SREL Reprint #2025

Quantitative comparisons of the morphology and ultrastructure of erythrocyte nuclei from seven freshwater fish species

Charles H. Jagoe1 and Dave A. Welter2

1The University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
2Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, GA 30912, USA

Abstract: Chromosome number and genomic DNA content vary widely among fish species, and ploidy can vary within species. This suggests that size, shape and morphological features of cell nuclei may also vary. Nucleated erythrocytes of fish are an easily sampled, homogenous population of differentiated cells ideal for inter- and intra-species comparisons. We collected blood samples from largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), chain pickerel (Esox niger), yellow perch (Perca flavescens), mosquitofish (Gambusia holbrooki), redeye bass (Micropterus coosae), and rainbow trout (Oncorhynchus mykiss), and removed cytoplasm and nuclear membranes from blood cells. Individual nuclei were examined and measured using scanning electron microscopy and a computerized image analysis system, and inter- and intra-species differences evaluated by nested analysis of variance. Nuclear size and shape varied significantly among species. Isolated nuclei had conspicuous apertures or holes, and the number and size of these holes also varied significantly among species. Variations in nuclear size and structure within species were small compared to interspecies differences. Little is known of the ultrastructure of erythrocyte nuclei in lower vertebrates, but their structure differs considerably from other vertebrate, non-erythroid cells, suggesting the organization of their DNA and associated proteins may be different.

SREL Reprint #2025

Jagoe, C.H. and D. Welter. 1995. Quantitiative comparisons of the morphology and ultrastructure of erythrocyte nuclei from seven freshwater fish species. Canadian Journal of Zoology 73:1951-1959.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).