the aim of the study was to compare the parthenogenetic activation and in vitro fertilization (ivf) of in vitro matured caprine oocytes. a total of 881 cumulus-oocyte complexes (coc’s) were collected from 243 ovaries. oocytes were matured in tcm-199 medium containing ecg (20 iu/ml), hcg (20 iuμg/ml), oestradiol-17β (1 μg/ml), bsa embryo tested (3 mg/ml) supplemented with 10% fetal bovine serum ...

The objective of this study was to determine an optimum maturation period of canine oocytes for the development in vitro after in vitro fertilization (IVF). Canine oocytes larger than 110 micrometers in diameter, which were collected from ovaries at the follicular phase of the reproductive cycle, were cultured for each time (48, 72 and 96 h) in TCM 199 medium supplemented with 10% canine serum,...

the aim of this investigation was to study macroscopic and microscopic structures of ovaries in barbus grypus of karoon river and their changes during annual maturation cycle. for this purpose, 120 adult  b.grypus with a mean weight of 835.0 to 1012.0 g, were caught from karoon river and transferred alive to the laboratory. after biometrical studies, the weights and morphological appearances of...

Population cycles in small mammal has attracted the attention of several generations of theoretical and experimental biologists and continues to generate controversy. Top-down and bottom-up trophic regulations are two recent competing hypotheses. The principal purpose of this paper is to answer the following simple question: What ecological factors control population cycles? For some species — ...

During critical periods, all cortical neural circuits are refined to optimize their functional properties. The prevailing notion is that the balance between excitation and inhibition determines the onset and closure of critical periods. In contrast, we show that maturation of silent glutamatergic synapses onto principal neurons was sufficient to govern the duration of the critical period for oc...

INVESTIGATIONS OF THE INDUCTION PERIOD OF AN IN VITRO HEMOLYSIN RESPONSE TO SHEEP ERYTHROCYTE ANTIGEN REVEALED THE FOLLOWING: 1. After antigen stimulation precursors of plaque-forming cells rapidly maturate to the point of hemolysin production. 2. Initial maturation probably occurs in the absence of cell division. 3. After initial maturation, a latent period of about 12 hr occurs before the fir...

This report describes observations on the rate of heme and globin synthesis within the maturation period of human marrow erythroid cells. Such studies have been designed to examine the hypothesis that heme and globin are synthesized with temporal independence during erythroid cell maturation and to establish the normal relationship of heme and globin synthesis. With such data it is hoped that f...

in order to determine the most effective hormones on the in vitro oocyte maturation (germinal vesicle breakdown - gvbd) in a hybrid sturgeon bester, ovarian follicles were incubated at the migratory nucleus stage in the presence of several steroids, gonadotropin preparations and forskolin. occurrence of gvbd and 17,20β-dihydroxy-4-pregnen-3 -one (dhp) production were followed during an expe...

Primary cultures of fetal rat calvarial osteoblasts undergo a developmental sequence with respect to the temporal expression of genes encoding osteoblast phenotypic markers. Based on previous suggestions that gene-nuclear matrix associations are involved in regulating cell- and tissue-specific gene expression, we investigated the protein composition of the nuclear matrix during this development...