Homopolar grafting in Blepharisma japonicum

Abstract

Results of homoplastic grafting in Blepharisma japonicum v. intermedium are described. The parabiotic homopolar fusion complex of two cells either simply splits into two singlets, or undergoes cell division. In the latter case the division results either in two doublets or in two singlets (praters) and a doublet (opisthe). If one or two of the systems of feeding organelles are removed after parabiotic homopolar fusion of two cells, the fusion complex does not split, but undergoes division. If an almost complete set of feeding organelles is lacking, the division of the graft complex usually results either in a singlet proter and a doublet opisthe or in two doublets. If two complete sets of feeding organelles have been excised from the graft complex, division occurs after the regeneration of the missing organelles, most frequently resulting in two doublets. The same operation on the graft complex with two primordium sites placed very close to each other may result in the regeneration of one normal and one reversed peristome, the latter being to the right of the former. The doublet biotypes derived from ,the graft complexes with or without further experimental changes usually reproduced true to type. The asymmetric doublet with two peristomes less than 180" apart tends to resorb the left peristome, that is, one with a larger left-hand somatic area than the other. The asymmetric doublet may also form a third peristome on the right side of the original left peristome. The third peristome is usually of reversed asymmetry. That the appearance of the third primordium site might be due to the presence of the original line of fusion of two components of the doublet, and that the tendency of the original primordium sites to reestablish themselves might give rise to the third one, when the original on.es fail discussed.

The Patterning of Ciliates1

“…Thus the regulating genically normal homopolar doublet had interposed a reversed cortical sector in the narrower semicell between two normal oral meridians. This phenomenon was observed repeatedly and reliably in Tetrahymena [40], and appeared in other ciliates as well (Blepharzsma [36], Glaucoma [50], Stylonychza [54,62]). In all of these triplets, the cortical structures of the central component are at least partially of a handedness opposite to that of the flanking two.…”

Nuclear and Cortical Regulation in Doublets of Paramecium: II. When and How do Two Cortical Domains Reorganize to One?

“…observ. ), in the heterotrich Blepharisma japonicum (Kumazawa 1979), and in side‐by‐side doublets of the spirotrichs Paraurostyla weissei (Jerka‐Dziadosz 1983), Stylonychia mytilus (Tuffrau and Totwen‐Nowakowska 1988), and S. pustulata (Yano and Suhama 1991).…”

“…More striking and widespread is the transient appearance of a partially‐reversed third oral apparatus near the middle of sc1 in Tetrahymena patula (Fauré‐Fremiet 1948), T. thermophila (Nelsen and Frankel 1986), Glaucoma scintillans (Suhama 1990), and in the distantly related heterotrich Blepharisma japonicum (Kumazawa 1979). A similar interposition also occurs in the transient side‐by‐side doublets of the spirotrichs Stylonychia mytilus (Tuffrau and Totwen‐Nowakowska 1988), S. pustulata (Yano and Suhama 1991), and Paraurostyla weissei (Jerka‐Dziadosz 1983).…”

The Regulation of Homopolar Doublets to Singlets in Glaucoma

“…Ciliary rows are gradually lost through generations due to the fact that the proliferation of basal bodies and the extension of kineties cease in some ciliary rows ( Fig. 13) and these ciliary rows are distributed unequally into two daughter cells, or into only one cell in cell division [2, 121. In homopolar doublets of the heterotrich ciliate B. japonicum, when two OAs approached, the left OA appeared abnormal and then disappeared [6]. This also might be adapted to the doublets ofParamecium aurelia complex [ 1 I] and T. pyrlformis complex [8], judging from figures and descriptions.…”

“…This regulation includes not only the regression of one of the two components (semicells) of the doublet, but involves certain phenomena caused by the interaction between these semicells. The fact that an excess and reversed oral apparatus is formed in a doublet during regulation has been described thus so far in Leucophrys (Tetrahymena) patula [3], Blepharisma japonicum [6] and Tetrahymena thermophila [9].…”