{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,12]],"date-time":"2026-04-12T14:08:16Z","timestamp":1776002896821,"version":"3.50.1"},"reference-count":45,"publisher":"PeerJ","license":[{"start":{"date-parts":[[2017,10,12]],"date-time":"2017-10-12T00:00:00Z","timestamp":1507766400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"JSPS Research Fellow","award":["17J01156"],"award-info":[{"award-number":["17J01156"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Although spermatozoa with normal morphology are assumed to have uniform fertilization ability, recent data show that even normal spermatozoa have considerable variation in their head shape which is associated with differences in fertilization ability. Appropriate quantitative indicators for good sperm morphology, however, remain unidentified.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Therefore, in an effort to identify such an indicator, we compared the nuclear contour of normal mouse spermatozoa by quantitative multivariate analysis using elliptic Fourier descriptors combined with principal component analysis. The spermatozoa were obtained from different strains and collection sites which have been shown to be associated with different fertilization abilities.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We found that the head was 5.7% thinner in spermatozoa from the B6D2F1 (BDF1) strain, known to have a higher fertilization rate, than in those from the C57BL\/6N (B6N) strain, which has a lower fertilization rate. Moreover, zona-penetrated spermatozoa in the perivitelline space consistently had 5.4% thinner heads than those isolated from the epididymis before ejaculation. The aspect ratio, which represents the sperm head thinness, uniquely distinguished these sperm populations, confirming its validity as a morphological indicator.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>Because aspect ratio has also been shown to characterize human spermatozoa, this unique morphometric indicator might be applicable to compare normal spermatozoa among multiple patients, which will greatly facilitate and enhance current reproductive technologies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.7717\/peerj.3913","type":"journal-article","created":{"date-parts":[[2017,10,12]],"date-time":"2017-10-12T04:09:27Z","timestamp":1507781367000},"page":"e3913","source":"Crossref","is-referenced-by-count":16,"title":["Mouse spermatozoa with higher fertilization rates have thinner nuclei"],"prefix":"10.7717","volume":"5","author":[{"given":"Daisuke","family":"Mashiko","sequence":"first","affiliation":[{"name":"Department of Biological Sciences, Osaka University, Toyonaka, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masahito","family":"Ikawa","sequence":"additional","affiliation":[{"name":"Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Koichi","family":"Fujimoto","sequence":"additional","affiliation":[{"name":"Department of Biological Sciences, Osaka University, Toyonaka, Osaka, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"4443","published-online":{"date-parts":[[2017,10,12]]},"reference":[{"key":"10.7717\/peerj.3913\/ref-1","doi-asserted-by":"publisher","first-page":"137","DOI":"10.1002\/jez.1401880203","article-title":"The occurrence and possible functional significance of -SS- crosslinks in sperm heads, with particular reference to eutherian mammals","volume":"188","author":"Bedford","year":"1974","journal-title":"Experimental Zoology"},{"issue":"1","key":"10.7717\/peerj.3913\/ref-2","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1016\/j.anireprosci.2004.04.019","article-title":"A comparison of morphometric characteristics of sperm from fertile Bos taurus and Bos indicus bulls in Brazil","volume":"85","author":"Beletti","year":"2005","journal-title":"Animal Reproduction