Studies of the ultrastructure of sea urchin eggs subjected to hypotonic and hypertonic medium.

Studies of the ultrastructure of sea urchin eggs subjected to hypotonic and hypertonic medium by Sunniva LoМ€nning Download PDF EPUB FB2

Studies of the ultrastructure of sea urchin eggs subjected to hypotonic and hypertonic medium. 1. Experiments regarding the effects of the hypotonic and hypertonic media on the volume changes are described and the conclusion that the eggs are passive as far as the transport of the salts and water are concerned is arrived at.

The rate of mortality observed when eggs with jelly and without jelly were subjected to hypotonic media is recorded and the conclusion that the envelop of Cited by: 6.

A cytological study of the relation of the cortical reaction to subsequent events of fertilization in urethane-treated eggs of the sea urchin, Arbacia punctulata. Cell Biol. 47, –Cited by: 6. The eggs were washed 3 times for 15 min in filtered sea water.

This was followed by treatment of the eggs with a 1 per cent solution of OS in sea water at 4. The eggs were then dehydrated and embedded in Epon, using the standard techniques.

To improve contrast, the sections were doublestained with ura- nyl acetate and lead by: 2. Experimental Cell Research 39 Ultrastructure of sea urchin eggs fragments Experimental Cell Research 39 M. Geuskens (5) A zone of yolk platelets which contains also ribosomes and mito- by: Activation of Sea-Urchin Eggs by a Calcium Ionophore.

transformation once subjected to hypotonic shock. In this study, coelomocytes from the sea urchins Lytechinus variegatus and Arbacia. Fertilization of sea urchin eggs gave rise to acid production under both aerobic and anaerobic conditions. Aerobically, acid production went on for 20 minutes after fertilization and amounted toper c.c.

egg. Acid production also took place in a hypertonic medium and in this case was greater in anaerobic than in aerobic conditions. A considerable production of acid took place in Cited by: 2.

played by sea urchin embryos in the emergence of develop-Normal development. Sperm, eggs, and fertilization. Sea urchin and sand dollar gametes can be obtained in large numbers by intracoelomic injection of M KCl or by electrical stimulation; this leads to the shedding of gametes into sea water (in the case of eggs) or 'dry' into a dish (in the.

Hagstrom B. Further experiments on jelly-free sea urchin eggs. Exp Cell Res. ;– Lonning S. Studies of the ultrastructure of sea urchin eggs and the changes induced at insemination. Sarsia. ;– Carroll EJ, Epel D. Isolation and biological activity of the proteases released by sea urchin eggs following Cited by: 3.

In lab six you will conduct an experiment examining the effects of: ons of various tonicity on day old chick embryos. onic and hypertonic solutions on sea urchin eggs and/or embryos. 3.a depressant and a stimulant on sea urchin embryonic development.

of these. on fungal growth and reproduction. Ultrastructural Study of Asters Induced by Microinjection with Sperm Centriolar Fraction in Sea Urchin Eggs Article in Development Growth and Regeneration 26(5) - July with 13 Reads.

In studies in situ, spermatozoa were found in sheep ampullae and five in man in particular calcium and the low molecular glycoproteins, in hypotonic medium, leads to a marked yet reversible decrease in fertilizability. Lonning S. Studies of the ultrastructure of sea urchin eggs and the changes induced at insemination.

Sarsia. Cited by: Sea urchin eggs continuously exposed to a hypertonic solution were ultrastructurally examined for osmotic-stress induced alterations. No fertilization membranes formed during the treatment and the surface-cortex complexes remained unaltered from the unfertilized state.

However, the osmotic stress did induce a number of subcellular by: 4. A Sea Urchin haploid cell contains 21 or 22 chromosomes, which contain the genetic information that is passed on to offspring.

They use external fertilization in reproduction. The male releases sperm and the female releases eggs. When the gametes meet, the sperm releases ancrosomal enzymes that digest the egg's. The role of sodium ions in fertilization and development of sea urchin (Arbacia punctulata and Strongylocentrotus purpuratus) eggs was studied by culturing eggs and embryos in low sodium (choline-substituted) sea water.

Hardening of the fertilization envelope was impaired in 19 mM Na+ as indicated by the collapse of this investment min after by: ECHINODERMS - FERTILIZATION AND EARLY SEA URCHIN DEVELOPMENT I. Introduction. Our next model organism is the sea urchin which has been used extensively to study the events of fertilization and cleavage.

The egg is small enough to be seen under the microscope, the gametes are produced in great abundance, and fertilization occurs naturally. Because diffusion across the egg membrane cannot occur, the water in the distilled water will attempt to rush into the egg to make up for the salt quantity in the egg.

So the egg is hypertonic to the distilled water, the water is hypotonic to the egg. ena associated with sea urchin sperm–egg interaction (fertilization) and egg activation. A sea urchin egg, with its hydrated jelly coat, is shown in Figure 2. Ap adults may require an electric shock of 6–10V to induce spawning.

As the Ap females spawn, one should collect the dark red/ purple eggs with a pipette as they are coming out of theFile Size: KB. In an hypotonic soution, the egg will gain mass. In a hypertonic solution, the egg will lose mass. Shells would keep the eggs from responding to the solutions as quickly, and the results would not be visible through the shell - unless the egg in the hypotonic solution gains so.

In Artificial Parthenogenesis Loeb describes his first experiments of exposing unfertilized sea urchins eggs to acids and bases to see if chemicals could provide the spark for parthenogenesis.

He gained some success by exposing eggs to individual hypertonic solutions of NaCl, KCl, CaCl2, and MgCl2 and then placing them in normal sea water. Sea urchins and their eggs are commonly used as indicator organisms in environmental studies.

The Environmental Protection Agency uses sea urchin development standards to test for the presence of water pollution. Public aquariums use an adult sea urchin's health as an indicator of the water quality in their tanks.Salt water is isotonic to the sea urchin eggs and embryos.

If sea urchin eggs and embryos were placed in hypotonic solution, they would lyse as water was pumped into the cells to match the molarity of the environment. If they were placed in hypertonic solution, the eggs and embryos would shrivel as water was pumped out of the cells.The perils of reduced pH on sea urchin development Jessica Poppe, Tufts University Havenhand JN, Buttler F‐R., Thorndyke MC, Williamson JE.

Near‐future levels of ocean acidification reduce fertilization success in a sea urchin. Current Biol. R‐RFile Size: KB.