Plant Genome II Conference
Town & Country Conference Center, San Diego, CA, January, 1994.
PG-II: PRELIMINARY KARYOTYPE IN PINUS ELLIOTTII ENGELM. ELLIOTTII
USING FLUORESCENCE IN SITU HYBRIDIZATION AND FLUOROCHROME BANDING
PATTERNS
PRELIMINARY KARYOTYPE IN PINUS ELLIOTTII ENGELM. ELLIOTTII
USING FLUORESCENCE IN SITU HYBRIDIZATION AND FLUOROCHROME BANDING
PATTERNS.
R.L. Doudrick, C.D. Nelson, W.L. Nance, J.S. Heslop-Harrison, and
T. Schwarzacher. R.L. Doudrick, C.D. Nelson, W.L. Nance,
U.S.D.A. Forest Service, Southern Forest Experiment Station,
Gulfport, MS, USA; J.S. Heslop-Harrison, T. Schwarzacher, John
Innes Centre, Karyobiology Group, Norwich, U.K.
Idiograms and a preliminary karyotype were prepared from
metaphase spreads of seedling root-tips in slash pine (Pinus
elliottii Engelm. elliottii; 2n =24). Each metaphase had 11
pairs of long metacentric chromosomes and one pair of short
submetacentrics. The long metacentric chromosomes were similar
in shape and length and could only be distinguished individually
by supplementing statistical analysis of characteristics with
Qualitative analysis of patterns of probe hybridization and
fluorochrome banding. Regions on chromosomes with homology to
previously described 18S - 25S ribosomal DNA (RDNA) and 5S RDNA
were located by fluorescence in situ hybridization. All cells
observed had at least 12, and as many as 14 18S - 25S rDNA sites,
on site present on each of seven separate pairs of chromosomes.
One region of hybridization was observed at the centromeric
region of an additional pair of chromosomes. A major site of 5S
rDNA hybridization was localized on a ninth pair of chromosomes
with minor sites on chromosomes with and without 18S - 25S sites.
Chromosomes were stained with the DNA base-specific binding
fluorochromes chromomycin A3 (CMA) and 4',
6-diamidino-2-phenylindole (DAPI). Bands of CMA appeared at
interstitial and/or proximal regions of several pairs of
chromosomes. The interstitial bands of CMA were mostly localized
at secondary constrictions, the hybridization sites of 18 - 25S
rDNA. Bands of DAPI appeared at interstitial and/or centromeric
regions of nearly all chromosomes. A pair of bands of DAPI were
observed near the centromeric region of one pair of chromosomes.
Return to Previous Page or Intl-PAG Homepage