Pleiotropic Roles of the Orthologue of the Drosophila melanogaster Intersex Gene in the Brown Planthopper

Intersex(ix), a gene involved in the sex-determining cascade of Drosophila melanogaster, works in concert with the female-specific product of doublesex (dsx) at the end of the hierarchy to implement the sex-specific differentiation of sexually dimorphic characters in female individuals. In this study, the ix homolog was identified in the brown planthopper (BPH), Nilaparvata lugens, which contained two splice variants expressed in both female and male insects. We found that Nlix played a vital role in the early nymphal development of BPH, showing an accumulated effect. RNAi-mediated knockdown of Nlix at 4th instar led to the external genital defects in both sexes, consequently resulting in the loss of reproductive ability in female and male individuals. After dsRNA injection, the males were normal on testes, while the females had defective ovarian development. Nlix was also required for early embryogenesis. Notably, when the dsNlix microinjection was performed in newly emerged females, the copulatory bursas were abnormally enlarged while the other tissues of the reproductive system developed normally. Our results demonstrated the pleiotropic roles of Nlix in embryogenesis and development of the reproductive system in a hemimetabolous insect species.

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A genetic analysis of intersex, a gene regulating sexual differentiation in Drosophila melanogaster females.

Genetics ◽

10.1093/genetics/139.4.1649 ◽

1995 ◽

Vol 139 (4) ◽

pp. 1649-1661 ◽

Cited By ~ 2

Author(s):

B A Chase ◽

B S Baker

Keyword(s):

Drosophila Melanogaster ◽

Genetic Analysis ◽

Sexual Differentiation ◽

Point Mutations ◽

Regulatory Genes ◽

Sexually Dimorphic ◽

Specific Product ◽

Sex Type ◽

A Cell ◽

Female Specific

Abstract Sex-type in Drosophila melanogaster is controlled by a hierarchically acting set of regulatory genes. At the terminus of this hierarchy lie those regulatory genes responsible for implementing sexual differentiation: genes that control the activity of target loci whose products give rise to sexually dimorphic phenotypes. The genetic analysis of the intersex (ix) gene presented here demonstrates that ix is such a terminally positioned regulatory locus. The ix locus has been localized to the cytogenetic interval between 47E3-6 and 47F11-18. A comparison of the morphological and behavioral phenotypes of homozygotes and hemizygotes for three point mutations at ix indicates that the null phenotype of ix is to transform diplo-X animals into intersexes while leaving haplo-X animals unaffected. Analysis of X-ray induced, mitotic recombination clones lacking ix+ function in the abdomen of diplo-X individuals indicates that the ix+ product functions in a cell-autonomous manner and that it is required at least until the termination of cell division in this tissue. Taken together with previous analyses, our results indicate that the ix+ product is required to function with the female-specific product of doublesex to implement appropriate female sexual differentiation in diplo-X animals.

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Disparate regulation of imd drives sex differences in infection pathology in Drosophila melanogaster

10.1101/2020.08.12.247965 ◽

2020 ◽

Author(s):

Crystal M. Vincent ◽

Marc S. Dionne

Keyword(s):

Drosophila Melanogaster ◽

Negative Regulator ◽

Sexually Dimorphic ◽

Wild Type ◽

Functional Importance ◽

Male And Female ◽

Immune Activity ◽

Imd Pathway ◽

Independent Effects ◽

Female Specific

AbstractMale and female animals exhibit differences in infection outcomes. One possible source of sexually dimorphic immunity is sex-specific costs of immune activity or pathology, but little is known about the independent effects of immune-induced versus microbe-induced pathology, and whether these may differ for the sexes. Here, through measuring metabolic and physiological outputs in wild-type and immune-compromised Drosophila melanogaster, we test whether the sexes are differentially impacted by these various sources of pathology and identify a critical regulator of this difference. We find that the sexes exhibit differential immune activity but similar bacteria-derived metabolic pathology. We show that female-specific immune-inducible expression of PGRP-LB, a negative regulator of the Imd pathway, enables females to reduce immune activity in response to reductions in bacterial numbers. In the absence of PGRP-LB, females are more resistant of infection, confirming the functional importance of this regulation and suggesting that female-biased immune restriction comes at a cost.

