Investigation Of Meiotic Recombination And Mutation In Neurospora Crassa

As the key point of sexual reproduction, meiosis plays an important role in alternation of generations. Crossover, noncrossover and mutation generated during meiosis is the most important force for genome variation. However, limited by experimental materials and methods, the numbers and distribution of recombination and mutation, especially for noncrossover event, remains poorly understood.In this study, we use next-generation sequencing to investigate recombination and mutation events in multicellular fungi Neurospora crassa. We choose two couples of hybrid parents with different divergence. And we sequenced 20 sets of all four meiotic products,10 for each couple of parents. On average, we found 16.15 crossover(CO) events and 7.6 noncrossover(NCO) events per meiosis per generation. The recombination rate of Neurospora crassa is 20.0cM/Mb. The distribution of crossover events is influenced by chromosome length and the divergence of parents. The distribution of CO and NCO events on different chromosomes was positively correlated with each other. We also discovered an average of mutation rate as 1.53*10-8 per nucleotide per meiosis. Meanwhile, we detected plenty of mitotic mutation events in meiotic products. The base-substitutional mutations in Neurospora crassa has a preference. The majority of mutations were from G/C to A/T. These result showed the meiotic recombination and mutation in multicellular fungi, providing evidences for studying evolution and recombination of multicellular organisms.