THE ENDOCRINE-GENETIC BASIS OF LIFE-HISTORY VARIATION: THE RELATIONSHIP BETWEEN THE ECDYSTEROID TITER AND MORPH-SPECIFIC REPRODUCTION IN THE WING-POLYMORPHIC CRICKET GRYLLUS FIRMUS
THE ENDOCRINE-GENETIC BASIS OF LIFE-HISTORY VARIATION: THE RELATIONSHIP BETWEEN THE ECDYSTEROID TITER AND MORPH-SPECIFIC REPRODUCTION IN THE WING-POLYMORPHIC CRICKET GRYLLUS FIRMUS
复制标题
生活史变异的内分泌遗传基础：翅多态蟋蟀中蜕皮甾类滴度与形态特异性繁殖之间的关系
DOI：
10.1111/j.0014-3820.2001.tb00787.x
复制
发表时间：
2001
影响因子：
16.8
通讯作者：
J. Bottsford
中科院分区：
文献类型：
--
作者：
A. Zera;J. Bottsford
生活史性状变异的激素基础是生命史进化中研究较少的课题。确定生活史变异的内分泌遗传学原因的一个重要步骤是记录激素滴度与生活史性状变化的基因型/表型之间的统计和功能关联。为此，我们比较了具有飞行能力的蟋蟀和不会飞行的蟋蟀成年后第一周的血液外激素滴度和卵巢质量。外甾体激素是一组结构相关的激素，调节昆虫生殖的许多重要方面。在成年后的第一周内，两种不会飞行的变形体的睾丸激素滴度和卵巢肿块都明显高于会飞行的变形体。来自不同选择系的变体之间的表皮甾体滴度和卵巢质量的遗传基础差异与来自相同对照（未选择）系的变体之间的表型基础差异相似。到成年期第7天，卵巢通常增大200-400%，而不会飞行的卵巢激素滴度比会飞行的卵巢激素滴度高60-300%。此外，在对照系或选择系的两种不会飞行和会飞行的蟋蟀的混合样本中，观察到外皮甾体滴度与卵巢质量之间高度显著的正表型相关。在没有飞行的变种中，蜕皮激素滴度被充分提高，以解释其卵巢生长的提高。这是第一次直接证明，自然发生的表型/基因型在早期繁殖力（一个关键的生活史特征）上存在差异，在潜在调节该特征的关键生殖激素的滴度上也存在表型和基因上的差异。
Abstract The hormonal basis of variation in life-history traits is a poorly studied topic in life-history evolution. An important step in identifying the endocrine-genetic causes of life-history variation is documenting statistical and functional associations between hormone titers and genotypes/phenotypes that vary in life-history traits. To this end, we compared the blood ecdysteroid titer and the mass of the ovaries during the first week of adulthood among a flight-capable morph and two flightless morphs of the wing-polymorphic cricket Gryllus firmus. Ecdysteroids are a group of structurally related hormones that regulate many important aspects of reproduction in insects. Both the ecdysteroid titer and ovarian mass were significantly higher in each of two flightless morphs compared with the flight-capable morph throughout the first week of adulthood. Genetically based differences in the ecdysteroid titer and ovarian mass between morphs from different selected lines were similar to phenotypically based differences among morphs from the same control (unselected) lines. By day 7 of adulthood, ovaries were typically 200–400% larger and the ecdysteroid titer was 60–300% higher in flightless versus the flight-capable morph. In addition, highly significant, positive, phenotypic correlations were observed between the ecdysteroid titer and ovarian mass in pooled samples of the two flightless and flight-capable crickets from control lines or from selected lines. The ecdysteroid titer was sufficiently elevated in the flightless morphs to account for their elevated ovarian growth. This is the first direct documentation that naturally occurring phenotypes/genotypes that differ in early fecundity, a key life-history trait, also differ phenotypically and genetically in the titer of a key reproductive hormone that potentially regulates that trait.