LIFE CYCLE OF PARAMECIUM BURSARIA SYNGEN 1 IN NATURE : Behavior Biology and Ecology-猫眼课题宝

草履虫 Bursaria SYNGEN 1 在自然界中的生命周期：行为生物学和生态学

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发表时间：

1990

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中科院分区：

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作者：

T. Kosaka

摘要。完成了对绿草履虫自然种群密度和个体所属生活史阶段的研究。在一年多的时间里，每隔20天从两条溪流中采集一次绿色参数：在Mikumarikyo溪流中，26个采集日期采集了413个个体，在Momijidani-gawa溪流中，23个采集日期采集了83个个体。自然界中的个体密度并不稳定，而是随月份而波动很大。看来，接合发生在4月至6月在Mikumarikyo流和5月至6月在Momijidani川流。具有交配能力的个体的出现可能与种群的增长密切相关，因此有性生殖可能发生在种群密度高峰附近。对来自Mikumarikyo溪流的413个个体进行了检查，以确定它们在生命周期中的位置; 309个（74%）是未成熟的，55个（13%）是青少年，49个（12%）是成熟的。未观察到老年人。具有交配能力的个体的比例在任何收集中通常小于30%。四个交配类型观察到发生在成熟的个体约相等的频率。结果表明，交配型（a和B）的隐性基因频率高于显性基因（A和B）。在来自桃寺谷川溪的83只个体中，44只（52%）为未成熟个体，21只（25%）为青少年个体，18只（21%）为成熟个体。同样，没有观察到老年人。因为只有两个交配型被发现，II和III（基因型aaB-和aabb），它似乎可能是显性基因A是罕见的或不存在的Momijidani-gawa人口。

ABSTRACT. Studies were completed on the natural population density of Paramecium bursaria syngen 1 and on the life cycle stages to which the individuals belonged. Green paramecia were collected from two streams once every 20 days for over one year: 413 individuals on 26 collection dates in Mikumarikyo stream and 83 individuals on 23 collection dates in Momijidani-gawa stream. Individuals in nature did not maintain at a steady density but fluctuated greatly depending on the month. It seems that conjugation occurred from April to June in the Mikumarikyo stream and from May to June in the Momijidani-gawa stream. The appearance of individuals with mating ability might be related closely to increasing population so that sexual reproduction probably occurred near the peak of the population density. The 413 individuals from Mikumarikyo stream were examined to determine their position within the life cycle; 309 (74%) were immature, 55 (13%) were adolescent, and 49 (12%) were mature. No senile individuals were observed. The fraction of individuals with mating ability was generally less than 30% at any collection. Four mating types were observed occurring with about equal frequencies in mature individuals. The results show the frequencies of the recessive genes for mating types (a and b) are higher than for dominant genes (A and B). Of 83 individuals from Momijidani-gawa stream, 44 (52%) were immature, 21 (25%) were adolescent, and 18 (21%) were mature. Again, no senile individuals were observed. Because only two mating types were found, II and III (genotypes aaB- and aabb), it seems possible that the dominant gene A was rare or absent in the Momijidani-gawa population.

Adolescence in Tetrahymena thermophila.