Limits...
Development and evaluation of male-only strains of the Australian sheep blowfly, Lucilia cuprina.

Scott MJ - BMC Genet. (2014)

Bottom Line: From the 1960s to the 1980s there was a major effort to develop "field female killing" or FFK strains of L. cuprina that could be used for a cost-effective genetic control program.Males did not die in the field as normal copies of the eye color genes had been translocated to the Y chromosome and an autosome.Although the FFK strains showed some promise in field tests, a genetic control program in mainland Australia was never implemented for several reasons including instability of the FFK strains during mass rearing.

View Article: PubMed Central - HTML - PubMed

ABSTRACT
The Australian sheep blowfly Lucilia cuprina (Wiedemann) is a major pest of sheep in Australia and New Zealand. From the 1960s to the 1980s there was a major effort to develop "field female killing" or FFK strains of L. cuprina that could be used for a cost-effective genetic control program. The FFK strains carried eye color mutations that were lethal to females in the field but not under conditions in the mass rearing facility. Males did not die in the field as normal copies of the eye color genes had been translocated to the Y chromosome and an autosome. Although the FFK strains showed some promise in field tests, a genetic control program in mainland Australia was never implemented for several reasons including instability of the FFK strains during mass rearing. A stable transgenic strain of L. cuprina that carried one or more dominant repressible female lethal genes offered the potential for efficient genetic control of blowfly populations. Here I review our research on tetracycline-repressible female lethal genetic systems, Lucilia germ-line transformation and sex determination genes that ultimately led to the successful development of transgenic "male-only" strains of L. cuprina. The technology developed for L. cuprina should be directly transferable to other blowfly livestock pests including L. sericata and the New World and Old World screwworm. 29.

Show MeSH

Related in: MedlinePlus

Marker gene expression in transgenic Lucilia cuprina. Adult flies or embryos were observed with either white light (A,E), a long pass GFP filter set (B,D) or a DsRed filter set (C,F). (A-C) Young adults (less than 2h after eclosion) from the wild-type stock (left), a transgenic line that carries the ZsGreen marker (center) and a line that has the DsRed-Express 2 (DsRedex2) marker (right) are shown. (D) A mixture of non-transgenic and transgenic (ZsGreen marker) late stage embryos. The transgenic embryos show strong green fluorescence and are easily separated from the non-transgenic embryos. (E,F) Embryos from the wild-type stock (left) and from a transgenic line that carries the DsRedex2 marker (right). Transgenic individuals show bright green or red fluorescence in all cells from the mid-embryo to young adult stage. In older adults that have darker cuticles, fluorescence is much more difficult to detect (not shown). Consequently, we routinely screen for transgenic individuals at the embryo and larval stages. (G,H) Schematic representations of the pB[Lchsp83-ZsGreen] and pB[Lchsp83-DsRedex2] transformation vectors The vectors contains the 5' flanking DNA, first exon and first intron from the Lchsp83 gene.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4255793&req=5

Figure 2: Marker gene expression in transgenic Lucilia cuprina. Adult flies or embryos were observed with either white light (A,E), a long pass GFP filter set (B,D) or a DsRed filter set (C,F). (A-C) Young adults (less than 2h after eclosion) from the wild-type stock (left), a transgenic line that carries the ZsGreen marker (center) and a line that has the DsRed-Express 2 (DsRedex2) marker (right) are shown. (D) A mixture of non-transgenic and transgenic (ZsGreen marker) late stage embryos. The transgenic embryos show strong green fluorescence and are easily separated from the non-transgenic embryos. (E,F) Embryos from the wild-type stock (left) and from a transgenic line that carries the DsRedex2 marker (right). Transgenic individuals show bright green or red fluorescence in all cells from the mid-embryo to young adult stage. In older adults that have darker cuticles, fluorescence is much more difficult to detect (not shown). Consequently, we routinely screen for transgenic individuals at the embryo and larval stages. (G,H) Schematic representations of the pB[Lchsp83-ZsGreen] and pB[Lchsp83-DsRedex2] transformation vectors The vectors contains the 5' flanking DNA, first exon and first intron from the Lchsp83 gene.

Mentions: Although we had succeeded in making transgenic L. cuprina, the overall efficiency was low and most experiments did not produce any transgenic flies. One reason for the low efficiency appeared to be because the D. melanogaster polyubiquitin promoter was weakly active in L. cuprina (and C. hominivorax), which made it difficult to distinguish transgenic from non-transgenic larvae. Consequently, we isolated the strong hsp83 gene promoter from L. cuprina [30]. In D. melanogaster, the hsp83 promoter has a high basal activity in all cells and is active in the germ-line [31]. The Lchsp83 promoter was used to make more strongly expressed fluorescent protein marker genes and piggyBac transposase helper. These modifications led to an efficient and reliable method for germ-line transformation of L. cuprina [32]. Transgenic individuals are readily identified at the late embryo or larval stages and show strong whole body fluorescence (Figure 2).


