TIME-COURSE MEASUREMENTS OF PHOSPHORUS DEPLETION AND CYST FORMATION IN THE DINOFLAGELLATE GONYAULAX-TAMARENSIS LEBOUR
TIME-COURSE MEASUREMENTS OF PHOSPHORUS DEPLETION AND CYST FORMATION IN THE DINOFLAGELLATE GONYAULAX-TAMARENSIS LEBOUR
复制标题
DOI：
10.1016/0022-0981(85)90039-5
复制
发表时间：
1985-01-01
影响因子：
2
通讯作者：
LINDQUIST, NL
中科院分区：
文献类型：
--
作者：
ANDERSON, DM;LINDQUIST, NL
在磷限制的分批培养过程中，对塔玛甲藻从无性生殖向有性生殖的转变和包囊形成进行了时程测量。生长初期以无性为主，在此期间，细胞内和细胞外的P库在光照和黑暗中稳步下降。随着分裂的停止，细胞P下降到27pg/细胞的生存细胞配额。在MU存在的情况下，细胞内P的逐渐减少。摩尔PO34-浓度表明，在高于分析检测下限的浓度下，该物种可能包囊在自然水域中，以响应营养限制。随着细胞接近平台期，无性生长停止，有性生殖发生，标志是平均细胞直径最初减小；随后随着配子融合，直径随着时间的推移而增加，形成游动合子(平面合子)；以及可能的分裂率激增。虽然活动种群似乎达到了典型的平台期或静止生长阶段，但随着浮合子的形成和胞囊从悬浮液中脱落，种群的组成正在发生变化。在4天的时间间隔内，平台受精卵的数量逐渐增加，6天后，包囊数量也随之增加。配子的形成和/或融合不是以突然的、同步的方式发生的，或者是整合子的发育持续时间随着分批培养的年龄而变化。大约20%的活动细胞成功地完成了包囊。
Time-course measurements were made during the transition from asexual to sexual reproduction and cyst formation in P-limited batch cultures of the dinoflagellate G. tamarensis Lebour. The initial phase of growth was predominantly asexual, during which time the intracellular and extracellular P pools decreased steadily in the light and the dark. Cellular P dropped to a subsistence cell quota of 27 pg/cell as division ceased. This gradual decrease in cellular P in the presence of .mu. molar PO34- concentrations suggests that this species may encyst in natural waters in response to nutrient limitation at concentrations above analytical detection limits. As the cells approached plateau phase, asexual growth ceased and sexual reproduction occurred, marked by an initial decrease in average cell diameter; a subsequent increase in diameter through time as gametes fused, forming swimming zygotes (planozygotes); and a possible surge in division rate. Although the motile population appeared to reach a typical plateau or stationary growth phase, the population was changing in composition as planozygotes formed and cysts fell from suspension. Planozygote numbers increased gradually over a 4-day interval, followed 6 days later by a parallel increase in cyst numbers. Gamete formation and/or fusion did not occur in sudden, synchronized fashion, or alternatively that the duration of planozygote development varied as the batch cultures aged. Approximately 20% of all motile cells successfully completed encystment.