FIGURE SUMMARY
Title

Morpho-histological and Transcriptome Analysis Reveal the Unreduced Sperm Formation Mechanism in cdk1-Depletion Zebrafish

Authors
Zhang, Y., Li, R., Li, H., Huang, Y., Mei, Y., Zheng, Y., Guo, Y., Zhou, Z., Yong, Z., Zhao, Y., Dong, W., Gao, J., Cao, X.
Source
Full text @ Mar. Biotechnol.

cdk1 mutation leads to delayed development of testes in zebrafish. A The expression levels of cdk1 gene in different tissues of zebrafish. B Immunofluorescence analysis of Cdk1 localization in zebrafish testes. Scale bar = 10 µm or 5 µm. C Schematic diagram of CRISPR/Cas9 target sites for zebrafish cdk1 gene knockout. D A representative chromatogram of PCR-product sequencing in cdk1+/−. E Anatomical examination of the testes of WT and cdk1+/− zebrafish. Scale bar = 0.5 cm. F Body weight analysis of male WT and cdk1+/− zebrafish (n = 6). G GSI of male WT and cdk1+/− zebrafish (n = 6). H Histological observations of the testes of WT and cdk1+/− zebrafish. Scale bar = 10 µm or 1 µm. I The proportions of testis cells at different stages in WT and cdk1+/− zebrafish, evaluated based on the area ratio. cdk1, cyclin-dependent kinase 1; DAPI, 4,6-diamidino-2-phenylindole; SG, spermatogonia; SC, spermatocytes; SZ, spermatozoa; WT, wild-type zebrafish; cdk1+/−, zebrafish with heterozygous mutation of Cdk1; GSI, gonadosomatic indexes; different lowercase letters indicated significant differences (p < 0.05). *p < 0.05 was considered significant, while **p < 0.01 indicated a very significant difference

Analysis of sperm quality of WT and cdk1+/− zebrafish. A Sperm dynamic trajectory curves of WT and cdk1+/− zebrafish. Scale bar = 20 µm. B, C, D, E, F Evaluation of sperm motility. BCF, beat cross frequency; VAP, velocity average path; VSL, straight-line velocity; VCL, curvilinear velocity; LIN, linearity. WT, wild-type zebrafish; cdk1, cyclin-dependent kinase 1; cdk1+/−, zebrafish with heterozygous mutation of cdk1. *p < 0.05 was considered significant

cdk1 mutation leads to the production of polyploid and aneuploid zebrafish. A Chromosome spreads of cells of 24-hpf embryos of WT zebrafish. Scale bar = 5 µm. B Chromosome spreads of cells of 24-hpf embryos of WT ♀ × cdk1+/− ♂ zebrafish. Scale bar = 5 µm. C Ploidy detection of 24-hpf embryos of WT zebrafish. D Ploidy detection of 24-hpf embryos of WT ♀ × cdk1+/− ♂ zebrafish. cdk1, cyclin-dependent kinase 1; WT, wild-type zebrafish; cdk1+/−, zebrafish with heterozygous mutation of cdk1; hpf, hour post fertilization; n, number; 2N, diploid; 3N, triploid; 3N + , hypertriploid; 5N, pentaploid; ♀, female; ♂, male

PHENOTYPE:
Fish:
Observed In:
Stage: Prim-5

Bivalent chromosome analysis and sperm ploidy detection of WT and cdk1+/− zebrafish. A Ploidy detection of sperms of WT zebrafish. B Ploidy detection of sperms of cdk1+/− zebrafish. C Assessment of sperm morphology of WT and cdk1+/− zebrafish. The black arrows indicated large-head sperms. Scale bar = 5 µm. D Measurement of sperm head of WT and cdk1+/− zebrafish. E Observations on the bivalent chromosome of WT zebrafish. Scale bar = 5 µm. F Observations on the bivalent chromosome of cdk1+/− zebrafish. Scale bar = 5 µm. cdk1, cyclin-dependent kinase 1; WT, wild-type zebrafish; cdk1+/−, zebrafish with heterozygous mutation of cdk1; n, number; 1N, haploid; 2N, diploid; 3N, triploid; 4N, tetraploid. ***p < 0.001 indicated an extremely significant difference

PHENOTYPE:
Fish:
Observed In:
Stage: Adult

Electron microscopic observation of WT and cdk1+/− zebrafish spermatogonia and transcriptome analysis of testis. A The ultrastructures of spermatogonia from WT and cdk1+/− zebrafish. Scale bar = 2 µm. B Measurement of spermatogonia diameter of WT and cdk1+/− zebrafish. C The numbers of up-regulated and down-regulated DEGs of cdk1+/− vs WT zebrafish. D KEGG pathway enrichment analysis of DEGs between WT and cdk1+/− zebrafish. E Expression heatmap of cell cycle-related genes. F Network interaction analysis of DEGs corresponding proteins. G Expression levels of Smc1a, Wee1, Smc3, Espl1, and Pp1 protein in the testes of WT and cdk1+/− zebrafish. cdk1, cyclin-dependent kinase 1; WT, wild-type zebrafish; cdk1+/−, zebrafish with heterozygous mutation of cdk1; DEGs, differentially expressed genes; KEGG, Kyoto Encyclopedia of Genes and Genomes

PHENOTYPE:
Fish:
Observed In:
Stage: Adult

Patterns of DNA replication-related genes expression and unreduced sperm production in the early testis of cdk1+/− zebrafish. A Expression heatmap of DNA replication-related genes. B Network interaction analysis of DNA replication-related DEGs corresponding proteins. C Pattern diagram of unreduced gametes production in cdk1+/− zebrafish. cdk1, cyclin-dependent kinase 1; WT, wild-type zebrafish; cdk1+/−, zebrafish with heterozygous mutation of cdk1; DEGs, differentially expressed genes

Acknowledgments
This image is the copyrighted work of the attributed author or publisher, and ZFIN has permission only to display this image to its users. Additional permissions should be obtained from the applicable author or publisher of the image. Full text @ Mar. Biotechnol.