Russian doll genes and complex chromosome rearrangements inOxytricha trifallax
| Autor: | Masahico Saito, Rafik Neme, Laura F. Landweber, Lukas Nabergall, Jasper Braun, Nataša Jonoska |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
030106 microbiology Genomics Chromosomal rearrangement Oxytricha Genome rearrangement QH426-470 Genome Germline 03 medical and health sciences Scrambled genes Nested genes Genetics Molecular Biology Gene Genetics (clinical) 030304 developmental biology 0303 health sciences Ciliates Macronucleus biology 030306 microbiology Chromosome Gene rearrangement biology.organism_classification Nested gene 030104 developmental biology Oxytricha trifallax Nanochromosomes |
| Zdroj: | G3: Genes, Genomes, Genetics, Vol 8, Iss 5, Pp 1669-1674 (2018) |
| DOI: | 10.1101/216440 |
| Popis: | Ciliates have two different types of nuclei per cell, with one acting as a somatic, transcriptionally active nucleus (macronucleus; abbr. MAC) and another serving as a germline nucleus (micronucleus; abbr. MIC). Furthermore,Oxytricha trifallaxundergoes extensive genome rearrangements during sexual conjugation and post-zygotic development of daughter cells. These rearrangements are necessary because the precursor MIC loci are often both fragmented and scrambled, with respect to the corresponding MAC loci. Such genome architectures are remarkably tolerant of encrypted MIC loci, because RNA-guided processes during MAC development reorganize the gene fragments in the correct order to resemble the parental MAC sequence. Here, we describe the germline organization of several nested and highly scrambled genes inOxytricha trifallax. These include cases with multiple layers of nesting, plus highly interleaved or tangled precursor loci that appear to deviate from previously described patterns. We present mathematical methods to measure the degree of nesting between precursor MIC loci, and revisit a method for a mathematical description of scrambling. After applying these methods to the chromosome rearrangement maps ofO. trifallaxwe describe cases of nested arrangements with up to five layers of embedded genes, as well as the most scrambled loci inO. trifallax. |
| Databáze: | OpenAIRE |
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