Science"},{"issue":"1","key":"10.7717\/peerj.3913\/ref-3","doi-asserted-by":"publisher","first-page":"10","DOI":"10.1038\/ng0501-10","article-title":"Packaging paternal chromosomes with protamine","volume":"28","author":"Braun","year":"2001","journal-title":"Nature Genetics"},{"issue":"3","key":"10.7717\/peerj.3913\/ref-4","doi-asserted-by":"publisher","first-page":"381","DOI":"10.1016\/0027-5107(74)90112-2","article-title":"Abnormalities in the shape of murine sperm after acute testicular X-irradiation","volume":"23","author":"Bruce","year":"1974","journal-title":"Mutation Research\/Fundamental and Molecular Mechanisms of Mutagenesis"},{"issue":"1","key":"10.7717\/peerj.3913\/ref-5","doi-asserted-by":"publisher","first-page":"73","DOI":"10.1093\/humupd\/4.1.73","article-title":"Predictive value of normal sperm morphology: a structured literature review","volume":"4","author":"Coetzee","year":"1998","journal-title":"Human Reproduction Update"},{"key":"10.7717\/peerj.3913\/ref-6","doi-asserted-by":"publisher","first-page":"297","DOI":"10.1530\/jrf.0.0390297","article-title":"Spermatozoa: the probable selection of a small population by the genital tract of the female rabbit","volume":"39","author":"Cohen","year":"1974","journal-title":"Journal of Reproduction and Fertility"},{"issue":"3","key":"10.7717\/peerj.3913\/ref-7","doi-asserted-by":"publisher","first-page":"211","DOI":"10.1111\/j.1439-0272.1988.tb01058.x","article-title":"Correlation between defects in chromatin condensation of human spermatozoa stained by aniline blue and semen characteristics","volume":"20","author":"Dadoune","year":"1988","journal-title":"Andrologia"},{"key":"10.7717\/peerj.3913\/ref-8","doi-asserted-by":"publisher","first-page":"54","DOI":"10.2307\/1538405","article-title":"Studies on the acrosome. I. Reaction to egg-water and other stimuli","volume":"103","author":"Dan","year":"1952","journal-title":"Biological Bulletin"},{"issue":"5","key":"10.7717\/peerj.3913\/ref-9","doi-asserted-by":"publisher","first-page":"1292","DOI":"10.1093\/humrep\/17.5.1292","article-title":"Polyploidy in large-headed sperm: FISH study of three cases","volume":"17","author":"Devillard","year":"2002","journal-title":"Human Reproduction"},{"issue":"1","key":"10.7717\/peerj.3913\/ref-10","doi-asserted-by":"publisher","first-page":"139","DOI":"10.1093\/oxfordjournals.humrep.a019007","article-title":"Sperm morphology assessment using strict criteria and male fertility under in-vivo conditions of conception","volume":"11","author":"Eggert-Kruse","year":"1996","journal-title":"Human Reproduction"},{"key":"10.7717\/peerj.3913\/ref-11","doi-asserted-by":"publisher","first-page":"337","DOI":"10.1530\/jrf.0.0620337","article-title":"Fertilization following mixed insemination with \u2018cervix-selected\u2019 and \u2018unselected\u2019 spermatozoa in the rabbit","volume":"62","author":"Fischer","year":"1981","journal-title":"Journal of Reproduction and Fertility"},{"key":"10.7717\/peerj.3913\/ref-12","doi-asserted-by":"publisher","first-page":"841","DOI":"10.1016\/S0015-0282(16)42738-X","article-title":"Morphology of postcoital spermatozoa in the cervical secretion and its clinical significance","volume":"28","author":"Fredricsson","year":"1977","journal-title":"Fertility and Sterility"},{"issue":"4","key":"10.7717\/peerj.3913\/ref-13","doi-asserted-by":"publisher","first-page":"830","DOI":"10.1093\/humrep\/15.4.830","article-title":"Study of apoptotic DNA fragmentation in human spermatozoa","volume":"15","author":"Gandini","year":"2000","journal-title":"Human Reproduction"},{"issue":"8","key":"10.7717\/peerj.3913\/ref-14","doi-asserted-by":"publisher","first-page":"1643","DOI":"10.1093\/humrep\/deg306","article-title":"Automated semen analysis: \u2018zona pellucida preferred\u2019sperm morphometry and straight-line velocity are related to pregnancy rate in subfertile couples","volume":"18","author":"Garrett","year":"2003","journal-title":"Human