Quality over quantity: unraveling the contributions to cytoplasmic incompatibility caused by two coinfecting Cardinium symbionts
Quality over quantity: unraveling the contributions to cytoplasmic incompatibility caused by two coinfecting Cardinium symbionts
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DOI：
10.1038/s41437-022-00507-3
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发表时间：
2022-02-05
期刊：
影响因子：
3.8
通讯作者：
Hunter, Martha S.
中科院分区：
文献类型：
--
作者：
Doremus, Matthew R.;Stouthamer, Corinne M.;Hunter, Martha S.
细胞质不相容（Cytoplasmic incompatibility， CI）是节肢动物由母体遗传的细菌共生体引起的一种常见的生殖破坏形式。CI是一个两步操作：首先，共生体改变男性宿主的精子，导致未受感染的受精胚胎死亡。其次，当雌性被一种兼容的菌株感染时，共生体会逆转受精卵中的精子修饰，使受感染雌性的后代存活下来，并在种群中传播共生体的频率很高。尽管CI在节肢动物的进化中发挥了作用，但对于许多共生体来说，CI的机制尚不清楚。hertigii是节肢动物中常见的一种诱导ci的共生体，包括拟寄生蜂，如partenopea。该黄蜂携带两个红雀菌株，cEina2和cEina3，并表现出较强的CI。这些菌株感染不同密度的黄蜂，其中cEina3的密度低于cEina2，以前不知道是哪种菌株引起了CI。通过差异处理cEina3黄蜂，我们发现这种低密度共生体负责CI，并在其蛹期改变雄性。cEina2不会改变宿主的繁殖，并可能通过与cEina3 CI“搭便车”或通过赋予未知的益处而传播。cEina3菌株在男性生殖组织中也显示出独特的定位模式。与其他诱导ci的共生体感染精子不同，cEina3细胞存在于睾丸基部和精囊周围的体细胞中。这可能允许低密度的cEina3有效地修饰宿主雄性，并表明cEina3使用不同于精子感染的CI共生体的修饰策略。
Cytoplasmic incompatibility (CI) is a common form of reproductive sabotage caused by maternally inherited bacterial symbionts of arthropods. CI is a two-step manipulation: first, the symbiont modifies sperm in male hosts which results in the death of fertilized, uninfected embryos. Second, when females are infected with a compatible strain, the symbiont reverses sperm modification in the fertilized egg, allowing offspring of infected females to survive and spread the symbiont to high frequencies in a population. Although CI plays a role in arthropod evolution, the mechanism of CI is unknown for many symbionts. Cardinium hertigii is a common CI-inducing symbiont of arthropods, including parasitoid wasps like Encarsia partenopea. This wasp harbors two Cardinium strains, cEina2 and cEina3, and exhibits strong CI. The strains infect wasps at different densities, with the cEina3 present at a lower density than cEina2, and it was previously not known which strain caused CI. By differentially curing wasps of cEina3, we found that this low-density symbiont is responsible for CI and modifies males during their pupal stage. cEina2 does not modify host reproduction and may spread by 'hitchhiking' with cEina3 CI or by conferring an unknown benefit. The cEina3 strain also shows a unique localization pattern in male reproductive tissues. Instead of infecting sperm like other CI-inducing symbionts, cEina3 cells are found in somatic cells at the testis base and around the seminal vesicle. This may allow the low-density cEina3 to efficiently modify host males and suggests that cEina3 uses a different modification strategy than sperm-infecting CI symbionts.