Welcome to the wonderful world of genetics! If you are interested in breeding your fish, it can be helpful to understand what is going on “behind the scenes”. I will try to keep this information pretty basic, but if you have any questions, or want to discuss some of the information given herein, feel free to add to this thread.
First, the basics….
Have you ever wondered why the offspring of the fish you breed are not exactly like their parents in appearance? If fish used asexual reproduction, they would produce offspring that looked exactly like them, because for all intents and purposes, asexual reproduction results in a clone of the parent. However, the offspring of your fish probably resemble their parents, but unlike the clones produced in asexual reproduction, they are genetically unique. This genetic variation is due to the fact that fish (and many other eukaryotic organisms) use sexual reproduction to propagate, which allows the “shuffling” or “mixing” of different genes. This, along with mutation, results in a unique individual genome.
Sexual reproduction results in the offspring receiving genetic information from both parents in the form of chromosomes. The parents pass these chromosomes on to their offspring by including them in the nucleus of their gamete, in the case of fish, either the sperm or the ovum (egg).
So, each fish is unique, with its own set of biological instructions programmed into its genome. It is important to remember that many of the instructions will be identical from fish to fish – only certain areas of the genomes, certain genes that will be unique. Have I confused you yet? Let’s think about this last concept a little more in depth.
Each fish has a unique genome, but many of the same genes. Why is this the case? Well, there are many things that are simply too important to change. Many of these genes are the ones concerned with development of the organism. This does not mean that mutations do not occur to change these genes in some cases, but you will not see these mutations in your fish tank because they are lethal to the fish.
Up next: That's great and all, cation, but why do my fish look the way they do?
Asexual Reproduction: Propagation of new individual organism from a single organism. Typically, the offspring are genetic clones, for all intents and purposes.
Chromosomes: The gene-carrying structure found in an organism's nucleus. Consists of a long DNA molecule and and its associated proteins.
Clone: A lineage of of genetically identical individuals
Eukaryotic: A type of cell with membrane contained organelles. Present in all fungi, plants, and animals.
Gamete: An egg or sperm cell.
Genetics: The study of biological inheritance. In other words, the study of physical traits and their underlying genetic code, as well as the manner in which said traits are passed down through related individuals of any given (sexually reproducing) species.
Gene: The heritable unit of information that can be passed on to an organism’s offspring. Genes are composed of specific sequences of nucleotides in DNA.
Genome: An individual’s unique genetic makeup – biological “instructions”
Mutation: A rare change in a gene.
Nucleus: The chromosome-containing organelle of a eukaryotic cell.
Sexual Reproduction: Reproduction in which two parents produce offspring which have unique combinations of genes inherited from parental gametes.
First, the basics….
Have you ever wondered why the offspring of the fish you breed are not exactly like their parents in appearance? If fish used asexual reproduction, they would produce offspring that looked exactly like them, because for all intents and purposes, asexual reproduction results in a clone of the parent. However, the offspring of your fish probably resemble their parents, but unlike the clones produced in asexual reproduction, they are genetically unique. This genetic variation is due to the fact that fish (and many other eukaryotic organisms) use sexual reproduction to propagate, which allows the “shuffling” or “mixing” of different genes. This, along with mutation, results in a unique individual genome.
Sexual reproduction results in the offspring receiving genetic information from both parents in the form of chromosomes. The parents pass these chromosomes on to their offspring by including them in the nucleus of their gamete, in the case of fish, either the sperm or the ovum (egg).
So, each fish is unique, with its own set of biological instructions programmed into its genome. It is important to remember that many of the instructions will be identical from fish to fish – only certain areas of the genomes, certain genes that will be unique. Have I confused you yet? Let’s think about this last concept a little more in depth.
Each fish has a unique genome, but many of the same genes. Why is this the case? Well, there are many things that are simply too important to change. Many of these genes are the ones concerned with development of the organism. This does not mean that mutations do not occur to change these genes in some cases, but you will not see these mutations in your fish tank because they are lethal to the fish.
Up next: That's great and all, cation, but why do my fish look the way they do?
Asexual Reproduction: Propagation of new individual organism from a single organism. Typically, the offspring are genetic clones, for all intents and purposes.
Chromosomes: The gene-carrying structure found in an organism's nucleus. Consists of a long DNA molecule and and its associated proteins.
Clone: A lineage of of genetically identical individuals
Eukaryotic: A type of cell with membrane contained organelles. Present in all fungi, plants, and animals.
Gamete: An egg or sperm cell.
Genetics: The study of biological inheritance. In other words, the study of physical traits and their underlying genetic code, as well as the manner in which said traits are passed down through related individuals of any given (sexually reproducing) species.
Gene: The heritable unit of information that can be passed on to an organism’s offspring. Genes are composed of specific sequences of nucleotides in DNA.
Genome: An individual’s unique genetic makeup – biological “instructions”
Mutation: A rare change in a gene.
Nucleus: The chromosome-containing organelle of a eukaryotic cell.
Sexual Reproduction: Reproduction in which two parents produce offspring which have unique combinations of genes inherited from parental gametes.
