The so-called genetic effect isprotein synthesisThere are direct orIndirect impactDNA fragments with genetic effects can directly guide orIndirect regulationBase sequence of protein synthesis.The study found that everysomatic cellchromosomeDNAShared onBase pairThree billion, most of whichgenetic informationIt will not be expressed, and has no direct impact on the traits. These DNA fragments are called DNA fragments without genetic effect, and conversely, they are called DNA fragments with genetic effectgene。GenescoreCoding areaandNon coding areaTwo parts, the non coding region can only regulate protein synthesis, but both the non coding region and the coding region are indispensable for the normal expression of biological traits, so they are part of the gene and have genetic effects.
The child's figure is usually similar to that of his parents, even the sameMoldThis is the effect of heredity. Similarly, the beauty and ugliness of people are also related to heredity.genetic genesIt can determine the shape and size of the fetal nose, the distance between eyes, the thickness of the lips, the shape of the face, the color of the skin, the curve of the chest, the length of the legs, and the size of the buttocks.People's external characteristics can be inherited not only from their parents, but also from their grandparents.The proportion of appearance, height, intelligence and personality inherited by the fetus from its parents is as follows:
Specific nuclei with genetic effects on molecules
Height is inherited from mother.stayNutritional statusUnder the same premise, the heredity of parents is the main factor determining the height of children, especially the height of mothers.The mother grows tall, and the child grows taller.Intelligence is inherited by mothers.IntellectualgeneticAt the same time, they are also exposed to environment, nutrition, education, etcAcquired factorImpact.According to scientists' assessment, heredity has an impact on intelligence of about 50% - 60%. As far as heredity is concerned, mothers are smart, and most of the children born are smart. If they are boys, they will be more smart.The reason for this is that human intelligence related genes are mainly concentrated on the X chromosome.Women have two X chromosomes and men only have one, so mother's intelligence plays a more important role in heredity.
Character is inherited by father.Of course, the formation of character has a congenital component, but it is mainly a post influence.In comparison, father's influence will be greater than mother's.Among them, the role of father love has a greater impact on daughters.A psychologist thought: "The father in the daughter'sSelf esteem, playing an important role in the formation of identity and gentle personality. "Another expert pointed out that fathers can teach their daughters many important lessons and experiences in life, which can make their daughters' character moreRich and colorful。
Looks are inherited from fathers.According to American psychologist Christanfeld, the face of a baby is more like a father no matter how it looks because the father gives his children genetic characteristics.The scientist further explained that this is also a reflection of human "self-protection" instinct, because there is no doubt who is the mother, but who is the father is not so sure, so we must be like the father, which is beneficial to the baby and can encourage the father to put more love into it.
Acquired influence
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Director Tian of Shanghai Marriott Hospital said: In fact, children inherit various physical elements from their parents at the same timeGenetic factor。Therefore, the influence of genetic factors obtained from mother or father is the same. Generally speaking, parents are beautiful, and children are also beautiful in adulthood, but it is not absolute. It depends on the body and mind of teenagersIntellectual development。If you are frustrated in school or seriously injured at home, even if you are beautiful when you are young, you will become ugly when you grow up.On the contrary, those who were ugly when they were young, but received good care and education from their families and society, can also become "like flowers and jade" when they grow up.
DNA fragment of genetic effect
According to relevant reports: South AmericaColumbiaHart Village is a world famous beauty village, where not only the women are beautiful, but also the men are very handsome. Even the old people have beautiful eyes and beautiful figures.Why is Hart Village blessed with beauty?It is said that since their ancestors, they have set a marriage rule: "Men marry thousands of miles away, women marry thousands of miles away." This can be avoidedInbreeding。There is also a rule that men who marry women are not worthy of "beauty", and those who are not physically strong are not worthy,AlcoholismSmokers are not qualified.The whole village adheres to this ancient marriage standard.It creates conditions for eugenics and makes our offspring more and more healthy and beautiful.
Mixed inheritance
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poplarGenetic effects of disease resistance traits
(1) Establish the main disease resistance traits of poplargene-Genetic model of polygenes, estimation of major genes and polygenesAdditive effectandDominant effect, and gene × environment interaction;
(2) Construction of high density poplar genetics with more than 500 markersLinkage map；
(3) FurtherMapping population OfCloneThe resistance to black spot was tested in vitro and in whole plant, and then QTLs were analyzed to map the resistance gene to black spot on the genetic map;
(4) The genetic effects estimated by the genetic model established by statistical genetics were compared with QTLs;
(5) ViaPathogenInduction and differencedisplay technique To isolate the genes related to black spot resistancecDNATo clarify the relationship between cDNA cloning and poplar black spot resistance genes.
Research results
(1) Built high-densityPopulus deltoides×Euramerican poplarTo map the disease resistance genes.Mapping group "three cross" group, from AmericaBlack poplar（female parent、Poplus deltoides Bartr. Cv. “Lux”(I-69/55)) andEurope and AmericaYang (male parent, P. euramericana cvI-45）It is produced by hybridization, in which Euramerican poplar is a hybrid of American black poplar and European black poplarNatural hybrid。useRandom amplified polymorphic DNA（RAPDs）、Amplified fragment length polymorphism(AFLP) and simple sequence repeat (ISSR) were performed on 93 individuals from 450 15 year old "three cross" progeny in the fieldlinkage analysis。Of the 839 polymorphic markers identified, 560 (67%) were quasi test cross markers, which were heterozygous in one parent and heterozygous in the other parentHomozygous(1:1 separation), 206 (25%)Dominant markerThey are heterozygous in both parents (3:1 separation), and 19 RAPD markers in the remaining 73 (9%) parents do not appearSpectral band, but in the offspring (1:1 separation), 54 AFLP markers wereCodominant(1:2:1 separation).Two linkage maps constructed with these markers, Populus deltoidesgenome(D) The genome (E) of Euramerican poplar, covering 3801cM and 3452cM respectively, is the genetic map with the highest density of poplar at home and abroad.
