Uroleptus mobilis, Engelm. I. History of the nuclei during division and conjugation

Conjugation in Stylonychia muscorum Kahl

“…Finally, about 6 days after mating, the first division of the exconjugant yields two daughter cells, each possessing two macronuclei and 2-4 micronuclei. DISCUSSION In the strain of Stylonychia muscorum Kahl studied by us the process of conjugation follows the general pattern described earlier in various Oxytrichidae (4,(7)(8)(9)(10)12). Nevertheless, we have observed certain peculiarities we believe interesting for a wider knowledge of this group of ciliates.…”

Timing of Life Cycle Morphogenesis in Synchronous Samples ofSterkiella histriomuscorum.II. The Sexual Pathway

“…From cultures of conjugants of S. histriomuscorum , using synchronous samples of conjugants, we obtained details of the timing of nuclear divisions during conjugation. The morphology of these nuclear events was previously described for several Oxytrichidae and other stichotrichs (Alonso and Silva 1965; Ammerman 1965, 1982; Ammermann and Schlegel 1983; Calkins 1919; Gregory 1923; Kay 1946; Maupas 1889; Moldenhauer 1965; Pieri 1966; Raikov 1972). Even though the nuclear events are essentially the same within the Oxytrichidae, there are differences between the two genera Stylonychia and Oxytricha , which are closely related to Sterkiella.…”

Developmental Heterochrony in Ciliated Protozoa: Overlap of Asexual and Sexual Cycles During Conjugation

“…The behaviour of the maternal macronuclei during conjugation has been described for other hypotrichs : Stylonychia (Alonso & Pkrez-Silva, 1965 ;Moldenhauer, 1965 ;Sapra & Dass, 197ob, 1973 ;Shi, 1975;Yano, 1985 a), Paraurostyla (Jerka-Dziadosz, 1975), Pseudourostyla (Takahashi, 1974;Jin & Ng, 1990), Oxytricha (Gregory, 1923 ;Kay, 1946;Diller, 1965;Ricci et al, 1975;Ricci & Banchetti, 1981), Pleurotricha (Manwell, 1928), Uroleptus (Calkins, 1919(Calkins, , 1930. Two or more macronuclei are usually present in these hypotrichs.…”

“…Apart from these two genera, preliminary mitosis does not occur during conjugation in other hypotrichs examined. These include Stylonychia, Oxytricha, Kahliella, Aspidisca, Paraurosytla, Diophrys, Pleurotricha, Onychodromus, Uroleptus and Uronychia (for citations see Raikov, 1972, Table I ; additional references: Calkins, 1919Calkins, , 1930Ito, 1963;JareAo, Alonso & Perez-Silva, 1969Diller, 1975;Jerka-Dziadosz & Janus, 1975;Shi, 1975;Ricci & Banchetti, 1981;Yano, 19856;Dini, Bracchi & Gianni, 1987; the references to the first micronuclear division during conjugation as preliminary mitosis in Stylonychia mytilus (Nakata,I 954), and in Diophrys scutum (Ito, 1954), may be regarded as misnomers).…”

“…These include Stylonychia, Oxytricha, Kahliella, Aspidisca, Paraurosytla, Diophrys, Pleurotricha, Onychodromus, Uroleptus and Uronychia (for citations see Raikov, 1972, Table I ; additional references: Calkins, 1919Calkins, , 1930Ito, 1963;JareAo, Alonso & Perez-Silva, 1969Diller, 1975;Jerka-Dziadosz & Janus, 1975;Shi, 1975;Ricci & Banchetti, 1981;Yano, 19856;Dini, Bracchi & Gianni, 1987; the references to the first micronuclear division during conjugation as preliminary mitosis in Stylonychia mytilus (Nakata,I 954), and in Diophrys scutum (Ito, 1954), may be regarded as misnomers). These include Stylonychia, Oxytricha, Kahliella, Aspidisca, Paraurosytla, Diophrys, Pleurotricha, Onychodromus, Uroleptus and Uronychia (for citations see Raikov, 1972, Table I ; additional references: Calkins, 1919Calkins, , 1930Ito, 1963;JareAo, Alonso & Perez-Silva, 1969Diller, 1975;Jerka-Dziadosz & Janus, 1975;Shi, 1975;Ricci & Banchetti, 1981;Yano, 19856;Dini, Bracchi & Gianni, 1987; the references to the first micronuclear division during conjugation as preliminary mitosis in Stylonychia mytilus (Nakata,I 954), and in Diophrys scutum (Ito, 1954), may be regarded as misnomers).…”