Karyotypic studies have been made on 21 wild species of
Compositae from North and Central India. Chromosome morphology of most of these
species was unknown previously.
Parameters for karyotypic comparison include chromosome size, haploid
length, symmetry and gradient indices, and type of karyotypic symmetry.
Depending upon the size of chromosome and position of primary constriction,
karyotypic formulae are worked out for all these taxa. Chromosomes are mostly
medium sized. Karyotypic symmetry of 2A and 2B types are the most Common.
Highly assymetrical karyotype of 4A type is represented in Pterotheca falconeri
with all the three pairs of chromosomes being acrocentric. Role of chromosomal
rearrangements in the evolution of the family is evident.
Showing posts with label Karyotype. Show all posts
Showing posts with label Karyotype. Show all posts
Tuesday, 28 January 2020
Thursday, 26 December 2019
KARYOTYPE AND BANDING PATTERN STUDY IN AN INDIAN MICROCHIROPTERA, MEGADERMA LYRA LYRA GEOFFROY
Karyomorphology and the C-, G-banding pattern analyses of
chromosomes of the microchiroptera Megaderma lyra lyra Geoflroy were done. The
diploid number 54 with the chromosome formulae n = 14m +12sm+Ist/t and NF = 107
for male, n = 14m+12sm + 1st and NF = 108 for female with relative percentage
length range from 5:23 ± 0.48 to 2.07 ± 0. 17 for autosomes, 5:08 ± 0.99 for
the X and 0.05 ± 0.01 for the Y have been detected. Comparison of the karyotype
and the banding patterns of chromosomes with that of the earlier reports on the
same species collected from different geographical regions showed a
considerable amount of differences in the fine structure of chromosomes, in the
amount of heterochromatin and in the distribution pattern of G-bands; which
might have occurred due to the variation among the different allopatric
populations of the same species. Unlike that of other bats, the presence of
very high amount of constitutive heterochromatin with a unique pattern of its
distribution have been pointed out. The possible roles of pericentric inversion
and addition of extraneous heterochromatin in the evolution of its karyotype
and in speciation in the family Megadermatidae have been discussed.
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