(2) UtilizationBSA(Bulk Segregations Analysis) technology to establish two DNA pools (susceptible pool and resistant pool) and screen out RAPD markers linked to high resistance to black spot: OperonAI17-1550, Operon AI13-900genotypeanalytical methodMarking - Traitslinkage analysis, two markers and high resistance genes to black spotgenetic distance29.9cM and 37.4cM respectively.It is the first time along the genus to study the resistance of forest trees to black spot, which lays a good foundation for cloning the genes related to black spot resistance.
(3) This study will for the first time reflectpopulation structure The concept of linkage disequilibrium of change was introduced into forest tree genes for research, and a more effective mapping strategy was proposed.ByMolecular markerBetween and potential QTLsInterlocking imbalanceCan be used for high resolution localization andGene cloningProvide an effective way.
Balsam pear heredity
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Balsam pearGenetic effect analysis of main economic traits
With three significantly different balsam pearinbred lineIs a material through self crossing, hybridization andbackcross, get twoHybrid combination(ZH967281 × G968031 and ZH961123 × G968031)B1And B2 generations, according toQuantitative geneticsThe first of its six generationsfemale flowerNode, single plantbear fruitNumbersimple fruitThe genetic effects of fruit quality, fruit length, fruit diameter and pulp thickness were studied.The results showed that the transmission of the six economic traits all conformed to the additive obvious livelihood effect model, and all were based onAdditive effectMainly, the first female flower node, number of fruit set per plant, single fruit quality, fruit length, and fruit diameter are partially expressed in hereditydominanceIn the first female flower node, the narrow sense heritability of fruit set number per plant, fruit weight per plant, fruit length, fruit diameter, and pulp thickness were 69.23%, 61.94%, 61.46%, 76.18%, 28.98%, and 35.09% respectively.
The genetic effects of radiation are biologicalgerm cellGenerally, the radiation genetic effect has the following characteristics:
(1) The genetic effect does not appear in the irradiated individual itself, but in some offspring of the individual, so it is difficult to find the relationship between the generation of the effect and the individual exposure
(2) The time between the exposure of the organism and the appearance of the genetic effect is too long (exceeding the life span of the organism, sometimes even several times of the life span, that is, several generations)
(3) Genetic effect is heritable, so theoretically, its influence may be great.
[Biocommunication]University of IllinoisA new study of Urbana Champaign supports the theory that the aging process can be safely slowed down by acting on genes that remain silent in early life but may have adverse effects in late life.
The research results were published in the Proceedings of the National Academy of Sciences this week.The researchers did not propose this method in the articleDelay senilityThey just described in detail their ideas based on mathematicsprediction model The process of testing two famous evolutionary theories on aging:age groupDrosophila melanogaster100 different genotypes of (Drosophila melanogaster)Reproduction success rateConduct analysis.
The test results show that more research is needed on which genes play a role in the aging process, what role they play and when they play a role, so that manual operation will not cause damage to the evolution of offspringEvolutionary biologyPlanned animalsbiologistKimberly A. Hughes said.
Hughes said that this study is mutation accumulation,MA）The theory provides the strongest support.This theory believes that aging is affected by early life reproductionDirectional selectionIt is difficult for scientists to test the theory that the process controls the accumulation of mutations in genes that are activated only in the late life.
Several examples of such genes include Huntington's disease and several late life episodescancerForm related genes.Such mutations exist in the initial reproductive development, but they are not noticed until later life.In old age, when reproduction is no longer the main function of organisms, mutation accumulation will not be inhibited by natural selection, thus increasing the risk of disease.
But another widely accepted antagonistic pleiotropy (AP)
The theory is that aging is due to genes that help in the reproductive stage, such as codingestrogenGenes ofHarmful effectsOccurs.According to the antagonistic multi effect theory,natural selectionPay attention to the impact of early life, because these early life impacts lead to reproduction and have no harm to the adverse impact of later life, Hughes explained.
Based on Hughes'University of ChicagoStudyPhD candidateShe and her colleagues trained fruit flies to examine the theoretical research on age-related inbreeding depression and genetic variabilityAbrupt delayWhat impact will it have.
This new study found that in the reproductive age group, the adverse effects of mutations on reproduction increased significantly with age - for both homozygous and heterozygous genotypes.However, inHomozygousIn the system,Reproduction success rateIt drops more rapidly, which is similar to MATheoretical predictionIs consistent with.
"This study allows us to detect certainDominant varianceOnly MA theory predicts that dominant variance will increase with age. "Hughes pointed out."The ability to detect these effects is critical for testing evolutionary aging theory, because the increase of age-related genetic effects is a unique prediction of MA theory, while other genetic effects are in twotheoretical modelWill increase in the forecast of.
Although this study supports the MA theory, the antagonistic multiple effect theory is not compromised."The two theories are not mutually exclusive," Hughes said."They all havePossible, two typesgeneCan be accumulated. "
If geneticists want to eliminate the adverse effects of a gene that plays an active role in early life on later life, the comprehensive function of this gene in the next generation will be negatively changed, Hughes said.But operating those genes that are not good for early life to eliminate their adverse effects on later life may not cause negative evolutionary changes in offspring.
