Document Type

Article

Publication Date

8-10-2012

Publication Title

Gene

Abstract

Chilodonella uncinata, like all ciliates, contains two distinct nuclei in every cell: a germline micronucleus and a somatic macronucleus. The macronucleus develops from the zygotic nucleus through a series of chromosomal rearrangements. Macronuclear development in C. uncinata yields a nucleus with highly amplified gene-sized chromosomes. The macronucleus is transcriptionally active during vegetative growth while there is no expression in the micronucleus except during a brief period following conjugation. Gene family evolution in ciliates occurs through complex processes including gene duplication and an alternative processing of scrambled genes. Here we use quantitative PCR to compare relative expression levels of eight genes (SSU-rDNA, actin, α-tubulin and five β-tubulin sequences) to their abundance as macronuclear chromosomes. We show that three strains of the morphospecies C. uncinata share similar patterns across all loci. For example, we find an inverse correlation among five β-tubulin genes whereby the more abundant macronuclear chromosomes have lower levels of expression compared to less abundant chromosomes. We discuss the implication of our findings, which suggest that epigenetic mechanisms maintain chromosome copy number in C. uncinata.

Keywords

Ciliate, Copy number variation, Gene expression, Macronucleus, Quantitative PCR, Tubulin

Volume

504

Issue

2

First Page

303

Last Page

308

DOI

10.1016/j.gene.2012.04.067

ISSN

03781119

Rights

© 2012 Elsevier B.V.

Comments

Peer reviewed accepted manuscript.

Included in

Biology Commons

COinS
 
 

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