Laboratório de Citogenética e Evolução, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Laboratório de Genética Toxicológica, Universidade Luterana do Brasil, Canoas, RS, Brazil.
Genome. 2022 Nov 1;65(11):563-572. doi: 10.1139/gen-2022-0018. Epub 2022 Aug 31.
The genus has been widely used in karyotype evolution studies due to the variation in their diploid numbers. is characterized by intraspecific variation in diploid number (2 = 42, 46, 48, and 50), which makes it an interesting model to investigate genomic rearrangements mechanisms that could lead to different cytotypes in this species. Thereupon, it has been already shown that DNA methylation may participate in chromosome structure. Therefore, we aimed to investigate whether telomeres and global DNA methylation had a role in the genome rearrangements that led to this variation in . We also realized an analysis for the presence of intrachromosomal telomeric repeats (ITRs) by fluorescence in situ hybridization. Our study demonstrated that neither telomere length nor DNA methylation had significant differences among the cytotypes. However, if only females were considered, there were significant differences for telomere length and methylation. Young individuals, regardless of their cytotypes, had the most methylated DNA. Regarding the ITRs, we found a signal on chromosome 1 in 2 = 50b. No evidence was found that telomere length or methylation could have influenced chromosomal rearrangements, although new cytotypes seem to have emerged within the distribution of parental cytotypes by the accumulation of different chromosomal rearrangements.
该属由于其二倍体数量的变化而被广泛应用于核型进化研究。其特征是二倍体数量的种内变异(2=42、46、48 和 50),这使其成为研究可能导致该物种不同细胞型的基因组重排机制的有趣模型。因此,已经表明 DNA 甲基化可能参与染色体结构。因此,我们旨在研究端粒和全基因组甲基化是否在导致这种变化的基因组重排中起作用。我们还通过荧光原位杂交进行了分析,以确定是否存在染色体内端粒重复(ITR)。我们的研究表明,在细胞型之间,端粒长度和 DNA 甲基化均无显着差异。然而,如果只考虑雌性,端粒长度和甲基化则存在显着差异。无论其细胞型如何,年轻个体的 DNA 甲基化程度最高。关于 ITR,我们在 2=50b 中发现了 1 号染色体上的信号。尽管新的细胞型似乎通过积累不同的染色体重排而在亲本细胞型的分布范围内出现,但没有证据表明端粒长度或甲基化会影响染色体重排。