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Meiosis and Nuclear Behavior in Tetrahymena pyriformis *
Author(s) -
RAY CHARLES
Publication year - 1956
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1956.tb02440.x
Subject(s) - macronucleus , bivalent (engine) , meiosis , biology , prophase , pronucleus , genetics , ploidy , mitosis , interphase , cell division , microbiology and biotechnology , zygote , dna , gene , chemistry , cell , embryogenesis , organic chemistry , metal
SUMMARY. Chromosome behavior of strains WH‐6, and WH‐14 mating types I and II respectively of variety 1, of T. pyriformis was studied during conjugation. Meiosis takes place during the first two prezygotic divisions. The chromosomes are at late pachytene‐early diplotene during the maximum elongation of the crescent in prophase of the first micronuclear division. As the crescent shortens, five bivalent chromosomes are readily recognized. Five dyads go to each pole at the end of the first division. Following a brief interphase the second meiotic division results in four micronuclear products, each with five chromosomes. Three of these products disintegrate; the fourth undergoes mitosis resulting in two pronuclei each with five chromosomes. Following a reciprocal interchange of the migratory pronuclei between the two conjugants, the synkaryon of each is formed just anterior to the macronucleus. The diploid number of ten chromosomes has been counted at the first division of the synkaryon.