Oocyte production and sperm utilization patterns in semi-fertile strains of Caenorhabditis elegans.
Oocyte production and sperm utilization patterns in semi-fertile strains of Caenorhabditis elegans.
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DOI：
10.1186/1471-213x-4-3
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发表时间：
2004-04-15
影响因子：
--
通讯作者：
Singson A
中科院分区：
文献类型：
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作者：
Kadandale P;Singson A
秀丽隐杆线虫雌雄同体能够产生数百个后代。然而，遗传和环境因素可能会使许多动物无法充分发挥繁殖潜力。在这些情况下，有效利用任何功能性配子对于繁殖成功变得更加重要。为了了解线虫生殖生物学的这一方面，我们检查了一组独特的半可育精子功能突变体中的卵母细胞产生和精子利用模式。在这里检查的突变体中，卵可能非常小，但精子诱导高水平的排卵。排卵率在成年的第一天和第二天达到最高水平。生育期排卵率保持较高水平，并随着年龄的增长逐渐下降。这些结果进一步证明了精子使卵母细胞受精和诱导排卵的能力的脱钩。我们还观察到，在我们的半可育突变体中，成功受精事件的高峰发生在卵母细胞大量产生之前。在没有精子竞争的条件下混合功能性和非功能性精子群体也表明功能性精子得到了有效利用。尽管不同突变菌株的总体育雏规模可能相似，但这些菌株精子利用模式的细微差异可能导致资源利用和种群增长的显着差异。这项研究首次详细描述了野生型和生育力受损的线虫品系在整个繁殖期的卵母细胞和后代生产模式。我们的突变体的表型为研究精子利用模式提供了一个理想的系统，因为它们只影响一个主要过程，即卵母细胞受精的能力。在半可育突变体中，生殖过程的性质和/或特定的分子机制确保任何有功能的精子都能被快速利用。我们的半不育突变体产生的精子中只有一小部分具有功能，而每个精子与卵母细胞受精的机会虽低但均等。除了产生的后代数量之外，后代产生的模式也对种群增长的动态产生重要影响。
Caenorhabditis elegans hermaphrodites are capable of producing hundreds of progeny. However, genetic and environmental factors can keep many animals from attaining their full reproductive potential. In these situations, efficient use of any functional gametes becomes more important for reproductive success. To learn about this aspect of C. elegans reproductive biology, we examined oocyte production and sperm utilization patterns in a unique collection of semi-fertile sperm function mutants. In the mutants examined here, broods can be very small but sperm induced high levels of ovulation. Ovulation rates reach maximum levels between the first and second day of adulthood. Ovulations rates remain high during the reproductive period and gradually decline with age. These results further demonstrate a decoupling of the ability of sperm to fertilize oocytes and induce ovulation. We also observe that in our semi-fertile mutants the peak of successful fertilization events precedes the bulk of oocyte production. Mixing populations of functional and nonfunctional sperm under conditions without sperm competition also shows that functional sperm are utilized efficiently. Although overall brood size can be similar for different mutant strains, slight differences in the pattern of sperm utilization in these strains can lead to significant differences in resource utilization and population growth. This study represents the first detailed description of oocyte and progeny production patterns over the entire reproductive period for wild-type and fertility impaired strains of C. elegans. The phenotype of our mutants provide an ideal system for studying sperm utilization patterns since they only affect one major process, the ability to fertilize oocytes. In semi-fertile mutants, the nature of the reproductive process and/or specific molecular mechanisms ensures that any functional sperm are utilized quickly. Only a fraction of the sperm produced by our semi-sterile mutants are functional as opposed to every sperm having a low but equal chance of fertilizing an oocyte. In addition to the number of progeny produced, the pattern of progeny production can have an important influence on the dynamics of population growth.