Development of the Polar Filament‐Polaroplast Complex in a Microsporidian Parasite*

Abstract

SYNOPSIS. The development of the polar filament in a microsporidian parasite was studied in the electron microscope. The polar filament is a peculiar and complex organelle with intricate anatomical relationships to other structures in the mature spore. The characteristic ultrastructure of the formative and mature stages of the polar filament made it possible to trace its development and study the interactions among various organelles during its formation. In sporoblasts the polar filament develops sequentially from 3 different regions. The base of the filament appears first and is derived from a dense body. The anterior part of the filament is formed from electron dense material located in the perinuclear cisterna and in agranular endoplasmic reticulum. The base and the anterior part of the filament move toward each other and fuse. Subsequently, the posterior part of the filament develops from the posterior part of the Golgi complex. The polar sac and the polaroplast surrounding the anterior segment of the filament are formed from the anterior region of the Golgi complex.Index Key Words: Microsporidian parasite ; polar filament-polaroplast complex, development of; electron microscopy.T was difficult to study the polar filament under the light I microscope because of the small size, marked density, and refractivity of thr spore. "Unless optical apparatus and microscopic technique are improved, thr controversy regarding the structure of the microsporidian spores will continue" ( 1 1 ) .

Seasonal prevalence of the microsporidan, Glugea stephani (Hagenmuller), in winter flounder, Pseudopleuronectes americanus (Walbaum), from the New York‐New Jersey Lower Bay Complex

“…Olson & Pratt (1973); Olson (1976Olson ( , 1978 and Burns (1980) indicate that the infection fluctuates on a seasonal basis. Additionally, it was noted that several other researchers obtained their Glugea stephani samples during the summer and early autumn (Johnstone, 1901 ;Woodcock, 1904;Jensen & Wellings, 1972). Stunkard & Lux (1965) presented data which indicated that infection increased during the summer and peaked in the autumn.…”

The Microsporidian Polar Tube and Spore Wall

“…Weidner (1970) proposed that the central core of the polar tube arose from the Golgi-like saccules and the outer envelope from the endoplasmic reticulum. Jensen and Wellings (1972) suggested that the base of the polar tube was derived from transformed nuclear material, the anterior part of the tube from cisternae and endoplasmic reticulum, and the posterior part from the Golgi complex. Jensen and Wellings (1972) suggested that the base of the polar tube was derived from transformed nuclear material, the anterior part of the tube from cisternae and endoplasmic reticulum, and the posterior part from the Golgi complex.…”

“…Jensen and Wellings (1972) suggested that the base of the polar tube was derived from transformed nuclear material, the anterior part of the tube from cisternae and endoplasmic reticulum, and the posterior part from the Golgi complex. The polaroplast, polar sac, and posterior vacuole have similarly been reported to be derived from the Golgi (Sprague & Vernick 1969;Jensen & Wellings 1972); however, Lom and Corliss (1967) and Weidner (1970) provide data that suggest that the polaroplast instead is derived from the endoplasmic reticulum. Staining of the polar tube core, its outer sheath, and its originating vacuoles with nucleoside diphosphatase (NDPase), which is a marker for endoplasmic reticulum as well as cis-Golgi membrane, was reported .…”

The microsporidian polar tube: A highly specialised invasion organelle

“…However, staining of the polar filament core, its outer sheath and its originating vacuoles was also seen with nucleoside disphosphatase (NDPase), which is a marker for endoplasmic reticulum as well as cis-Golgi membrane (Takvorian and Cali, 1996). The polaroplast has also been reported to be derived from the Golgi Jensen and Wellings, 1972) and the endoplasmic reticulum (Lom and Corliss, 1967;Weidner, 1970).…”