Enzyme Cytochemistry of the Alveolar Sacs and Golgian‐Like Cisternae in the Ciliate Ichthyophthirius multifiliis

Abstract

In the cell cortex of the parasitic ciliate Ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. The thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. Using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs of trophozoites. In the endoplasmic reticulum acid phosphatase activity was not detected and only very small amounts of thiamine pyrophosphatase and nucleoside diphosphatase reaction product were observed. After exit from the host, a reduction in acid phosphatase activity was evident in the alveolar sacs. At theront stage acid phosphatase activity is absent from these structures. However, high thiamine pyrophosphatase and nucleoside diphosphatase activities remain in the alveolar sacs during the whole life cycle. On the other hand, acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in thick membrane cisternae of theronts. Based on the morphological aspects and enzymatic content the thick membrane cisternae of the cell cortex are designated as golgian-like cisternae. The cytochemical results point out a relationship between the alveolar sacs and the Golgi complex.

Real-time gene expression analysis in carp (Cyprinus carpio L.) skin: Inflammatory responses caused by the ectoparasite Ichthyophthirius multifiliis

“…The parasitic stage of the parasite invades the epidermis of the fish and forms a cavity enclosed by epithelial cells. The damage in the fish epithelium is caused by the feeding mechanism of the parasite, which is most likely mediated by a combination of mechanical and enzymatic actions [3,4]. Although a humoral immune response against I. multifiliis has been clearly demonstrated [5,6], it is likely that the innate part of the fish immune system contributes significantly to the achievement of a protective response [7].…”

Ultrastructural localization of phosphatases with cerium in a ciliated protozoan.

“…However, the functions of these cisternae arranged in a single layer beneath the cell membrane are unknown (17). In a previous paper we have reported AcPase, TPPase and nucleoside diphosphatase activities in the alveolar sacs of I. multifiliis (12). These former results obtained by lead methods have now been confirmed by cerium techniques.…”

“…In other ciliates the endoplasmic reticulum and transition vesicles can be observed close to the golgian cisternae (1,5), but in I. multfihiis this relationship is not evident in many AcPase and TPPase positive cisternae that have been considered as golgian-like because of their morphology and enzymatic content (12).…”

“…The ultrastructure, pathology and life cycle of I. multifiliis have been the subjects of many papers (3, 6, 7,16), but only recently cytochemical techniques were employed in the study of this important fish parasite (11,12). Following those cytochemical studies cerium-based techniques were used in an attempt to improve the results of phosphatases detection by lead techniques.…”

“…The former results of acid phosphatase and thiamine pyrophosphatase detection by lead methods in I. mult filiis (11,12) are compared with the results obtained with cerium.…”