Dobson S L, Tanouye M A
Department of Environmental Science, Policy and Management, University of California, Berkeley 94720, USA.
Heredity (Edinb). 1998 Sep;81 ( Pt 3):261-9. doi: 10.1046/j.1365-2540.1998.00372.x.
Here we examine the potential for interspecific movement of a supernumerary or B chromosome and its subsequent stability. B chromosomes differ from autosomes in that they are nonvital, nonpairing chromosomes which vary in number between conspecific individuals. According to one generally accepted hypothesis, B chromosomes originate from the autosomes of their host. However, previous comparisons of B chromosome and host autosome sequences have suggested an additional evolutionary route: that B chromosomes originating in one species may be subsequently transferred into another species via interspecific hybridization. To examine B chromosome movement, hybrid crosses were utilized to introduce the paternal sex ratio chromosome (PSR) of Nasonia vitripennis into N. giraulti and N. longicornis. The results demonstrate that these transfers occur at high rates and that the meiotic drive system of PSR continues to function in both species, resulting in the maintenance of PSR at high frequencies. The relevance of these results to origin hypotheses of PSR is discussed here, as are the potential ecological effects of naturally occurring PSR movement and the potential applied uses of the mechanisms of PSR.
在此，我们研究了多余染色体或B染色体种间转移的可能性及其随后的稳定性。B染色体与常染色体不同，它们是非必需的、不配对的染色体，在同种个体之间数量各异。根据一个普遍接受的假说，B染色体起源于其宿主的常染色体。然而，先前对B染色体和宿主常染色体序列的比较表明了另一条进化途径：起源于一个物种的B染色体可能随后通过种间杂交转移到另一个物种中。为了研究B染色体的转移，利用杂交来将丽蝇蛹集金小蜂的父本性别比染色体（PSR）导入到吉氏金小蜂和长角金小蜂中。结果表明，这些转移发生率很高，并且PSR的减数分裂驱动系统在这两个物种中都继续发挥作用，从而导致PSR在高频率下得以维持。本文讨论了这些结果与PSR起源假说的相关性，以及自然发生的PSR转移的潜在生态影响和PSR机制的潜在应用用途。
