Sequence analysis of antifreeze proteins genes and their 3’-UTRs from desert insect Microdera punctipennies and Anatolica polita

Author of the article:HOU Xiao-Juan, LIANG Na, QIU Li-Ming, MA Ji

Author's Workplace： Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology

Key Words： Anatolica polita, Microdera punctipennis, Antifreeze protein, 3’-UTR, variation

Abstract：Anatolica polita Kaszab and Microdera punctipennis Kaszab are wide species and endemic species respectively in Junggar Basin of Xinjiang. They have quite different life habit in that A.polita is daily active in a wide area while M. punctipennies is light avoiding and night active in a relatively narrow area. However, both of them produce multiple copies of antifreeze protein genes (afps) which are also expressed in hot summer. To study if there are any differences of AFPs between these two insects and between those expressed in winter and summer, afp cDNAs were cloned both from A. polita and M. punctipennis collected in summer and winter respectively with universal primers designed according to previously cloned afp cDNAs. 3’-UTR sequences of antifreeze protein genes from these two species were also cloned. Sequence analysis results showed that the AFPs from both insects in summer and winter all have different numbers of TCTXSXXCXXAX motifs, the feature of antifreeze proteins in tenebrionid insects, but A. polita AFPs were more varied in their N-terminal ends and in the much conserved sites in TCTXSXXCXXAX motif than those in M.punctinpennis. However, M.punctinpennis AFPs showed almost no variation in the conserved sites in TCTXSXXCXXAX motif, while its C-terminal ends showed variations both in amino acid length and composition. In addition, sequence analysis of 3’UTRs of afps in these two insects showed that the 3’-UTRs in A. polita varied much more than those in M. punctipennis. We speculate that these differences in antifreeze protein genes may be responsible to the expression regulation of the antifreeze protein genes and may relate to the adaptability of these insects to their micro environments.