Cytoplasmic Inheritance of the Organization of the Cell Cortex in Paramecium Aurelia

Abstract

Y1,Y2,.. . be a sequence of independent two-valued random variables, Yn+i =-s or f3 + ns with probabilities (1-W) and W, where s is a small positive number and W is then determined by the condition-E(Y.) = aV(Yn). Verify that the probability that for some n,-3 + Y, +. .. + Yn > 0 converges to 1/(1 + ad) as s-. 0, and let X,, = Yn-E(Yn). This completes the proof. The theorem can be extended to say that for each y > 0, if rT is the least n if any for which (Xi +. .. + Xn) .-yT +GI +. .. + An) + .(V. + * * * + Vn). then the probability that there is some n < rz for which (1) holds is less than (,y/((+ 3))(1/(1 + ac)); and this bound is sharp. The material of this note, including proofs of Lemmas 1 and 2, will appear as part of our forthcoming book, How to Gamble If You Must (New York: McGraw-Hill), Theorems 2.12.1 and 9.4.1, and an illustrative application of the theorem will appear in the forthcoming article, "A sharper form of the Borel-Cantelli lemma and the strong law" by L. E. Dubins and D. A. Freedman.

Peptidoglycan architecture can specify division planes in Staphylococcus aureus

“…We are compelled to assume the existence of heterogeneity in the spatial distribution of non-DNA cell components that either template septum formation or mark the location of previous division planes. Th e importance of such epigenetic information in cell cortex 6 , membrane 7,8 and prion 9 structure is well established.…”

Structural inheritance in Paramecium: ultrastructural evidence for basal body and associated rootlets polarity transmission through binary fission⋆

“…This basic structural polarity strictly correlates with functional expression. As already discussed by others (Boisvieux-Ulrich et al, 1985;Sleigh and Silvester, 1983;Tamm et al, 1975), the orientation of ciliary beating is fixed with respect to the kinetid polarity; when nucleated according to a centriolar pathway, new basal bodies always appear in a precise orientation with respect to the rootlets (Beisson and Sonneborn, 1965;Aufderheide et al, 1999;Beisson and Jerka-Dziadosz, 1999).…”

“…In protozoan cells, this asymmetry is permanently expressed even when the basal body complex anchors the spindle microtubule organising centre as centrioles do in the centrosome (Viscogliosi and Brugerolle, 1994). In ciliated protozoans, kinetid polarity strictly correlates to that of the cell and is transmitted epigenetically through duplication (Aufderheide et al, 1999;Beisson and Sonneborn, 1965). Thus, beyond the problem of their assembly, the paradox between the functional similarity between the centriole/centrosome and the basal body/kinetid versus their specific radial symmetry/circumferential asymmetry thus asks for the origin of this polarity: is it, regardless to centriole or basal body expression, intrinsic to the nine-fold structure itself, as suggested by the Mignot's hypothesis (Mignot, 1996) or imposed by the immediate environment at the time of its assembly?…”

“Just” in time: Gene theory and the biology of the cell surface

“…The best-known form of structural inheritance is the organization of the longitudinal ciliary rows that cover the surfaces of most ciliates. In a now classical experiment, Beisson and Sonneborn (1965) first demonstrated that an inversion (180 rotation) of one or more of the ciliary rows was nongenically inherited. This demonstration was repeated for Tetrahymena thermophila and for other ciliates (see Nanney, 1980;Frankel, 1989).…”