| Anopheles sinensis is an important member of Anopheles hyrcanus group within Diptera Culicidae genus Anopheles subgenus Anopheles.As an important epidemic vector of malaria and filariasis,it has a wild distribution in China excepting Qinghai and Xinjiang province.Besides,the presence of high-quality of polytene chromosomes in the salivary gland from forth-instar larvae makes it a perfect system for cytogenetic study.A high-resolution polytene chromosome map of An.sinensis can be used for the identification of close-related species,the microspecies of complex and geographic strains and is also a valuable tool for building physical map for this species.In recent years,the availability of the whole genome sequences of An.sinensis confers a solid foundation of researches of their ecological habits and capabilities of malaria transmission.But the absence of the physical map for An.sinensis hinders the analysis of An.sinensis evolution and related researches.In this research,by analyzing the whole genome sequence of An.sinensis,52 scaffolds were selected for physical mapping.Two DNA probes were designed for both ends of each scaffold and labeled.Fluorescence in situ hybridization was performed to locate the DNA probes to the polytene chromosome of An.sinensis.A total of 104 DNA fluorescent probes were anchored on the ploytene chromosomes.This physical map of An.sinensis contains 52 scaffolds(83.43 Mb),which composes approximately 38%of the whole genome sequence(220.8 Mb).Among them,48 scaffolds were oriented,and the rest scaffolds had no orientation because of their small sizes.The 3R chromosome,the shortest one of five arms,had 14 scaffolds spanning 11.01 Mb.The scaffolds on 2R chromosome are the longest and composing 10%of the whole genome of An.sinensis.AS2_scf7180000696055 is the longest scaffold spanning 5,918,260bp composing 2.68%of the whole genome and localized to 38C-39C region of 3L chromosome.The physical map of An.sinensis provides great convenience of the comparative genome and the analysis of chromosomal evolution.Anopheles lesteri is a sibling species of An.sinensis within Anopheles hycanus group They are morphologically identical and it is very difficult to distinguish them using the traditional methods.An.lesteri also presents high quality of polytene chromosomes from salivary glands.The chromosomal banding pattern of An.lesteri are generally similar with those of An.sinensis.Nevertheless,significant differences in some specific chromosome regions,can be used for important landmarks to distinguish these two species.Although both of An.lesteri and An.sinensis are important vectors of Plasmodium vivax,the habit,distribution and the capability of malaria transmission of An.lesteri are different from those of An,sinensis.This research on the genetic difference will provide valuable information for revealing their different capabilities of malaria transmission.We made a high-resolution polytene chromosome map for An.esteri and compared it with the chromosome map of An.sinensis.The description of bands on chromosomes will provide an effective method to identify these two different species.We also mapped 31 conserved DNA markers of An.sinensis to An.lesteri using fluorescence in situ hybridization.By comparing the physical locations of the probes on An.lesteri and An.sinensis,we demonstrated that all five arms are homologous(X =X;2R= 2R;2L =2L;3R=3R;3L=3L).The results further confirm the evolutionary relationships between the two mosquito species.The chromosome map of An.lesteri and the comparative analysis with An.sinensis will lay solid the foundation for the classification,identification and the difference of malaria transmission. |
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