scholarly journals Nix confers heritable sex-conversion in Aedes aegypti and myo-sex is needed for male flight

2019 ◽  
Author(s):  
Azadeh Aryan ◽  
Michelle Anderson ◽  
James K. Biedler ◽  
Yumin Qi ◽  
Justin M. Overcash ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Chain Gene ◽  
Wild Type ◽  
Myosin Heavy Chain Gene ◽  
Protein Coding ◽  
Hemizygous Male ◽  
Male Sex ◽  
Determining Factor ◽  
Transmit Disease

A dominant and hemizygous male-determining locus (M locus) establishes the male sex (M/m) in the yellow fever mosquito, Aedes aegypti. Nix is a male-determining factor (M factor) in the M locus and its transient expression in females (m/m) results in partial masculinization. Here, we show that the Nix transgene alone was sufficient to convert females into fertile males, which continued to produce sex-converted progeny in subsequent generations. However, assisted mating with wild-type females was necessary, as the converted m/m males could not fly. Knockout of myo-sex, a myosin heavy chain gene and the only other protein-coding gene reported in the M locus, rendered wild-type males flightless. Thus, Nix alone converts female Ae. aegypti to fertile males and myo-sex is required for male flight. Only female Ae. aegypti mosquitoes bite and transmit disease-causing viruses. Nix-mediated female-to-male conversion is 100% penetrant and stable over many generations, indicating great potential for mosquito control.

scholarly journals Nixalone is sufficient to convert femaleAedes aegyptiinto fertile males andmyo-sexis needed for male flight

2020 ◽  
Vol 117 (30) ◽  
pp. 17702-17709 ◽  
Author(s):  
Azadeh Aryan ◽  
Michelle A. E. Anderson ◽  
James K. Biedler ◽  
Yumin Qi ◽  
Justin M. Overcash ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Control Strategies ◽  
Reproductive Organs ◽  
Dominant Male ◽  
Chain Gene ◽  
Sexually Dimorphic ◽  
Wild Type ◽  
Transgenic Lines ◽  
Male Sex ◽  
Male Specific

A dominant male-determining locus (M-locus) establishes the male sex (M/m) in the yellow fever mosquito,Aedes aegypti.Nix, a gene in the M-locus, was shown to be a male-determining factor (M factor) as somatic knockout ofNixled to feminized males (M/m) while transient expression ofNixresulted in partially masculinized females (m/m), with male reproductive organs but retained female antennae. It was not clear whether any of the other 29 genes in the 1.3-Mb M-locus are also needed for complete sex-conversion. Here, we report the generation of multiple transgenic lines that expressNixunder the control of its own promoter. Genetic and molecular analyses of these lines provided insights unattainable from previous transient experiments. We show that theNixtransgene alone, in the absence of the M-locus, was sufficient to convert females into males with all male-specific sexually dimorphic features and male-like gene expression. The converted m/m males are flightless, unable to perform the nuptial flight required for mating. However, they were able to father sex-converted progeny when presented with cold-anesthetized wild-type females. We show thatmyo-sex, a myosin heavy-chain gene also in the M-locus, was required for male flight as knockout ofmyo-sexrendered wild-type males flightless. We also show thatNix-mediated female-to-male conversion was 100% penetrant and stable over many generations. Therefore,Nixhas great potential for developing mosquito control strategies to reduce vector populations by female-to-male sex conversion, or to aid in a sterile insect technique that requires releasing only non-biting males.

scholarly journals Structures of spontaneous deletions in Caenorhabditis elegans.

