Single-cell RNA sequencing reveals gonadal dynamic changes during sex differentiation in hermaphroditic protogynous orange-spotted grouper (<i>Epinephelus coioides</i>)

Abstract

A: Gonadal histological morphology of orange-spotted grouper by hematoxylin-eosin (H&E) staining at 80 dph, 120 dph, and 180 dph. Enlarged figure shows higher magnification view of boxed area in previous figure. Black arrows represent blood vessels. Dph, day post-hatching. Scale bar: 50 μm. B: Overview of whole experiment. Fish were dissected from the cloacal aperture, with gonads and connective tissue then removed. Gonads were dissociated into single-cell suspensions for sequencing ( n =2) and analysis. C: Visualization of 15 cell types among six samples in UMAP plot. Colors mark 25 distinct clusters identified by unsupervised clustering and characterized with differential gene expression and gene set enrichment analyses. Each dot represents a cell. D: Cluster 4 subcluster UMAP plot, with cells color-coded by computationally determined cell subtypes. E: Gene expression plots of selected genes. Cells expressing indicated genes are in blue, and relative intensity indicates relative expression levels. F: Histogram of distribution of cell clusters in three developmental stages. G: Schematic representation of potential differentiation of cluster 4 subclusters from 80 dph to 180 dph. FC, follicle cell; pFC, pre-follicle cell.