Spatial and temporal patterns of parthenogenesis and parasitism in the freshwater snail Melanoides tuberculata
Spatial and temporal patterns of parthenogenesis and parasitism in the freshwater snail Melanoides tuberculata
复制标题
DOI：
10.1111/j.1420-9101.2004.00791.x
复制
发表时间：
2005-01-01
影响因子：
2.1
通讯作者：
Heller, J
中科院分区：
文献类型：
--
作者：
Ben-Ami, F;Heller, J
红皇后假说预测，在寄生虫严重感染的种群中，性行为应该比在没有寄生虫的种群中更常见。在自然种群中存在有性繁殖和孤雌繁殖两种个体，且部分种群受吸虫严重侵袭的水生蜗牛中，对这一假说进行了研究。可育雄性的存在和双性恋群体较高的遗传多样性表明有性生殖。我们比较了1990年、1999年和2001年的地点，我们寻找雄性和寄生虫频率之间的正相关关系。男性感染频率与个体感染频率无相关性。回顾性功效分析再次证实了这种相关性的缺乏。在9年的时间里，男性感染频率下降，但感染水平上升。这些结果不支持红皇后假说。在雄性频率高的样本中，胚胎数量低，这可能表明雄性可能对胚胎数量有负面影响。男性对健康的影响可能表明，性的代价是更少的胚胎。胚胎数量的减少也可能代表了交配和产卵成本之间的权衡。
The Red Queen hypothesis predicts that sex should be more common in populations heavily infested with parasites, than in those without. This hypothesis was investigated in the aquatic snail Melanoides tuberculata, in which both sexual and parthenogenetic individuals exist in natural populations, and some populations are heavily infested by trematodes. The presence of fertile males and the higher genetic diversity of bisexual populations are indicative of sexual reproduction. We compared sites in 1990, 1999, and 2001, and we looked for a positive correlation between male and parasite frequencies. Male frequency was not correlated with the frequency of individuals infected by trematodes. This lack of correlation was reconfirmed in a retrospective power analysis. In a period of 9 years, male frequencies decreased but infection levels increased. These results do not support the Red Queen hypothesis. In samples with high male frequency the number of embryos was low, perhaps indicating that males may have a negative effect on embryo numbers. This effect of males on fitness could perhaps suggest that the cost of sex is fewer embryos. The reduction in embryo numbers may also represent a trade-off between mating and egg production costs.