Abstract Supernumerary, or B, chromosomes are present in several eukaryotes, including characid fish of the genus Psalidodon. Notably, Psalidodon paranae carries the most studied B chromosome variant, a macro-B chromosome. The origin of this element was determined to be an isochromosome; however, data regarding its inheritance remain unavailable due to methodological barriers such as the lack of an efficient, non-invasive, and rapid protocol for identifying B-carrying individuals that would enable the design of efficient crossing experiments. Thus, in this study, we primarily aimed was to develop two non-invasive and fast (approximately 2 h) methods to identify the presence of B chromosomes in live specimens of P. paranae based on satellite DNA (satDNA) sequences known to be present in this element. The methods include fluorescence in situ hybridization in interphase nuclei and relative gene quantification of satDNAs using quantitative polymerase chain reaction. Our results reveal the efficiency of quick-fluorescence in situ hybridization and quantitative polymerase chain reaction for identifying B-carrying individuals using the proposed satDNA sequences and open up new possibilities to study B chromosomes.

中文翻译：

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建立快速和非侵入性的协议以鉴定携带P假单胞菌的B个体

摘要超数染色体（或B染色体）存在于几种真核生物中，包括Psalidodon属的嗜酸性鱼。值得注意的是，Psalidodon paranae携带着研究最多的B染色体变异，即大B染色体。该元素的来源被确定为同染色体。但是，由于方法上的障碍，例如缺乏有效，非侵入性和快速的协议来鉴定携带B的个体，因此无法进行有效的交叉实验设计，因此有关其遗传的数据仍然不可用。因此，在这项研究中，我们的主要目的是开发两种非侵入性和快速（约2小时）方法，以根据已知的卫星DNA（satDNA）序列鉴定副对虾活体标本中B染色体的存在。在这个元素中。该方法包括在相间核中进行荧光原位杂交，并使用定量聚合酶链反应对satDNA进行相对基因定量。我们的研究结果揭示了快速荧光原位杂交和定量聚合酶链反应用于利用提出的satDNA序列鉴定携带B的个体的效率，并为研究B染色体开辟了新的可能性。