Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, Ciudad Universitaria, 04510 México DF, Mexico.
Parasitol Res. 2012 Aug;111(2):509-14. doi: 10.1007/s00436-012-2974-y. Epub 2012 May 31.
Trypanosoma cruzi is a species of parasitic protozoa that causes American trypanosomiasis or Chagas disease. These parasites go through a complex life cycle in Triatominae insects and vertebrate hosts. Epimastigotes are replicative forms that colonize the digestive tract of the vector and can be cultured in axenic media. The growth curve of epimastigotes allows assessment of differences in cells undergoing growth rate transitions from an exponential growth to a stationary phase. Since the classical descriptions of T. cruzi, it has been noted that the growth curve of epimastigotes in culture can give rise, in the stationary phase, to nonreplicating forms of metacyclic trypomastigotes. Metacyclogenesis therefore regards to the development process by which epimastigote transform into infective metacyclic trypomastigotes. In nature, these metacyclic forms allow the spread of Chagas disease when transmitted from an infected vector to a vertebrate host. This work reviews cellular phenomena that occur during the growth rate transitions of epimastigotes in culture, which may be related to very early physiological conditions for metacyclogenesis. Many of these events have not been thoroughly investigated. Their analysis can stimulate new hypotheses and future research in an important area not fully exploited.
克氏锥虫是一种寄生原生动物，可引起美洲锥虫病或恰加斯病。这些寄生虫在三锥虫科昆虫和脊椎动物宿主中经历复杂的生命周期。滋养体是复制形式，定殖于媒介的消化道，可在无共生培养基中培养。滋养体的生长曲线可评估处于从指数生长到静止期的生长速率转换的细胞之间的差异。自克氏锥虫的经典描述以来，人们注意到培养中的滋养体生长曲线在静止期会产生非复制的循环型锥鞭毛体形式。因此，循环生成是指滋养体转化为感染性循环型锥鞭毛体的发育过程。在自然界中，这些循环型形式允许当从受感染的媒介传播到脊椎动物宿主时，恰加斯病的传播。本综述回顾了培养中的滋养体生长速率转换过程中发生的细胞现象，这些现象可能与循环生成的早期生理条件有关。这些事件中的许多尚未得到彻底研究。对它们的分析可以刺激新的假设，并为尚未充分利用的重要领域的未来研究提供动力。
