Karyotypic evolution in squamate reptiles compara

Authors: Kornsorn Srikulnath Chizuko Nishida Kazumi Matsubara Yoshinobu Uno Amara Thongpan Saowanee Suputtitada Somsak Apisitwanich Yoichi Matsuda

Publish Date: 2009/11/24

Volume: 17, Issue: 8, Pages: 975-

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Abstract

The butterfly lizard Leiolepis reevesii rubritaeniata has the diploid chromosome number of 2n = 36 comprising two distinctive components macrochromosomes and microchromosomes To clarify the conserved linkage homology between lizard and snake chromosomes and to delineate the process of karyotypic evolution in Squamata we constructed a cytogenetic map of L reevesii rubritaeniata with 54 functional genes and compared it with that of the Japanese fourstriped rat snake E quadrivirgata 2n = 36 Six pairs of the lizard macrochromosomes were homologous to eight pairs of the snake macrochromosomes The lizard chromosomes 1 2 4 and 6 corresponded to the snake chromosomes 1 2 3 and Z respectively LRE3p and LRE3q showed the homology with EQU5 and EQU4 respectively and LRE5p and LRE5q corresponded to EQU7 and EQU6 respectively These results suggest that the genetic linkages have been highly conserved between the two species and that their karyotypic difference might be caused by the telomeretotelomere fusion events followed by inactivation of one of two centromeres on the derived dicentric chromosomes in the lineage of L reevesii rubritaeniata or the centric fission events of the biarmed macrochromosomes and subsequent centromere repositioning in the lineage of E quadrivirgata The homology with L reevesii rubritaeniata microchromosomes were also identified in the distal regions of EQU1p and 1q indicating the occurrence of telomeretotelomere fusions of microchromosomes to the p and q arms of EQU1

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