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STUDIES ON THE SEX-SPECIFIC LETHALS OF DROSOPHILA MELANOGASTER. V. SEX TRANSFORMATION CAUSED BY INTERACTIONS BETWEEN A FEMALE-SPECIFIC LETHAL, Sxl f#1, AND THE MALE-SPECIFIC LETHALS mle(3)132, msl-2 27, AND mle

Genetics ◽

10.1093/genetics/102.2.233 ◽

1982 ◽

Vol 102 (2) ◽

pp. 233-243

Author(s):

T Uenoyama ◽

A Fukunaga ◽

K Ioshi

Keyword(s):

Drosophila Melanogaster ◽

Morphological Changes ◽

External Genitalia ◽

Sexually Dimorphic ◽

Female Progeny ◽

Lethal Mutant ◽

Male Type ◽

Male Specific Lethal ◽

Female Specific ◽

Male Specific

ABSTRACT Interactions between a female-specific lethal mutant, Sxlf #1, and each of three male-specific lethal mutants, mle(3)132, msl-2 27 and mle, of Drosophila melanogaster were observed to produce morphological changes in various sexually dimorphic external characters. Chromosomal females heterozygous for Sxlf #1 and homozygous for any one of the male-specific lethals (and to a lesser degree heterozygous for male-specific lethals) sometimes had sex combs, male-type tergites, male-type sternites, male-type anal plates or male-type external genitalia. Penetrance was not high and expression was often incomplete; single individuals never had all the sexually dimorphic structures transformed. When mothers were homozygous for male-specific lethals, higher proportions of female progeny were affected than when mothers were heterozygous, suggesting a maternal effect.

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Determination and distribution of a female-specific protein in the brown planthopper, Nilaparvata lugens Stal (Homoptera: Delphacidae)

Tissue and Cell ◽

10.1016/j.tice.2004.09.003 ◽

2005 ◽

Vol 37 (1) ◽

pp. 37-45 ◽

Cited By ~ 11

Author(s):

Dor-Jih Cheng ◽

Roger F. Hou

Keyword(s):

Brown Planthopper ◽

Nilaparvata Lugens ◽

Specific Protein ◽

Nilaparvata Lugens Stål ◽

Female Specific

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Disparate regulation of IMD signaling drives sex differences in infection pathology in Drosophila melanogaster

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2026554118 ◽

2021 ◽

Vol 118 (32) ◽

pp. e2026554118

Author(s):

Crystal M. Vincent ◽

Marc S. Dionne

Keyword(s):

Drosophila Melanogaster ◽

Immune Responses ◽

Negative Regulator ◽

Sexually Dimorphic ◽

Wild Type ◽

Functional Importance ◽

Immune Activity ◽

Imd Pathway ◽

Independent Effects ◽

Female Specific

Male and female animals exhibit differences in infection outcomes. One possible source of sexually dimorphic immunity is the sex-specific costs of immune activity or pathology, but little is known about the independent effects of immune- versus microbe-induced pathology and whether these may differ for the sexes. Here, by measuring metabolic and physiological outputs in Drosophila melanogaster with wild-type and mutant immune responses, we test whether the sexes are differentially impacted by these various sources of pathology and identify a critical regulator of this difference. We find that the sexes exhibit differential immune activity but similar bacteria-derived metabolic pathology. We show that female-specific immune-inducible expression of PGRP-LB, a negative regulator of the immune deficiency (IMD) pathway, enables females to reduce immune activity in response to reductions in bacterial numbers. In the absence of PGRP-LB, females are more resistant to infection, confirming the functional importance of this regulation and suggesting that female-biased immune restriction comes at a cost.

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