Vertebrate oocyte maturation is an extreme form of asymmetric cell division, producing a mature egg alongside a diminutive polar body. Critical to this process is the attachment of one spindle pole to the oocyte cortex prior to anaphase. We report here that asymmetric spindle pole attachment and anaphase initiation are required for localized cortical activation of Cdc42, which in turn defines t...

a myxozoan parasite belonging to the genus thelohanellus kudo, 1933 (cnidaria, myxosporea, bivalvulida) was isolated from the fins of labeo dero inhabiting ranjit sagar wetland, punjab, india. the plasmodium was 0.5-0.7 mm in diameter each containing 80- 100 number of myxospores. myxospores were egg shaped to ovoidal in valvular view having bluntly pointed anterior and broad rounded posterior e...

Many species experience large fluctuations in food availability and depend on energy from fat and protein stores for survival, reproduction and growth. Body condition and, more specifically, energy stores thus constitute key variables in the life history of many species. Several indices exist to quantify body condition but none can provide the amount of stored energy. To estimate energy stores ...

The objective of the study was to characterize the ultrastructure changes and biochemical mechanisms underlying the expulsion of the entire chromosome complement in chemically enucleated mouse oocytes. The ultrastructural studies demonstrated that the morphology of cytoplasts produced by etoposide-cycloheximide treatment were indistinguishable from intact metaphase I and II oocytes. Moreover, p...

For a convex body of given volume in spherical space, the total invariant measure of hitting great subspheres becomes minimal, equivalently the volume of the polar body becomes maximal, if and only if the body is a spherical cap. This result can be considered as a spherical counterpart of two Euclidean inequalities, the Urysohn inequality connecting mean width and volume, and the Blaschke-Santa...

In order to understand the mechanism of unequal division, polar body formation was investigated using the oocytes of the starfish, Asterina pectinifera. Cortical actin filaments were quantitatively measured after staining the maturing oocytes with fluorescently labeled phalloidin using a computer and image-processing software. Before polar body formation, at first the actin filaments at the ani...

In this study we evaluated the value of short-time insemination and early rescue intra-cytoplasmic sperm injection (ICSI) in preventing the occurrence of complete fertilisation failure for mild or moderate male infertility patients. A total of 866 couples with borderline semen who underwent in vitro fertilisation treatment in 2010 were included. Regular insemination was performed between Januar...

Pre-implantation genetic diagnosis (PGD) or screening (PGS) technology, has emerged and developed in the past few years, benefiting couples as it allows the selection and transfer of healthy embryos during IVF treatments. These techniques can be performed in oocytes (polar-body biopsy) or embryos (blastomere or trophectoderm biopsy). In this case report, we describe the first two live births to...

Three isosporan species are described from the double-collared seedeater, Sporophila caerulescens from Eastern Brazil. Isospora sporophilae n. sp. oocysts spherical to subspherical; oocyst wall bi-layered, smooth, inner layer colorless to pale yellowish, 21.6 x 20.9 (19.20-23.20 x 18.40-22.60) microm, shape-index 1.03 +/- 0.02 (1-1.10), with no micropyle or oocyst residuum. Polar bodies splinte...