Compositions and methods for insect control

Abstract

Described herein are expression vectors encoding the Wolbachia protein WalE1. Also described are insects transformed with an expression vector of the present disclosure, and progeny thereof. Also described are methods for improving Wolbachia replication and transmission in its insect host by overexpressing WalE1 in the insect host. Improved Wolbachia replication and transmission provides for insect population control and pathogen resistance in insects, which can reduce disease transmission.

1 . An expression vector comprising a polynucleotide that encodes WalE1 (WD0830) or a functional fragment of WalE1 (WD0830), wherein the polynucleotide is operably linked to an expression control sequence and the expression vector is expressible in an insect. 
     
     
         2 . The expression vector of  claim 1 , wherein the insect is Aedes albopictus, Aedes aegypti,  Anopheles gamibiae, Anopheles stephansi, Culex ppiens, Culex tarsalis, Culex quinquefasciatus,  an insect of the Culicidae family, or an insect of the Drosophilidae family. 
     
     
         3 . The expression vector of  claim 1 , wherein the functional fragment of WalE1 (WD0830) comprises a synuclein domain. 
     
     
         4 . The expression vector of  claim 3 , wherein the synuclein domain is an alpha-synuclein domain. 
     
     
         5 . The expression vector of  claim 1 , wherein the polynucleotide is codon optimized. 
     
     
         6 . The expression vector of  claim 1 , wherein WalE1 (WD0830) or the functional fragment of WalE1 (WD0830) comprises a polypeptide having an amino acid sequence at least 90% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs: 3-10 and 12-14. 
     
     
         7 . The expression vector of  claim 1 , wherein WalE1 (WD0830) has an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 2. 
     
     
         8 . The expression vector of  claim 1 , wherein the vector is a viral vector. 
     
     
         9 . An insect transformed with the expression vector of  claim 1 , or progeny of an insect transformed with the expression vector of  claim 1 . 
     
     
         10 . The insect of  claim 9 , wherein the insect or progeny of the insect overexpresses WalE1 (WD0830) or a functional fragment of WalE1 (WD0830) relative to an insect that was not transformed with the expression vector. 
     
     
         11 . A method for increasing  Wolbachia  replication and transmission in an insect population, the method comprising overexpressing WalE1 (WD0830) or a functional fragment of WalE1 (WD0830) in at least one insect capable of breeding with the insect population, and introducing the at least one insect overexpressing WalE1 (WD0830) or a functional fragment of WalE1 (WD0830), or progeny thereof, into the insect population, wherein overexpression is relative to a control insect. 
     
     
         12 . The method of  claim 11 , wherein overexpression is achieved by expressing an expression vector in the at least one insect, the expression vector comprises a polynucleotide that encodes WalE1 (WD0830) or a functional fragment of WalE1 (WD0830) and the polynucleotide is operably linked to an expression control sequence 
     
     
         13 . The method of  claim 12 , further comprising crossing the at least one insect with at least one other insect to produce progeny overexpressing WalE1 (WD0830) or a functional fragment of WalE1 (WD0830) prior to introducing the at least one insect overexpressing WalE1 (WD0830) or a functional fragment of WalE1 (WD0830) into the insect population. 
     
     
         14 . The method of  claim 12 , wherein the functional fragment of WalE1 (WD0830) comprises a synuclein domain. 
     
     
         15 . The method of  claim 12 , wherein the synuclein domain is an alpha-synuclein domain. 
     
     
         16 . The method of  claim 12 , wherein the polynucleotide is codon optimized. 
     
     
         17 . The method of  claim 14 , wherein WalE1 (WD0830) or the function fragment of WalE1 (WD0830) comprises a polypeptide having an amino acid sequence at least 90% identical to an amino acid sequence selected from the group consisting of SEQ ID NOs: 3-10 and 12-14. 
     
     
         18 . The method of  claim 12 , wherein WalE1 (WD0830) has an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 2. 
     
     
         19 . The method of  claim 11 , wherein the overexpression is induced in one or more insects harboring  Wolbachia  prior to the overexpression. 
     
     
         20 . The method of  claim 11 , further comprising infecting the at least one insect with  Wolbachia  before, concurrently with, or after inducing the overexpression. 
     
     
         21 . The method of  claim 12 , wherein the pathogen is selected from the group consisting of a virus, a protozoan, and a worm. 
     
     
         22 . The method of  claim 21 , wherein the virus is selected from the group consisting of Chikungunya virus, dengue virus, West-Nile virus, Yellow Fever virus. 
     
     
         23 . The method of  claim 21 , wherein the protozoan is a malaria parasite of the genus  Plasmodium.    
     
     
         24 . The method of  claim 21 , wherein the worm is a filarial nematode. 
     
     
         25 . The method of  claim 11 , wherein the insect is  Aedes albopictus, Aedes aegypti, Anopheles gamibiae, Anopheles stephansi, Culex pipiens, Culex tarsalis, Culex quinquefasciatus,  an insect of the Culicidae family, or an insect of the Drosophilidae family. 
     
     
         26 . A method for controlling an insect population, and/or conferring or increasing viral resistance in the insect population, the method comprising expressing the expression vector of  claim 1  in at least one insect of the insect population. 
     
     
         27 . A CRISPR-on system comprising dCas9 fused with a transcriptional activation domain, and a single guide RNA (sgRNA) having a complementary nucleic acid sequence to a WalE1 (WD0830) expression control element.