Reproduction"},{"issue":"50","key":"10.7717\/peerj.3913\/ref-15","doi-asserted-by":"publisher","first-page":"20008","DOI":"10.1073\/pnas.1116965108","article-title":"Acrosome-reacted mouse spermatozoa recovered from the perivitelline space can fertilize other eggs","volume":"108","author":"Inoue","year":"2011","journal-title":"Proceedings of the National Academy of Sciences of the United States of America"},{"issue":"suppl 1","key":"10.7717\/peerj.3913\/ref-16","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1093\/humrep\/13.suppl_1.33","article-title":"Epidemiology and aetiology of male infertility","volume":"13","author":"Irvine","year":"1998","journal-title":"Human Reproduction"},{"key":"10.7717\/peerj.3913\/ref-17","doi-asserted-by":"publisher","first-page":"384","DOI":"10.1093\/jhered\/93.5.384","article-title":"SHAPE: a computer program package for quantitative evaluation of biological shapes based on elliptic Fourier descriptors","volume":"93","author":"Iwata","year":"2002","journal-title":"Journal of Heredity"},{"issue":"5","key":"10.7717\/peerj.3913\/ref-18","doi-asserted-by":"publisher","first-page":"379","DOI":"10.1111\/j.1365-2605.1988.tb01011.x","article-title":"Male factors and the likelihood of pregnancy in infertile couples. I. Study of sperm characteristics","volume":"11","author":"Jouannet","year":"1988","journal-title":"International Journal of Andrology"},{"issue":"1","key":"10.7717\/peerj.3913\/ref-19","doi-asserted-by":"publisher","first-page":"81","DOI":"10.1530\/jrf.0.0380081","article-title":"The passage of abnormal spermatozoa through the uterotubal junction of the mouse","volume":"38","author":"Krzanowska","year":"1974","journal-title":"Journal of Reproduction and Fertility"},{"key":"10.7717\/peerj.3913\/ref-20","doi-asserted-by":"publisher","first-page":"236","DOI":"10.1016\/0146-664X(82)90034-X","article-title":"Elliptic Fourier features of a closed contour","volume":"18","author":"Kuhl","year":"1982","journal-title":"Computer Graphics and Image Processing"},{"issue":"9","key":"10.7717\/peerj.3913\/ref-21","doi-asserted-by":"publisher","first-page":"1942","DOI":"10.1093\/oxfordjournals.humrep.a019521","article-title":"Andrology: analysis of chromosome constitution of human spermatozoa with normal and aberrant head morphologies after injection into mouse oocytes","volume":"11","author":"Lee","year":"1996","journal-title":"Human Reproduction"},{"issue":"3","key":"10.7717\/peerj.3913\/ref-22","doi-asserted-by":"publisher","first-page":"465","DOI":"10.1016\/S0015-0282(16)55247-9","article-title":"Tests of human sperm function and fertilization in vitro","volume":"58","author":"Liu","year":"1992","journal-title":"Fertility and Sterility"},{"issue":"11","key":"10.7717\/peerj.3913\/ref-23","doi-asserted-by":"publisher","first-page":"2382","DOI":"10.1093\/humrep\/deg456","article-title":"Low proportions of sperm can bind to the zona pellucida of human oocytes","volume":"18","author":"Liu","year":"2003","journal-title":"Human Reproduction"},{"issue":"2","key":"10.7717\/peerj.3913\/ref-24","doi-asserted-by":"publisher","first-page":"535","DOI":"10.1095\/biolreprod.102.015149","article-title":"A comparison of the frequency of sperm chromosome abnormalities in men with mild, moderate, and severe oligozoospermia","volume":"69","author":"Martin","year":"2003","journal-title":"Biology of Reproduction"},{"issue":"4","key":"10.7717\/peerj.3913\/ref-25","doi-asserted-by":"publisher","first-page":"346","DOI":"10.1002\/mrd.1080300409","article-title":"Sperm selection capacity of the human zona pellucida","volume":"30","author":"Menkveld","year":"1991","journal-title":"Molecular Reproduction and Development"},{"issue":"5","key":"10.7717\/peerj.3913\/ref-26","doi-asserted-by":"publisher","first-page":"586","DOI":"10.1093\/oxfordjournals.humrep.a137150","article-title":"The evaluation of morphological characteristics of human