ◽  
Author(s):  
Kun Yang ◽  
Hecui Zhang ◽  
Richard Converse ◽  
Yong Wang ◽  
Xiaoying Rong ◽  
...  

Parasitology ◽  
1999 ◽  
Vol 119 (3) ◽  
pp. 315-321 ◽  
Author(s):  
A. IMASE ◽  
T. KUMAGAI ◽  
H. OHMAE ◽  
Y. IRIE ◽  
Y. IWAMURA

Localization of the type 2 Alu sequence (B2), a highly repetitive DNA sequence in the mouse genome, was examined by in situ polymerase chain reaction (in situ PCR) in schistosomes. The signals to the B2 sequence were detected in the cytoplasm of the tegumental membrane and in the nuclei of the mesenchymal, testicular, ovarian and vitelline cells of 8- week Schistosoma japonicum. In contrast, it was difficult to detect any signals of this sequence in 8-week S. mansoni, whereas in 24-week male S. mansoni the signals were observed in the cytoplasm of the tegumental tubercles and in the nuclei of the mesenchymal and testicular cells. On the other hand, in 24-week female S. mansoni the signals were found in the nuclei of the mesenchymal, ovarian and vitelline cells but not found in the tegument. On the contrary, no hybridization band of the B2 sequence was detected in the amplified DNA of 3-week schistosomula of either species. These observations proved that the host DNA sequences existed in restricted schistosome cells and were accumulated in the schistosome body during their development.


1988 ◽  
Vol 48 (2) ◽  
pp. 99-102 ◽  
Author(s):  
M.G. Kent ◽  
K.O. Elliston ◽  
W. Shroeder ◽  
K.S. Guise ◽  
S.S. Wachtel

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1014 ◽  
Author(s):  
Ana Paço ◽  
Renata Freitas ◽  
Ana Vieira-da-Silva

Eukaryotic genomes are rich in repetitive DNA sequences grouped in two classes regarding their genomic organization: tandem repeats and dispersed repeats. In tandem repeats, copies of a short DNA sequence are positioned one after another within the genome, while in dispersed repeats, these copies are randomly distributed. In this review we provide evidence that both tandem and dispersed repeats can have a similar organization, which leads us to suggest an update to their classification based on the sequence features, concretely regarding the presence or absence of retrotransposons/transposon specific domains. In addition, we analyze several studies that show that a repetitive element can be remodeled into repetitive non-coding or coding sequences, suggesting (1) an evolutionary relationship among DNA sequences, and (2) that the evolution of the genomes involved frequent repetitive sequence reshuffling, a process that we have designated as a “DNA remodeling mechanism”. The alternative classification of the repetitive DNA sequences here proposed will provide a novel theoretical framework that recognizes the importance of DNA remodeling for the evolution and plasticity of eukaryotic genomes.


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