| dc.contributor | Universidade Estadual Paulista (UNESP) | |
| dc.creator | La Fountain Jr., James | |
| dc.creator | Oldenbourg, Rudolf | |
| dc.date | 2016-10-26T17:48:23Z | |
| dc.date | 2016-10-26T17:48:23Z | |
| dc.date.accessioned | 2017-04-06T11:39:33Z | |
| dc.date.available | 2017-04-06T11:39:33Z | |
| dc.identifier | http://acervodigital.unesp.br/handle/unesp/361019 | |
| dc.identifier | http://objetoseducacionais2.mec.gov.br/handle/mec/10249 | |
| dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/957301 | |
| dc.description | Presents the events of meiosis II in two living spermatocytes obtained from the testis of a crane-fly larva are viewed in polarized light and recorded in this time-lapse sequence beginning at prophase II through telophase II to the near completion of cytokinesis following meiosis II.
Noteworthy features of meiosis in crane-fly spermatocytes:
a) The duration between nuclear envelope breakdown (NEB) and the onset of anaphase II lasts on average about 45 minutes.
b) Upon NEB, birefringent microtubules are assembled from the two polar centrosomes, and some of these attach to the kinetochores of dyad chromosomes.
c) Kinetochore fibers appear distinct due to their birefringence, which is readily detected with polarized light microscopy.
d) At metaphase, the spindle has a characteristic bi-cone shape, and its kinetochore fibers have striking bright birefringent contrast.
e) Anaphase A (kinetochore fibers shorten) is followed by anaphase B (spindle elongation) resulting in segregation of haploid chromosome sets to opposite poles of the cells.
f) Within a few hours of the completion of cytokinesis, the resultant spermatids begin to elongate as they begin the process of spermiogenesis that will result over the course of several days in formation of mature haploid spermatozoa | |
| dc.description | Componente Curricular::Educação Superior::Ciências Biológicas::Biologia Geral | |
| dc.publisher | The American Society for Cell Biology, ASBC Image & Video Library | |
| dc.relation | http://objetoseducacionais2.mec.gov.br/handle/mec/10240 | |
| dc.relation | Meiosis II Time Lapse Movie.mov | |
| dc.rights | You may use the Images only for research and educational purposes in an educational institution. Images may be stored on a network server, hard drive or removable media, but only while this Agreement remains in effect. All of the Images you use must be accompanied by a notice stating, "© [Date and Author's or Owner's Name]. All rights reserved. Reprinted under license from The American Society for Cell Biology." The notice shall appear with the Images or on a credits page. "Educational purposes" means (i) non-commercial instruction or curriculum based teaching by educators to students at nonprofit educational institutions, (ii) planned non-commercial study, investigation or research directed toward making a contribution to a field of knowledge, or (iii) presentation of research findings at non-commercial peer conferences, workshops or seminars, but in any event there must be express written permission from ASCB before an Image can be published. "Educational institutions" include K-12 schools, colleges and universities. Libraries, museums, hospitals, research institutes and other nonprofit organizations are considered educational institutions when they engage in nonprofit instructional, research or scholarly activities for educational purposes | |
| dc.subject | Meiosis | |
| dc.subject | Spermatocyte | |
| dc.subject | Cell | |
| dc.subject | Spermatozoa | |
| dc.subject | Educação Superior::Ciências Biológicas::Biologia Geral | |
| dc.title | Meiosis in a living crane fly spermatocyte [Meiosis II] | |
| dc.type | Videos | |
