Genetics of Neurospora

正在进行的项目利用了该实验室在神经孢子菌生物学和遗传学方面的长期经验。这些项目涉及突变和表观遗传基因沉默、子囊发育事件、减数分裂驱动和物种描述。大多数实验都集中在生命周期的性阶段，并利用神经孢子虫的特征，使其有利于研究，而这些研究不能轻易地用酵母进行。例如：(1)子囊发育的遗传和规划。已知影响性相的基因的表达和作用位点将使用绿色荧光蛋白（GFP）进行检测。显微镜下的研究将继续研究未配对DNA在沉默基因中的作用，这些基因在性阶段表达。(2)四asperma的生殖遗传学和生物学。该物种的子囊发育被重新编程为产生自育异核产物。交配型位点和着丝粒之间的杂交被取消，大多数交配型染色体的重组也被阻止。目前正在研究该块的遗传基础，并在其他属的4孢子种中研究子囊规划模式。(3)四asperma的隐动力元件。在8孢子子囊中，具有敏感核的子囊孢子在杂合的杂交中被孢子杀手减数分裂驱动元件（Sk）杀死。然而，如果敏感核和杀伤核被包裹在同一个子囊孢子中，它们就能存活。由于四asperma在每个异核子囊孢子中通常有两种类型的细胞核，因此Sk元素可能存在，即使它们不明显。用自然种群的菌株进行的实验将检验这种可能性。(4)基因座特异性突变子。涉及草稻中eas基因的特定等位基因的杂交产生的后代在特定的非连锁位点发生突变。这种行为表明，目标基因的重复拷贝与eas突变相关联，导致RIP（重复诱导点突变）。这一假设正在用一个缺乏RIP的突变体的杂交纯合子进行检验。这个实验室长期致力于将神经孢子虫作为一种模式生物进行研究。模式生物是科学的巨大财富，因为从中获得的见解可以用来指导和经常加速对其他相关但不太了解的生物的研究。实验室提供的大量遗传和生物信息使神经孢子虫成为比较其他丝状真菌的理想参考生物，包括植物和动物病原体、商业上重要的物种和无数生态上重要的形式。

Ongoing projects take advantage of this laboratory's long experience with Neurospora biology and genetics. The projects concern mutational and epigenetic gene silencing, developmental events in the ascus, meiotic drive, and the delineation of species. Most of the experiments center on the sexual phase of the life cycle and exploit features of Neurospora that make it advantageous for investigations that cannot be readily carried out with yeast. Examples include the following: (1) Genetics and programming of ascus development. The expression and sites of action of genes known to affect the sexual phase will be examined using green fluorescent protein (GFP). Microscopic studies will continue on the effect of unpaired DNA in silencing genes that are expressed in the sexual phase.. (2) The reproductive genetics and biology of N. tetrasperma. Ascus development in this species is reprogrammed to produce self-fertile heterokaryotic products. Crossing over is abolished between the mating type locus and the centromere and recombination is also blocked over most of the mating-type chromosome. The genetic basis of the block is being studied, and modes of ascus programming are being examined in 4-spored species of other genera. (3) Cryptic drive elements in N. tetrasperma. In 8-spored asci, ascospores with sensitive nuclei are killed in crosses that are heterozygous for a Spore-killer meiotic drive element (Sk). Sensitive nuclei survive, however, if they are enclosed in the same ascospore with a killer nucleus. Because N. tetrasperma normally has two types of nuclei in each heterokaryotic ascospore, Sk elements may be present even though they are not apparent. Experiments with strains from natural populations will examine this possibility. (4) A locus-specific mutator. Crosses involving a particular allele of the eas gene in N. crassa produce progeny that are mutated at a specific unlinked locus. The behavior suggests that a duplicate copy of the target gene is linked to the eas mutation, resulting in RIP (repeat induced point mutation). This hypothesis is being tested using crosses homozygous for a mutant that is deficient in RIP.This laboratory has long been devoted to developing Neurospora as a model organism. Model organisms are great assets to science, for the insights gained from them can be used to guide and often accelerate studies of other related but less well-understood organisms. The vast store of genetic and biological information to which the laboratory has contributed makes Neurospora an ideal reference organism with which to compare other filamentous fungi, including plant and animal pathogens, commercially important species, and innumerable ecologically important forms.