scholarly journals TWO CLOSELY LINKED MUTATIONS IN DROSOPHILA MELANOGASTER THAT ARE LETHAL TO OPPOSITE SEXES AND INTERACT WITH DAUGHTERLESS

Genetics ◽  
1978 ◽  
Vol 90 (4) ◽  
pp. 683-697
Author(s):  
Thomas W Cline
Keyword(s):  
Maternal Effect ◽  
Spontaneous Mutation ◽  
Dominant Male ◽  
Lethal Effects ◽  
Male Specific Lethal ◽  
Constitutive Mutation ◽  
Sex Lethal ◽  
The Right ◽  
Female Specific ◽  
Male Specific

ABSTRACT A new spontaneous mutation named Sex-lethal, Male-specific #1 (SxlM1) is described that is lethal to males, even in the presence of an Sxl  + duplication. Females homozygous for SxlM1 are fully viable. This dominant, male-specific lethal mutation is on the X chromosome approximately 0.007 map units to the right of a previously isolated female-specific mutation, Female-lethal, here renamed Sex-lethal, Female-specific #1 (SxlF1). SxlM1 and SxlF1 are opposite in nearly every respect, particularly with regard to their interaction with the maternal effect of the autosomal mutation, daughterless (da). Females that are homozygous for da produce defective eggs that cannot support female (XX) development. A single dose of SxlM1 enables daughters to survive this da female-specific lethal maternal effect. A duplication of the Sxl locus weakly mimics this action of SxlM1. In contrast, SxlF1 and a deficiency for Sxl, strongly enhance the female-lethal effects of da. The actions of SxlM1 and SxlF1 are explained by a model in which expression of the Sxl locus is essential for females, lethal for males, and under the control of a product of the da locus. It is suggested that SxlM1 is a constitutive mutation at the Sxl locus.

The msl-2 dosage compensation gene of Drosophila encodes a putative DNA-binding protein whose expression is sex specifically regulated by Sex-lethal

Development ◽  
1995 ◽  
Vol 121 (10) ◽  
pp. 3245-3258 ◽  
Author(s):  
G.J. Bashaw ◽  
B.S. Baker
Keyword(s):  
Dna Binding ◽  
X Chromosome ◽  
Dosage Compensation ◽  
Ring Finger ◽  
The Other ◽  
Male Specific Lethal ◽  
Alternatively Spliced ◽  
Sex Lethal ◽  
Specific Regulation ◽  
Male Specific

In Drosophila dosage compensation increases the rate of transcription of the male's X chromosome and depends on four autosomal male-specific lethal genes. We have cloned the msl-2 gene and shown that MSL-2 protein is co-localized with the other three MSL proteins at hundreds of sites along the male polytene X chromosome and that this binding requires the other three MSL proteins. msl-2 encodes a protein with a putative DNA-binding domain: the RING finger. MSL-2 protein is not produced in females and sequences in both the 5′ and 3′ UTRs are important for this sex-specific regulation. Furthermore, msl-2 pre-mRNA is alternatively spliced in a Sex-lethal-dependent fashion in its 5′ UTR.

scholarly journals A record of bilateral gynandromorphism in Epeolus (Hymenoptera: Apidae: Nomadinae)

2018 ◽  
pp. 1-6 ◽  
Author(s):  
Thomas M Onuferko
Keyword(s):  
Natural History ◽  
North American ◽  
American Museum ◽  
The Right ◽  
Female Specific ◽  
Male Specific

The discovery of a gynandromorph of a North American Epeolus Latreille is reported. A specimen of E. flavofasciatus Smith from Flagstaff, Arizona, USA discovered in the collection of the American Museum of Natural History (AMNH) exhibits male-specific features on the left and female-specific features on the right, consistent with bilateral gynandromorphism (the first known case in the genus). Descriptions and images of the aberrant features exhibited by the specimen are presented.

scholarly journals STUDIES ON THE SEX-SPECIFIC LETHALS OF DROSOPHILA MELANOGASTER. II. FURTHER STUDIES ON A MALE-SPECIFIC LETHAL GENE, MALELESS

Genetics ◽  
1976 ◽  
Vol 84 (2) ◽  
pp. 257-266
Author(s):  
Atsumi Tanaka ◽  
Akihiro Fukunaga ◽  
Kugao Oishi
Keyword(s):  
Drosophila Melanogaster ◽  
Larval Stage ◽  
Maternal Effect ◽  
Sex Differentiation ◽  
Pupal Stage ◽  
Imaginal Discs ◽  
Lethal Gene ◽  
Male Specific Lethal ◽  
Male Specific

