Zinc is an essential trace element for spermatogenesis.
Zinc (Zn) plays important roles in various biological activities but there is little available information regarding its functions in spermatogenesis. In our current study, we further examined the role of Zn during spermatogenesis in the Japanese eel (Anguilla japonica). Human CG (hCG) was injected into the animals to induce spermatogenesis, after which the concentration of Zn in the testis increased in tandem with the progression of spermatogenesis. Staining of testicular cells with a Zn-specific fluorescent probe revealed that Zn accumulates in germ cells, particularly in the mitochondria of spermatogonia and spermatozoa. Using an in vitro testicular organ culture system for the Japanese eel, production of a Zn deficiency by chelation with N,N,N',N'-tetrakis (2-pyridylemethyl)ethylenediamine (TPEN) caused apoptosis of the germ cells. However, this cell death was rescued by the addition of Zn to the cultures. Furthermore, an induced deficiency of Zn by TPEN chelation was found to inhibit the germ cell proliferation induced by 11-ketotestosterone (KT), a fish specific androgen, 17alpha,20beta-dihydroxy-4-pregnen-3-one (DHP), the initiator of meiosis in fish, and estradiol-17beta (E2), an inducer of spermatogonial stem-cell renewal. We also investigated the effects of Zn deficiency on sperm motility and observed that TPEN treatment of eel sperm suppressed the rate and duration of their motility but that co-treatment with Zn blocked the effects of TPEN. Our present results thus suggest that Zn is an essential trace element for the maintenance of germ cells, the progression spermatogenesis, and the regulation of sperm motility.
Yamaguchi
Sonoko
S
Research Group for Reproductive Physiology, South Ehime Fisheries Research Center, Ehime University, Ainan, Ehime 798-4131, Japan.
Miura
Chiemi
C
Kikuchi
Kazuya
K
Celino
Fritzie T
FT
Agusa
Tetsuro
T
Tanabe
Shinsuke
S
Miura
Takeshi
T
D000811:Anguilla / Q000378:metabolism / Q000502:physiology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005029:Ethylenediamines / Q000494:pharmacology; D006801:Humans; D006908:Hydroxyprogesterones / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D008297:Male; D009924:Organ Culture Techniques; D012708:Sertoli Cells / Q000378:metabolism; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013087:Spermatids / Q000378:metabolism; D013090:Spermatocytes / Q000378:metabolism; D013091:Spermatogenesis / Q000187:drug effects / Q000502:physiology*; D013093:Spermatogonia / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism; D013739:Testosterone / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors; D014131:Trace Elements / Q000172:deficiency / Q000378:metabolism* / Q000494:pharmacology; D015032:Zinc / Q000172:deficiency / Q000378:metabolism* / Q000494:pharmacology
D002614:Chelating Agents; D006063:Chorionic Gonadotropin; D005029:Ethylenediamines; D006908:Hydroxyprogesterones; D014131:Trace Elements; C007433:17,20-dihydroxy-4-pregnen-3-one; D013739:Testosterone; D004958:Estradiol; D015032:Zinc; C003600:11-ketotestosterone; C044387:N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine