Neumann Dietrich
Lehrstuhl für Physiologische Ökologie, Zoologisches Institut der Universität Köln, Köln, Deutschland.
Oecologia. 1971 Mar;8(1):1-20. doi: 10.1007/BF00345623.
The intertidal midge Clunio marinus is distributed along the European coast-line. Stocks from distinct locations differ in the programming of their emergence time. They represent ecological races. The crossability between 7 stocks was examined.Between some stocks a non-reciprocal cross sterility has been found, characterized by fertile hybrids in one cross direction, and no offspring in the reciprocal crosses.The cross Jean ♀xSan ♂ was fertile, while the cross San ♀xJean ♂ was sterile. After three backcrosses of the hybrid females to San males, the sterility in the reciprocal crosses with San females had not been changed. The maternal inheritance of this non-reciprocal sterility is compared with similar studies in Culex pipiens by Laven.According to aspects of population genetics, the non-reciprocal cross sterility is considered in view of elimination of crossing types, of gene flow and reproductive isolation. With regard to the significance of the non-reciprocal cross sterility in the field, three hypotheses are discussed: 1. by-product of evolutionary divergence in ecological races, 2. unilateral reproductive isolation which blocks the gene flow between adjacent populations only in one direction, and 3. speciation.
潮间带蠓虫海滨粗脉摇蚊分布于欧洲海岸线。来自不同地点的种群在羽化时间的编程上存在差异。它们代表生态小种。研究了7个种群之间的杂交可育性。在一些种群之间发现了单向杂交不育现象，其特征是在一个杂交方向上杂种可育，而在反向杂交中没有后代。Jean♀×San♂的杂交是可育的，而San♀×Jean♂的杂交是不育的。杂种雌性与San雄性回交三次后，与San雌性反向杂交的不育性并未改变。将这种单向不育的母系遗传与拉文对致倦库蚊的类似研究进行了比较。根据群体遗传学的观点，从消除杂交类型、基因流动和生殖隔离的角度考虑单向杂交不育现象。关于单向杂交不育在野外的意义，讨论了三种假说：1. 生态小种进化分歧的副产品；2. 单向生殖隔离，仅在一个方向上阻止相邻种群之间的基因流动；3. 物种形成。
