Ref ID : 4913
Xiaozhong Hu, Weibo Song, and Toshikazu Suzuki; Morphogenesis of Holosticha bradburyae (Protozoa, Ciliophora) during asexual reproduction cycle. Europ.J.Protistol. 39:173-181, 2003
Reprint : In File
Notes : Morphogenetic events during the division of the marine hypotrichous ciliate Holosticha bradburyae Gong et al. 2001, collected from mollusc culturing waters off the coast of Qingdao, China are described, based on protargol-impregnated specimens. Its morphogenesis is characterized by the following features: (1) in the proter, a new oral primordium is formed on the bottom and at the right of the parental buccal cavity; disorganization of the undulating membrane does not contribute to the formation of this oral primordium, which develops to replace the posterior part of the parental buccal apparatus, while the anterior part is retained; (2) fronto-ventral-transverse cirral anlagen in both division parts originate de novo as a row of oblique streaks; (3) each of these oblique streaks divides into three segments (new cirri), except for the last two anlagen which produce four or five each, the last anlage of which contributes two frontoterminal cirri; (4) marginal anlagen are also formed de novo; (5) the generating mode of the dorsal kineties is of a two-group type, that is, two groups of dorsal kinety anlagen develop de novo near the leftmost and rightmost dorsal kineties respectively, which evolve to replace the old structures; (6) replication bands of macronuclear segments appear at early morphogenetic stages. Based on available morphogenetic data, Holosticha exhibits multiple phylogenetic patterns, which possibly indicates that this genus has reached a branching point in terms of evolution.