scholarly journals Identification and Characterization of the Masculinizing Function of the Helicoverpa armigera Masc Gene

2021 ◽  
Vol 22 (16) ◽  
pp. 8650
Author(s):  
Zhongyuan Deng ◽  
Yakun Zhang ◽  
Yalu Li ◽  
Kaiyuan Huang ◽  
Xuewei Chen ◽  
...  
Keyword(s):  
Sex Determination ◽  
Helicoverpa Armigera ◽  
Embryonic Cell ◽  
Z Chromosome ◽  
Downstream Target ◽  
Sex Development ◽  
Downstream Target Gene ◽  
Helicoverpa Armígera ◽  
Splicing Isoforms ◽  
Female Specific

The Masculinizer (Masc) gene has been known to control sex development and dosage compensation in lepidopterans. However, it remains unclear whether its ortholog exists and plays the same roles in distantly related lepidopterans such as Helicoverpa armigera. To address this question, we cloned Masc from H. armigera (HaMasc), which contains all essential functional domains of BmMasc, albeit with less than 30% amino acid sequence identity with BmMasc. Genomic PCR and qPCR analyses showed that HaMasc is a Z chromosome-linked gene since its genomic content in males (ZZ) was two times greater than that in females (ZW). RT-PCR and RT-qPCR analyses revealed that HaMasc expression was sex- and stage-biased, with significantly more transcripts in males and eggs than in females and other stages. Transfection of a mixture of three siRNAs of HaMasc into a male embryonic cell line of H. armigera led to the appearance of female-specific mRNA splicing isoforms of H. armigera doublesex (Hadsx), a downstream target gene of HaMasc in the H. armigera sex determination pathway. The knockdown of HaMasc, starting from the third instar larvae resulted in a shift of Hadsx splicing from male to female isoforms, smaller male pupa and testes, fewer but larger/longer spermatocytes and sperm bundles, delayed pupation and internal fusion of the testes and follicles. These data demonstrate that HaMasc functions as a masculinizing gene in the H. armigera sex-determination cascade.

Population differentiation between Australian and Chinese Helicoverpa armigera occurs in distinct blocks on the Z-chromosome

2018 ◽  
Vol 108 (6) ◽  
pp. 817-830 ◽  
Author(s):  
S.V. Song ◽  
C. Anderson ◽  
R.T. Good ◽  
S. Leslie ◽  
Y. Wu ◽  
...  
Keyword(s):  
Population Structure ◽  
Helicoverpa Armigera ◽  
Nucleotide Diversity ◽  
Selective Sweep ◽  
Rare Variants ◽  
Population Expansion ◽  
Z Chromosome ◽  
Chinese Populations ◽  
Continental Population ◽  
Helicoverpa Armígera

AbstractOver the last 40 years, many types of population genetic markers have been used to assess the population structure of the pest moth species Helicoverpa armigera. While this species is highly vagile, there is evidence of inter-continental population structure. Here, we examine Z-chromosome molecular markers within and between Chinese and Australian populations. Using 1352 polymorphic sites from 40 Z-linked loci, we compared two Chinese populations of moths separated by 700 km and found virtually no population structure (n = 41 and n = 54, with <1% of variation discriminating between populations). The levels of nucleotide diversity within these populations were consistent with previous estimates from introns in Z-linked genes of Australian samples (π = 0.028 vs. 0.03). Furthermore, all loci surveyed in these Chinese populations showed a skew toward rare variants, with ten loci having a significant Tajima's D statistic, suggesting that this species could have undergone a population expansion. Eight of the 40 loci had been examined in a previous study of Australian moths, of which six revealed very little inter-continental population structure. However, the two markers associated with the Cyp303a1 locus that has previously been proposed to be a target of a selective sweep, exhibited allele structuring between countries. Using a separate dataset of 19 Australian and four Chinese moths, we scanned the molecular variation distributed across the entire Z-chromosome and found distinct blocks of differentiation that include the region containing Cyp303a1. We recommend some of these loci join those associated with insecticide resistance to form a set of genes best suited to analyzing population structure in this global pest.

scholarly journals Altered specificity of Hint-W123Q supports a role for Hint inhibition by ASW in avian sex determination

