Department of Biochemistry

Permanent URI for this community

https://hdl.handle.net/10919/24226

Browse

Browsing Department of Biochemistry by Author "Adelman, Zach N."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Characterization of a female germline and early zygote promoter from the transcription factor bZip1 in the dengue mosquito Aedes aegypti
    Kojin, Bianca B.; Biedler, James K.; Tu, Zhijian Jake; Adelman, Zach N. (2020-07-17)
    Background The wide distribution of Aedes aegypti, the main vector of dengue and yellow fever viruses, currently puts three billion people in the world at risk of infection with these viruses. Continuous transmission of these and other viruses despite aggressive efforts to prevent this emphasizes the need to develop new control strategies. Proposals to control disease transmission based on vector engineering, including both population suppression and population replacement, rely on the development of transgenes under the control of regulatory elements able to drive molecules in a specific tissue, time and strength. Methods Here we report the characterization of a promoter active in both the female germline and early zygote, derived from the transcription factor bZip1 in the mosquito Ae. aegypti, using transposon-based methods and RT-qPCR. Results We generated seven transgenic lines carrying AabZip1-reporter constructs and observed expression in both the ovary and early embryo. RT-qPCR analysis was performed to evaluate transcript expression patterns for each line, confirming that transgenic expression from the AabZip1 promoter largely recapitulated the endogenous expression pattern, albeit the strength of maternal expression appeared to be strongly influenced by chromosomal position. Conclusions This study provides a new regulatory sequence that can be useful for generating transgenic lines that can become a tool in vector control strategies.
  • Thumbnail Image
    Characterization of the adult Aedes aegypti early midgut peritrophic matrix proteome using LC-MS
    Whiten, Shavonn R.; Ray, W. Keith; Helm, Richard F.; Adelman, Zach N. (PLOS, 2018-03-23)
    The Aedes aegypti mosquito is the principal vector of arboviruses such as dengue, chikungunya, yellow fever, and Zika virus. These arboviruses are transmitted during adult female mosquito bloodfeeding. While these viruses must transverse the midgut to replicate, the blood meal must also reach the midgut to be digested, absorbed, or excreted, as aggregation of blood meal metabolites can be toxic to the female mosquito midgut. The midgut peritrophic matrix (PM), a semipermeable extracellular layer comprised of chitin fibrils, glycoproteins, and proteoglycans, is one such mechanism of protection for the mosquito midgut. However, this structure has not been characterized for adult female Ae. aegypti. We conducted a mass spectrometry based proteomic analysis to identify proteins that comprise or are associated with the adult female Ae. aegypti early midgut PM. Altogether, 474 unique proteins were identified, with 115 predicted as secreted. GO-term enrichment analysis revealed an abundance of serine-type proteases and several known and novel intestinal mucins. In addition, approximately 10% of the peptides identified corresponded to known salivary proteins, indicating Ae. aegypti mosquitoes extensively swallow their own salivary secretions. However, the physiological relevance of this remains unclear, and further studies are needed to determine PM proteins integral for midgut protection from blood meal derived toxicity and pathogen protection. Finally, we describe substantial discordance between previously described transcriptionally changes observed in the midgut in response to a bloodmeal and the presence of the corresponding protein in the PM. Data are available via ProteomeXchange with identifier PXD007627.
  • Thumbnail Image
    Insights into the Preservation of the Homomorphic Sex-Determining Chromosome of Aedes aegypti from the Discovery of a Male-Biased Gene Tightly Linked to the M-Locus
    Hall, Andrew Brantley; Timoshevskiy, Vladimir A.; Sharakhova, Maria V.; Jiang, Xiaofang; Basu, Sanjay; Anderson, Michelle A. E.; Hu, Wanqi; Sharakhov, Igor V.; Adelman, Zach N.; Tu, Zhijian Jake (Oxford University Press, 2014-01-01)
    The preservation of a homomorphic sex-determining chromosome in some organisms without transformation into a heteromorphic sex chromosome is a long-standing enigma in evolutionary biology. A dominant sex-determining locus (or M-locus) in an undifferentiated homomorphic chromosome confers the male phenotype in the yellow fever mosquito Aedes aegypti. Genetic evidence suggests that the M-locus is in a nonrecombining region. However, the molecular nature of the M-locus has not been characterized. Using a recently developed approach based on Illumina sequencing of male and female genomic DNA, we identified a novel gene, myo-sex, that is present almost exclusively in the male genome but can sporadically be found in the female genome due to recombination. For simplicity, we define sequences that are primarily found in the male genome as male-biased. Fluorescence in situ hybridization (FISH) on A. aegypti chromosomes demonstrated that the myo-sex probe localized to region 1q21, the established location of theM-locus.Myo-sex is a duplicated myosin heavy chain gene that is highly expressed in the pupa and adult male.Myo-sex shares 83% nucleotide identity and 97% amino acid identity with its closest autosomal paralog, consistent with ancient duplication followed by strong purifying selection. Compared with males, myo-sex is expressed at very low levels in the females that acquired it, indicating that myo-sexmay be sexually antagonistic. This study establishes a framework to discover male-biased sequences within a homomorphic sex-determining chromosome and offers new insights into the evolutionary forces that have impeded the expansion of the nonrecombining M-locus in A. aegypti.
  • Thumbnail Image
    Nix alone is sufficient to convert female Aedes aegypti into fertile males and myo-sex is needed for male flight
    Aryan, Azadeh; Anderson, Michelle A. E.; Biedler, James K.; Qi, Yumin; Overcash, Justin M.; Naumenko, Anastasia N.; Sharakhova, Maria V.; Mao, Chunhong; Adelman, Zach N.; Tu, Zhijian Jake (NAS, 2020-06-12)
    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 of Nix led to feminized males (M/m) while transient expression of Nix resulted 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 sexconversion. Here, we report the generation of multiple transgenic lines that express Nix under the control of its own promoter. Genetic and molecular analyses of these lines provided insights unattainable from previous transient experiments. We show that the Nix transgene 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 that myo-sex, a myosin heavy-chain gene also in the M-locus, was required for male flight as knockout of myo-sex rendered wild-type males flightless. We also show that Nix-mediated female-to-male conversion was 100% penetrant and stable over many generations. Therefore, Nix has 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.