In teleost, the structural characteristics of fertilized egg and egg envelope are very important for classification of genus or species. The structures of fertilized egg and egg envelope from Corydoras adolfoi and Corydoras sterbai, Callichthyidae, Siluriformes in teleost were examined by scanning and transmission electron microscopes to confirm whether these morphological structures have specificities of species and family or not. The fertilized eggs of C. adolfoi and C. sterbai were non-transparent, spherical, demersal, and strong adhesive. There were no structural differences between two species through the light microscope. The size of the fertilized eggs of C. adolfoi was 1.95 ± 0.03 mm (n = 20), and that of C. sterbai was 1.92 ± 0.03 mm (n = 20). The perivitelline space was almost not developed in both species. In both species, the adhesive protuberances structures were on the outer surface of egg envelope. And fibrous structures were specially located at attachment part of spawning bed. And the egg envelope consisted of two layers, an inner lamellae layer and an outer strong adhesive layer with high electron dense protuberances structures in cross section. Consequentially, the fertilized eggs, outer surface on the egg envelope and cross section of egg envelope have identical structure. So, these structural characteristics of fertilized eggs and egg envelope show genus Corydoras specificity.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jemt.23057 | DOI Listing |
J Cell Biol
March 2025
Université Paris Cité, CNRS, Institut Jacques Monod , Paris, France.
At the end of cell division, the nuclear envelope reassembles around the decondensing chromosomes. Female meiosis culminates in two consecutive cell divisions of the oocyte, meiosis I and II, which are separated by a brief transition phase known as interkinesis. Due to the absence of chromosome decondensation and the suppression of genome replication during interkinesis, it has been widely assumed that the nuclear envelope does not reassemble between meiosis I and II.
View Article and Find Full Text PDFScience
November 2024
California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA.
Sexual reproduction relies on robust quality control during meiosis. Assembly of the synaptonemal complex between homologous chromosomes (synapsis) regulates meiotic recombination and is crucial for accurate chromosome segregation in most eukaryotes. Synapsis defects can trigger cell cycle delays and, in some cases, apoptosis.
View Article and Find Full Text PDFMicron
January 2025
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Bankowa 9, Katowice 40-007, Poland.
EMBO Rep
November 2024
Institute of Women, Children and Reproductive Health, Shandong University, 250012, Jinan, China.
CHK1 mutations could cause human zygote arrest at the pronuclei stage, a phenomenon that is not well understood at the molecular level. In this study, we conducted experiments where pre-pronuclei from zygotes with CHK1 mutation were transferred into the cytoplasm of normal enucleated fertilized eggs. This approach rescued the zygote arrest caused by the mutation, resulting in the production of a high-quality blastocyst.
View Article and Find Full Text PDFJ Biochem
December 2024
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!