Mab-3 is a direct tra-1 target gene regulating diverse aspects of C. elegans male sexual development and behavior

Development ◽  
2000 ◽  
Vol 127 (20) ◽  
pp. 4469-4480 ◽  
Author(s):  
W. Yi ◽  
J.M. Ross ◽  
D. Zarkower
Keyword(s):  
Transcription Factor ◽  
Sex Determination ◽  
Sexual Development ◽  
Sexual Differentiation ◽  
Sense Organ ◽  
Yolk Protein ◽  
Bhlh Transcription Factor ◽  
Organ Differentiation ◽  
And Behavior ◽  
Protein Transcription

Sex determination is controlled by global regulatory genes, such as tra-1 in Caenorhabditis elegans, Sex lethal in Drosophila, or Sry in mammals. How these genes coordinate sexual differentiation throughout the body is a key unanswered question. tra-1 encodes a zinc finger transcription factor, TRA-1A, that regulates, directly or indirectly, all genes required for sexual development. mab-3 (male abnormal 3), acts downstream of tra-1 and is known to be required for sexual differentiation of at least two tissues. mab-3 directly regulates yolk protein transcription in the intestine and specifies male sense organ differentiation in the nervous system. It encodes a transcription factor related to the products of the Drosophila sexual regulator doublesex (dsx), which also regulates yolk protein transcription and male sense-organ differentiation. The similarities between mab-3 and dsx led us to suggest that some aspects of sex determination may be evolutionarily conserved. Here we find that mab-3 is also required for expression of male-specific genes in sensory neurons of the head and tail and for male interaction with hermaphrodites. These roles in male development and behavior suggest further functional similarity to dsx. In male sensory ray differentiation we find that MAB-3 acts synergistically with LIN-32, a neurogenic bHLH transcription factor. Expression of LIN-32 is spatially restricted by the combined action of the Hox gene mab-5 and the hairy homolog lin-22, while MAB-3 is expressed throughout the lateral hypodermis. Finally, we find that mab-3 transcription is directly regulated in the intestine by TRA-1A, providing a molecular link between the global regulatory pathway and terminal sexual differentiation.

scholarly journals Grasses use an alternatively wired bHLH transcription factor network to establish stomatal identity

2016 ◽  
Vol 113 (29) ◽  
pp. 8326-8331 ◽  
Author(s):  
Michael T. Raissig ◽  
Emily Abrash ◽  
Akhila Bettadapur ◽  
John P. Vogel ◽  
Dominique C. Bergmann
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Brachypodium Distachyon ◽  
Bhlh Transcription Factor ◽  
Stomatal Development ◽  
Helix Loop Helix ◽  
Factor Module ◽  
Forward Genetic Screens ◽  
Conserved Genes ◽  
And Behavior

Stomata, epidermal valves facilitating plant–atmosphere gas exchange, represent a powerful model for understanding cell fate and pattern in plants. Core basic helix–loop–helix (bHLH) transcription factors regulating stomatal development were identified in Arabidopsis, but this dicot’s developmental pattern and stomatal morphology represent only one of many possibilities in nature. Here, using unbiased forward genetic screens, followed by analysis of reporters and engineered mutants, we show that stomatal initiation in the grass Brachypodium distachyon uses orthologs of stomatal regulators known from Arabidopsis but that the function and behavior of individual genes, the relationships among genes, and the regulation of their protein products have diverged. Our results highlight ways in which a kernel of conserved genes may be alternatively wired to produce diversity in patterning and morphology and suggest that the stomatal transcription factor module is a prime target for breeding or genome modification to improve plant productivity.

Similarity of DNA binding and transcriptional regulation by Caenorhabditis elegans MAB-3 and Drosophila melanogaster DSX suggests conservation of sex determining mechanisms

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 873-881 ◽  
Author(s):  
W. Yi ◽  
D. Zarkower
Keyword(s):  
Dna Binding ◽  
Sex Determination ◽  
Dna Sequences ◽  
Sexual Development ◽  
Yolk Protein ◽  
Binding Motif ◽  
C Elegans ◽  
A Site

