commonly used to describe preservation of the precise order of genes on a chromosome passed down from a common ancestor, despite more "old school" geneticists rejecting what they perceive as a misappopriation of the term, preferring collinearity instead. The analysis of synteny in the gene order sense has several applications in genomics. Shared synteny is one of the most reliable criteria for establishing the orthology of genomic regions in different species. Additionally, exceptional conservation of synteny can reflect important functional relationships between genes. For example, the order of genes in the "Hox cluster", which are key determinants of the animal body plan and which interact with each other in critical ways, is essentially preserved throughout the animal kingdom. Synteny is widely used in studying complex genomes, as comparative genomics allows the presence and possibly function of genes in a simpler, model organism to infer those in a more complex one. For example, wheat has a very large, complex genome which is difficult to study. In 1994 research from the John Innes Centre in England and the National Institute of Agrobiological Research in Japan demonstrated that the much smaller rice genome had a similar structure and gene order to that of wheat. Further study found that many cereals are syntenic and thus plants such as rice or the grass Brachypodium could be used as a model to find genes or genetic markers of interest which could be used in wheat breeding and research. In this context, synteny was also essential in identifying a highly important region in wheat, the Ph1 locus involved in genome stability and fertility, which was located using information from syntenic regions in rice and Brachypodium. Synteny is also widely used in microbial genomics. In Hyphomicrobiales and Enterobacteriales, syntenic genes encode a large number of essential cell functions and represent a high level of functional relationships. Patterns of shared synteny or synteny breaks can also be used as characters to infer the phylogenetic relationships among several species, and even to infer the genome organization of extinct ancestral species. A qualitative distinction is sometimes drawn between macrosynteny, preservation of synteny in large portions of a chromosome, and microsynteny, preservation of synteny for only a few genes at a time. Computational detection Shared synteny between different species can be inferred from their genomic sequences. This is typically done using a version of the MCScan algorithm, which finds syntenic blocks between