Duplicated ribosomal protein (RP) genes in the Drosophila melanogaster eRpL22 family encode structurally-divergent and differentially-expressed rRNA-binding RPs. eRpL22 is expressed ubiquitously and eRpL22-like expression is tissue-restricted with highest levels in the adult male germline. We explored paralogue functional equivalence using the GAL4-UAS system for paralogue knockdown or overexpression and a conditional eRpL22-like knockout in a heat- shock flippase/FRT line. Ubiquitous eRpL22 knockdown with Actin-GAL4 resulted in embryonic lethality, confirming eRpL22 essentiality. eRpL22-like knockdown (60%) was insufficient to cause lethality; yet, conditional eRpL22-like knockout at one hour following egg deposition caused lethality within each developmental stage. Therefore, each paralogue is essential. Variation in timing of heat-shock-induced eRpL22-like knockout highlighted early embryogenesis as the critical period where eRpL22-like expression (not compensated for by eRpL22) is required for normal development of several organ systems, including testis development and subsequent sperm production. To determine if eRpL22-like can substitute for eRpL22, we used Actin-GAL4 for ubiquitous eRpL22 knockdown and eRpL22-like-FLAG (or FLAG-eRpL22: control) overexpression. Emergence of adults demonstrated that ubiquitous eRpL22-like-FLAG or FLAG-eRpL22 expression eliminates embryonic lethality resulting from eRpL22 depletion. Adults rescued by eRpL22-like-FLAG (but not by FLAG-eRpL22) overexpression had reduced fertility and longevity. We conclude that eRpL22 paralogue roles are not completely interchangeable and include functionally-diverse roles in development and spermatogenesis. Testis-specific paralogue knockdown revealed molecular phenotypes, including increases in eRpL22 protein and mRNA levels following eRpL22-like depletion, implicating a negative crosstalk mechanism regulating eRpL22 expression. Paralogue depletion unmasked mechanisms, yet to be defined that impact paralogue co-expression within germ cells.

果蝇eRpL22家族中的重复核糖体蛋白（RP）基因编码结构差异和差异表达的rRNA结合RP。È RPL22普遍表达和e RPL22样表达是组织限制性与在成年雄性生殖系最高水平。我们探索了使用GAL4-UAS系统进行旁系同源敲除或过表达以及在热休克flippase / FRT系中有条件的eRpL22样敲除的旁系同源功能等效性。用肌动蛋白-GAL4进行无处不在的e RpL22敲低导致胚胎致死率，证实了eRpL22的重要性。Ë RPL22样击倒（60％）不足以造成致命性；然而，卵沉积后一小时的条件性eRpL22样敲除会在每个发育阶段造成致死性。因此，每个旁白都是必不可少的。热休克诱导的类似eRpL22的基因敲除时间的变化突出了早期胚胎发生，因为关键时期是几个器官系统正常发育（包括睾丸发育和随后的精子产生）需要eRpL22样表达（未被eRpL22补偿）的关键时期。为了确定eRpL22-like是否可以替代eRpL22，我们使用肌动蛋白-GAL4进行普遍存在的eRpL22敲低和e RpL22-like-FLAG（或FLAG-eRpL22：控制）过表达。成人的出现表明普遍存在的eRpL22-like-FLAG或FLAG-eRpL22表达消除了因eRpL22耗尽而导致的胚胎致死性。通过类似eRpL22-FLAG（但不是通过FLAG-eRpL22）拯救的成年人的生育力和寿命下降。我们得出的结论是，eRpL22旁白角色并非完全可互换，并且在发育和精子发生中包括功能多样的角色。睾丸特异的旁系同源基因敲低揭示了分子表型，包括在eRpL22样耗竭后eRpL22蛋白和mRNA水平增加，暗示了调节eRpL22的负串扰机制表达。旁系耗竭揭示了尚未公开的机制，该机制影响生殖细胞内旁系同源表达。