核外遗传即细胞质遗传

1、YANGTZE NORMAL UNIVERSITYChapter 9 Extranuclear inheritanceExtranuclear inheritanceCytoplasmic inheritance, genetic factors in cytoplasm control the hereditary phenomenon in eukaryote.Maternal inheritanceFilial phenotypes are not determined by their genotypes, but by their maternal genotypestransien

2、t maternal inheritancepermanent maternal inheritance核外遗传：核外遗传：即细胞质遗传，真核生物中染色体以外的遗传因子所决定的遗传现象母性影响：母性影响：子代表型不由自身的基因决定而与母本表型相同的现象 短暂的母性影响短暂的母性影响 持久的母性影响持久的母性影响 色氨酸色氨酸(tryptophan) 犬尿氨酸犬尿氨酸(kynurenine) 色素色素(pigment) 卵细胞中积累卵细胞中积累(pigment in the egg cell)灰色灰色(gray)AYANGTZE NORMAL UNIVERSITY3:1Permanent mat

3、ernal inheritanceDextrol shell (dominance D) versus sinistral shell (recessiveness d) in Limnaea peregra 椎实螺外壳右旋（椎实螺外壳右旋（D）对左旋（）对左旋（d）显性）显性P XDD ddDdF1F2F3Dextrol全右旋全右旋YANGTZE NORMAL UNIVERSITYNature and characteristics of cytoplasmic inheritance核外遗传的性质和特点核外遗传的性质和特点u Cytoplasmic genetic factors resi

4、de on mitochondrion or chloroplast DNA, replicate by themselves, and pass from one generation to the next through cytoplasmu The inheritance pattern is inconsistent with that of nuclear genes. Filial phenotypes are determined by maternal characters. The cytoplasm of a zygote derives from the female

5、gamete while the male gamete provides only nuclear chromosomesu 核外遗传因子存在于线粒体或叶绿体核外遗传因子存在于线粒体或叶绿体基因组中，它们能够自主复制，通过基因组中，它们能够自主复制，通过细胞质由一代传到另一代细胞质由一代传到另一代u 遗传传递行为不按核基因的方式进行遗传传递行为不按核基因的方式进行，杂交子代中往往只表现母方的性状，杂交子代中往往只表现母方的性状，杂交后所合成的合子其细胞质几乎，杂交后所合成的合子其细胞质几乎来自雌性配子，雄性配子只提供一个来自雌性配子，雄性配子只提供一个核（染色体）核（染色体）YANGTZE

6、NORMAL UNIVERSITY Section 3 Sensitive substance inheritance in cell细胞内敏感性物质的遗传The inheritance pattern of Kappa particles in Paramecium aurelia particles transfer by cytoplasm, maintain by nuclear gene K, and can not maintain as well as proliferate an individual with genotype kk Infective inheritance

7、 in DrosophilaSigma()Sex ratio(SR)草履虫卡巴粒（草履虫卡巴粒（）的遗传）的遗传卡巴粒通过细胞质传递，但它的保持要依赖于核基因（K）的存在，kk个体细胞质中的不能保持和增殖 果蝇的感染性遗传果蝇的感染性遗传 颗粒 性比（SR）现象YANGTZE NORMAL UNIVERSITYYANGTZE NORMAL UNIVERSITYSection 4 Inheritance and molecular mechanism of mitochondrion Mitochondrion genome character (mtDNA) Naked DNA double-

8、helix, non-repetitive DNA sequences, short polynucleotide sequences, semiconservative replication by, D loop, as well as rolling loop, the synthetic regulation independent on that of nuclear DNA, and the replication controlled by nuclear genesMitochondrion transcription and translation Mitochondrion

9、 is not all indepent for its heredity function. mtDNA can pass to the offspring, transcript to mRNA, and translate to polypeptides in mitochondrion. Mitochondrion has 55S to 80S ribosomes consisted of two subunits, each with a rRNA transcripted by mtDNA. There existed difference in genetic codes bet

