Classification of the spermatogenic cycle, seasonal changes of seminiferoustubule morphology and estimation of the breeding season of the large Japanese field mouse(Apodemus speciosus) in Toyama and Aomori prefectures,Japan

Journal of Veterinary Medical Science

Masanori TAMAOKI³  Nobuyoshi NAKAJIMA³  Junji SHINDO⁴  Hiroko ISHINIWA³  Noriko AZUMA¹  Manabu ONUMA³  Tsukasa OKANO³  Yasushi YOKOHATA² 

[1] Graduate School of Fisheries Sciences, Hokkaido University, 3�?1�?1 Minato, Hakodate, Hokkaido 041�?8611, Japan;Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930�?8555, Japan;Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16�?2 Onogawa, Tsukuba, Ibaraki 305�?8506, Japan;Laboratory of Wildlife Science, School of Veterinary Medicine, Kitasato University, 23�?35�?1 Towada, Aomori 034�?8628, Japan

关键词: Apodemus speciosus;    histological observation;    seasonal change;    spermatogenesis;    testis;   

DOI  :  10.1292/jvms.14-0411

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(43)Cited-By(1)The large Japanese field mouse, Apodemus speciosus, is apotential indicator of environmental stress, but this function has not been confirmed byhistological studies. Since environmental stress affects the reproductive function ofmice, we determined the reproductive characteristics of this species at two locations:Toyama (36°35ʹN, 137°24ʹE) and Aomori (40°35ʹN, 140°57ʹE). Mice were captured duringMay–November (n=119) and July–November (n=146) at these locations, respectively. Weclassified the breeding season from the numbers of pregnant females and young, in additionto the spermatogenic cycle and seasonal changes in seminiferous tubule morphology ofmales. Testicular weight was measured, and seminiferous tubule morphology was examinedhistologically. Fourteen stages were found in the seminiferous epithelium cycle based onacrosome formation and spermatid head morphology. At both locations, the breeding seasonpeaked from late summer to early autumn and possibly in spring. Spermatogenic activity wasclassified into 4 periods from June to November: resting around June and October–November;resumptive around July; active around August; and degenerative around September. Duringthe resting period, the seminiferous tubules consisted of Sertoli cells, spermatogonia andspermatocytes. Spermatogenesis began during the resumptive period, and spermatids wereobserved. During the active period, active spermatogenesis and a broad lumen wereobserved. During the degenerative period, spermatogenesis ended, and Sertoli cells,spermatogonia, spermatocytes and degenerating exfoliated round spermatids were observed.This study provides scientific information about the testicular histopathologicalevaluations of the large Japanese field mouse for its use as an index species ofenvironmental pollution.

【 授权许可】

Unknown