[A simple and effective method for assessing chromatin diminution values in copepods using qPCR]

Area of Science:

• Genetics
• Evolutionary Biology
• Zoology

Background:

• Chromatin diminution (CD) is a phenomenon with varying significance across freshwater cyclopoid copepod species.
• The biological and evolutionary implications of these variations in CD are not well understood.
• A need exists for an efficient method to evaluate CD distribution and magnitude in copepods.

Purpose of the Study:

• To develop and validate a rapid and simple method for assessing chromatin diminution (CD) in freshwater cyclopoid copepods.
• To quantify the magnitude of CD in selected copepod species using the developed method.

Main Methods:

• A novel approach using quantitative real-time PCR (qPCR) was employed for CD assessment.
• Genome size changes were evaluated by comparing qPCR fluorescence curves of target genes.
• The method was applied to four species: Cyclops kolensis, Acanthocyclops vernalis, C. insignis, and Megacyclops viridis.

Main Results:

• The qPCR method provided rapid and simple CD assessment with minimal material requirements.
• CD magnitudes were quantified: Cyclops kolensis (95.3 ± 1.2%), Acanthocyclops vernalis (94.6 ± 0.8%), C. insignis (82.3 ± 5.2%).
• Chromatin diminution was identified for the first time in Megacyclops viridis (91.1 ± 2.6%).

Conclusions:

• The developed qPCR approach is effective for evaluating CD magnitude in copepods.
• This method facilitates broader studies on CD distribution and its evolutionary significance.
• The findings expand the known distribution of CD within cyclopoid copepods.