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  • 复杂轨迹 - 高级

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    What does it mean to be dominant?
    ::占支配地位意味着什么?

    Well, if you're in this gorilla's troop, it better be obvious. Could there be more than one dominant gorilla in a troop? No. So what happens if there are two dominant alleles of the same gene . Do they fight until one leaves? Or do they figure out how to get along?
    ::那么,如果你在这个大猩猩的队伍里, 最好是显而易见的。 一支队伍里可能不止一个大猩猩? 不。 那么, 如果有两个同基因的主要异灵, 会发生什么? 他们战斗到一个离开吗? 或者他们知道如何相处吗?

    Complex Traits
    ::复杂轨迹

    Traits inherited in a simple Mendelian pattern are either dominate or recessive . The trait is produced by only one gene. But this is not the case for many traits; rarely is inheritance as simple as one gene with two , and either dominant or recessive inheritance. More complex patterns of inheritance are common. These were introduced in the concept.
    ::以简单的Mendelian模式继承的遗产要么是支配性的,要么是消亡性的。 其特性只有一个基因产生。 但许多特性并非如此;很少像一个基因一样简单,有两种基因的遗产继承,以及主导性的遗产或休眠的遗产继承。 更复杂的遗产继承模式是常见的。 这一概念中引入了这些特征。

    Mendel’s showed complete dominance of one allele over the other. The offspring always completely looked like one of the parents – there was never any phenotype “in between” the two parents. The heterozygous individuals were indistinguishable from the homozygous dominant individuals. Is it possible for both alleles to be dominant, or neither to be completely dominant? The answer to both of these questions is yes.
    ::门德尔的统治者表现出一个异性人完全凌驾于另一个异性人之上。 后代长得总是完全像父母中的一方 — — 父母之间从未有过任何“芬诺型 ” 。 异体zygous人与同性人占主导地位的个人是无法区分的。 这两种异体人能否都占据主导地位,或者不能完全占据主导地位? 这两个问题的答案都是肯定的。

    Codominance
    ::共居情况

    Codominance is when two alleles are both expressed in the heterozygous individual; that is, they both affect the phenotype in separate and distinguishable ways ( Figure ). The A, B alleles of the ABO group system are a classic example, and these have been discussed in the Non-Mendelian Inheritance concept. The A and B alleles are codominant with each other. When a person has both an A and a B allele, the person has type AB blood. When two persons with AB have children, the children can be type A, type B, or type AB. There is a 1A:2AB:1B phenotype ratio instead of the 3:1 phenotype ratio found when one allele is dominant and the other is recessive.
    ::共占优势的是,当两个所有者都以异体阳性人的个人表示,即它们都以单独和可辨别的方式影响苯型(图 ) 。 ABO 组系的 A, B 类所有者是一个典型的例子,在非Mendelian 继承概念中已经讨论过这些例子。 A 类和 B类所有者是彼此共占优势的。当一个人同时有A 和 B 类所有者同时有 AB 血时,该人有 AB 类血。当两个有 AB 的人有子女时,孩子可以是 A 类、 B 类或 AB 类。 有一种 1A: 2AB: 1B 型比 , 而不是当一个所有者占主导地位时发现的 3:1 个苯型比率, 而另一个是休眠 。

    Bloodtype as Determined by Multiple Alleles
    I A I B i
    I A I A I A Type A I A I B Type AB I A i Type A
    I B I A I B Type AB I B I B Type B I B i Type B
    i iI A Type A iI B Type B ii Type O

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    Codominant Inheritance. The A and B alleles are codominant. An AB heterozygous individual has type AB blood.
    ::共同继承。A和B等同系同系异系异系异系异系。AB异系同系异系异系人有AB血。

    Hemoglobin Beta Gene
    ::血红蛋白 Beta Gene

    Hemoglobin is the iron-containing oxygen- transport protein in the red blood cells of all vertebrates . The hemoglobin molecule is an assembly of four globular subunits, each tightly associated with a non-protein heme group. The heme group binds to the iron ion . The most common hemoglobin is hemoglobin A, a tetramer consisting of two alpha and two beta subunits, denoted as α2β2.
    ::血红蛋白是所有脊椎动物红细胞中的含铁氧迁移蛋白,血红蛋白分子由四个球状子单位组成,每个单位均与非蛋白性肝细胞组紧密相连。血红蛋白组与铁离子结合。最常见的血红蛋白是血红蛋白A,一种四聚物,由两个α和两个β子单位组成,称为α2β2。

    Another example of codominance in humans is with the locus for the Beta-globin component of hemoglobin. The two alleles Hb A and Hb S produce three polypeptides complexes based on the combinations of alleles: Hb A /Hb A , Hb A /Hb S , and Hb S /Hb S . In heterozygous individuals, both the alleles are expressed. Normal hemoglobin is produced with the Hb A allele, while Hb S turns normal, round red blood cells into abnormally curved (sickle) shapes. Hb S /Hb S results in sickle- disease , whereas the heterozygous Hb A /Hb S results in the phenotypically distinct sickle-cell trait .
    ::人类的共生优势的另一个例子是血红蛋白的Beta-globin成分的露天地。两种异形HbA和HbS根据异形的组合产生三种聚苯醚复合体:HbA/HbA、HbA/HbS和HbS。在血色突厥人中,这两种异形都有表象。正常的血红蛋白与HbA allele一起产生,而HbS则变成正常的圆红血细胞,形成异常的曲线(希氏)形状。HbS/HbS导致镰状病,而异形的HbA/HbS则导致异形的镰状细胞特征。