spermatozoa according to stricter criteria","volume":"5","author":"Menkveld","year":"1990","journal-title":"Human Reproduction"},{"issue":"3","key":"10.7717\/peerj.3913\/ref-27","doi-asserted-by":"publisher","first-page":"959","DOI":"10.1095\/biolreprod.104.028647","article-title":"Selective passage through the uterotubal junction of sperm from a mixed population produced by chimeras of calmegin-knockout and wild-type male mice","volume":"71","author":"Nakanishi","year":"2004","journal-title":"Biology of Reproduction"},{"key":"10.7717\/peerj.3913\/ref-28","doi-asserted-by":"publisher","first-page":"119","DOI":"10.1002\/mrd.1120100102","article-title":"The transport of morphologically abnormal sperm in the female reproductive tract of mice","volume":"10","author":"Nestor","year":"1984","journal-title":"Gamete Research"},{"key":"10.7717\/peerj.3913\/ref-29","doi-asserted-by":"publisher","first-page":"185","DOI":"10.1534\/genetics.106.062976","article-title":"Disruption of genetic interaction between two autosomal regions and the X chromosome causes reproductive isolation between mouse strains derived from different subspecies","volume":"175","author":"Oka","year":"2007","journal-title":"Genetics"},{"key":"10.7717\/peerj.3913\/ref-30","doi-asserted-by":"crossref","first-page":"584","DOI":"10.1002\/j.1939-4640.2001.tb02218.x","article-title":"Measurement of sperm nuclear shape using Fourier harmonic amplitudes","volume":"22","author":"Ostermeier","year":"2001","journal-title":"Journal of Andrology"},{"issue":"285\u2013296","key":"10.7717\/peerj.3913\/ref-31","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1109\/TSMC.1979.4310076","article-title":"A threshold selection method from gray-level histograms","volume":"11","author":"Otsu","year":"1975","journal-title":"Automatica"},{"issue":"8810","key":"10.7717\/peerj.3913\/ref-32","doi-asserted-by":"publisher","first-page":"17","DOI":"10.1016\/0140-6736(92)92425-F","article-title":"Pregnancies after intracytoplasmic injection of single spermatozoon into an oocyte","volume":"340","author":"Palermo","year":"1992","journal-title":"The Lancet"},{"issue":"s4","key":"10.7717\/peerj.3913\/ref-33","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1111\/rda.12404","article-title":"Understanding sperm heterogeneity: biological and practical implications","volume":"49","author":"Ram\u00f3n","year":"2014","journal-title":"Reproduction in Domestic Animals"},{"issue":"1","key":"10.7717\/peerj.3913\/ref-34","doi-asserted-by":"publisher","first-page":"50","DOI":"10.1016\/j.anireprosci.2009.12.007","article-title":"Evaluation of shape variability of stallion sperm heads by means of image analysis and Fourier descriptors","volume":"119","author":"Severa","year":"2010","journal-title":"Animal Reproduction Science"},{"key":"10.7717\/peerj.3913\/ref-35","doi-asserted-by":"publisher","first-page":"237","DOI":"10.1530\/jrf.0.0660237","article-title":"In-vitro fertilization in the mouse and the relevance of different sperm\/egg concentrations and volumes","volume":"66","author":"Siddiquey","year":"1982","journal-title":"Journal of Reproduction and Fertility"},{"issue":"6","key":"10.7717\/peerj.3913\/ref-36","doi-asserted-by":"publisher","first-page":"1774","DOI":"10.1095\/biolreprod63.6.1774","article-title":"In vitro fertilization with cryopreserved inbred mouse sperm","volume":"63","author":"Sztein","year":"2000","journal-title":"Biology of Reproduction"},{"issue":"3","key":"10.7717\/peerj.3913\/ref-37","doi-asserted-by":"publisher","first-page":"143","DOI":"10.1111\/j.1439-0272.1995.tb01085.x","article-title":"Value of sperm morphology assessed by strict criteria for prediction of the outcome of artificial (intrauterine) insemination","volume":"27","author":"Toner","year":"1995","journal-title":"Andrologia"},{"issue":"2","key":"10.7717\/peerj.3913\/ref-38","doi-asserted-by":"publisher","first-page":"901","DOI":"10.1534\/genetics.166.2.901","article-title":"A