scholarly journals Proteasomal Ubiquitin Receptor RPN-10 Controls Sex Determination in Caenorhabditis elegans

2006 ◽  
Vol 17 (12) ◽  
pp. 5356-5371 ◽  
Author(s):  
Masumi Shimada ◽  
Kenji Kanematsu ◽  
Keiji Tanaka ◽  
Hideyoshi Yokosawa ◽  
Hiroyuki Kawahara
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
Ubiquitin Ligase ◽  
26S Proteasome ◽  
Female Development ◽  
Ubiquitin Pathway ◽  
Downstream Target ◽  
Ubiquitin Binding ◽  
Client Proteins ◽  
Fate Decision

The ubiquitin-binding RPN-10 protein serves as a ubiquitin receptor that delivers client proteins to the 26S proteasome. Although ubiquitin recognition is an essential step for proteasomal destruction, deletion of the rpn-10 gene in yeast does not influence viability, indicating redundancy of the substrate delivery pathway. However, their specificity and biological relevance in higher eukaryotes is still enigmatic. We report herein that knockdown of the rpn-10 gene, but not any other proteasome subunit genes, sexually transforms hermaphrodites to females by eliminating hermaphrodite spermatogenesis in Caenorhabditis elegans. The feminization phenotype induced by deletion of the rpn-10 gene was rescued by knockdown of tra-2, one of sexual fate decision genes promoting female development, and its downstream target tra-1, indicating that the TRA-2–mediated sex determination pathway is crucial for the Δrpn-10–induced sterile phenotype. Intriguingly, we found that co-knockdown of rpn-10 and functionally related ubiquitin ligase ufd-2 overcomes the germline-musculinizing effect of fem-3(gf). Furthermore, TRA-2 proteins accumulated in rpn-10-defective worms. Our results show that the RPN-10–mediated ubiquitin pathway is indispensable for control of the TRA-2–mediated sex-determining pathway.

Genetic control of sex determination in the germ line of Caenorhabditis elegans

1988 ◽  
Vol 322 (1208) ◽  
pp. 11-18 ◽  
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
Genetic Control ◽  
Germ Line ◽  
Female Development ◽  
Tissue Specific ◽  
C Elegans ◽  
Male Development

The nematode Caenorhabditis elegans normally exists as one of two sexes: self-fertilizing hermaphrodite or male. Development as hermaphrodite or male requires the differentiation of each tissue in a sex-specific way. In this review, I discuss the genetic control of sex determination in a single tissue of C. elegans : the germ line. Sex determination in the germ line depends on the action of two types of genes: - those that act globally in all tissues to direct male or female development and those that act only in the germ line to specify either spermatogenesis or oogenesis. First, I consider a tissue-specific sex-determining gene, fog-1 , which promotes spermatogenesis in the germ line. Second, I consider the regulation of the hermaphrodite pattern of germ ­ line gametogenesis where first sperm and then oocytes are produced.

Novel players fine-tune plant trade-offs

2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano
Keyword(s):  
Ubiquitin Ligase ◽  
Feedback Loop ◽  
Molecular Level ◽  
26S Proteasome ◽  
Signalling Molecules ◽  
Transcriptional Reprogramming ◽  
Trade Offs ◽  
Jaz Proteins ◽  
Regulatory Feedback Loop ◽  
Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

scholarly journals Hakai is required for stabilization of core components of the m6A mRNA methylation machinery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Praveen Bawankar ◽  
Tina Lence ◽  
Chiara Paolantoni ◽  
Irmgard U. Haussmann ◽  
Migle Kazlauskiene ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sex Determination ◽  
Ubiquitin Ligase ◽  
Mammalian Cells ◽  
E3 Ubiquitin Ligase ◽  
Human Cells ◽  
Biological Functions ◽  
Mrna Metabolism ◽  
Mrna Methylation ◽  
Core Components

AbstractN6-methyladenosine (m6A) is the most abundant internal modification on mRNA which influences most steps of mRNA metabolism and is involved in several biological functions. The E3 ubiquitin ligase Hakai was previously found in complex with components of the m6A methylation machinery in plants and mammalian cells but its precise function remained to be investigated. Here we show that Hakai is a conserved component of the methyltransferase complex in Drosophila and human cells. In Drosophila, its depletion results in reduced m6A levels and altered m6A-dependent functions including sex determination. We show that its ubiquitination domain is required for dimerization and interaction with other members of the m6A machinery, while its catalytic activity is dispensable. Finally, we demonstrate that the loss of Hakai destabilizes several subunits of the methyltransferase complex, resulting in impaired m6A deposition. Our work adds functional and molecular insights into the mechanism of the m6A mRNA writer complex.

Weak male-determining genes and female heterogamety in Chironomus tentans

1984 ◽  
Vol 26 (6) ◽  
pp. 748-751
Author(s):  
Ray Feraday
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Chironomus Tentans ◽  
Female Development ◽  
Female Heterogamety ◽  
Dominant Female

Female heterogamety in the midge Chironomus tentans has been previously reported and attributed to a dominant female determiner. Published results are not consistent with the interpretation, and the female heterogamety, if any, can be better explained by a model involving a weakened male determiner. Suggestions are made for crosses between populations with different sex-determining mechanisms that would discriminate between models for the evolution of female heterogamety, and serve to determine whether indeed female development is the norm in the absence of any parental sex chromosomes.Key words: Chironomus, heterogamety, sex determination, sex chromosome.