2004 ◽  
Vol 20 (1) ◽  
pp. 12-14 ◽  
Author(s):  
Kristen P. Parks ◽  
Heather Seidle ◽  
Nathan Wright ◽  
Jeffrey B. Sperry ◽  
Pawel Bieganowski ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Sex Determination ◽  
Dominant Negative ◽  
Z Chromosome ◽  
Enzyme Specificity ◽  
W Chromosome ◽  
Dominant Component ◽  
Lysine Modification ◽  
Female Specific

Hint is a universally conserved, dimeric AMP-lysine hydrolase encoded on the avian Z chromosome. Tandemly repeated on the female-specific W chromosome, Asw encodes a potentially sex-determining, dominant-negative Hint dimerization partner whose substrate-interacting residues were specifically altered in evolution. To test the hypothesis that Gln127 of Asw is responsible for depression and/or alteration of Hint enzyme activity, a corresponding mutant was created in the chicken Hint homodimer, and a novel substrate was developed that links reversal of AMP-lysine modification to aminomethylcoumarin release. Strikingly, the Hint-W123Q substitution reduced kcat/ Km for AMP-lysine hydrolysis 17-fold, while it increased specificity for AMP- para-nitroaniline hydrolysis by 160-fold. The resulting 2,700-fold switch in enzyme specificity suggests that Gln127 could be the dominant component of Asw dominant negativity in avian feminization.

scholarly journals A conserved role of the duplicated Masculinizer gene in sex determination of the Mediterranean flour moth, Ephestia kuehniella

2021 ◽  
Author(s):  
Sander Visser ◽  
Anna Voleníková ◽  
Petr Nguyen ◽  
Eveline C. Verhulst ◽  
František Marec
Keyword(s):  
Sex Determination ◽  
Early Embryogenesis ◽  
Ephestia Kuehniella ◽  
Z Chromosome ◽  
Female Development ◽  
Biased Sex Ratio ◽  
The Mediterranean ◽  
Female Specific ◽  
Mediterranean Flour Moth

AbstractSex determination in the silkworm, Bombyx mori, is based on Feminizer (Fem), a W-linked Fem piRNA that triggers female development in WZ individuals, and the Z-linked Masculinizer (Masc), which initiates male development and dosage compensation in ZZ individuals. While Fem piRNA is missing in a close relative of B. mori, Masc determines sex in several representatives of distant lepidopteran lineages. We studied the molecular mechanisms of sex determination in the Mediterranean flour moth, Ephestia kuehniella (Pyralidae). We identified an E. kuehniella Masc ortholog, EkMasc, and its paralog resulting from a recent duplication, EkMascB. Both genes are located on the Z chromosome and encode a similar Masc protein that contains two conserved domains but has lost the conserved double zinc finger domain. We developed PCR-based genetic sexing and demonstrated a peak in the expression of EkMasc and EkMascB genes only in early male embryos. Simultaneous knock-down experiments of both EkMasc and EkMascB using RNAi during early embryogenesis led to a shift from male- to female-specific splicing of the E. kuehniella doublesex gene (Ekdsx), their downstream effector, in ZZ embryos and resulted in a strong female-biased sex-ratio. Our results thus confirmed the conserved role of both EkMasc and EkMascB genes in masculinization. We suggest that the C-terminal proline-rich domain, we have identified in all functionally confirmed Masc proteins, in conjunction with the masculinizing domain, is important for transcriptional regulation of sex determination in Lepidoptera. The function of the Masc double zinc finger domain is still unknown, but appears to have been lost in E. kuehniella.Author summaryThe sex-determining cascade in the silkworm, Bombyx mori, differs greatly from those of other insects. In B. mori, female development is initiated by Fem piRNA expressed from the W chromosome during early embryogenesis. Fem piRNA silences Masculinizer (Masc) thereby blocking the male pathway resulting in female development. It is currently unknown whether this cascade is conserved across Lepidoptera. In the Mediterranean flour moth, Ephestia kuehniella, we identified an ortholog of Masc and discovered its functional duplication on the Z chromosome, which has not yet been found in any other lepidopteran species. We provide two lines of evidence that both the EkMasc and EkMascB genes play an essential role in masculinization: (i) they show a peak of expression during early embryogenesis in ZZ but not in WZ embryos and (ii) their silencing by RNAi results in female-specific splicing of the E. kuehniella doublesex gene (Ekdsx) in ZZ embryos and in a female-biased sex ratio. Our results suggest a conserved role of the duplicated Masc gene in sex determination of E. kuehniella.

