Relationship between physical and genetic distances along the zebra finch Z chromosome.
Nine bacterial artificial chromosomes containing genes linked to the Z chromosome of the zebra finch (Taeniopygia guttata) were localized using FISH on synaptonemal complex spreads. Their positions were correlated with those previously reported on the mitotic Z chromosome, showing a linear relationship between positions along the mitotic chromosome and its synaptonemal complex. Distances in cM between the genes were calculated using a cytological map of the crossing-over based on the distribution of MLH1 foci along the ZZ synaptonemal complex (MLH1-cM map). It is shown that physical and genetic distances lack a linear relationship along most of the chromosome length, due to clustering of crossover events around the telomeres. This relationship departs strongly from that observed in the chicken Z chromosome and reflects the existence of different recombination rates and patterns among birds in spite of wide genomic conservation.
Pigozzi
María Inés
MI
Instituto de Investigaciones en Reproducción, Universidad de Buenos Aires, Buenos Aires, Argentina. mpigozzi@fmed.uba.ar
D000818:Animals; D002503:Centromere / Q000235:genetics; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics*; D046369:Finches / Q000235:genetics*; D023061:Gene Order; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008540:Meiosis; D008938:Mitosis; D009687:Nuclear Proteins / Q000235:genetics; D049471:Pachytene Stage; D020161:Physical Chromosome Mapping; D013094:Spermatozoa / Q000166:cytology; D013573:Synaptonemal Complex / Q000378:metabolism
D009687:Nuclear Proteins