Major sex-determining genes and the control of sexual dimorphism in Caenorhabditis elegans

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 625-637 ◽  
Author(s):  
Jonathan Hodgkin ◽  
Andrew D. Chisholm ◽  
Michael M. Shen
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
X Chromosome ◽  
Germ Line ◽  
Cell Lineage ◽  
Regulatory Genes ◽  
Nematode Caenorhabditis Elegans ◽  
X Chromosomes ◽  
The Many ◽  
Lineage Analysis

Sex determination in Caenorhabditis elegans involves a cascade of major regulatory genes connecting the primary sex determining signal, X chromosome dosage, to key switch genes, which in turn direct development along either male or female pathways. Animals with one X chromosome (XO) are male, while animals with two X chromosomes (XX) are hermaphrodite: hermaphrodite development occurs because the action of the regulatory genes is modified in the germ line so that both sperm and oocytes are made inside a completely female soma. The regulatory genes are being examined by both genetic and molecular means. We discuss how these major genes, in particular the last switch gene in the cascade, tra-1, might regulate the many different sex-specific events that occur during the development of the hermaphrodite and of the male.Key words: nematode, Caenorhabditis elegans, sex determination, sexual differentiation, cell lineage analysis.

scholarly journals The role of Caenorhabditis elegans sex-determination homologs, Mi-sdc-1 and Mi-tra-1 in Meloidogyne incognita

2021 ◽  
Author(s):  
Anil Baniya ◽  
Soumi Joseph ◽  
Larry Duncan ◽  
William Crow ◽  
Tesfamariam Mengistu
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
Meloidogyne Incognita ◽  
Egg Production ◽  
Target Genes ◽  
Parasitic Nematode ◽  
Plant Parasitic Nematode ◽  
Root Knot Nematode ◽  
Model Free ◽  
Plant Parasitic

AbstractSex determination is a key developmental event in all organisms. The pathway that regulates sexual fate has been well characterized at the molecular level in the model free-living nematode Caenorhabditis elegans. This study aims to gain a preliminary understanding of sex-determining pathways in a plant-parasitic nematode Meloidogyne incognita, and the extent to which the roles of the sex determination genes are conserved in a hermaphrodite species, C. elegans, and plant-parasitic nematode species, M. incognita. In this study, we targeted two sex-determining orthologues, sdc-1 and tra-1 from M. incognita using RNA interference (RNAi). RNAi was performed by soaking second-stage juveniles of M. incognita in a solution containing dsRNA of either Mi-tra-1or Mi-sdc-1 or both. To determine the effect of RNAi of the target genes, the juveniles treated with the dsRNA were inoculated onto a susceptible cultivar of cowpea grown in a nutrient pouch at 28 °C for 5 weeks. The development of the nematodes was analyzed at different time points during the growth period and compared to untreated controls. Our results showed that neither Mi-sdc-1 nor Mi-tra-1 have a significant role in regulating sexual fate in M. incognita. However, the silencing of Mi-sdc-1 significantly delayed maturity to adult females but did not affect egg production in mature females. In contrast, the downregulation of Mi-tra-1 transcript resulted in a significant reduction in egg production in both single and combinatorial RNAi-treated nematodes. Our results indicate that M. incognita may have adopted a divergent function for Mi-sdc-1 and Mi-tra-1distinct from Caenorhabditis spp. However, Mi-tra-1 might have an essential role in female fecundity in M. incognita and is a promising dsRNA target for root-knot nematode (RKN) management using host-delivered RNAi.

The dual role of hermaphrodite in the Drosophila sex determination regulatory hierarchy

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 99-111 ◽  
Author(s):  
M.A. Pultz ◽  
B.S. Baker
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Regulatory Protein ◽  
Female Offspring ◽  
Normal Female ◽  
Female Development ◽  
Salivary Gland Cells ◽  
Maternal Function ◽  
Different Levels

The hermaphrodite (her) locus has both maternal and zygotic functions required for normal female development in Drosophila. Maternal her function is needed for the viability of female offspring, while zygotic her function is needed for female sexual differentiation. Here we focus on understanding how her fits into the sex determination regulatory hierarchy. Maternal her function is needed early in the hierarchy: genetic interactions of her with the sisterless genes (sis-a and sis-b), with function-specific Sex-lethal (Sxl) alleles and with the constitutive allele SxlM#1 suggest that maternal her function is needed for Sxl initiation. When mothers are defective for her function, their daughters fail to activate a reporter gene for the Sxl early promoter and are deficient in Sxl protein expression. Dosage compensation is misregulated in the moribund daughters: some salivary gland cells show binding of the maleless (mle) dosage compensation regulatory protein to the X chromosome, a binding pattern normally seen only in males. Thus maternal her function is needed early in the hierarchy as a positive regulator of Sxl, and the maternal effects of her on female viability probably reflect Sxl's role in regulating dosage compensation. In contrast to her's maternal function, her's zygotic function in sex determination acts at the end of the hierarchy. This zygotic effect is not rescued by constitutive Sxl expression, nor by constitutive transformer (tra) expression. Moreover, the expression of doublesex (dsx) transcripts appears normal in her mutant females. We conclude that the maternal and zygotic functions of her are needed at two distinctly different levels of the sex determination regulatory hierarchy.

Sign in / Sign up

Export Citation Format

Share Document