Genetic Basis of Differential Heat Resistance between Two Species of Congeneric Freshwater Snails: Insights from Quantitative Proteomics and Base Substitution Rate Analysis.
We compared the heat tolerance, proteomic responses to heat stress, and adaptive sequence divergence in the invasive snail Pomacea canaliculata and its noninvasive congener Pomacea diffusa. The LT50 of P. canaliculata was significantly higher than that of P. diffusa. More than 3350 proteins were identified from the hepatopancreas of the snails exposed to acute and chronic thermal stress using iTRAQ-coupled mass spectrometry. Acute exposure (3 h exposure at 37 °C with 25 °C as control) resulted in similar numbers (27 in P. canaliculata and 23 in P. diffusa) of differentially expressed proteins in the two species. Chronic exposure (3 weeks of exposure at 35 °C with 25 °C as control) caused differential expression of more proteins (58 in P. canaliculata and 118 in P. diffusa), with many of them related to restoration of damaged molecules, ubiquitinating dysfunctional molecules, and utilization of energy reserves in both species; but only in P. diffusa was there a shift from carbohydrate to lipid catabolism. Analysis of orthologous genes encoding the differentially expressed proteins revealed two genes having clear evidence of positive selection (Ka/Ks > 1) and seven candidates for more detailed analysis of positive selection (Ka/Ks between 0.5 and 1). These nine genes are related to energy metabolism, cellular oxidative homeostasis, signaling, and binding processes. Overall, the proteomic and base substitution rate analyses indicate genetic basis of differential resistance to heat stress between the two species, and such differences could affect their further range expansion in a warming climate.
Department of Biology, Hong Kong Baptist University , Hong Kong, P. R. China.
Huawei
H
Mu
Department of Biology, Hong Kong Baptist University , Hong Kong, P. R. China.
Jin
J
Sun
Instrumental Analysis and Research Center, Sun Yat-Sen University , Guangzhou, P. R. China.
Ling
L
Fang
Instrumental Analysis and Research Center, Sun Yat-Sen University , Guangzhou, P. R. China.|MOE Key Laboratory of Aquatic Product Safety, School of Life Sciences, Sun Yat-Sen University , Guangzhou, P. R. China.
Tiangang
T
Luan
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong , Pokfulam Road, Hong Kong, P. R. China.
Gray A
GA
Williams
Department of Biology and Chemistry, City University of Hong Kong , Hong Kong, P. R. China.
Siu Gin
SG
Cheung
Department of Biology, Hong Kong Baptist University , Hong Kong, P. R. China.
Chris K C
CK
Wong
Department of Biology, Hong Kong Baptist University , Hong Kong, P. R. China.
Jian-Wen
JW
Qiu
D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D050260:Carbohydrate Metabolism / Q000235:genetics; D002853:Chromatography, Liquid; D004734:Energy Metabolism / Q000235:genetics; D005618:Fresh Water; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D043143:Hepatopancreas / Q000737:chemistry / Q000378:metabolism; D006358:Hot Temperature; D050356:Lipid Metabolism / Q000235:genetics; D058977:Molecular Sequence Annotation; D009154:Mutation; D010455:Peptides / Q000032:analysis*; D059748:Proteolysis; D020543:Proteome / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012908:Snails / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity; D013194:Staining and Labeling; D013312:Stress, Physiological / Q000235:genetics; D026801:Synteny; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000737:chemistry
D010455:Peptides; D020543:Proteome; D014357:Trypsin
Ka/Ks; Pomacea; congener; invasive species; proteomics; temperature