Frank SA
Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697-2525, U.S.A.
J Theor Biol. 1998 May 21;192(2):213-218. doi: 10.1006/jtbi.1998.0652.
Wolbachia infections occur in many arthropods. These matrilineally inherited bacteria cause cytoplasmic incompatibility, in which a cross produces no offspring when between an infected male and an uninfected female. Some populations harbour multiple Wolbachia strains. Females fail to produce offspring when crossed to a male with a strain that the female lacks. Prior theoretical work showed that a panmictic population cannot maintain polymorphism for different strains when each female carries only a single strain. A few authors suggested that doubly infected females can stabilize multistrain polymorphism, but conditions for invasion and location of stable equilibrium were not analysed in detail. For two strains, I describe the conditions under which a multiply infected class can spread. Spread of the doubly infected type stabilizes polymorphism of the singly infected classes. This analysis also suggests an interesting extension to higher multiplicity of infection. For an arbitrary number of strains, N, a panmictic population cannot maintain different classes with N-1 infections unless the class with N infections is also present. This pyramid of polymorphism may explain the puzzling diversity of incompatibility types observed in some Culex mosquitos. Multiple infection also has interesting consequences for the dynamics of spatial variation and reproductive isolation.Copyright 1998 Academic Press Limited
沃尔巴克氏体感染存在于许多节肢动物中。这些母系遗传的细菌会导致细胞质不亲和，即当感染的雄性与未感染的雌性杂交时，不会产生后代。一些种群携带着多种沃尔巴克氏体菌株。当雌性与携带其自身所缺乏菌株的雄性杂交时，雌性无法产生后代。先前的理论研究表明，当每个雌性仅携带单一菌株时，随机交配的种群无法维持不同菌株的多态性。一些作者认为，双重感染的雌性可以稳定多菌株多态性，但未详细分析入侵条件和稳定平衡点的位置。对于两种菌株，我描述了双重感染类型能够传播的条件。双重感染类型的传播稳定了单一感染类型的多态性。该分析还表明了对更高感染多样性的一个有趣扩展。对于任意数量的菌株N，随机交配的种群无法维持具有N - 1种感染的不同类型，除非同时存在具有N种感染的类型。这种多态性金字塔可能解释了在一些库蚊中观察到的不相容类型的令人困惑的多样性。多重感染对空间变异动态和生殖隔离也有有趣的影响。版权所有1998年学术出版社有限公司
