Augustinos Antonios A, Drosopoulou Elena, Gariou-Papalexiou Aggeliki, Asimakis Elias D, Cáceres Carlos, Tsiamis George, Bourtzis Kostas, Zacharopoulou Antigone
Department of Biology, University of Patras, Patras, Greece; Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Seibersdorf, Vienna, Austria; Department of Environmental and Natural Resources Management, University of Patras, Agrinio, Greece.
Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Zookeys. 2015 Nov 26(540):273-98. doi: 10.3897/zookeys.540.9857. eCollection 2015.
The Bactrocera dorsalis species complex, currently comprising about 90 entities has received much attention. During the last decades, considerable effort has been devoted to delimiting the species of the complex. This information is of great importance for agriculture and world trade, since the complex harbours several pest species of major economic importance and other species that could evolve into global threats. Speciation in Diptera is usually accompanied by chromosomal rearrangements, particularly inversions that are assumed to reduce/eliminate gene flow. Other candidates currently receiving much attention regarding their possible involvement in speciation are reproductive symbionts, such as Wolbachia, Spiroplasma, Arsenophonus, Rickettsia and Cardinium. Such symbionts tend to spread quickly through natural populations and can cause a variety of phenotypes that promote pre-mating and/or post-mating isolation and, in addition, can affect the biology, physiology, ecology and evolution of their insect hosts in various ways. Considering all these aspects, we present: (a) a summary of the recently gained knowledge on the cytogenetics of five members of the Bactrocera dorsalis complex, namely Bactrocera dorsalis s.s., Bactrocera invadens, Bactrocera philippinensis, Bactrocera papayae and Bactrocera carambolae, supplemented by additional data from a Bactrocera dorsalis s.s. colony from China, as well as by a cytogenetic comparison between the dorsalis complex and the genetically close species, Bactrocera tryoni, and, (b) a reproductive symbiont screening of 18 different colonized populations of these five taxa. Our analysis did not reveal any chromosomal rearrangements that could differentiate among them. Moreover, screening for reproductive symbionts was negative for all colonies derived from different geographic origins and/or hosts. There are many different factors that can lead to speciation, and our data do not support chromosomal and/or symbiotic-based speciation phenomena in the taxa under study.
橘小实蝇物种复合体目前包含约90个实体，备受关注。在过去几十年里，人们投入了大量精力来界定该复合体中的物种。这些信息对农业和世界贸易至关重要，因为该复合体包含几种具有重大经济意义的害虫物种以及其他可能演变成全球威胁的物种。双翅目中的物种形成通常伴随着染色体重排，尤其是倒位，据推测倒位会减少/消除基因流动。目前，其他可能参与物种形成的备受关注的候选因素是生殖共生体，如沃尔巴克氏体、螺原体、产砷菌、立克次氏体和卡丁氏菌。这类共生体往往能在自然种群中迅速传播，并能导致多种表型，促进交配前和/或交配后的隔离，此外，还能以各种方式影响其昆虫宿主的生物学、生理学、生态学和进化。考虑到所有这些方面，我们呈现：(a) 关于橘小实蝇复合体五个成员（即橘小实蝇指名亚种、入侵橘小实蝇、菲律宾橘小实蝇、番木瓜橘小实蝇和杨桃橘小实蝇）细胞遗传学的最新知识总结，并补充来自中国的橘小实蝇指名亚种群体的额外数据，以及橘小实蝇复合体与亲缘关系较近的物种——昆士兰实蝇之间的细胞遗传学比较；(b) 对这五个分类单元的18个不同定殖种群进行生殖共生体筛选。我们的分析未发现能区分它们的染色体重排。此外，对来自不同地理来源和/或宿主的所有菌落进行的生殖共生体筛选均为阴性。有许多不同因素可导致物种形成，而我们的数据不支持所研究分类单元中基于染色体和/或共生体的物种形成现象。
