Eggs, developing

Friesen KJ, Kaufman WR (2003) Cypermethrin inhibits egg development in the ixodid tick, Amblyomma hebraeum. Pestic Biochem Physiol 76 25-35... 

The effect on molluscs shows a wide variability, with reports of significant reductions in the percentage of fertilised oyster eggs developing normally at concentration of LAS as low as 0.025 mgL-1... 

Humans and cats both begin life as fertilized eggs, which look fairly similar. Why does a fertilized cat egg develop into a kitten, while a fertilized human egg develops into a child (Figure 2.20) A very special type of polymer, located in the cell nucleus, directs the formation of the proteins from which an organism develops. 

Alpine waters are sensitive ecosystems with unique features and resources. Extreme environmental conditions (altitude, gradient, low nutrients, duration of snow cover) shape special habitats that are only suitable for highly-adapted fishes. Only cold stenothermic species can inhabit Alpine waters. During spawning and the period of egg development, water temperature is low and can reach 0°C. Therefore, only a few of the native fishes were able to colonize and inhabit Alpine waters. In the last decades, non-native cold water resistant fish appeared in many Alpine waters. Nonnative species have inhabited alpine lakes since the late 19th century Salvelinus namaycush were stocked in 1886 in small alpine lakes in the Swiss Alps [92]) and started to reproduce in many lakes. Over the last decades in many Alpine streams, non-native, cold stenothermic species have established self-reproducing populations and appear well-adapted to the harsh environmental conditions. 

Larter, R. Strickholm, A. Ortoleva, P. Cell, "A Detailed Model of the Electrical Symmetry-Breaking Transition in Early Fucus Egg Development" (submitted for publication). 

No doubt it is the technical difficulties involved that have caused the metabolism of cestode eggs to remain almost unstudied. Since cyclophyl-lidean eggs develop within a proglottis while still within the host, direct... 

Follicle-stimulating hormone (FSH) Glycoprotein, MW 34,000, two subunits Same as for LH Unknown Egg development (ovary) in female and spermatogenesis in male... 

Egg Development Neurosecretory Hormone Activity in the Mosquito Aedes aegypti... 

M. domestica oostatic hormone seems to Inhibit the release or synthesis of egg development neurosecretory hormone (EDNH) (12), but in mosquitoes the hormone seems to act directly on the ovary (6). R, prolixus oostatic hormone, which has been partially purified (13), is a small peptide of M, 1,411 as determined on Sephadex G-50. Kelly et al. (5) prepared a crude extract of oostatic hormone from M, domestica, injected it into the autogenous mosquito Aedes atropalpus, and demonstrated inhibition of both egg development and ecdysteroid biosynthesis. They suggested that oostatic hormone functions at a point subsequent to release of EDNH. They were unable, however, to exclude the possibility that release of EDNH, itself, was inhibited. 

Table II. Inhibition of Egg Development with Purified Oostatic...

Female A. aegypti were fed blood on a chicken, immediately injected with oostatic hormone, and 24 h later analyzed for egg development. M, of oostatic hormone was used as 1047.6 based on mass spectra analysis of the purified hormone for nmol calculations. 

It Is Important to understand the regulation of the corpora allata (CA) because the modulation of the titer of juvenile hormone (JH), which parallels CA activity (1), is required for the maintenance of larval characteristics, the absence of JH Is necessary for metamorphosis of larva to adult, and In the adult female, JH Is required, in most species, for egg development. 

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