Tuesday, 4 May 2010

Notes on Slime Molds

To gain a greater more detailed understanding of the life cycle of Cellular Slime Molds, i gathered samples of useful information and combined all the knowledge together to create a more detailed definition of the life cycle.

From what i can gather, the life cycle is not too complicated, the only complications being that there are two types of slime mold which have minor differences and it can be quite difficult in noticing the differences. A quick explanation of the two different types of slime molds would be;

Plasmodial Slime Molds:

A plasmodial slime mold is essentially a giant single cell which consists of thousands of nuclei. The slime mold forms when individual flagellated cells swarm together and fuse. This forms to create a large bag of cytoplasm which consists of diploid nuclei.

Once formed this slime like substance named plasmodium, creeps about in the motile phase of its life cycle in an ameboid state. The plasmodium then creeps about and feeds on bacteria or any other microorganism.

The plasmodim then enters its reproductive state, but before hand it must find a suitable climate condition, the conditions need to be dry and well lit, for example a top of a log. In its reproductive stage of its life cycle, the plasmodium forms into various structures named Fruiting Bodies.

The Fruiting Body is built up using the nuclei which is then topped by a Spore producing capsule and then releases them when the time is right.

These Spores are cellulose-walled, then once released, they then germinate in wet locations which in turn release naked cells, these naked cells then go through an ameboid or flagellated stage, which is then followed by sexual fusions and cell divisions.

These diploid ameboid cells, known as the zygote, then grows its nuclei and divides repeatedly, forming the new plasmodium by swarming together, which in then repeats the process over and over again.

Cellular Slime Molds: (asexual)

The cellular slime mold spend most of the lives as ameboid cells, but upon release of a chemical signal, these individual ameboid cells, like the plasmodial slime mold, aggregate into a mass swarm of cells.

These cells then flow together forming a multicellular mass named Pseudoplasmodium which resembles that of a slug which crawls around ingesting bacterial food similar to the plasmodial slime mold.

The slug like slime then finds a suitable location which is dry and well lit where it will begin its reproductive stage of its life cycle. In this stage of its life cycle, the pseudoplasmodium forms into Fruiting Body.

The spores are then released from the fruiting body, which then develop into a single ameboid cell and then feed on bacteria until other starving cells release a chemical signal which then causes those cells to aggregate into a new pseudoplasodium, which then allows the process to repeat itself again and again.

Cellular Slime Molds: (sexually reproductive)

Sexually reproductive cellular slime molds, use the same process with a few minor differences. In its sexual reproduction stage, two Haploid ameboid cells fuse, which then engulf surrounding ameboids to form a single organism named Macrocyst. This macrocyst then undergoes Meiosis and Mitosis which then releases Haploid ameboids, which then follow the process of the asexual slime mold, but instead sexual again and again.

Glossary of terms:

Asexual
A reproductive system/life cycle which does not involve sexual combination of two gametes.

Flagellated
The plural for a cell which has a tail-like projection, which can create movement, similar to that of a sperm cell.

Cytoplasm
A jelly-like substance which surrounds the nuclei of a cell.

Diploid
Two sets of chromosomes, both mother and father.

Motile
A term which refers to the ability of a substance to move spontaneously and actively, consuming energy in the process.

Ameboid
Similar to flagellated, a single cell which can change shape.

Fruiting Body
A multicellular structure which is created to produce and release spores in a reproductive stage.

Spore
A small, usually single-celled asexual reproductive body.

Cell-Wall
A tough, flexible wall which surrounds a cell.

Germinate
The process of when a spore begins to grow.

Zygote
The resulting cell formed out the a Diploid cell, a cell which contains both sex genes.

Aggregate
An assembled mass which consists of seperate elements that are considered as a whole.

Pseudoplasmodium
A cellular slime mold.

Haploid
A cell which consists of only one set of complete chromosomes.

Macrocyst
An aggregate of cells formed during sexual reproduction which is then enclosed in a cellulose wall.

Meiosis
A cell division which produces reproductive cells which are used in sexually reproductive organisms.

Mitosis
A cell division in which the nucleus divides into nuclei containing the same number of chromosomes.

Now with a greater understanding of the life cycle from each slime mold, i now can understand and visualise what i want to create far more than before the research, it has also given me the upper hand in creating an animation which will be scientifically correct.

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