Although most animals occur in two sexes, the molecular pathways they employ to control sexual development vary considerably. The only known molecular similarity between phyla in sex determination is between two genes, mab-3 from C. elegans, and doublesex (dsx) from Drosophila. Both genes contain a DNA binding motif called a DM domain and they regulate similar aspects of sexual development, including yolk protein synthesis and peripheral nervous system differentiation. Here we show that MAB-3, like the DSX proteins, is a direct regulator of yolk protein gene transcription. We show that despite containing different numbers of DM domains MAB-3 and DSX bind to similar DNA sequences. mab-3 mutations deregulate vitellogenin synthesis at the level of transcription, resulting in expression in both sexes, and the vitellogenin genes have potential MAB-3 binding sites upstream of their transcriptional start sites. MAB-3 binds to a site in the vit-2 promoter in vitro, and this site is required in vivo to prevent transcription of a vit-2 reporter construct in males, suggesting that MAB-3 is a direct repressor of vitellogenin transcription. This is the first direct link between the sex determination regulatory pathway and sex-specific structural genes in C. elegans, and it suggests that nematodes and insects use at least some of the same mechanisms to control sexual development.

Genetics of sex determination: what can we learn from Drosophila?

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 17-24
Author(s):  
Rolf Nöthiger ◽  
Monica Steinmann-Zwicky
Keyword(s):  
Molecular Biology ◽  
Sex Determination ◽  
Genetic Control ◽  
Sexual Development ◽  
Sexual Differentiation ◽  
Regulatory Elements ◽  
Negative Control ◽  
Homeotic Genes ◽  
Specific Expression ◽  
X Chromosomes

The combined efforts of genetics, developmental and molecular biology have revealed the principles of genetic control of sexual differentiation in Drosophila. In combination with maternal components, a quantitative chromosomal signal, provided by the ratio of X chromosomes to sets of autosomes (X: A), regulates a key gene (Sxl). The functional state, ON or OFF, of Sxl, via a few subordinate regulatory genes, controls a switch gene (dsx) that can express two mutually exclusive functions, M or F. These serve to repress either the female or the male set of differentiation genes, thus directing the cells either into the male or into the female sexual pathway. Investigations of control genes and their regulation show that they have properties of homeotic genes. Their role is to select one of two alternative developmental programs. Their function, or lack of function, is required throughout development to maintain the cells in their respective sexual pathway. Differentiation genes are under negative control by dsx. We discuss the cis- and tams-regulatory elements that are needed for sex-, tissue- and stage-specific expression of the differentiation genes. A comparison of Drosophila to other organisms such as Caenorhabditis, mammals and other insects indicates similarities that we interpret as evidence for a basically invariant genetic strategy used by various organisms to regulate sexual development.

scholarly journals Hemimetabolous insects elucidate the origin of sexual development via alternative splicing

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Judith Wexler ◽  
Emily Kay Delaney ◽  
Xavier Belles ◽  
Coby Schal ◽  
Ayako Wada-Katsumata ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Alternative Splicing ◽  
Sexual Development ◽  
Sexual Differentiation ◽  
Splicing Factor ◽  
Male And Female ◽  
Hemimetabolous Insect ◽  
Alternatively Spliced

Insects are the only known animals in which sexual differentiation is controlled by sex-specific splicing. The doublesex transcription factor produces distinct male and female isoforms, which are both essential for sex-specific development. dsx splicing depends on transformer, which is also alternatively spliced such that functional Tra is only present in females. This pathway has evolved from an ancestral mechanism where dsx was independent of tra and expressed and required only in males. To reconstruct this transition, we examined three basal, hemimetabolous insect orders: Hemiptera, Phthiraptera, and Blattodea. We show that tra and dsx have distinct functions in these insects, reflecting different stages in the changeover from a transcription-based to a splicing-based mode of sexual differentiation. We propose that the canonical insect tra-dsx pathway evolved via merger between expanding dsx function (from males to both sexes) and narrowing tra function (from a general splicing factor to dedicated regulator of dsx).

scholarly journals CRISPR/Cas9-mediated mosaic mutation of SRY gene induces hermaphroditism in rabbits

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Yuning Song ◽  
Yuanyuan Xu ◽  
Mingming Liang ◽  
Yuxin Zhang ◽  
Mao Chen ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sexual Development ◽  
Sexual Differentiation ◽  
Rabbit Model ◽  
Gonad Development ◽  
High Mobility ◽  
Testicular Tissue ◽  
Spermatogenic Cells ◽  
Sry Gene ◽  
Male Sex

