01960naa a2200205 a 450000100080000000500110000800800410001910000190006024501110007926000090019052013750019965000130157465300130158765300240160065300140162465300280163870000200166670000200168677300480170619224412012-04-16       2011    bl uuuu     u00u1 u    #d1 aCAIXETA, E. T.  aModified protocol for obtaining isolated and high-resolution pachytene chromosomes.h[electronic resource]  c2011  aThe expansion of molecular cytogenetics has called for the evaluation of pachytene chromosomes as targets for in situ hybridization (ISH) and microdissection. These techniques represent powerful tools for chromosome identification, karyotype comparison, physical mapping and phylogenetic analyses. Because cytogenetic preparations showing well-individualized and cytoplasm-free chromosomes are pre-requisites for ISH and micro-dissection, this work was performed with the aim of developing an improved methodology to obtain individualized pachytene chromosomes of maize (Zea mays L.). The used protocol, based on two steps of enzymatic treatment for establishment of cell suspension, released the pollen mother cells (PMCs) from maize anthers. All slides, prepared from maize PMC suspensions, showed pachytene cells with at least one individualized bivalent. This result was considered a major methodological advance, since it facilitated the scattering of all bivalents. These chromosomes were digitally straightened and four morphological parameters were established to characterize all ten maize bivalents. Considering the conditions of an excellent pachytene cytogenetic preparation for ISH and micro-dissection, the results showed that the applied methodology provided adequate pachytene chromosomes for distinct purposes and can be adapted for other plant species.  aZea Mays  aBivalent  aIsolated chromosome  aPachytene  aStraightened chromosome1 aCARVALHO, C. R.1 aCLARINDO, W. R.  tIn: Nucleusgv.54, n.1, p.3-7, april, 2011.