new deletion of the mouse Y chromosome long arm associated with the loss of Ssty expression, abnormal sperm development and sterility","volume":"166","author":"Tour\u00e9","year":"2004","journal-title":"Genetics"},{"key":"10.7717\/peerj.3913\/ref-39","doi-asserted-by":"publisher","first-page":"147","DOI":"10.1262\/jrd1955.16.147","article-title":"Studies on the fertilization of mouse eggs in vitro","volume":"16","author":"Toyoda","year":"1971","journal-title":"Japanese Journal of Animal Reproduction"},{"issue":"6","key":"10.7717\/peerj.3913\/ref-40","doi-asserted-by":"publisher","first-page":"1573","DOI":"10.1016\/j.fertnstert.2013.01.100","article-title":"Evaluation of sperm head shape at high magnification revealed correlation of sperm DNA fragmentation with aberrant head ellipticity and angularity","volume":"99","author":"Utsuno","year":"2013","journal-title":"Fertility and Sterility"},{"issue":"5","key":"10.7717\/peerj.3913\/ref-41","doi-asserted-by":"publisher","first-page":"495","DOI":"10.1093\/humupd\/7.5.495","article-title":"Predictive value of normal sperm morphology in intrauterine insemination (IUI): a structured literature review","volume":"7","author":"Van Waart","year":"2001","journal-title":"Human Reproduction Update"},{"issue":"4","key":"10.7717\/peerj.3913\/ref-42","first-page":"186","article-title":"Relation between morphological defects in human spermatozoa and spontaneous abortions in patients undergoing ICSI","volume":"102","author":"Vilyana","year":"2017","journal-title":"Annuaire De L\u2019Universit\u00e9 De Sofia \u201cSt. Kliment Ohridski\u201d Faculte De Biologie"},{"issue":"2","key":"10.7717\/peerj.3913\/ref-43","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1016\/0165-7992(91)90113-I","article-title":"Effects of selenium deficiency on sperm morphology and spermatocyte chromosomes in mice","volume":"262","author":"Watanabe","year":"1991","journal-title":"Mutation Research Letters"},{"key":"10.7717\/peerj.3913\/ref-44","volume-title":"WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction","author":"World Health Organization (WHO)","year":"2010","edition":"5"},{"issue":"11","key":"10.7717\/peerj.3913\/ref-45","doi-asserted-by":"publisher","first-page":"4425","DOI":"10.1073\/pnas.72.11.4425","article-title":"Chemical induction of sperm abnormalities in mice","volume":"72","author":"Wyrobek","year":"1975","journal-title":"Proceedings of the National Academy of Sciences of the United States of America"}],"container-title":["PeerJ"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/peerj.com\/articles\/3913.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/3913.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/3913.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/3913.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,27]],"date-time":"2024-06-27T14:07:30Z","timestamp":1719497250000},"score":1,"resource":{"primary":{"URL":"https:\/\/peerj.com\/articles\/3913"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,10,12]]},"references-count":45,"alternative-id":["10.7717\/peerj.3913"],"URL":"https:\/\/doi.org\/10.7717\/peerj.3913","archive":["CLOCKSS","LOCKSS","Portico"],"relation":{"has-review":[{"id-type":"doi","id":"10.7287\/peerj.3913v0.2\/reviews\/1","asserted-by":"object"},{"id-type":"doi","id":"10.7287\/peerj.3913v0.2\/reviews\/2","asserted-by":"object"},{"id-type":"doi","id":"10.7287\/peerj.3913v0.2\/reviews\/3","asserted-by":"object"},{"id-type":"doi","id":"10.7287\/peerj.3913v0.1\/reviews\/1","asserted-by":"object"},{"id-type":"doi","id":"10.7287\/peerj.3913v0.1\/reviews\/3","asserted-by":"object"},{"id-type":"doi","id":"10.7287\/peerj.3913v0.1\/reviews\/2","asserted-by":"object"}]},"ISSN":["2167-8359"],"issn-type":[{"value":"2167-8359","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,10,12]]},"article-number":"e3913"}}