Original Title: Recent Advances In Genomic And Genetic Studies In The ArchaeaThe accumulation of archaeal genomes has lagged significantly behind the Bacteria; however, in the last several years the coverage of the major phyla of Archaea has been significantly improved. There are now multiple genomes in several important genera such as Pyrobaculum, Sulfolobus, Thermococcus/Pyrococcus, Halobacterium, Methanosarcina, Methanopyrus and Methanocaldococcus. Comparative genomic studies are now under way, and in many cases there are several consortial multilaboratory groups, such as the SulfoSys community, which have started to break into new systems biology initiatives. At the same time, access to streamlined genetic approaches in the genera Sulfolobus, Thermococcus, Methanosarcina, and Halobacterium/Haloferax has improved significantly and is leveraging the genomic information in the Archaea. The result has been that genome-driven studies of metabolism, DNA replication and repair, transcription and translation, and posttranslational processing have become more detailed and that basic research findings are burgeoning. The areas of global gene regulation, the roles of small RNAs and mechanisms of transcription and DNA replication will be focus areas in the guidelines of this Research Topic. Recently, insights into the unique characteristics of archaeal transcription and the ability to study the effects of mutation in vivo following knock-in gene replacement have resulted in incisive findings.