Light and electron microscopic studies on the Y organ of the freshwater crab Travancoriana schirnerae

Abstract

The fine structure of the premoult Y organ in the freshwater crab Travancoriana schirnerae revealed elliptical epithelial gland cells with large, eccentric, multinucleolated nuclei and ample cytoplasm. The cytoplasm showed numerous polymorphic mitochondria with tubular cristae, highly anastomosed tubules and vesicles of smooth endoplasmic reticulum (SER), rich free ribosomes, small amounts of cisternae of rough endoplasmic reticulum (RER), microtubules and was devoid of Golgi complexes. Mitochondria were of two types the more abundant micromitochondria with electron dense matrix and the less abundant macromitochondria with moderately dense matrix. The tubular SER was particularly concentrated towards the basal region of the cell, intermingled with mitochondria and dense patches of free ribosomes while the vesicular SER lie close to the lateral plasma membrane. Large vesicles with flocculent substances, a few electron dense granules and multivesicular bodies could also be noticed in the gland cell cytoplasm. Aggregations of microvesicles which appeared close to the lateral plasma membrane, in association with dilated SER cisternae and microtubules, possibly suggest the intercellular exchange of substances. The plasma membrane beneath the basal lamina was composed of invaginations and the apical surface possessed numerous microvilli which serve to increase the surface area for metabolic exchange. Towards the apical region, the lateral plasma membrane of adjacent cells was linked by tight junctions. The presence of extraordinarily abundant tubular SER, high proportion of mitochondria with tubular cristae and rich free ribosomes could well be elucidated in favour of steroid production by the gland cells.

The light-oxygen effect in biological cells enhanced by highly localized surface plasmon-polaritons

“…The mitochondria due to its unique highest membrane structure packing per volume are ideal object for such study. This is due to the presence of cristae, the mitochondrial inner membrane structure, ranging in size from 100 to 500 nm 51–53 . Two cell types, a human cancer and non-cancerous animal, were chosen for our experiments, correspondently human colorectal cancer cell line HCT116 (ATCC CCL-247TM, Manassas, VA, USA) and the Chinese hamster ovary cell line CHO-K1 cells (ATCC CCL-61TM, Manassas, VA, USA).…”

Effect of 20-OH ecdysone and methyl farnesoate on histomorphology of the Y-organ during late intermoult and postmoult stages in the freshwater crab Travancoriana schirnerae Bott, 1969 (Crustacea: Gecarcinucidae)

“…Travancoriana schirnerae Bott, 1969 is an edible freshwater crab commonly distributed in the wetlands of Wayanad, Kerala, India. Previous studies on ultrastructure of the premoult YO of this species have shown numerous polymorphic mitochondria with tubular cristae, highly anastomosed tubules and vesicles of SER and abundant free ribosomes (Sudha Devi et al, 2015). Further studies on moult cyclerelated and destalked crab YO histology in the same species revealed cellular hypertrophy, cytoplasmic granulations and secretory vesicles (Smija and Sudha Devi, 2016).…”