A comparative molecular cytogenetic characterization of the Atlantic bottlenose dolphin : a dissertation /
ABSTRACT: The great variety of karyotypes among eutherian mammals initially led to the expectation that the chromosomes of different eutherian orders had been shuffled beyond recognition. Although banding pattern similarities among the chromosomes of different mammalian species suggest that homolog...
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| Format: | Thesis Book |
| Language: | English |
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College Station, TX :
Texas A&M University,
1998.
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| Summary: | ABSTRACT: The great variety of karyotypes among eutherian mammals initially led to the expectation that the chromosomes of different eutherian orders had been shuffled beyond recognition. Although banding pattern similarities among the chromosomes of different mammalian species suggest that homology exists between specific chromosomal regions, detecting interspecific banding similarities can be difficult, especially for those species whose karyotypes have undergone extensive rearrangement. An unsuccessful attempt to identify homologous chromosome banding patterns of man and the Atlantic bottlenose dolphin, Tursiops truncatus, on the basis of their G-band patterns was followed by hybridization of commercially available human chromosome-specific paints (HSA probes) to dolphin metaphase spreads to identify conserved chromosomal segments between these two distantly related species. Extraordinary conservation of both entire chromosomes and chromosomal blocks was detected in the karyotypes of man and dolphin. All human chromosomal paints, except for Y, hybridized to Tursiops counterparts, and every dolphin chromosome was painted except for the smallest pair, TTR sm11. We identified 36 segments of conserved synteny common to the human and dolphin which suggests that extensive conservation of genome organization has occurred since the divergence of lineages leading to man and dolphin. However, a comparison of each dolphin chromosome painted exclusively by a single HSA probe showed differences in the centromeric position of several dolphin chromosomes relative to their human counterparts. These differences in chromosome arm lengths (arm ratios) may be due to internal rearrangements such as pericentric inversions or the distribution of heterochromatin that have occurred since these two species diverged. |
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| Item Description: | "Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of Doctor of Philosophy May 1998". "Major Subject: Genetics". Approved as to style and content by: David L. Busbee, Raymond J. Tarpley, James E. Womack, Linda A. Guarino, James N. Derr, Gerald R. Bratton. Vita. |
| Physical Description: | xii, 107 leaves : illustrations (mostly color) ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references (leaves 96-105). |