[2] [2] GAN H, WEN L, LIAO S, et al. Dynamics of 5-hydroxymethylcytosine during mouse spermatogenesis［J］. Nature Communications, 2013, 4: 1995.

[3] [3] CORDEN J L. RNA polymerase II C-terminal domain: tethering transcription to transcript and template［J］. Chemical Reviews, 2013, 113(11): 423-8455.

[4] [4] ZHOU Y, ZHU L, SUN Y, et al. Localization of RNA Pol II CTD (S5) and transcriptome analysis of testis in diploid and tetraploid hybrids of red crucian carp (♀) × common carp (♂) ［J］. Frontiers in Genetics, 2021, 12: 717871.

[5] [5] EICK D, GEYER M. The RNA polymerase II carboxy-terminal domain (CTD) code［J］. Chemical Reviews, 2013, 113(11): 8456-8490.

[6] [6] SINGH S K, MAEDA K, EID M A, et al. GANP regulates recruitment of AID to immunoglobulin variable regions by modulating transcription and nucleosome occupancy［J］. Nature Communications, 2013, 4: 1830.

[11] [11] SRINIVASAN S, DORIGHI K M, TAMKUN J W. Drosophila kismet regulates histone H3 lysine 27 methylation and early elongation by RNA polymerase II［J］. PLOS Genetics, 2008, 4(10): e1000217.

[12] [12] ZHANG C, LI Q, ZHU L, et al. Abnormal meiosis in fertile and sterile triploid cyprinid fish［J］. Science China Life Sciences, 2021, 64(11): 1917-1028.

[13] [13] ZHANG H, SUN Y, ZHU S, et al. Localization of 5S rDNA analysis of homologous pairing in tetraploid hybrids of red crucian carp (♀)?×?common carp (♂)［J］. Journal of the World Aquaculture Society, 2021: 1-10.

[14] [14] WANG M, LIU X, CHANG G, et al. Single-cell RNA sequencing analysis reveals sequential cell fate transition during human spermatogenesis ［J］. Cell Stem Cell, 2018, 23(4): 599-614.

[16] [16] XU H Y, LI M Y, GUI J F, et al. Fish germ cells［J］. Science China Life Sciences, 2010, 53(4): 435-446.

[17] [17] WEIDINGER G, STEBLER J, SLANCHEV K, et al. dead end, a novel vertebrate germ plasm component, is required for zebrafish primordial germ cell migration and survival［J］. Current Biology, 2003, 13(16): 1429-1434.

[18] [18] LI M, HONG N, GUI J, et al. Medaka piwi is essential for primordial germ cell migration［J］. Current Molecular Medicine, 2012, 12(8): 1040-1049.

[19] [19] K?PRUNNER M, THISSE C, THISSE B, et al. A zebrafish nanos-related gene is essential for the development of primordial germ cells［J］. Genes & Development, 2001, 15(21): 2877-2885.

[20] [20] DOYLE O, CORDEN J L, MURPHY C, et al. The distribution of RNA polymerase II largest subunit (RPB1) in the Xenopus germinal vesicle［J］. Journal of Structural Biology, 2002, 140(1/3): 154-166.

[21] [21] WEI H J, WANG Q, DU J, et al. Unique subcellular distribution of RPB1 with a phosphorylated C-terminal domain (CTD) in mouse oocytes during meiotic division and its relationship with chromosome separation［J］. The Journal of Reproduction and Development, 2015, 61(6): 541-548.

[22] [22] HINTERMAIR C, HEIDEMANN M, KOCH F, et al. Threonine-4 of mammalian RNA polymerase II CTD is targeted by polo-like kinase 3 and required for transcriptional elongation［J］. The EMBO Journal, 2012, 31(12): 2784-2797.

[23] [23] DOTTERMUSCH-HEIDEL C, KLAUS E S, GONZALEZ N H, et al. H3K79 methylation directly precedes the histone-to-protamine transition in mammalian spermatids and is sensitive to bacterial infections［J］. Andrology, 2014, 2(5): 655-665.