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首页> 外文期刊>Journal of Parasitology >MORPHOLOGICAL DIFFERENTIATION AND FUNCTION OF THE COELOMOCYTES IN THE PARASITIC STAGES OF NIPPOSTRONGYLUS BRASILIENSIS
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MORPHOLOGICAL DIFFERENTIATION AND FUNCTION OF THE COELOMOCYTES IN THE PARASITIC STAGES OF NIPPOSTRONGYLUS BRASILIENSIS

机译：巴西念珠菌寄生期的鞘细胞形态学分化及功能

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Female and male worms of Nippostrongylus brasiliensis exhibited sexual dimorphism based on the number of coelomocytes present. A surprising multiplicity of diverse morphological types of coelomocytes developed in both female and male worms during the parasitic cycle. Cytoplasmic processes began to appear on the surface membrane of coelomocytes in the late third-stage larvae (L3s) in the lungs, and they increased greatly in type, size, and morphology during the fourth and fifth stages. These structures were characterized primarily as complex filopodia, pseudopodia, and cytoplasmic pearls, which resulted in the formation of highly pleomorphic cells. Pearls, starting as small protuberances, progressively increased in size and number with larval growth and development. In the adult worms, a novel process of autocannibalism was initiated in many of the very large coelomocytes. The pearls grew enormously in size at the expense of the cytoplasm, forming a peripheral garland in 1 plane surrounding a residual, small, flat, cytoplasmic core containing the nucleus. The underlying “strategy” was to increase the surface-to-volume ratio of these huge cells to overcome the restriction imposed by eutely; the coelomocytes do not undergo cell division. This morphological innovation makes possible a more efficient uptake of nutrients and exocytosis of waste matter. Vesicles (presumably lysosomes) in the coelomocytes of the infective L3 store an extraordinarily high concentration of vitamin B12 (cobalamin, Cbl). At present, the only physiological function that can be assigned to coelomocytes of N. brasiliensis is the uptake, concentration, and storage of Cbl in the free-living stages, with the subsequent release of the molecule from the vesicles in the early phase of parasitism. Thus, stored Cbl in the infective L3 is made available for biochemical processes during the critical period of larval growth and differentiation initiated in the lung. A model of a hypothetical coelomocyte is presented relative to the processing and use of Cbl. Based on many criteria, it is possible that functional differences exist between different morphological types of coelomocytes in the parasitic stages of N. brasiliensis and that future studies will have to address this matter.
机译：基于存在的结肠细胞数量，巴西夜蛾的雌虫和雄虫表现出性二态性。在寄生虫周期中，在雌性和雄性蠕虫中都产生了令人惊讶的多种形态学类型的结肠细胞。在肺的晚期第三阶段幼虫（L3s）的结肠细胞表面膜上开始出现细胞质过程，并且在第四和第五阶段它们的类型，大小和形态大大增加。这些结构的主要特征是复杂的丝状伪足，假伪足和胞质珍珠，从而导致高度多形性细胞的形成。珍珠从小突起开始，随着幼虫的生长和发育，其大小和数量逐渐增加。在成虫中，许多非常大的结肠细胞开始了一种新的自相残杀过程。珍珠的大小极大地增长，以细胞质为代价，在1个平面上形成一个环绕的花环，围绕着包含细胞核的残留的，小的，扁平的细胞质核心。潜在的“策略”是增加这些巨大细胞的表面积与体积之比，以克服严格地施加的限制。内皮细胞不进行细胞分裂。这种形态上的创新使得更有效地吸收养分和废物胞吐成为可能。感染性L3的内皮细胞中的囊泡（可能是溶酶体）储存了非常高浓度的维生素B12（钴胺素，Cbl）。目前，唯一可赋予巴西布鲁斯猪肝细胞的生理功能是其在自由生活阶段对Cbl的摄取，浓度和储存，随后在寄生虫的早期从小泡中释放该分子。 。因此，在幼虫生长和在肺中开始分化的关键时期，感染性L3中存储的Cbl可用于生化过程。提出了相对于Cbl的加工和使用的假设的结肠细胞模型。基于许多标准，在巴西猪笼草的寄生阶段，不同形态类型的粒细胞之间可能存在功能差异，未来的研究将不得不解决这一问题。

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