Mouse spermatozoa with higher fertilization rates have thinner nuclei
Background 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 f...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
PeerJ Inc.
2017-10-01
|
| Series: | PeerJ |
| Subjects: | |
| Online Access: | https://peerj.com/articles/3913.pdf |
| _version_ | 1797423884707823616 |
|---|---|
| author | Daisuke Mashiko Masahito Ikawa Koichi Fujimoto |
| author_facet | Daisuke Mashiko Masahito Ikawa Koichi Fujimoto |
| author_sort | Daisuke Mashiko |
| collection | DOAJ |
| description | Background 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. Methods 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. Results 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. Discussion 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. |
| first_indexed | 2024-03-09T07:53:14Z |
| format | Article |
| id | doaj.art-0bae2ea053e14533b7f6914a25657767 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T07:53:14Z |
| publishDate | 2017-10-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-0bae2ea053e14533b7f6914a256577672023-12-03T01:20:27ZengPeerJ Inc.PeerJ2167-83592017-10-015e391310.7717/peerj.3913Mouse spermatozoa with higher fertilization rates have thinner nucleiDaisuke Mashiko0Masahito Ikawa1Koichi Fujimoto2Department of Biological Sciences, Osaka University, Toyonaka, Osaka, JapanResearch Institute for Microbial Diseases, Osaka University, Suita, Osaka, JapanDepartment of Biological Sciences, Osaka University, Toyonaka, Osaka, JapanBackground 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. Methods 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. Results 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. Discussion 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.https://peerj.com/articles/3913.pdfElliptic Fourier analysisSperm head shapeSpermImage analysisMorphometry |
| spellingShingle | Daisuke Mashiko Masahito Ikawa Koichi Fujimoto Mouse spermatozoa with higher fertilization rates have thinner nuclei PeerJ Elliptic Fourier analysis Sperm head shape Sperm Image analysis Morphometry |
| title | Mouse spermatozoa with higher fertilization rates have thinner nuclei |
| title_full | Mouse spermatozoa with higher fertilization rates have thinner nuclei |
| title_fullStr | Mouse spermatozoa with higher fertilization rates have thinner nuclei |
| title_full_unstemmed | Mouse spermatozoa with higher fertilization rates have thinner nuclei |
| title_short | Mouse spermatozoa with higher fertilization rates have thinner nuclei |
| title_sort | mouse spermatozoa with higher fertilization rates have thinner nuclei |
| topic | Elliptic Fourier analysis Sperm head shape Sperm Image analysis Morphometry |
| url | https://peerj.com/articles/3913.pdf |
| work_keys_str_mv | AT daisukemashiko mousespermatozoawithhigherfertilizationrateshavethinnernuclei AT masahitoikawa mousespermatozoawithhigherfertilizationrateshavethinnernuclei AT koichifujimoto mousespermatozoawithhigherfertilizationrateshavethinnernuclei |