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Sex chromosome difference and Origin of Snake

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, The sex of the snake is determined by the sex chromosome and belongs to the ZZ/ZW mechanism. In order to study the origin and evolution of snake sex chromosomes, KazumiMatsubara, a researcher at the Creative Scientific Research Institute (CreativeResearch.InitiativeSousei,CRIS) of Hokkaido University in Japan, identified Japanese four-stripedrat snake (Elaphequadrivirg) by fluorescence in situ hybridization (fish).

The sex of the snake is determined by the sex chromosome and belongs to the ZZ/ZW mechanism. In order to study the origin and evolution of snake sex chromosomes, KazumiMatsubara, a researcher from the Creative Science Research Institute (CreativeResearch.InitiativeSousei,CRIS) of Hokkaido University, Japan, used fluorescence in situ hybridization (fish) to measure the cytogenetic map (cytogeneticmap) of Japanese four-stripedrat snake (Elaphequadrivirgata). The article was published in PNAS on November 28th.

There are 109 cDNA clones in the map, 11 of which are located on Z chromosome. The genes of humans and birds corresponding to the Z chromosome genes of snakes are located on autosomal (autosomes), indicating that the sex chromosomes of snakes, mammals and birds originated from different autosomal pairs of common ancestors. The researchers also mapped 11 Z-linked genes (Z-linkedgenes) of E.quadrivirgat, Burmese python (Pythonmolurusbivittatus) and rattlesnake (Trimeresurusflavoviridis) to study the differences in W chromosomes. It was found that all 11 clones were found in the Z chromosome of P.molurus and E.quadrivirgata, 3 clones were found in the W chromosome of P.molurus and E.quadrivirgata, and cDNA was not detected on the W chromosome of T.flavoviridis. The results of comparative mapping (Comparativemapping) showed that there was little change in sex chromosomes in P.molurus, but there was a great difference in T.flavoviridis. E.quadrivirgata was in the excessive stage of sex chromosome differentiation. This sex chromosome difference may occur in the short arm terminal region of the pre-sex chromosome of the autosomal common ancestor (protosexchromosome), and then deletions and heterochromatin (heterochromatizationprogressed) occur during the evolution from the most primitive boids to the highly evolved viperids.

 
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