During the winter and spring of 2002 and 2003, we used time-integrated fertilization assays to monitor sperm availability in three populations of the green sea urchin Strongylocentrotus droebachiensis in Maine: a naturally occurring population of .40,000 urchins and two smaller groups (,1,000) of transplanted urchins isolated from other aggregations. Episodes of sperm release coincided in two p...

the pollution of aquatic ecosystems may affect natural reproduction of fish populations by decreasing the fertilization efficiency. among the various sources of pollution, heavy metals are important group, being found in both freshwater and marine environment. the present study investigated changes of sperm characteristics of caspimyzon wagneri when exposed to manganese (mn). spermatozoids were...

Oocyte production, maturation and ovulation must be coordinated with sperm availability for successful fertilization. In C. elegans this coordination involves signals from the sperm to the oocyte and somatic gonad, which stimulate maturation and ovulation. We have found that the C. elegans early growth response factor family member EGRH-1 inhibits oocyte maturation and ovulation until sperm are...

In the current model of vertebrate sex determination and sexual differentiation, gonadal sex is fixed at fertilization by specific chromosomes, a process known as genotypic sex determination (GSD). Only after the gonad is formed do hormones begin to exert an influence that modifies specific structures that eventually will differ the sexes. Many egg-laying reptiles do not exhibit GSD but rather ...

OBJECTIVE To investigate the effect of Coriolus versicolor polysaccharide-B (CVPs-B) on the biological characteristics of human esophageal carcinoma cell line Eca109 in vitro. METHODS The cells of experimental group (EG) were cultured in DMEM with 10% FCS and 150µg/mL CVPs-B, the cells of control group (CG) were cultured in DMEM with 10% FCS without CVPs-B. MTT reduction assay was performed t...

In this study, age-dependent changes of sperm quality parameters in Rutilus frisii were investigated. Also, fertilization capacity of breeders was tested using two age groups of males (3 and 4 year old breeders) and one female group (i.e. 4 year old breeders). For fertilization trials, the breeders were crossed randomly among age classes. Between the two age groups, spermatological parameters d...