title: Dependence of paracentric inversion rate on tract length.
abstract: BACKGROUND
  We develop a Bayesian method based on MCMC for estimating the relative rates of pericentric and paracentric inversions from marker data from two species. The method also allows estimation of the distribution of inversion tract lengths.
  
  
  RESULTS
  We apply the method to data from Drosophila melanogaster and D. yakuba. We find that pericentric inversions occur at a much lower rate compared to paracentric inversions. The average paracentric inversion tract length is approx. 4.8 Mb with small inversions being more frequent than large inversions. If the two breakpoints defining a paracentric inversion tract are uniformly and independently distributed over chromosome arms there will be more short tract-length inversions than long; we find an even greater preponderance of short tract lengths than this would predict. Thus there appears to be a correlation between the positions of breakpoints which favors shorter tract lengths.
  
  
  CONCLUSIONS
  The method developed in this paper provides the first statistical estimator for estimating the distribution of inversion tract lengths from marker data. Application of this method for a number of data sets may help elucidate the relationship between the length of an inversion and the chance that it will get accepted.
authors.affiliation: Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, USA. tly2@cornell.edu
authors.forename: Thomas L
authors.initials: TL
authors.lastname: York
authors.forename: Rick
authors.initials: R
authors.lastname: Durrett
authors.forename: Rasmus
authors.initials: R
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D007446:Chromosome Inversion; D002874:Chromosome Mapping / Q000379:methods*; D004330:Drosophila / Q000235:genetics*; D005787:Gene Frequency; D005819:Genetic Markers / Q000235:genetics*; D007438:Introns / Q000235:genetics*
chemical_list: D005819:Genetic Markers