选择作用下家鸡淀粉酶的遗传多态性研究 ――基因频率分化、相关效应估计和标记辅助选择试验

对“三黄”鸡4个品系的血液淀粉酶(Amy-1)基因频率进行了估计, 结果表明: Amy-1基因频率具有明显的品系特异性, 父系Amy-1A高; 母系Amy-1B频率高。人工选择可能是导致两个具有相同遗传来源的品系（Ⅱ系和Ⅲ系）Amy-1基因频率发生分化的原因。利用线性模型估计了Amy-1基因的加性效应,结果表明：Amy-1B有利于产蛋性能, 而Amy-1A有利于体重和蛋重的提高。标记辅助选择试验结果表明, 选择Amy-1遗传型来改变家禽品系类型是可能的, 但效果有限, 因此, 对Amy-1的选择应结合于综合的选择方案之中。 Abstract　Gene frequencies at Amy-1 locus were estimated in 4 grand-parent lines of yellow broilers. The results indicated that the male lines exhibited higher frequency of Amy-1A while the female lines were featured by higher frequency of Amy-1B. Differentiation in gene frequencies at Amy-1 locus in line Ⅱ and Ⅲ, which were of identical origin, might be attributable to varied history of selection. Estimation of genotypic and gene effects suggested that Amy-1B was associated with higher laying performance, while Amy-1A was favorable for increased body and egg weights. It was also revealed that changing types of poultry lines by means of altering genotypes at locus Amy-1 was feasible, but its effect was limited. Accordingly, it is preferable to incoporate biochemical marker-assisted selection into complex programs of selection.     

家鸡血浆淀粉酶的多态现象

本研究采用水平平板聚丙烯酞胺凝胶电泳法,测定了杏花鸡、石歧杂鸡、粤黄鸡、郑州红鸡、长沙黄 鸡和白来航鸡的血浆淀粉酶。发现各鸡种的AMY-1位点均存在多态现象,还发现在杏花鸡中存在着 控制血浆淀粉酶的另一位点（Amy-2), Amy-2位点上有一对显隐性基因（Amy-2t, Amy-2')。经交 配试验,发现Amy-2位点与Amy-1位点是紧密连锁的,重组率为二。3030     

中国地方鸡种血液淀粉酶Amy-1多态性

本文用聚丙烯酰胺水平凝胶电泳法测定了我国 10个地方鸡种的血液淀粉酶Amy-1多态性,发现我国地方鸡种Amy-1的AA、BB型纯合子基因型频率很低, AB型基因型频率很高,杂合子显著过量,且普遍存在Amy-1分布不平衡。还发现Amy-1A和Amy-1B两个等位基因频率在所有10个鸡种中几乎均为0.5。 Abstract:Blood amylase-1 polymorphism in 10 Chinese native chicken breeds was determined with polyacrylamide horizontal gel electrophoresis.It was found that both AA and BB genotype frequencies were very low,but AB genotype frequency was very high in Chinese native chicken breeds and that amylase-1 distribution in these breeds was widely deviated from Hardy-Weinberg equilibrum proportion.Both Amy-1A and Amy-1B gene frequencies were nearly 0.5 in all 10 breeds.     

选择作用下家鸡淀粉酶的遗传多态性研究--基因频率分化、相关效应估计和标记辅助选择试验

对“三黄”鸡4个品系的血液淀粉酶（Amy-l）基因频率进行了估计,结果表明：Amy-l基因频率具有明显的品系特异性,父系Amy－lA高;母系Amy-lB频率高．人工选择可能是导致两个具有相同遗传来源的品系（Ⅱ系和Ⅲ系）Amy-l基因频率发生分化的原因．利用线性模型估计了Amy－l基因的加性效应,结果表明：Amy-lB有利于产蛋性能,而Amy－l4有利于体重和蛋重的提高。标记辅助选择试验结果表明,选择Amy-l传型来改变家禽品系类型是可能的,但效果有限,因此,对Amy-l的选择应结合于综合的选择方案之中．     

藏鸡线粒体全基因组序列的测定和分析

通过PCR扩增,测序,拼接,获得藏鸡（Tibetan Chicken）线粒体全基因组序列并进行数据分析处理。藏鸡线粒体全基因组序列全长16783bp,共有13个蛋白质编码基因、2个rRNA基因、22个tRNA基因和1个D-loop区。模拟电子酶切结果显示,藏鸡DraI酶的酶切结果和先前报道的原鸡,茶花鸡,尼西鸡和大理漾濞黄鸡的酶切结果都不相同,为藏鸡特有。基于D-loop区全序列和13个蛋白质编码基因序列,采用N-J算法与原鸡属4个种,3个亚种和3个家鸡品系构建系统进化树：初步确定藏鸡起源于红原鸡,与家鸡中的来航鸡、白洛克鸡亲缘关系最近,但是藏鸡的进化与来航鸡、白洛克鸡这两个家鸡品系又显得相对独立。推测可能原因是藏鸡的祖先在进入高原以后处于相对封闭的环境,从而形成了独特群体遗传特性。     

