Molecular delineation of the Y-borne Sry gene in the Formosan pangolin (Manis pentadactyla pentadactyla) and its phylogenetic implications for Pholidota in extant mammals.
The systematic status of Pholidota has been a matter of debate, particularly regarding the apparent inconsistency between morphological and molecular studies. The Sry gene, a master regulator of male sex determination in eutherian mammals, has not yet been used for phylogenetic analyses of extant mammals. The objective of the present study was to clone and characterize the complete gene (1300 base pairs; bp) and amino acid sequences (229 residues) of Sry from the Formosan pangolin (Manis pentadactyla pentadactyla), a member of Pholidota. The Sry amino acid identity between pangolin and other reported species ranged from 42.5% (mouse, Mus musculus) to 84.1% (European hare, Lepus europaeus). Sequence conservation was primarily in the high motility group (HMG) box (234 bp), whereas homology outside the HMG box was low. The cloned Sry was mapped to the pangolin Y chromosome by fluorescence in situ hybridization (FISH); this was confirmed to be the first Y-borne molecular marker identified in Pholidota. Based on Bayesian phylogenetic analysis for Sry HMG sequences from 36 representative taxa, including the Formosan pangolin, Pholidota was more closely related to Carnivora than to Xenarthra, consistent with the emerging molecular tree inferred from markers not located on the Y chromosome. In conclusion, this study characterized the gene structure of Sry of the Formosan pangolin and provided insights into the phylogenetic position of Pholidota.
Yu
Hon-Tsen
HT
Institute of Zoology, Department of Life Science, National Taiwan University, Taipei, Taiwan.
Ma
Gwo-Chin
GC
Lee
Dong-Jay
DJ
Chin
Shih-Chien
SC
Tsao
Hsien-Shao
HS
Wu
Sheng-Hai
SH
Shih
Shu-Yi
SY
Chen
Ming
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D003001:Cloning, Molecular; D017124:Conserved Sequence; D024282:Genes, sry; D017404:In Situ Hybridization, Fluorescence; D008322:Mammals / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020539:Sequence Analysis, Protein; D014998:Y Chromosome / Q000737:chemistry