Search

Porcine circovirus type 3 (PCV3), which currently lacks effective preventive measures, has caused tremendous economic losses to the pig husbandry. Obtaining the strain of PCV3 is the key to preparing related vaccines and developing corresponding antiviral drugs. In this study, according to the linear sequence of PCV3 DNA published on GenBank, the sequence was rearranged with SnapGene gene-editing software, and after rearrangement, the HindIII restriction endonuclease site was added to the end of the linear DNA, so that both ends have the same restriction endonuclease site. On this basis, the rearranged linear DNA is obtained by gene synthesis, PCR amplification, DNA purification, etc., and is digested and connected in vitro to obtain cyclized DNA. PCV3 infectious clones were obtained by transfecting 3D4/21 cell lines. The obtained PCV3 was identified by PCR, Western blotting, and indirect immunofluorescence tests. The results showed that this study successfully obtained the strain of PCV3 in vitro. To further evaluate the pathogenicity of the obtained PCV3 infectious clones, this study established an animal model of Kunming mice infected with PCV3. The results of RT-PCR, Western blotting and immunohistochemistry showed that PCV3 can infect myocardium and alveoli of Kunming mice, but no PCV3 was detected in other tissues. The above studies indicate that PCV3 circular DNA can be used to construct PCV3 infectious clones. This research will provide a new method for the construction of circular DNA viruses and lay the foundation for the research and pathogenesis of PCV3 vaccine.

Porcine circovirus type 3 (PCV3), which currently lacks effective preventive measures, has caused tremendous economic losses to the pig husbandry. Obtaining the strain of PCV3 is the key to preparing related vaccines and developing corresponding antiviral drugs. In this study, according to the linear sequence of PCV3 DNA published on GenBank, the sequence was rearranged with SnapGene gene-editing software, and after rearrangement, the Hin dIII restriction endonuclease site was added to the end of the linear DNA, so that both ends have the same restriction endonuclease site. On this basis, the rearranged linear DNA is obtained by gene synthesis, PCR amplification, DNA purification, etc., and is digested and connected in vitro to obtain cyclized DNA. PCV3 infectious clones were obtained by transfecting 3D4/21 cell lines. The obtained PCV3 was identified by PCR, Western blotting, and indirect immunofluorescence tests. The results showed that this study successfully obtained the strain of PCV3 in vitro. To further evaluate the pathogenicity of the obtained PCV3 infectious clones, this study established an animal model of Kunming mice infected with PCV3. The results of RT-PCR, Western blotting and immunohistochemistry showed that PCV3 can infect myocardium and alveoli of Kunming mice, but no PCV3 was detected in other tissues. The above studies indicate that PCV3 circular DNA can be used to construct PCV3 infectious clones. This research will provide a new method for the construction of circular DNA viruses and lay the foundation for the research and pathogenesis of PCV3 vaccine. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Image & Graphics is the property of Editorial Office of Journal of Image & Graphics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polyploidization is a major genome modification that results in plant species with multiple chromosome sets. Parental genome adjustment to co-habit a new nuclear environment results in additional innovation outcomes. We intended to assess genomic changes in polyploid model species with small genomes using inter retrotransposons amplified polymorphism (IRAP) and retrotransposon microsatellite amplified polymorphism (REMAP). Comparative analysis among diploid and autotetraploid A. thaliana and A. suecica lines with their parental lines revealed a marginal fraction of novel bands in both polyploids, and a vast loss of parental bands in allopolyploids. Sequence analysis of some remodelled bands shows that A. suecica parental band losses resulted mainly from sequence changes restricted to primer domains. Moreover, in A. suecica, both parental genomes presented rearrangement frequencies proportional to their sizes. Overall rates of genomic remodelling events detected in A. suecica were similar to those observed in species with a large genome supporting the role of retrotransposons and microsatellite sequences in the evolution of most allopolyploids.