Development and evaluation of male-only strains of the Australian sheep blowfly, Lucilia cuprina.

Scott MJ - BMC Genet. (2014)

Marker gene expression in transgenic Lucilia cuprina. Adult flies or embryos were observed with either white light (A,E), a long pass GFP filter set (B,D) or a DsRed filter set (C,F). (A-C) Young adults (less than 2h after eclosion) from the wild-type stock (left), a transgenic line that carries the ZsGreen marker (center) and a line that has the DsRed-Express 2 (DsRedex2) marker (right) are shown. (D) A mixture of non-transgenic and transgenic (ZsGreen marker) late stage embryos. The transgenic embryos show strong green fluorescence and are easily separated from the non-transgenic embryos. (E,F) Embryos from the wild-type stock (left) and from a transgenic line that carries the DsRedex2 marker (right). Transgenic individuals show bright green or red fluorescence in all cells from the mid-embryo to young adult stage. In older adults that have darker cuticles, fluorescence is much more difficult to detect (not shown). Consequently, we routinely screen for transgenic individuals at the embryo and larval stages. (G,H) Schematic representations of the pB[Lchsp83-ZsGreen] and pB[Lchsp83-DsRedex2] transformation vectors The vectors contains the 5' flanking DNA, first exon and first intron from the Lchsp83 gene.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255793&req=5

Figure 2: Marker gene expression in transgenic Lucilia cuprina. Adult flies or embryos were observed with either white light (A,E), a long pass GFP filter set (B,D) or a DsRed filter set (C,F). (A-C) Young adults (less than 2h after eclosion) from the wild-type stock (left), a transgenic line that carries the ZsGreen marker (center) and a line that has the DsRed-Express 2 (DsRedex2) marker (right) are shown. (D) A mixture of non-transgenic and transgenic (ZsGreen marker) late stage embryos. The transgenic embryos show strong green fluorescence and are easily separated from the non-transgenic embryos. (E,F) Embryos from the wild-type stock (left) and from a transgenic line that carries the DsRedex2 marker (right). Transgenic individuals show bright green or red fluorescence in all cells from the mid-embryo to young adult stage. In older adults that have darker cuticles, fluorescence is much more difficult to detect (not shown). Consequently, we routinely screen for transgenic individuals at the embryo and larval stages. (G,H) Schematic representations of the pB[Lchsp83-ZsGreen] and pB[Lchsp83-DsRedex2] transformation vectors The vectors contains the 5' flanking DNA, first exon and first intron from the Lchsp83 gene.
Mentions: Although we had succeeded in making transgenic L. cuprina, the overall efficiency was low and most experiments did not produce any transgenic flies. One reason for the low efficiency appeared to be because the D. melanogaster polyubiquitin promoter was weakly active in L. cuprina (and C. hominivorax), which made it difficult to distinguish transgenic from non-transgenic larvae. Consequently, we isolated the strong hsp83 gene promoter from L. cuprina [30]. In D. melanogaster, the hsp83 promoter has a high basal activity in all cells and is active in the germ-line [31]. The Lchsp83 promoter was used to make more strongly expressed fluorescent protein marker genes and piggyBac transposase helper. These modifications led to an efficient and reliable method for germ-line transformation of L. cuprina [32]. Transgenic individuals are readily identified at the late embryo or larval stages and show strong whole body fluorescence (Figure 2).

Bottom Line: From the 1960s to the 1980s there was a major effort to develop "field female killing" or FFK strains of L. cuprina that could be used for a cost-effective genetic control program.Males did not die in the field as normal copies of the eye color genes had been translocated to the Y chromosome and an autosome.Although the FFK strains showed some promise in field tests, a genetic control program in mainland Australia was never implemented for several reasons including instability of the FFK strains during mass rearing.

View Article: PubMed Central - HTML - PubMed

ABSTRACT
The Australian sheep blowfly Lucilia cuprina (Wiedemann) is a major pest of sheep in Australia and New Zealand. From the 1960s to the 1980s there was a major effort to develop "field female killing" or FFK strains of L. cuprina that could be used for a cost-effective genetic control program. The FFK strains carried eye color mutations that were lethal to females in the field but not under conditions in the mass rearing facility. Males did not die in the field as normal copies of the eye color genes had been translocated to the Y chromosome and an autosome. Although the FFK strains showed some promise in field tests, a genetic control program in mainland Australia was never implemented for several reasons including instability of the FFK strains during mass rearing. A stable transgenic strain of L. cuprina that carried one or more dominant repressible female lethal genes offered the potential for efficient genetic control of blowfly populations. Here I review our research on tetracycline-repressible female lethal genetic systems, Lucilia germ-line transformation and sex determination genes that ultimately led to the successful development of transgenic "male-only" strains of L. cuprina. The technology developed for L. cuprina should be directly transferable to other blowfly livestock pests including L. sericata and the New World and Old World screwworm. 29.

Show MeSH
Related in: MedlinePlus