Transition of basic protein during spermatogenesis of Fenneropenaeus chinensis (Osbeck, 1765)

Abstract

According to the ultrastructural characteristic observation of the developing male germ cells, spermatogenesis of the crustacean shrimp, Fenneropenaeus chinensis, is classified into spermatogonia, primary spermatocytes, secondary spermatocyte, four stages of spermatids, and mature sperm. The basic protein transition during its spermatogenesis is studied by transmission electron microscopy of ammoniacal silver reaction and immunoelectron microscopical distribution of acetylated histone H4. The results show that basic protein synthesized in cytoplasm of spermatogonia is transferred into the nucleus with deposition on new duplicated DNA. In the spermatocyte stage, some nuclear basic protein combined with RNP is transferred into the cytoplasm and is involved in forming the cytoplasmic vesicle clumps. In the early spermatid, most of the basic protein synthesized in the new spermatid cytoplasm is transferred into the nucleus, and the chromatin condensed gradually, and the rest is shifted into the pre-acrosomal vacuole. In the middle spermatid, the nuclear basic protein linked with DNA is acetylated and transferred into the proacrosomal vacuole and assembled into the acrosomal blastema. At the late spermatid, almost all of the basic protein in the nucleus has been removed into the acrosome. During the stage from late spermatid to mature sperm, some de novo basic proteins synthesized in the cytoplasm belt transfer into the nucleus without a membrane and almost all deposit in the periphery to form a supercoating. The remnant histone H4 accompanied by chromatin fibers is acetylated in the center of the nucleus, leading to relaxed DNA and activated genes making the nucleus non-condensed.

Three‐dimensional reconstruction of black tiger prawn (Penaeus monodon) spermatozoa using serial block‐face scanning electron microscopy

“…The existence of mitochondria‐like structures in penaeid spermatozoa has been confirmed in the cytoplasm of P. monodon , P. kerathurus , P. japonicus , F. paulensis , and F. chinensis (Medina et al, ; Ge et al, ; Braga et al, ). The change of mitochondrial morphology, especially the degeneration and disappearance of cristae, is presumably associated with the corresponding immobile character of the mature sperm cell (Tudge, ).…”

“…Sandwiched between the nuclear region and the acrosomal vesicle, the shape and inner materials of the subacrosomal area vary greatly in the different penaeid species. P. monodon , F. chinensis , L. vannamei , L. stylirostris , L. occidentalis , and P. kerathurus all have a concave subacrosomal area, whereas P. japonicus and F. paulensis possess a flat structure (Medina et al, ; Alfaro et al, ; Ge et al, ; Braga et al, ). Our study showed the subacrosomal area of P. monodon spermatozoa in the spermatophore appeared less electron‐lucent and flocculent than the capacitated spermatozoa in the thelycum, as noted by Pongtippatee et al ().…”

Ultrastructure of spermiogenesis and the distribution of spermatozoal nuclear histones in the Japanese mantis shrimp, Oratosquilla oratoria (Crustacea: Stomatopoda)

“…Kurtz et al (2009) and Li et al (2017) found that histone H3 in the sperm nuclei of the brachyuran crab is acetylated. The noncondensed nucleus may be caused by remanent acetylated histone H4 accompanied by chromatin fibers in Fenneropenaeus chinensis (Ge et al, 2011). Additionally, histone H3 methylation is important for sperm functioning and embryonic development, and histone H3 lysine 4 trimethylation (H3K4me3) plays a critical role in chromatin condensation and mitotic division during male gametogenesis (Pinon, Yao, Dong, & Shen, 2017;Song et al, 2011;Spina et al, 2014;Verma et al, 2015).…”

“…Earlier research indicated that the chromatin of crustacean sperm is not highly packaged due to a lack of basic proteins. However, several studies on Cancer pagurus (Kurtz, Martínez-Soler, Ausió, & Chiva, 2008), Cancer magister (Kurtz et al, 2008), Maja brachydactyla (Kurtz, Ausió, & Chiva, 2009), Portunus pelagicus (Stewart et al, 2010), Fenneropenaeus chinensis (Ge et al, 2011), Astacus (Niksirat, James, Andersson, Kouba, & Kozák, 2015), and Eriocheir sinensis (Li et al, 2017;Wu et al, 2016;Wu, Kang, Guo, Mu, & Zhang, 2015;Zhang et al, 2016) have indicated that these decapod spermatozoal nuclei have a common characteristic, namely, that they contain parts of histones and some histone modifications. Because of the diversity of crustacean species, an integrated understanding of the origin of this special decapod sperm nuclei has not been achieved.…”

Spermatogenesis and sperm assessment in the Black Tiger Prawn, Penaeus monodon

“…Fenneropenaeus chinensis (Ge et al, 2011) and Litopenaeus vannamei (Alfaro-Montoya et al, 2017). There has been no specific study on the complete spermatogenesis of P. monodon.…”