Urbach Davnah, Britschgi Adrian, Jacob Alain, Bittner David, Bernet Daniel, Wahli Thomas, Yoccoz Nigel G, Wedekind Claus
Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
Dis Aquat Organ. 2008 Aug 27;81(2):119-25. doi: 10.3354/dao01952.
In recent years, numerous cases of morphological gonadal alterations in fish have been recorded throughout the world and across a wide range of species. In the whitefish Coregonus fatioi from the pre-alpine Lake Thun (Switzerland), the frequency of gonadal alterations is particularly high and the variety of alteration types large. Little is known about the proximal causes and the direct consequences of these morphological features on population persistence. In particular, the potential for the observed alterations to be the phenotypic expression of reduced genetic quality has not yet been addressed. In this study, we used offspring survival during embryogenesis as a proximate indicator of male genetic quality and tested whether the presence of gonadal alterations in males is an indicator of reduced quality. Embryos resulted from in vitro fertilizations of gametes from 126 males and females. We found no significant correlation between embryo survival and gonadal alteration in adults. Our findings suggest that in C. fatioi of Lake Thun, alterations in gonad morphology are not a phenotypic expression of variation in genetic quality.
近年来，世界各地记录了大量鱼类性腺形态改变的案例，涉及多种鱼类。在瑞士前阿尔卑斯地区图恩湖的法氏白鲑（Coregonus fatioi）中，性腺改变的频率特别高，改变类型也多种多样。对于这些形态特征的近端原因以及对种群存续的直接后果，人们了解甚少。特别是，尚未探讨所观察到的改变是否为遗传质量下降的表型表达。在本研究中，我们将胚胎发育过程中的后代存活率作为雄性遗传质量的近端指标，并测试雄性性腺改变的存在是否是质量下降的指标。胚胎来自126只雄性和雌性配子的体外受精。我们发现胚胎存活率与成年鱼的性腺改变之间没有显著相关性。我们的研究结果表明，在图恩湖的法氏白鲑中，性腺形态的改变不是遗传质量变异的表型表达。