ABSTRACT Effects of a second chromosome male-specific lethal gene, maleless (mle), of Drosophila melanogaster were further studied. It was shown that, although no maternal effect was seen with respect to the male-specific lethality, the lethal stage was influenced by whether parental females were homozygous or heterozygous for mle. Thus, in the former mle/mle males died mostly in the late third instar larval stage, while in the latter practically all males survived to the pupal stage. In the dying mle/mle male pupae complete differentiation of adult external head and thorax structures was often observed but that of abdominal structures was incomplete forming only a few segments in most cases. Imaginal discs from third instar mle/mle male larvae which were produced by mle/mle mothers and were destined to die as larvae were able to differentiate into adult structures upon transplantation into normal third instar larval hosts.—A somewhat elaborated version of the previously presented hypothesis (Fukunaga, Tanaka and Oishi 1975) was discussed as to the possible presence of a class of sex-specific lethals which are not related to the process of primary sex differentiation

scholarly journals Both Loss-of-Function and Gain-of-Function Mutations in snf Define a Role for snRNP Proteins in Regulating Sex-lethal Pre-mRNA Splicing in Drosophila Development

Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 95-108
Author(s):  
Helen K Salz ◽  
Thomas W Flickinger
Keyword(s):  
Sex Determination ◽  
Rna Splicing ◽  
Loss Of Function ◽  
Functional Homology ◽  
Snrnp Protein ◽  
A Cell ◽  
Sex Lethal ◽  
Mutant Phenotypes ◽  
Female Specific ◽  
Male Specific

Abstract The Drosophila snf gene encodes a protein with functional homology to the mammalian UlA and U2B″ snRNP proteins. Studies, based on the analysis of three viable alleles, have suggested a role for snf in establishing the female-specific splicing pattern of the sex determination switch gene, Sex-lethal. Here, we show that the non-sex-specific lethal null allele is required for female sex determination, arguing against the formal possibility that the viable alleles disrupt a function unrelated to snf's wild-type function. Moreover, we find snf is required for normal cell growth and/or survival, as expected for a protein involved in a cell-vital process such as RNA splicing. We also show that of the three viable alleles only one, snfJA2, is a partial loss-of-function mutation. The other two viable alleles, snf1621 and snfe8H, encode antimorphic proteins. We find the antimorphic proteins are mislocalized and correlate their mislocalization with their molecular lesions and mutant phenotypes. Finally, we provide genetic evidence that the antimorphic alleles interfere with the autoregulatory splicing function of the Sex-lethal protein. Based on these studies we suggest a model in which the snRNP protein, Snf, functions with Sex-lethal to block recognition of the regulated male-specific exon.

scholarly journals Modulation of MSL1 Abundance in Female Drosophila Contributes to the Sex Specificity of Dosage Compensation

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 699-709 ◽  
Author(s):  
Kimberly A Chang ◽  
Mitzi I Kuroda
Keyword(s):  
Dosage Compensation ◽  
Ectopic Expression ◽  
Negative Regulation ◽  
Limiting Factor ◽  
Control Mechanisms ◽  
Linked Gene ◽  
Male Specific Lethal ◽  
Sex Specificity ◽  
Female Specific ◽  
Male Specific

Abstract Dosage compensation in Drosophila is the mechanism by which X-linked gene expression is made equal in males and females. Proper regulation of this process is critical to the survival of both sexes. Males must turn the male-specific lethal (msl)-mediated pathway of dosage compensation on and females must keep it off. The msl2 gene is the primary target of negative regulation in females. Preventing production of MSL2 protein is sufficient to prevent dosage compensation; however, ectopic expression of MSL2 protein in females is not sufficient to induce an insurmountable level of dosage compensation, suggesting that an additional component is limiting in females. A candidate for this limiting factor is MSL1, because the amount of MSL1 protein in females is reduced compared to males. We have identified two levels of negative regulation of msl1 in females. The predominant regulation is at the level of protein stability, while a second regulatory mechanism functions at the level of protein synthesis. Overcoming these control mechanisms by overexpressing both MSL1 and MSL2 in females results in 100% female-specific lethality.

scholarly journals Histone Acetylation and Gene Expression Analysis of Sex lethal Mutants in Drosophila

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 753-763
Author(s):  
Utpal Bhadra ◽  
Manika Pal-Bhadra ◽  
James A Birchler
Keyword(s):  
Gene Expression ◽  
Sex Determination ◽  
Sex Chromosome ◽  
Autosomal Gene ◽  
Single Sex ◽  
Dosage Effects ◽  
Male Specific Lethal ◽  
Sex Lethal ◽  
Male Specific ◽  
Sex Determination Mechanisms

Abstract The evolution of sex determination mechanisms is often accompanied by reduction in dosage of genes on a whole chromosome. Under these circumstances, negatively acting regulatory genes would tend to double the expression of the genome, which produces compensation of the single-sex chromosome and increases autosomal gene expression. Previous work has suggested that to reduce the autosomal expression to the female level, these dosage effects are modified by a chromatin complex specific to males, which sequesters a histone acetylase to the X. The reduced autosomal histone 4 lysine 16 (H4Lys16) acetylation results in lowered autosomal expression, while the higher acetylation on the X is mitigated by the male-specific lethal complex, preventing overexpression. In this report, we examine how mutations in the principal sex determination gene, Sex lethal (Sxl), impact the H4 acetylation and gene expression on both the X and autosomes. When Sxl expression is missing in females, we find that the sequestration occurs concordantly with reductions in autosomal H4Lys16 acetylation and gene expression on the whole. When Sxl is ectopically expressed in SxlM mutant males, the sequestration is disrupted, leading to an increase in autosomal H4Lys16 acetylation and overall gene expression. In both cases we find relatively little effect upon X chromosomal gene expression.