Hermaphroditism is a rare disorder that affects sexual development, resulting in individuals with both male and female sexual organs. Hermaphroditism is caused by anomalies in genes regulating sex determination, gonad development, or expression of hormones and their receptors during embryonic development during sexual differentiation. SRY is a sex-determination gene on the Y chromosome that is responsible for initiating male sex determination in mammals. In this study, we introduced CRISPR/Cas9-mediated mutations in the high-mobility-group (HMG) region of the rabbit SRY. As expected, SRY-mutant chimeric rabbits were diagnosed with hermaphroditism, characterized by possessing ovotestis, testis, ovary and uterus simultaneously. Histopathology analysis revealed that the testicular tissue was immature and lacked spermatogenic cells, while the ovarian portion appeared normal and displayed follicles at different stages. This is the first report of a rabbit hermaphroditism model generated by the CRISPR/Cas9 system. This novel rabbit model could advance our understanding of the pathogenesis of hermaphroditism, and identify novel therapies for human clinical treatment of hermaphroditism.

scholarly journals Conserved and non-conserved functions of the rice homologs of the Arabidopsis trichome initiation-regulating MBW complex proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kaijie Zheng ◽  
Xutong Wang ◽  
Yating Wang ◽  
Shucai Wang
Keyword(s):  
Transcription Factor ◽  
Anthocyanin Biosynthesis ◽  
Transcriptional Activator ◽  
Myb Transcription Factor ◽  
Bhlh Transcription Factor ◽  
Seed Color ◽  
Transcription Activator ◽  
Root Hair Formation ◽  
Protoplast Transfection ◽  
Mbw Complex

Abstract Background Trichome initiation in Arabidopsis is regulated by a MYB-bHLH-WD40 (MBW) transcriptional activator complex formed by the R2R3 MYB transcription factor GLABRA1 (GL1), MYB23 or MYB82, the bHLH transcription factor GLABRA3 (GL3), ENHANCER OF GLABRA3 (EGL3) or TRANSPARENT TESTA8 (TT8), and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). However, the functions of the rice homologs of the MBW complex proteins remained uncharacterized. Results Based on amino acid sequence identity and similarity, and protein interaction prediction, we identified OsGL1s, OsGL3s and OsTTG1s as rice homologs of the MBW complex proteins. By using protoplast transfection, we show that OsGL1D, OsGL1E, OsGL3B and OsTTG1A were predominantly localized in the nucleus, OsGL3B functions as a transcriptional activator and is able to interact with GL1 and TTG1. By using yeast two-hybrid and protoplast transfection assays, we show that OsGL3B is able to interact with OsGL1E and OsTTG1A, and OsGL1E and OsTTG1A are also able to interact with GL3. On the other hand, we found that OsGL1D functions as a transcription activator, and it can interact with GL3 but not OsGL3B. Furthermore, our results show that expression of OsTTG1A in the ttg1 mutant restored the phenotypes including alternations in trichome and root hair formation, seed color, mucilage production and anthocyanin biosynthesis, indicating that OsTTG1A and TTG1 may have similar functions. Conclusion These results suggest that the rice homologs of the Arabidopsis MBW complex proteins are able to form MBW complexes, but may have conserved and non-conserved functions.

scholarly journals Effect of wing scalloping mutations on cut expression and sense organ differentiation in the Drosophila wing margin.

Genetics ◽  
1992 ◽  
Vol 131 (2) ◽  
pp. 353-363 ◽  
Author(s):  
J Jack ◽  
Y DeLotto
Keyword(s):  
Sense Organ ◽  
Epidermal Cells ◽  
Additive Effect ◽  
Mutant Phenotype ◽  
Wing Margin ◽  
Transcriptional Enhancer ◽  
Organ Differentiation ◽  
Notch Activity ◽  
Neural Fate ◽  
Drosophila Wing

Abstract A number of wing scalloping mutations have been examined to determine their effects on the mutant phenotype of cut mutations and on the expression of the Cut protein. The mutations fall into two broad classes, those which interact synergistically with weak cut wing mutations to produce a more extreme wing phenotype than either mutation alone and those that have a simple additive effect with weak cut wing mutations. The synergistically interacting mutations are alleles of the Notch, Serrate and scalloped genes. These mutations affect development of the wing margin in a manner similar to the cut wing mutations. The mutations inactivate the cut transcriptional enhancer for the wing margin mechanoreceptors and noninnervated bristles and prevent differentiation of the organs. Surprisingly, reduction of Notch activity in the wing margin does not have the effect of converting epidermal cells to a neural fate as it does in other tissues of ectodermal origin. Rather, it prevents the differentiation of the wing margin mechanoreceptors and noninnervated bristles.

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