Fanciers all over the world are very admiring of the Jensen brothers, the breeding pigeons from the jensen brothers' original shed are not spared, at the expense of high prices, but how the jensen brothers' breeding pigeons are bred, but few people can say clearly, The Taiwan pigeon world hero - Mr. Wu Gaoping used his understanding of the Jensen brothers pigeons and his life's energy, seriously summarized and summarized, completed the writing of his book "Jensen Breeding Principles", provided fanciers with good spiritual food, Mr. Wu Gaoping wrote a paragraph (golden mother selection method), After reading it, I was very touched and wrote out my after-reading feelings about this paragraph and my personal understanding and understanding, and discussed it with the fanciers. Below I combine my genetic knowledge to uncover the genetic secret of the Jensen brothers' two-headed golden mother method - cytoplasmic inheritance of golden oocytes and the predetermination of golden oocyte nucleus genes.
The main features of cytoplasmic inheritance
1. The results of positive and negative cross-fertilization in cytoplasmic inheritance are not the same, hybrids only show maternal traits, which are maternally inherited, and the results of positive and negative cross-fertilization in nuclear inheritance are the same;
2, cytoplasmic inheritance does not follow Mendel's laws of inheritance. In the process of cell division, cytoplasmic genes show unequal distribution, and nuclear inheritance is the opposite;
3. Cytoplasmic genes only exist in certain components of the cytoplasm and cannot be located on chromosomes, and nuclear genes can be located on chromosomes.
In the process of hybrid backbringing, the hybrid does the mother and one of the parents for backcrossing, after many generations, although the nuclear gene has been mostly replaced, but the cytoplasm has basically not changed, the backcrossing offspring still shows the maternal trait, nuclear gene control of the inheritance In the process of backbringing, due to the replacement of nuclear genes, the offspring are more and more like reincarnation parents. This shows that cytoplasmic genes are independent to a certain extent, not interfered with by nuclear genes, and a very important feature of cytoplasmic inheritance is maternal inheritance.
In other words, maternal inheritance is controlled by cytoplasm, in maternal inheritance, the decisive genetic material is present in the cytoplasm, is some component of the cytoplasm, in the process of hybridization, hybrids only show maternal traits, the root cause is that the sperm-egg combination of the zygotes provided by both parents of the unequal caused, in the protoplasts of the hybrid fertilized egg, both the nucleus of the mother and the entire cytoplasm of the mother. The father's sperm, on the other hand, when fertilized, only enters the egg cell with the nucleus, but its cytoplasm rarely or even cannot enter the egg cell. In this way, in the zygote, the nuclear gene is from both parents accounting for half, and the cytoplasm is basically from the mother, and the traits controlled by the nuclear gene are expressed by both parents, for example, the pigeon feather color inheritance that we are familiar with is controlled by the nuclear genes from both parents in the zygote, and there is a difference in performance between dominant, recessive and codominant. Traits controlled by cytoplasmic genes only show the maternal side, and the Jensen brothers' golden mother selection method takes advantage of a very important feature of cytoplasmic inheritance------ maternal inheritance phenomenon.
In the phenomenon of maternal inheritance, the cocks can inherit the excellent characteristics of the golden mother, including the excellent characteristics of the pigeons that the majority of fanciers want, but the cocks cannot pass it on, and if the next hen with very poor characteristics in terms of pigeon racing is paired with this, their descendants will show the characteristics of this hen with very poor characteristics in terms of pigeon racing, and the excellent pigeon characteristics will be lost and lost. Therefore, I remind fanciers that when you get a good male racing pigeon, you must be careful with the hen, if conditions permit, it is best to find a female or straight granddaughter of its mother to pair with it, or to find a proven excellent breeding hen to pair, so as to keep the excellent characteristics of excellent male racing pigeons unchanged.
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The material basis of cytoplasmic inheritance and its role
Cytoplasm has genes that control genetic traits, this gene is called cytoplasmic genes, cytoplasmic genes and nuclear genes, all have stability, continuity and variability, so what exactly is cytoplasmic genes? Microscopic observation shows that the same structure as the chromosomes in the nucleus cannot be found in the cytoplasm, but there are many organelles, which are as stable and continuous as the chromosomes in the nucleus. At present, the containing of DNA has been clearly found in many organelles. For example, the plastids, mitochondria of plant cells, and the motifs, motifs, and central spheres in animal cells. Some detoxified grasshoppers have a particle called kaba grain in their cytoplasm that also belongs to this structure. There is a structure in the cytoplasm of E. coli called plasmids, which is actually a circular DNA molecule, and we all know that the plasmids in the bacterial cytoplasm are very important genetic material for bacteria to transmit drug resistance traits in medicine. Some traits of living things are inherited through them, so the genetic material in these cytoplasmic structures (organelles and some granular matter) is generally called cytoplasmic genes.
I have talked about many examples of maternal inheritance and cytoplasmic inheritance, but in addition, I would like to talk about the effect of maternal oocyte nucleus genes on the cytoplasm of maternal oocytes. Is it possible that in the process of hybridization, all the phenomena of hybrids showing only maternal traits are maternal inheritance? Not necessarily, because some of the manifestations of the inheritance of maternal traits, is the result of the predetermined action of the maternal nucleus gene, is not the real cytoplasmic inheritance, the egg cell is under the influence of the maternal nuclear gene, developed in the mother's body, so the embryonic characteristics produced by the egg cell, affected by the maternal nuclear gene is stronger than the parent, the maternal nuclear gene on the cytoplasm sometimes produces a predetermined effect, which is called the maternal influence, this effect only has an impact on the child generation, to the second generation of the child, the effect disappears then the trait inheritance also changes.
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Relationship between cytoplasmic genes and nucleus genes
Although nuclear inheritance and cytoplasmic inheritance each have relative independence, this does not mean that they are not related to each other in the slightest. The nucleus and cytoplasm are both important components of the cell, co-existing in a unified body, and they must be interdependent, mutually restrictive, and inseparable. The genetic phenomena they control must also interact with each other, so their independence is conditional and limited.
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The two-headed golden mother made the method
In order to ensure that the excellent characteristics of the pigeons in their own loft are continuously passed down, how do the Jensen brothers and some of the pioneers do it?
Let's first take a look at how the Jensen brothers select breeding hens, the American Jensen expert Garros said: the eyes are red and white (yellow), the rainbow is ribbon-like, wide shoulders and thick chest, waist and thick tail, this is the most satisfactory form of the Jensen brothers, the Jensen brothers and some of the pioneers are the most satisfied with the practice: the most outstanding male racing pigeons in the house, with the proven breeding ability of the "golden mother, the hens are retained, the cocks are raced, if the performance is outstanding, they are upgraded to breeding pigeons, and then they are mated to another "golden mother". That is to say, a Jansen pigeon, its mother or maternal grandmother, and the father's grandmother, must contain two "golden mothers". This method seems simple, but it is not! Vision theorist Bishabo has an unusual theory, he most value the mother of the hen, that is, the grandmother, the implication is that the golden mother will give birth to the golden mother, the daughter of the golden mother may give birth to the super seed mother, and then effectively use the laws of genetics, you can break through the bottleneck in breeding.