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 ◽  
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.

scholarly journals The Nab2 RNA binding protein promotes sex-specific splicing of Sex lethal in Drosophila neuronal tissue

2020 ◽  
Author(s):  
Binta Jalloh ◽  
J. Christopher Rounds ◽  
Brianna E. Brown ◽  
Isaac J. Kremsky ◽  
Ayan Banerjee ◽  
...  
Keyword(s):  
Rna Binding ◽  
Molecular Level ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Neuronal Tissue ◽  
Multiple Phenotypes ◽  
Axon Projection ◽  
Sex Lethal ◽  
Female Specific ◽  
Male Specific

AbstractThe Drosophila polyadenosine RNA binding protein Nab2, which is orthologous to a human protein lost in a form of inherited intellectual disability, controls axon projection, locomotion, and memory. Here we define an unexpectedly specific role for Nab2 in regulating splicing of ~150 exons/introns in the head transcriptome and link the most prominent of these, female retention of a male-specific exon in the sex determination factor Sex-lethal (Sxl), to a role in m6A-dependent mRNA splicing. Genetic evidence indicates that aberrant Sxl splicing underlies multiple phenotypes in Nab2 mutant females. At a molecular level, Nab2 associates with Sxl pre-mRNA and ensures proper female-specific splicing by preventing m6A hypermethylation by Mettl3 methyltransferase. Consistent with these results, reducing Mettl3 expression rescues developmental, behavioral and neuroanatomical phenotypes in Nab2 mutants. Overall these data identify Nab2 as a required regulator of m6A-regulated Sxl splicing and imply a broad link between Nab2 and Mettl3-regulated brain RNAs.

AUTOREGULATORY FUNCTIONING OF A DROSOPHILA GENE PRODUCT THAT ESTABLISHES AND MAINTAINS THE SEXUALLY DETERMINED STATE

Genetics ◽  
1984 ◽  
Vol 107 (2) ◽  
pp. 231-277
Author(s):  
Thomas W Cline
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Cellular Response ◽  
Regulatory Gene ◽  
Activity Level ◽  
Loss Of Function ◽  
Lethal Effects ◽  
Epigenetic Effect ◽  
Female Specific ◽  
Male Specific

ABSTRACT Sxl appears to head a regulatory gene hierarchy that controls Drosophila sexual dimorphism in response to the X chromosome/autosome balance. Only XXAA cells normally have Sxl  + activity. It maintains both the female morphogenetic sequence and a level of X-linked dosage-compensated gene expression compatible with diplo-X cell survival. In the absence of this activity, male sexual development and dosage-compensated gene hyperactivation ensure. Loss-of-function Sxl mutations generally have female-specific lethal effects caused by upsets in dosage compensation. New female-viable Sxl mutant alleles and combinations which lack Sxl's female sex determination function, yet still provide sufficient dosage compensation function for diplo-X survival, are described here. Consequently, such mutants cause genotypic females to develop as phenotypic males. Some of these sex-transforming Sxl mutants do not require the maternally produced da  + activity that is normally essential for the functioning of zygotic Sxl alleles. In this paper, products of these unusual alleles are shown to act in trans to induce the expression of zygotic Sxl  + alleles that would otherwise be unable to function due to a lack of maternal da  + activity. This result indicates a third function for Sxl  + product: a positive autoregulatory role. Controls for the autoregulation experiments demonstrated the sex-trans-forming epigenetic effect of the da mutation for the first time in diploids. In these experiments the female-specific zygotic lethal effects that normally would have accompanied loss of maternal da  + activity were suppressed by mutations known to block dosage-compensation gene hyperactivation-the autosomal, male-specific lethals. Three types of abnormal sexual phenotypes were produced in the experiments described here, each with important implications for the mechanism of sex determination: (1) a true intersex phenotype produced by one particular Sxl allele shows that Sxl  + must be involved in the cellular response to the X/A balance rather than in its establishment; (2) a maternally induced, female-sterile phenotype indicates that either the process of autoregulation or the mutants used to demonstrate it are tissue specific and (3) a mosaic intersexual phenotype whose character implies that the Sxl  + activity level is set early in development, both by the da  +-mediated X/A balance signal and by autoregulation, and is maintained subsequently in a cell autonomous fashion, independent of the initiating X/A balance signal. Thus, this study supports the view that sex determination is truly determinative in the standard developmental sense, and that Sxl is the carrier of the sexually determined state.

Sign in / Sign up

Export Citation Format

Share Document