10、ween mitochondrion and nucleus. Organellas such as mitochondrion are controlled by both the nuclear genome and mitochondrion genomeYANGTZE NORMAL UNIVERSITY第三节第三节 线粒体的传递方式及其分子基础线粒体的传递方式及其分子基础 线粒体基因组的一般特点线粒体基因组的一般特点 裸露的DNA双链分子；绝大多数mtDNA无重复序列，含有短的多聚核苷酸序列；半保留复制，以形式、D环合成和滚环方式； mtDNA的合成调节与核DNA的合成调节彼此独立，但

11、它的复制仍受核基因的控制 线粒体的转录与翻译系统线粒体的转录与翻译系统 线粒体是半自主性的，mtDNA能传递给后代，还能转录所编码的遗传信息，合成线粒体自身所特有的多肽；线粒体中有核糖体，大小55S80S，由两亚基组成，每亚基有一条rRNA，它由mtDNA转录而成；线粒体遗传密码与通用遗传密码有差别；线粒体这类细胞器是受核基因组和线粒体基因组两套遗传系统控制 YANGTZE NORMAL UNIVERSITYYANGTZE NORMAL UNIVERSITYSection 5 Inheritance and molecular foundation of chloroplast Chlorop

12、last genome(ctDNA) Naked two-loop double helical DNA molecule composed of 120 to 127kb, DNA sequences which do not include 5-methylcytosine to indicate the ctDNA purification, two inverted repeat sequences separated by two non-repetitive sequences, ctDNA can replicate by itself with the replicase en

13、coded by nuclear genes, and independently perform transcription and translation. 70S ribosome, subunit 50S and 30S composed of rRNA 23S, 4.5S, 5S,16S encoded by ctDNA. Additionally, ctDNA contains approximately 30 sequences to encode tRNA with introns being in some genes Heredity pattern of Chloropl

14、ast A small number of polypeptides in chloroplast is controlled by ctDNA while both nuclear DNA and ctDNA determine its growth, proliferation, and function. Chroloplast is not all independent in genetic function. For Its protein synthesis, chroloplast is classified as three types; that is, 1) protei

15、n PSp700 chla and membrane protein PbA encoded by ctDNA and synthesized on 70S ribosome, 2) PSchla/b protein encoded by nuclear DNA and synthesized on 80S ribosome in cytoplasm，and 3) the large subunit and small subunit of ribulose bisphosphate carboxylase controlled by ctDNA and nuclear DNA, respec

16、tivelyYANGTZE NORMAL UNIVERSITY第五节第五节 叶绿体遗传及分子基础叶绿体遗传及分子基础 叶绿体基因组叶绿体基因组(ctDNA) 环状裸露的双环状双螺旋分子，120-127kb，碱基序列中不含5-甲基胞嘧啶（作为鉴定ctDNA提纯的指标）；两个反向重复序列，其间由两段大小不等的非重复序列间隙；能自我复制，复制酶由核基因编码；有自己的转录翻译系统，核糖体属70S型，组成50S、30S亚基的23S、4.5S、5S、16S的rRNA由ctDNA编码，ctDNA中还有30多个tRNA基因的编码序列，一些基因中发现有内含子 叶绿体的半自主性叶绿体的半自主性: ctDNA只对组

17、成叶绿体的部分多肽有控制作用，而整个叶绿体的发育、增殖及其机能的正常发挥却是由核DNA和ctDNA共同控制的，也是半自主性细胞器；就叶绿体蛋白质的合成而言，可分为3类：A、ctDNA编码：在70S核糖体上合成PSp700chla蛋白质、膜蛋白PbA，B、核DNA编码：在细胞质中80S核糖体上合成PSchla/b蛋白质，C、由ctDNA和核DNA共同控制：二磷酸核酮糖羧化酶的大亚基由ctDNA编码、小亚基由核DNA编码YANGTZE NORMAL UNIVERSITYSection 6 Cytoplasmic inheritance and plant male sterility核外遗传与植物

18、雄性不育 Plant male sterility Plant pollen abortion is called plant male sterility Nuclear male sterility Genes on chromosomes in nucleus determine male sterility, pollen abortion occurres in spore mother cell in meiosis and is complete Cytoplasmic -nuclear male sterility Male sterility is controlled ty cytoplasmic-nuclear genes and pollen abortion occurres in micr