Gamones and mating types in the genusBlepharismaand their possible taxonomic application

Abstract

Mating types I and II of Blepharisma japonicum v. intermedium excrete gamones 1 (blepharmone J) and 2 (blepharismone) respectively. The gamone of one type transforms cells of the other type so that they can conjugate with each other. We found that three other species, B. america-•num, B. musculus and B. stoltei, have two types of cells homologous to those in B. japonicum; one (type II) excretes a factor which has the same activity as gamone 2 of B. japonicum, the other (type I) responds to this gamone by cell union. Type I cells of these species also excrete a gamone which induces pairs in type II cells of particular strains. Complementarity for mating is observed in some combinations of the two types.These results indicate that each of the four species has at least one pair of complementary mating types, I and II, with the gamones of the type II's being the same molecule, blepharismone, while gamones of type I's are species-or syngen-specific blepharmone. These . generic and specific gamones can be utilized to clarify existing taxonomic and evolutionary questions in the genus Blepharisma.

Identification, characterization, and complete amino acid sequence of the conjugation-inducing glycoprotein (blepharmone) in the ciliate Blepharisma japonicum

“…(ii) It is interesting that B. japonicum uses very different molecules, gamone 1, a temperature-sensitive glycoprotein, and gamone 2, a tryptophan-derived small molecule, as conjugation-inducing substances. In some species of Blepharisma (B. stoltei, B. americanum, B. musculus, B. tropicum and B. japonicum), gamone 1 seems to be species-specific, whereas gamone 2 is common in all of the five species (32). Gamones of ancestral ciliates are assumed to have been probably small molecules such as blepharismone (gamone 2).…”

Ciliate pheromone structures and activity: a review

“…Purified preparations of Gamone 1 were reported to be very unstable at ambient temperatures -quite a striking trait for an environmental signal -and needed to be stored at freezing temperatures and protected by the addition of serum albumin (Miyake & Beyer 1974). In contrast, Gamone 2 has been identified with a very stable tryptophan derivative, namely a calcium-3-(2'-formyl-amino-5'-hydroxybenzoil) lactate (Figure 1), which appears to be synthesized also by other species of Blepharisma in addition to B. japonicum (Miyake & Bleyman 1976). This molecule has also been obtained through chemical synthesis (Entzeroth & Jaenicke 1981), and its laboratory copies are active like the original ones at nanomolar concentrations in inducing chemo-attraction and mating of type-I cells (Sugiura et al 2010).…”

“…In Heterotrichea Stein, 1859, it has been reported in Blepharisma japonicum (Suzuki, 1954) Giese, 1973, B. americanum Suzuki, 1954, B. musculus Penard, 1922, B. stoltei Isquith, 1966and B. tropicum Bhandary, 1962(Miyake & Bleyman 1976; in Spirotrichea Butschli, 1889, in Euplotes patella (Kimball 1942;Sato 1983;Akada 1985Akada , 1986), E. woodruffi Gaw, 1939 (Kosaka 1990), E. raikovi Agamaliev, 1966Miceli et al 1983), E. octocarinatus Carter, 1972 (Weischer et al 1985), E. nobilii Valbonesi andLuporini, 1990 (Felici et al 1999;Alimenti et al 2002Alimenti et al , 2003, E. crassus (Dujardin) Kahl, 1932 and Oxytricha bifaria Stokes, 1887 (Esposito et al 1976 (Sonneborn 1978). Among these pheromone-secreting species, pheromones have effectively been isolated and their structures determined to varying degrees of complexity only in five species, namely B. japonicum, E. raikovi, E. octocarinatus, E. nobilii and E. crassus.…”

“…Despite the substantial differences that distinguish Gamones 1 and 2 in structure, behavior, activity and evolution -the non-species-specific Gamone 2 has been inferred to precede the evolution of the speciesspecific Gamone 1 (Miyake & Bleyman 1976) -the two pheromones have been assumed to engage in a very symmetric interplay. In a model known as the "gamone-receptor hypothesis" (Miyake 1981), Gamones 1 and 2 would find their specific receptors on type II and type I cells, respectively, and these two symmetric gamone receptor-binding reactions would determine the activation of a positive feedback loop responsible for the physiological transformation of B. japonicum vegetative cells into sexually complementary mating partners.…”

The Accidental Protozoologist—My Journey Through the World of Ciliates1,2

“…All the mt II cells secreted the same molecule. By the time our work (Miyake and Bleyman 1976) was published, Akio had left Berlin for Italy.…”