Sex chromosome-autosome translocations in the leaf-nosed bats, family Phyllostomidae.
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1984.
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| Online Access: | Link to ProQuest Copy Link to OAKTrust copy |
| Abstract: | The widespread occurrence of sex chromosome-autosome translocations in the bat family Phyllostomidae has offered a unique opportunity to test the general model of mammalian sex chromosome evolution. Two types of analyses were employed. A mitotic analysis was conducted using G-, C- and RBA-banding. In the Stenodermatinae an early replicating autosomal region is found on the short arm of the X. Its homologue is either a free autosome (XY(,1)Y(,2) types) or is translocated to the Y (neo-XY types). A second, intermediate autosomal replicating region is located interstitially on the long arm of the X. It lacks a homologous counterpart and may represent a more ancient translocation event than the autoxomal short arm of the X as it is also present in the subfamily Phyllostominae. In the subfamily Carolliinae an early replicating autosomal region is located on the distal portion of the long arm of the X chromosome. Its homologue is a free autosome. G- and C-banding corroborate these findings. Both giemsa and silver staining were used in the meiotic analyses. The absence of a typical mammalian sex vesicle in males in the subfamilies Stenodermatinae, Phyllostominae and Carolliinae can be correlated with differential replication banding of the allocyclic X in females. In the stenodermatines and carolliines the autosomal portions of the X with their homologous counterparts behave like autosomal bivalents. Homologous pairing is inferred by the presence of a chiasma between autosomal segments of the X and Y. In neo-XY stenodermatines pairing between autosomal segments of the X and Y appear to replace an association between the original X and Y as a preliminary requirement for disjunction at anaphase I. The autosomal short arm of the X in stenodermatines and the autosomal portion of the long arm of the X in carolliines behave autonomously from the original X in both mitotic and meiotic cells and can be correlated with their separation from the original X by centromeric heterochromatin in stenodermatines and by a NOR in carolliines. The interstitial autosomal region on the X long arm in both the stenodermatines and phyllostomines does not behave autonomously from the original X. Its interstitial position and intermediate replication pattern may reflect a rearrangement of the X and a subsequent loss of autonomy. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI |
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| Item Description: | "Major subject: Wildlife and Fisheries Sciences." Typescript (photocopy). Vita. |
| Physical Description: | xxi, 177 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 159-167). |