云南省三个地方鸡种血液淀粉酶多态性分析

采用垂直平板聚丙烯酰胺凝胶电泳法,测定了版纳斗鸡、武定鸡、尼西鸡的血液淀粉酶(Amy)。发现云南3个地方鸡种Amy-1的AA、BB型纯合子基因型频率很低, 其中尼西鸡为0,而AB型杂合子基因型频率很高,杂合子显著过量,均偏离Hardy-Weinberg平衡。在版纳斗鸡少数个体中还发现控制血液淀粉酶的另一位点Amy-2。 Abstract:Blood amylase polymorphism in 3 Yunnan local chicken breeds(Banna ganme chicken,Wuding chicken.Nixi chicken)was determined with polyacrylamide gel electrophoresis,It was found that frequen cies of both AA and BB homozygous genotype were very low,while AB heterozyote genotype frequency was very high in 3 Yunnan local chicken breeds and that Amy-1 distribution in these breeds was widely deviated from Hardy-Weinberg equilibrium proportion.We have also found that there is another locus Amy-2 which controls the amylase in a few Banna game chickens.     

华山松印度块菌菌根中的块菌交配型基因的初步研究

印度块菌属于子囊菌门异宗配合真菌,其交配型基因(mating type gene)的表达调控与块菌子囊果的形成和发育直接相关。已有研究表明在种植园内,两种交配型基因竞争性地感染宿主植物且不同交配型菌株的时空分布吻合概率可能是决定子实体产出及产量的关键因素之一。为增加印度块菌子囊果形成的几率,本研究以交配型基因MAT1-1-1及MAT1-2-1作为分子标记,检测了接种印度块菌菌剂后6个月、24个月和36个月的华山松菌根中块菌的两种交配型基因的动态变化,结果表明接种后24个月的单株苗存在两种交配型基因的菌根苗占总菌根苗的比例最高,暗示在此时间点进行块菌菌根苗室外移栽,有望在后期提高两种交配型菌株的时空分布吻合概率,从而提高子实体产生的几率。     

选择作用下家鸡淀粉酶的遗传多态性研究—基因频率分化,相关效应估计和标

对“三黄”鸡４个品系的血液淀粉酶基因频率进行了估计,结果表明：Ａｍｙ－１基因频率具有明显的品系特异性,父系Ａｍｙ－１＾Ａ高;母系Ａｍｙ－１＾Ｂ频率。     

基于F-2群体的藏鸡羽色、胫色性状的遗传分析

采用白来航、寿光鸡分别与藏鸡进行正反交交配,F1代进行自群交配产生F2群体,观察F1和F2代中羽色、胫色的表现和分离比例。结果表明,白来航鸡的白羽和寿光鸡的黑羽对藏鸡麻羽的遗传方式是完全显性遗传;麻羽是由两个或两个以上的等位基因决定的,只有同时存在这两个或两个以上的等位基因,才可能表现出麻羽来;决定胫色性状的Id/id基因为伴性遗传,隐性基因id在纯合子时有个逐步表达的过程;本研究证实了所用白来航公鸡胫色性状的基因型为显性纯合子。     

钙蛋白酶Ⅰ(CAPN1)基因多态性与鸡肉嫩度和屠体性状的相关研究

为了探讨CAPN1基因作为影响鸡肌肉嫩度候选基因的可能性, 寻找与鸡嫩度性状相关的分子标记, 对钙蛋白酶Ⅰ(CAPN1)基因的CDS区进行SNPs 检测, 分析不同基因型在5个优质肉鸡纯品系和3个配套系间分布规律。利用测序和单链构象多态(SSCP)的方法进行SNPs 检测和基因型的分析, 计算等位基因频率、各位点多态信息含量。结果发现2546位(位点A) 处发生点突变由C→T和3535位(位点B)处发生点突变由G→A。各位点的3 种基因型与肉鸡生产性状的最小二乘分析结果表明,各位点的各种基因型个体在肌纤维密度和部分屠体性状指标存在显著差异(P< 0.05)。初步推断CAPN1基因可能是影响鸡嫩度性状潜在的主效基因或与主效基因连锁, 并且这些位点具有成为分子标记的潜在可能。     

Alleles at plasma alpha-amylase locus(Amy-1) of the house musk shrew(Suncus murinus): frequency distribution and new variants in laboratory lines and local Asian populations

Among nine laboratory shrew lines originating from the Japanese islands (Nag, Tok, TKU, Ize, Tr and OKI lines), West Java (Bog), Bangladesh (BAN) and Sri Lanka (SRI), Nag, Tr and Bog were fixed with Amy-1b and SRI with Amy-1a. The remaining lines were still highly polymorphic with the two alleles. A new electrophoretic band C was found in the BAN line and concluded to be expressed by a codominant allele, Amy-1c, which was carried by a single heterozygous female from among eleven wild shrews of the original breeding stock. In most local populations of the Asian shrews surveyed, Amy-1b was more common than Amy-1a. The Sri Lanka population was clearly distinguishable from the others, being nearly fixed with Amy-1a. The C band was found in eleven (one homozygous) of 86 wild shrews caught in Bangladesh. Of a total of 234 wild shrews collected from four Japanese and two Indonesian islands, Bangladesh, and Sri Lanka, only two showed different AMY-bands from AMY-A, -B and -C, and such bands were not found in the laboratory-bred shrews examined.     

