The smaller, reproductive, transcriptionally inert nucleus in the cells of ciliate protozoans, as distinguished from the larger, vegetative, transcriptionally active MACRONUCLEUS. Micronuclei participate in MEIOSIS and autogamy during GENETIC CONJUGATION.

Synonyms: Germline Micronucleus, Micronuclei, Germline, Micronucleus, Germinal, Germline Micronuclei, Micronucleus, Germline, Germinal Micronucleus