Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | World Health Organization (WHO)-Global Index Medicus |
|---|---|
| Author | Hunter, R. H. |
| Abstract | The process of incorporation and metamorphosis of the sperm head within the vitellus has been examined by phase-contrast microscopy in a large series of pig eggs exhibiting either normal monospermic fertilization or extensive polyspermy. This latter condition was induced in vivo after increasing the numbers of capacitated spermatozoa in the Fallopian tubes by pre-ovulatory surgical insemination. Attention was drawn in monospermic eggs to the initial fusion between the spermatozoon and vitelline surface which produced a characteristic constriction in the equatorial region of the head. Immediately following cytoplasmic contact with the sperm nucleus, an increase in size was detectable in this structure, remnants of the inner acrosomal membrane having apparently been displaced during incorporation. In fixed preparations of activated eggs, there was some evidence that the morphologically transformed sperm nucleus underwent a brief period of shrinkage before commencing pronuclear formation. The most striking feature of the polyspermic condition was the number of spermatozoa that had entered the vitellus (2 to greater than 80), and the formation of aggregates of sperm head chromatin in eggs penetrated by more than 20-30 spermatozoa; the heads of at least 8 or 9 spermatozoa could participate in the formation of such an aggregate. Various unusual configurations were noted during breakdown of the midpiece in polyspermic eggs, and degeneration was also a general feature of the cytoplasm in situations of excessive polyspermy. Aspects of the block to polyspermy are discussed, and it is inferred that highly polyspermic pig eggs can still exhibit a zona reaction. |
| File Format | HTM / HTML |
| ISSN | 14697580 |
| e-ISSN | 14697580 |
| Journal | Journal of Anatomy |
| Issue Number | Pt 1 |
| Volume Number | 122 |
| Language | English |
| Publisher | Wiley |
| Publisher Date | 1976-09-01 |
| Publisher Place | Great Britain (UK) |
| Access Restriction | Open |
| Subject Keyword | Discipline Anatomy Fertilization Sperm-ovum Interactions Animals Cell Membrane Cell Nucleus Chromatin Meiosis Ovum Cytology Sperm Agglutination Sperm Head Sperm Tail Swine Vitelline Membrane |
| Content Type | Text |
| Resource Type | Article |
| Subject | Anatomy Cell Biology Developmental Biology Histology Molecular Biology Ecology, Evolution, Behavior and Systematics |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|