Main conclusion: The analysis of early generations of triticale showed numerous rearrangements of the genome. Complexed transformation included loss of chromosomes, t-heterochromatin content changes and the emergence of retrotransposons in new locations. This study investigated certain aspects of genomic transformations in the early generations (F5 and F8) of the primary octoploid triticale derived from the cross of hexaploid wheat with the diploid rye. Most of the plants tested were hypoploid; among eliminated chromosomes were rye chromosomes 4R and 5R and variable number of wheat chromosomes. Wheat chromosomes were eliminated to a higher extent. The lower content of telomeric heterochromatin was also found in rye chromosomes in comparison with parental rye. Studying the location of selected retrotransposons from Ty1-copia and Ty3-gypsy families using fluorescence in situ hybridization revealed additional locations of these retrotransposons that were not present in chromosomes of parental species. ISSR, IRAP and REMAP analyses showed significant changes at the level of specific DNA nucleotide sequences. In most cases, the disappearance of certain types of bands was observed, less frequently new types of bands appeared, not present in parental species. This demonstrates the scale of genome rearrangement and, above all, the elimination of wheat and rye sequences, largely due to the reduction of chromosome number. With regard to the proportion of wheat to rye genome, the rye genome was more affected by the changes, thus this study was focused more on the rye genome. Observations suggest that genome reorganization is not finished in the F5 generation but is still ongoing in the F8 generation. [ABSTRACT FROM AUTHOR]

Polyploidization is a major genome modification that results in plant species with multiple chromosome sets. Parental genome adjustment to co-habit a new nuclear environment results in additional innovation outcomes. We intended to assess genomic changes in polyploid model species with small genomes using inter retrotransposons amplified polymorphism (IRAP) and retrotransposon microsatellite amplified polymorphism (REMAP). Comparative analysis among diploid and autotetraploid A. thaliana and A. suecica lines with their parental lines revealed a marginal fraction of novel bands in both polyploids, and a vast loss of parental bands in allopolyploids. Sequence analysis of some remodelled bands shows that A. suecica parental band losses resulted mainly from sequence changes restricted to primer domains. Moreover, in A. suecica, both parental genomes presented rearrangement frequencies proportional to their sizes. Overall rates of genomic remodelling events detected in A. suecica were similar to those observed in species with a large genome supporting the role of retrotransposons and microsatellite sequences in the evolution of most allopolyploids. [ABSTRACT FROM AUTHOR]

Abstract: The set of nonnegative integers is an asymptotic basis of order h if every sufficiently large integer can be represented as the sum of h elements of . If for some real number , then α is called an additive eigenvalue of order h. The additive spectrum of order h is the set consisting of all additive eigenvalues of order h. It is proved that there is a positive number such that or . The proof uses results about the construction of supersequences of sequences with prescribed asymptotic growth, and also about the asymptotics of rearrangements of infinite sequences. For example, it is proved that there does not exist a strictly increasing sequence of integers such that and B contains a subsequence such that . [Copyright &y& Elsevier]

We established 99 JC virus (JCV) DNA clones directly from the brain of a single patient with progressive multifocal leukoencephalopathy (PML). Based upon restriction patterns, the cloned viral DNAs were classified into two major groups (NY-1A and -1B) containing 53 and 35 clones, respectively, and several minor groups containing one or a few clones. The regulatory sequences of representative clones were compared with the archetypal regulatory sequence, which has been detected in JCV DNAs cloned from the urine of healthy and nonimmunosuppressed individuals. The regulatory sequence of NY-1B had the two structural features common to most PML-type regulatory regions, duplication and deletion of specific segments in the archetypal sequence, while that of NY-1A contained a small deletion and an insertion of a 29-bp sequence originating from the early region of the JCV genome. A regulatory region similar to that of NY-1A has never been detected in JCV isolates obtained thus far. [ABSTRACT FROM AUTHOR]

The physical mapping of Aval, BstEII and EcoR1 restriction sites on the chloroplast genome of the green alga Chlamydomonas eugametos is presented. The circular map, with a size of 243 kilobase pairs, is the largest yet reported for a chloroplast genome. It features a large inverted repeat sequence, part of which encodes the 16S and 23S ribosomal RNAs (rRNAs), the large subunit of ribulose-1,5-bisphosphate carboxylase-oxygenase (rbcL) and the '32-kdodalton' thylakoid membrane protein (psbA). Such an rRNA-encoding inverted repeat sequence is also found in the chloroplast genomes of Chlamydomonas reinhardtii and most land plants. These genomes, however, differ from that of C. eugametos by the absence of the rbcL gene from the inverted repeat sequence of C. reinhardtii and by the absence of both the rbcL and psbA genes from the inverted repeat sequence of land plants. Possible evolutionary implications of these differences are discussed. [ABSTRACT FROM AUTHOR]