Hybridization between Helicoverpa armigera and Helicoverpa assulta (Lepidoptera: Noctuidae): development and morphological characterization of F1 hybrids

2005 ◽  
Vol 95 (5) ◽  
pp. 409-416 ◽  
Author(s):  
X.-C. Zhao ◽  
J.-F. Dong ◽  
Q.-B. Tang ◽  
Y.-H. Yan ◽  
I. Gelbic ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Reproductive Organs ◽  
Morphological Characterization ◽  
F1 Hybrids ◽  
Z Chromosome ◽  
Normal Male ◽  
Helicoverpa Assulta ◽  
Helicoverpa Armígera ◽  
The Cross ◽  
Normal Offspring

AbstractReciprocal hybridizations between Helicoverpa armigera (Hübner) and Helicoverpa assulta (Guenée) were studied. The cross between females of H. armigera and males of H. assulta yielded only fertile males and sterile individuals lacking an aedeagus, valva or ostium bursae. A total of 492 larvae of the F1 generation were obtained and 374 of these completed larval development and pupated. Only 203 pupae were morphologically normal males, the remaining 171 pupae were malformed. Larvae and pupae that gave rise to morphologically abnormal adults exhibited longer development times. Sterility was not only associated with malformed external sex organs, but also a range of abnormalities of the internal reproductive system: (i) loss of internal reproductive organs, (ii) with one to three copies of an undeveloped bursa copulatrix; or (iii) with one or two undeveloped testes. Normal male hybrid adults showed higher flight activity in comparison with males of both species. In contrast, the cross between females of H. assulta and males of H. armigera yielded morphologically normal offspring (80 males and 83 females). The interaction of the Z-chromosome from H. assulta with autosomes from H. armigera might result in morphological abnormalities found in hybrids and backcrosses, and maternal-zygotic incompatibilities might contribute to sex bias attributed to hybrid inviability.

scholarly journals A ZZ/ZW Sex Chromosome System in Cephalochordate Amphioxus

Genetics ◽  
2020 ◽  
Vol 214 (3) ◽  
pp. 617-622
Author(s):  
Chenggang Shi ◽  
Xiaotong Wu ◽  
Liuru Su ◽  
Chaoqi Shang ◽  
Xuewen Li ◽  
...  
Keyword(s):  
Sex Determination ◽  
Mutant Strain ◽  
Sex Chromosome ◽  
Female Offspring ◽  
Phylogenetic Position ◽  
Z Chromosome ◽  
Transcription Activator ◽  
Sex Chromosome System ◽  
Female Specific ◽  
Determination Mechanism

Sex determination is remarkably variable among animals with examples of environmental sex determination, male heterogametic (XX/XY) and female heterogametic (ZZ/ZW) chromosomal sex determination, and other genetic mechanisms. The cephalochordate amphioxus occupies a key phylogenetic position as a basal chordate and outgroup to vertebrates, but its sex determination mechanism is unknown. During the course of generating Nodal mutants with transcription activator-like effector nucleases (TALENs) in amphioxus Branchiostoma floridae, serendipitously, we generated three mutant strains that reveal the sex determination mechanism of this animal. In one mutant strain, all heterozygous mutant offspring over three generations were female and all wild-type descendants were male. This pattern suggests the Nodal allele targeted is on a female-specific W chromosome. A second mutant showed the same W-linked inheritance pattern, with a female heterozygote passing the mutation only to daughters. In a third mutant strain, both male and female offspring could be heterozygous, but a female heterozygote passed the mutation only to sons. This pattern is consistent with the targeted allele being on a Z chromosome. We found an indel polymorphism linked to a Nodal allele present in most females, but no males in our cultured population. Together, these results indicate that Nodal is sex chromosome-linked in B. floridae, and that B. floridae has a ZZ/ZW sex chromosome system.

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