    Sickle cell disease confers some resistance to malaria parasitization of red blood cells, so that individuals with sickle-cell trait (heterozygotes), who do not have sickle-cell disease, have a selective advantage in some environments.
    ::镰状细胞疾病对红细胞的疟疾寄生性具有一定的抗药性,因此,没有镰状细胞病的有镰状细胞(异体细胞)特征的人在某些环境中有选择性的优势。

    Sickle cell anemia

    In sickle cell disease or sickle cell anemia, Hb S /Hb S homozygotes have sickle shaped red blood cells which block blood flow. Due to codominance, Hb A /Hb S heterozygotes have a mixture of normal and sickle shaped cells.
    ::在镰状细胞病或镰状细胞贫血病中,HbS/HbS同性锥体有镰状红细胞,这些红细胞阻断了血液流动,HbA/HbS异性锥体混合了正常和镰状细胞。

    Incomplete Dominance
    ::不完全占多数

    Incomplete dominance is seen in heterozygous individuals with an intermediate phenotype. For example, if had ever observed a medium length plant when a tall and short plant were crossed, that would have suggested incomplete dominance. In incomplete dominant situations, the phenotype expression is dependent on the dosage of the genes. Two copies of the gene result in full expression, while only one copy produces partial expression and an intermediate phenotype.
    ::例如,如果曾观察到过中长的、短的、高的、短的植物,那么就表明其具有不完全的支配地位。 在不完全的主导情况下,苯型的表达方式取决于基因的剂量。 两种基因的复制件导致完全的表达方式,而只有一种则产生部分表达方式和中间的苯型。

    The most well-studied example of incomplete dominance in humans occurs in the genes for curly hair. Inheriting a gene for curly hair from one parent and a gene for straight hair from the other parent will give a hair with a phenotype intermediate between curly and straight hair, which is wavy hair. Human height is also due to incomplete dominance, although there is more than one gene involved in height.
    ::人类不完全占支配地位的最受人研究的例子出现在卷发的基因中。 父母一方继承卷发的基因,而父母另一方继承直发的基因,将产生卷发和直发之间带有发型型中间体的发型,即卷发。 人高还因为不完全占支配地位,尽管身高涉及不止一个基因。

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    In this replica of Michaelangelo's David, wavy hair is apparent.
    ::在麦可朗基罗的大卫的复制品中, 卷发是显而易见的。

    Summary
    ::摘要

    • Codominance is when two alleles are both expressed in the heterozygous individual.
      ::共占优势的是,两个异体都以异体zygous个人表示。
    • Incomplete dominance is seen in heterozygous individuals with an intermediate phenotype.
      ::在具有中间苯型的异体兹古斯人中可以看到不完全的支配地位。

    Review
    ::回顾

    1. Discuss the difference between codominance and incomplete dominance. Give examples.
      ::讨论占优势和不完全占优势之间的区别。请举例说明。
    2. Pegasus is one of the best known creatures in Greek mythology that is part horse and part bird. A cross between a blue female Pegasus and a white male Pegasus produces offspring that are silver. The color of a Pegasus is determined by two alleles, H B for blue and H W for white.
      1. What type of inheritance is this an example of?
        ::这是哪一种继承的例子?
      2. If a heterozygous female mates with a heterozygous male, what are the genotypes of the parents?
        ::如果一个异体突变的女伴和一个异体突变的男伴 父母的基因类型是什么?
      3. Predict the genotypic and phenotypic ratios that would result from a cross between these two parents.
        ::预测这两个父母之间的交叉导致的基因和基因比率。

      ::Pegasus是希腊神话中最有名的生物之一,它是部分马和部分鸟。 蓝色女性Pegasus与白男性Pegasus之间的十字架会产生银色的后代。 Pegasus的颜色由两个同龄人决定, HB为蓝色, HW为白色。 这个继承是哪一种例子? 如果一个异体zygous与男性异体动物的异体女伴,父母的基因类型是什么? 预测出这两个父母之间的交叉会形成基因和血型比率。
    3. The Gajasimha in Indian mythology is a magical creature with the body of a lion and head of an elephant. A cross between a blue female Gajasimha and a white male Gajasimha produces offspring that has blue and white fur. The color of a Gajasimha is determined by two alleles, H B for blue and H W for white.
      1. What type of inheritance is this an example of?
        ::这是哪一种继承的例子?
      2. A blue female mates with a heterozygous male, what are the genotypes of the parents?
        ::蓝色女性伴侣和异性恋男性 父母的基因类型是什么?
      3. Predict the genotypic and phenotypic ratios that would result from a cross between these two parents.
        ::预测这两个父母之间的交叉导致的基因和基因比率。

      ::印度神话中的Gajasimha是一个有狮子和大象头部的神奇生物。 蓝色女性Gajasimha和白男性Gajasimha之间的十字架产生了蓝毛和白毛的后代。 Gajasimha的颜色是由两个同龄人决定的, 蓝色是HB,白色是HW。 这是什么样的继承例子? 一个蓝女性伴侣和一个男性异性动物, 父母的基因类型是什么? 预测出这两个父母之间的交叉会产生的基因和血型比率。