昆虫学报 ›› 2016, Vol. 59 ›› Issue (3): 247-259.doi: 10.16380/j.kcxb.2016.03.001

• 研究论文 •    下一篇

高桥氏果蝇表型频率变化和胁迫相关性状的分析:季节性适应研究(英文)

Seema RAMNIWAS*,  Babita KAJLA, Ravi PARKASH   

  1. (Department of Genetics, Maharshi Dayanand University, Rohtak124001, India)
  • 出版日期:2016-03-20 发布日期:2016-03-20
  • 作者简介:Corresponding author, E-mail: seema.ramniwas@gmail.com
  • 基金资助:

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Changes in phenotypic frequencies and the analysis of stress related traits of Drosophila takahashii: a study of seasonal acclimation(In English)

Seema RAMNIWAS*,  Babita KAJLA, Ravi PARKASH   

  1. (Department of Genetics, Maharshi Dayanand University, Rohtak124001, India)
  • Online:2016-03-20 Published:2016-03-20

摘要: 【目的】 昆虫中经常可见体色变化,但是关于其作用价值了解甚少。高桥氏果蝇 Drosophila takahashii 在遗传上表现出腹部黑化的不连续变化。为了测定生理性状是否可能受黑化的影响,我们调查了3个不同色型个体腹部黑化的变化和胁迫相关性状,检验了季节性环境条件将增强相应的季节性表型的适应性这一假说。【方法】从不同海拔地点采集高桥氏果蝇,对深色和浅色纯育品系的遗传杂交进行的孟德尔分析证实存在一个主要位点,为D等位基因显性。对种群以及3种色型果蝇的生理生态学性状进行了统计分析。【结果】 在旱季观察到深色等位基因频率的显著增加,在雨季会出现体色较浅的果蝇,这说明气候选择起着重要作用。不过,在这两个季节中体色居中的果蝇均很多。中间色型的果蝇由于适应而表现出所有性状的 F 值均显著增加( P<0.001),但在深色和浅色纯育品系中未观察到这类适应效果( P≥0.42)。【结论】通过不同性状的测定结果我们提出,在干冷胁迫条件下,在深色型中观察到显著更高的生理学耐性;而在湿热条件下,在浅色型中观察到显著更高的生理学耐性。有意思的是,中间表型在这两种条件下均有较强的适应能力。而且,我们发现温湿度的季节性改变给胁迫相关的性状施加了选择压力。

关键词: 高桥氏果蝇, 等位基因频率, 生活史变化;分离的表型, 杂合体的灵活性

Abstract: 【Aim】 Variation in coloration is frequently found in insects, but little is known about its functional value.  Drosophila takahashii exhibits genetically coded discontinuous variation in abdominal melanisation. To determine whether physiological performance is likely to be affected by melanisation pattern, in this study we investigated the variation in abdominal melanisation and stress related traits among individuals belonging to three different color morphs, and tested the hypothesis that seasonal environmental conditions would enhance the adaptation of the corresponding seasonal phenotype. 【Methods】 D. takahashii  flies were collected from altitudinal sites and a Mendelian analysis of genetic crosses from true breeding dark and light color strains confirmed the occurrence of a major locus, with dominance of D allele. Ecophysiological traits in populations as well as flies of three body color phenotypes were statistically analyzed. 【Results】A significant increase in the frequency of the dark allele was observed during the dry season and lighter flies occur in the wet season, which suggests that climatic selection plays a role. However, intermediate flies were abundant in both seasons. There were significant  F  values for increase in all traits for intermediate phenotypes ( P<0.001) due to acclimation but no such acclimation effects were observed in dark and light true breeding strains of D. takahashii (P ≥0.42). 【Conclusion】 As per our hypothesis, significantly higher physiological tolerance was observed in dark morph under cool-dry stress conditions, and in light morph under hot-wet conditions, respectively, as determined by different traits. Interestingly, intermediate phenotypes showed higher capability to acclimation to both conditions. Further, we found seasonal changes in temperature and humidity to confer selection pressures on stress-related traits.

Key words: Drosophila takahashii, allele frequency, life history variation, discrete phenotypes, heterozygote flexibility