Genetic variants found in plasma alpha-amylase and erythrocyte carbonic anhydrase in the musk shrew (Suncus murinus)

Genetic variants of plasma alpha-amylase and erythrocyte carbonic anhydrase in the musk shrew (Suncus murinus) were found by electrophoreses using cellulose acetate plates. It was demonstrated that phenotypic differences of alpha-amylase are controlled by two codominant alleles (Amy-1a and Amy-1b) at a single autosomal locus (Amy-1). The segregation data of the carbonic anhydrase phenotypes in the progeny supported the genetic theory of two codominant alleles (Car-1a and Car-1b) at a single autosomal locus (Car-1). The data suggested that there was no close linkage between the two loci, Amy-1 and Car-1. The Car-1 locus was fixed with one of the two alleles in each of the four lines, i.e. Nag, Oki , Tar and Jak originating from wild animals captured in Nagasaki and Naha and Tarama Island, Okinawa, Japan, and in Jakarta, Indonesia, respectively. Oki and Tar lines still showed segregation of the two alleles at the Amy-1 locus.     

Simultaneous expression of salivary and pancreatic amylase genes in cultured mouse hepatoma cells.

The tissue-specific expression of two types of mouse amylase genes does not overlap in vivo; the Amy-1 locus is transcribed in the parotid gland and the liver, while expression of Amy-2 is limited to the pancreas. We identified a mouse hepatoma cell line, Hepa 1-6, in which both amylase genes can be simultaneously expressed. Amy-1 is constitutively active in these cells and is inducible by dexamethasone at the level of mRNA. We demonstrated that the liver-specific promoter of Amy-1 is utilized by the dexamethasone-treated hepatoma cells, and that glucocorticoid consensus sequences are present upstream of this promoter. Amy-2 is not detectable constitutively, but can be activated if the cells are cultured in serum-free medium containing dexamethasone. Expression of Amy-2 in a nonpancreatic cell type has not previously been observed. We speculate that induction of Amy-1 and activation of Amy-2 may involve different regulatory mechanisms. Hepa 1-6 cells provide an experimental system for molecular analysis of these events.     

Genetic control of blood pressure in spontaneously hypertensive rats (SHR)

Genetic control of blood pressure in the SHR strain was studied by three separate experiments which consist of cross analysis between the SHR and Donryu, two-way selecton for high and low blood pressure levels, and successive backcrosses to the parental strains. The results obtained were as follows. 1. The data from genetic crosses between the SHR and Donryu showed the phenotype segregation ratio of 1:1 at the backcross and 1:2:1 at the F2 generation. 2. Two-way selection for high and low blood pressure levels was performed from the F2 generation onward. The separation between the two lines occurred immediately after the first selection. Thereafter, the difference increased gradually with generation. The blood pressure level at the seventh generation of selection became approximately equal to those of the parental strains. 3. Two types of the successive backcross were performed from the F1 hybrids by mating the males showing the highest blood pressure level to Donryu females and the females showing the lowest blood pressure level to SHR males on the other. Bimodality was observed in the distribution of blood pressure levels at each generation. Their phenotypic segregation ratios were accordant with 1:1 on the whole. At the intercross generation during successive backcrosses, a trimodal distribution was observed. 4. These results confirmed that the hypertensive trait of the SHR is regulated by a single major gene and other several genes with minor effect. A gene symbol ht was proposed for this major gene. Concurrently, a congenic strain having the ht gene on the genetic background of the Donryu was developed by the successive backcross system.     

Tissue-specific and insulin-dependent expression of a pancreatic amylase gene in transgenic mice.

The regulatory properties of mouse pancreatic amylase genes include exclusive expression in the acinar cells of the pancreas and dependence on insulin and glucocorticoids for maximal expression. We have characterized a murine pancreatic amylase gene, Amy-2.2y, whose promoter sequence is 30% divergent from those of previously sequenced amylase genes. To localize sequences required for tissue-specific and hormone-dependent activation, we established two lines of transgenic mice. The first line contained a single copy of the complete Amy-2.2y gene as well as 9 kilobases of 5'-flanking sequence and 5 kilobases of 3'-flanking sequence. The second line carried a minigene which included 208 base pairs of 5'-flanking sequence and 300 base pairs of 3'-flanking sequence. In both lines the transgene was expressed at high levels exclusively in the pancreas. Both constructs were dependent on insulin and induced by dexamethasone. Thus, the transferred genes contained the sequences required for tissue-specific and hormonally regulated expression.