Molecular Evolution of the RNASE A in Afrotheria

Purposes To trace and demonstrate the molecular evolution of RNASE A in Afrotheria.

Methods RNASE A sequences were identified in 7 Afrotheria species using Blastn and tBlastn methods, then functional sequences were translated to proteins by ClustalX and MEGA 7. We predicted the isoelectric point (pI) of each protein on the web (http://isoelectric.ovh.org). Phylogenetic tree was reconstructed using MrBayes v3.1.2.

Result We obtained 82 RNASE A sequences that include 64 functional genes and 18 pseudogenes. These sequences range from 377 to 654 bp in length. The trait of RNASE A is relative conserved in RNase1−8, whereas it is variable in the non-typical RNASE A members (RNase9−13). The isoelectric points range from 5.03 to 9.17. Gene duplications of RNase1, RNase6 and RNase4 were identified in the Loxodonta africana and Orycteropus afer, respectively. The evolution pattern of the " birth and death” was identified in L. africana.

Conclusions We firstly denomstrated the molecular evolution of the Afrotheria RNASE A, increasing the understanding of the RNASE A and established foundation for the future studies.