1988 ◽  
Vol 8 (9) ◽  
pp. 3748-3754 ◽  
Author(s):  
R A Pulak ◽  
P Anderson
Keyword(s):  
Caenorhabditis Elegans ◽  
Structural Features ◽  
Chain Gene ◽  
Wild Type ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
Base Pairs ◽  
Average Size ◽  
Distinguishing Features ◽  
Small Average Size

We have investigated the structural features of spontaneous deletions in Caenorhabditis elegans. We cloned and sequenced the junctions of 16 spontaneous deletions affecting the unc-54 myosin heavy-chain gene and compared their sequences with those of the wild type. We analyzed these sequences in an attempt to identify structural features of the gene that are consistently involved in the spontaneous deletion process. Most deletions (15 of 16) removed a single contiguous region of DNA, with no nucleotides inserted or rearranged at the deletion junctions; one deletion was more complex. unc-54 deletions were small, averaging 600 base pairs in length, and were randomly distributed throughout the gene. Unlike deletions that occur in Escherichia coli, spontaneous unc-54 deletions did not contain statistically significant direct or inverted repeats at or near their termini. Except for their small average size, we have not identified any distinguishing features of their sequence or structure. We discuss these results with regard to the mechanisms for spontaneous deletion in eucaryotic and procaryotic cells.

scholarly journals A SECOND INFORMATIONAL SUPPRESSOR, SUP-7 X, IN CAENORHABDITIS ELEGANS

Genetics ◽  
1981 ◽  
Vol 97 (2) ◽  
pp. 307-325
Author(s):  
Robert H Waterston
Keyword(s):  
Suppressor Gene ◽  
Null Alleles ◽  
Chain Gene ◽  
Wild Type ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
C Elegans ◽  
X Linkage ◽  
Suppressor Mutations ◽  
Dose Dependent

ABSTRACT More than 30 independent suppressor mutations have been obtained in the nematode C. elegans through reversion analysis of two unc-13 mutants. Many of the new isolates map to the region of the previously identified informational suppressor, sup-5 III (Waterston and Brenner 1978). Several of the other suppressor mutations map to the left half of the X-linkage group and define a second suppressor gene, sup-7 X. In tests against 40 mutations in six genes, the sup-7(st5) allele was found to suppress to a greater extent the same alleles acted on by sup-5(e1464). Like sup-5(e1464), sup-7(st5) acts on null alleles of the myosin heavy-chain gene unc-54 I (MacLeod et al. 1977; MacLeod, Waterston and Brenner 1977) and the putative paramyosin gene unc-15 I (Waterston et al. 1977). Chemical analysis of unc-15(e1214); sup-7(st5) animals show that paramyosin is restored to more than 30% of the wild-type level. —As was observed for sup-5(e1464), suppression by sup-7(st5) is dose dependent and is greater in animals grown at 15° than at 25°. However, associated with this increased suppression is a decreased viability of sup-7(st5) homozygotes. Reversion of the lethality has resulted in the isolation of deficiency mutations that complement st5 lethality, but lack suppressor function. These properties of sup-7(st5) suggest that it, like sup-5(e1464), is an informational suppressor of null alleles, and its reversion via deficiencies further narrows the possible explanations of its action.

scholarly journals Releasing incompatible males drives strong suppression across populations of wild and Wolbachia-carrying Aedes aegypti in Australia

2021 ◽  
Vol 118 (41) ◽  
pp. e2106828118
Author(s):  
Nigel W. Beebe ◽  
Dan Pagendam ◽  
Brendan J. Trewin ◽  
Andrew Boomer ◽  
Matt Bradford ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Local Strain ◽  
Mosquito Vector ◽  
Population Declines ◽  
Wild Type ◽  
Strong Suppression ◽  
Incompatible Insect Technique ◽  
Community Consent ◽  
Proven Method

Releasing sterile or incompatible male insects is a proven method of population management in agricultural systems with the potential to revolutionize mosquito control. Through a collaborative venture with the “Debug” Verily Life Sciences team, we assessed the incompatible insect technique (IIT) with the mosquito vector Aedes aegypti in northern Australia in a replicated treatment control field trial. Backcrossing a US strain of Ae. aegypti carrying Wolbachia wAlbB from Aedes albopictus with a local strain, we generated a wAlbB2-F4 strain incompatible with both the wild-type (no Wolbachia) and wMel-Wolbachia Ae. aegypti now extant in North Queensland. The wAlbB2-F4 strain was manually mass reared with males separated from females using Verily sex-sorting technologies to obtain no detectable female contamination in the field. With community consent, we delivered a total of three million IIT males into three isolated landscapes of over 200 houses each, releasing ∼50 males per house three times a week over 20 wk. Detecting initial overflooding ratios of between 5:1 and 10:1, strong population declines well beyond 80% were detected across all treatment landscapes when compared to controls. Monitoring through the following season to observe the ongoing effect saw one treatment landscape devoid of adult Ae. aegypti early in the season. A second landscape showed reduced adults, and the third recovered fully. These encouraging results in suppressing both wild-type and wMel-Ae. aegypti confirms the utility of bidirectional incompatibility in the field setting, show the IIT to be robust, and indicate that the removal of this arbovirus vector from human-occupied landscapes may be achievable.

