1. Hypothetical self-replicating units of cytoplasm that were once thought to carry hereditary information independently of nuclear genes; now largely discredited in modern genetics.
Usage: biology; historical; plural form of plasmagene

Examples

• Early 20th-century biologists proposed plasmagenes as an explanation for non-Mendelian inheritance patterns.
• The theory of plasmagenes was eventually abandoned as molecular genetics revealed the central role of nuclear DNA.
• Some researchers investigated whether plasmagenes could account for maternal inheritance in certain organisms.
• The concept of plasmagenes represented an important but ultimately incorrect hypothesis in the history of genetics.