Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs)
The nucleolus organizer regions (NORs) demonstrate differences in genomic dispersion and transcriptional activity among all organisms. I postulate that such differences stem from distinct genomic structures and their interactions from chromosome observations using fluorescence in situ hybridization...
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MDPI AG
2020-04-01
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| Series: | Cells |
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| Online Access: | https://www.mdpi.com/2073-4409/9/4/971 |
| _version_ | 1797570623556288512 |
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| author | Hirohisa Hirai |
| author_facet | Hirohisa Hirai |
| author_sort | Hirohisa Hirai |
| collection | DOAJ |
| description | The nucleolus organizer regions (NORs) demonstrate differences in genomic dispersion and transcriptional activity among all organisms. I postulate that such differences stem from distinct genomic structures and their interactions from chromosome observations using fluorescence in situ hybridization and silver nitrate staining methods. Examples in primates and Australian bulldog ants indicate that chromosomal features indeed play a significant role in determining the properties of NORs. In primates, rDNA arrays that are located on the short arm of acrocentrics frequently form reciprocal associations (“affinity”), but they lack such associations (“non-affinity”) with other repeat arrays—a binary molecular effect. These “rules” of affinity vs. non-affinity are extrapolated from the chromosomal configurations of meiotic prophase. In bulldog ants, genomic dispersions of rDNA loci expand much more widely following an increase in the number of acrocentric chromosomes formed by centric fission. Affinity appears to be a significantly greater force: associations likely form among rDNA and heterochromatin arrays of acrocentrics—thus, more acrocentrics bring about more rDNA loci. The specific interactions among NOR-related genome structures remain unclear and require further investigation. Here, I propose that there are limited and non-limited genomic dispersion systems that result from genomic affinity rules, inducing specific chromosomal configurations that are related to NORs. |
| first_indexed | 2024-03-10T20:27:11Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2073-4409 |
| language | English |
| last_indexed | 2024-03-10T20:27:11Z |
| publishDate | 2020-04-01 |
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| series | Cells |
| spelling | doaj.art-7d640ba876124a889b6c50c2cda387ad2023-11-19T21:40:33ZengMDPI AGCells2073-44092020-04-019497110.3390/cells9040971Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs)Hirohisa Hirai0Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, JapanThe nucleolus organizer regions (NORs) demonstrate differences in genomic dispersion and transcriptional activity among all organisms. I postulate that such differences stem from distinct genomic structures and their interactions from chromosome observations using fluorescence in situ hybridization and silver nitrate staining methods. Examples in primates and Australian bulldog ants indicate that chromosomal features indeed play a significant role in determining the properties of NORs. In primates, rDNA arrays that are located on the short arm of acrocentrics frequently form reciprocal associations (“affinity”), but they lack such associations (“non-affinity”) with other repeat arrays—a binary molecular effect. These “rules” of affinity vs. non-affinity are extrapolated from the chromosomal configurations of meiotic prophase. In bulldog ants, genomic dispersions of rDNA loci expand much more widely following an increase in the number of acrocentric chromosomes formed by centric fission. Affinity appears to be a significantly greater force: associations likely form among rDNA and heterochromatin arrays of acrocentrics—thus, more acrocentrics bring about more rDNA loci. The specific interactions among NOR-related genome structures remain unclear and require further investigation. Here, I propose that there are limited and non-limited genomic dispersion systems that result from genomic affinity rules, inducing specific chromosomal configurations that are related to NORs.https://www.mdpi.com/2073-4409/9/4/971acrocentric chromosome associationsubtelomeric associationchromosomal configurationectopic recombinationgenomic dispersionprimates |
| spellingShingle | Hirohisa Hirai Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs) Cells acrocentric chromosome association subtelomeric association chromosomal configuration ectopic recombination genomic dispersion primates |
| title | Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs) |
| title_full | Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs) |
| title_fullStr | Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs) |
| title_full_unstemmed | Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs) |
| title_short | Chromosome Dynamics Regulating Genomic Dispersion and Alteration of Nucleolus Organizer Regions (NORs) |
| title_sort | chromosome dynamics regulating genomic dispersion and alteration of nucleolus organizer regions nors |
| topic | acrocentric chromosome association subtelomeric association chromosomal configuration ectopic recombination genomic dispersion primates |
| url | https://www.mdpi.com/2073-4409/9/4/971 |
| work_keys_str_mv | AT hirohisahirai chromosomedynamicsregulatinggenomicdispersionandalterationofnucleolusorganizerregionsnors |