Structures of spontaneous deletions in Caenorhabditis elegans

1988 ◽  
Vol 8 (9) ◽  
pp. 3748-3754
Author(s):  
R A Pulak ◽  
P Anderson
Keyword(s):  
Caenorhabditis Elegans ◽  
Structural Features ◽  
Chain Gene ◽  
Wild Type ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
Base Pairs ◽  
Average Size ◽  
Distinguishing Features ◽  
Small Average Size

We have investigated the structural features of spontaneous deletions in Caenorhabditis elegans. We cloned and sequenced the junctions of 16 spontaneous deletions affecting the unc-54 myosin heavy-chain gene and compared their sequences with those of the wild type. We analyzed these sequences in an attempt to identify structural features of the gene that are consistently involved in the spontaneous deletion process. Most deletions (15 of 16) removed a single contiguous region of DNA, with no nucleotides inserted or rearranged at the deletion junctions; one deletion was more complex. unc-54 deletions were small, averaging 600 base pairs in length, and were randomly distributed throughout the gene. Unlike deletions that occur in Escherichia coli, spontaneous unc-54 deletions did not contain statistically significant direct or inverted repeats at or near their termini. Except for their small average size, we have not identified any distinguishing features of their sequence or structure. We discuss these results with regard to the mechanisms for spontaneous deletion in eucaryotic and procaryotic cells.

scholarly journals Transformation of Drosophila melanogaster with the wild-type myosin heavy-chain gene: rescue of mutant phenotypes and analysis of defects caused by overexpression.

1994 ◽  
Vol 126 (3) ◽  
pp. 689-699 ◽  
Author(s):  
R M Cripps ◽  
K D Becker ◽  
M Mardahl ◽  
W A Kronert ◽  
D Hodges ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Copy Number ◽  
Chain Gene ◽  
Wild Type ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
Flight Muscles ◽  
Mutant Phenotypes

We have transformed Drosophila melanogaster with a genomic construct containing the entire wild-type myosin heavy-chain gene, Mhc, together with approximately 9 kb of flanking DNA on each side. Three independent lines stably express myosin heavy-chain protein (MHC) at approximately wild-type levels. The MHC produced is functional since it rescues the mutant phenotypes of a number of different Mhc alleles: the amorphic allele Mhc1, the indirect flight muscle and jump muscle-specific amorphic allele Mhc10, and the hypomorphic allele Mhc2. We show that the Mhc2 mutation is due to the insertion of a transposable element in an intron of Mhc. Since a reduction in MHC in the indirect flight muscles alters the myosin/actin protein ratio and results in myofibrillar defects, we determined the effects of an increase in the effective copy number of Mhc. The presence of four copies of Mhc results in overabundance of the protein and a flightless phenotype. Electron microscopy reveals concomitant defects in the indirect flight muscles, with excess thick filaments at the periphery of the myofibrils. Further increases in copy number are lethal. These results demonstrate the usefulness and potential of the transgenic system to study myosin function in Drosophila. They also show that overexpression of wild-type protein in muscle may disrupt the function of not only the indirect flight but also other muscles of the organism.

scholarly journals Tissue-specific regulation of the alpha-myosin heavy chain gene promoter in transgenic mice.

1991 ◽  
Vol 266 (36) ◽  
pp. 24613-24620
Author(s):  
A. Subramaniam ◽  
W.K. Jones ◽  
J. Gulick ◽  
S. Wert ◽  
J. Neumann ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Gene Promoter ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Myosin Heavy Chain Gene ◽  
Tissue Specific ◽  
Specific Regulation
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