scholarly journals CRISPR Disruption of BmOvo Resulted in the Failure of Emergence and Affected the Wing and Gonad Development in the Silkworm Bombyx mori

Insects ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 254 ◽  
Author(s):  
Honglun Bi ◽  
Xia Xu ◽  
Xiaowei Li ◽  
Yong Zhang ◽  
Yongping Huang ◽  
...  
Keyword(s):  
Sex Determination ◽  
Bombyx Mori ◽  
Wnt Signaling Pathway ◽  
Gonad Development ◽  
Wing Disc ◽  
Wild Type ◽  
Lepidopteran Insect ◽  
Gene Expression Analyses ◽  
Wing Discs ◽  
Germline Sex Determination

The domesticated silkworm is an economically important insect that is widely used as a lepidopteran insect model. Although somatic sex determination in the silkworm is well characterized, germline sex determination is not. Here, we used the transgenic-based CRISPR/Cas9 genome editing system to study the function of the Ovo gene in Bombyx mori. BmOvo is the homolog of a factor important in germline sex determination in Drosophila melanogaster. BmOvo mutants had abnormally shaped eggs that were disordered in the ovarioles, and gonad development was abnormal. Interestingly, wing discs and wings did not develop properly, and most of the mutants failed to eclose. Gene expression analyses by qRT-PCR showed that BmOvo gene was highly expressed in the wing disc and epidermis. Genes involved in the WNT signaling pathway and wing development genes BmWCP10 and BmE74 were downregulated in the BmOvo mutants when compared with wild-type animals. These results demonstrate that the BmOvo gene product plays an important role in wing metamorphosis. Thus, this study provides new insights into the multiple functions of BmOvo beyond germline sex determination.

scholarly journals The mir-35 family links maternal germline sex to embryonic viability in C. elegans

2019 ◽  
Author(s):  
Lars Benner ◽  
Katherine Prothro ◽  
Katherine McJunkin
Keyword(s):  
Sex Determination ◽  
Germ Cells ◽  
Sex Reversal ◽  
Loss Of Function ◽  
Wild Type ◽  
Partial Loss ◽  
C Elegans ◽  
Germline Sex Determination ◽  
Embryonic Viability ◽  
Male Gene

AbstractThe germline sex determination pathway in C. elegans determines whether germ cells develop as oocytes or sperm, with no previously known effect on viability. The mir-35 family of microRNAs are expressed in the C. elegans germline and embryo and are essential for both viability and normal hermaphroditic sex determination, preventing aberrant male gene expression in XX hermaphrodite embryos. Here we show that combining feminizing mutations with partial loss of function of the mir-35 family results in enhanced penetrance embryonic lethality that preferentially kills XO animals. This lethal phenotype is due to altered signaling through the germline sex determination pathway, and maternal germline feminization is sufficient to induce enhanced lethality. These findings reveal a surprising pleiotropy of sperm-fate promoting pathways on organismal viability. Overall, our results demonstrate an unexpectedly strong link between sex determination and embryonic viability, and suggest that in wild type animals, mir-35 family members buffer against misregulation of pathways outside the sex determination program, allowing for clean sex reversal rather than deleterious effects of perturbing sex determination genes.

scholarly journals The mog-1 gene is required for the switch from spermatogenesis to oogenesis in Caenorhabditis elegans.

Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 919-931 ◽  
Author(s):  
P L Graham ◽  
J Kimble
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
Germ Cells ◽  
Germ Line ◽  
Loss Of Function ◽  
Wild Type ◽  
Per Se ◽  
Post Transcriptional Regulation ◽  
Germline Sex Determination ◽  
Embryonic Death

Abstract Caenorhabditis elegans hermaphrodites make first sperm, then oocytes. By contrast, animals homozygous for any of six loss-of-function mutations in the gene mog-1 (for masculinization of the germ line) make sperm continuously and do not switch into oogenesis. Therefore, in mog-1 mutants, germ cells that normally would become oocytes are transformed into sperm. By contrast, somatic sexual fates are normal, suggesting that mog-1 plays a germ line-specific role in sex determination. Analyses of double mutants suggest that mog-1 negatively regulates the fem genes and/or fog-1: mog-1; fem and mog-1; fog-1 double mutants all make oocytes rather than sperm. Therefore, we propose that wild-type mog-1 is required in the hermaphrodite germ line for regulation of the switch from spermatogenesis to oogenesis rather than for specification of oogenesis per se. In addition to its role in germline sex determination, maternal mog-1 is required for embryogenesis: most progeny of a mog-1; fem or mog-1; fog-1 mother die as embryos. How might the roles of mog-1 in the sperm/oocyte switch and embryogenesis be linked? Previous work showed that fem-3 is regulated post-transcriptionally to achieve the sperm/oocyte switch. We speculate that mog-1 may function in the post-transcriptional regulation of numerous germ-line RNAs, including fem-3. A loss of mog-1 might inappropriately activate fem-3 and thereby abolish the sperm/oocyte switch; its loss might also lead to misregulation of maternal RNAs and thus embryonic death.

scholarly journals STUDIES IN BIOCHEMICAL GENETICS IN DROSOPHILA

1948 ◽  
Vol 31 (4) ◽  
pp. 337-345 ◽  
Author(s):  
Claude A. Villee
Keyword(s):  
Ascorbic Acid ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Imaginal Discs ◽  
Wing Disc ◽  
Biochemical Genetics ◽  
Wild Type ◽  
Respiratory Enzymes ◽  
Copper Porphyrin ◽  
Wing Discs

The metabolism of the imaginal discs of wild type, miniature, vestigial, and four-jointed varieties of Drosophila was investigated using the Cartesian diver ultramicrorespirometer. Wild type and vestigial wing disc respiration is inhibited by cyanide and azide and thus is mediated by an iron or copper porphyrin system, presumable cytochrome-cytochrome oxidase. Respiration is also inhibited by certain hydroxynaphthoquinones, believed to inactivate some enzyme between cytochromes b and c. The respiration of the vestigial and miniature wing discs is increased to normal by the addition of ascorbic acid and to a lesser extent by p-phenylenediamine and hydroquinone, hence the cytochrome oxidase and cytochrome c systems of vestigial and miniature wing discs are normal and the effects of these genes are on enzymes below cytochrome c in the respiratory chain. The respiratory enzymes of the developing imaginal discs of insects are similar to those of a wide variety of cells from bacteria to mammals. The correlation of these biochemical findings with embryological studies of the discs is discussed.

scholarly journals Transcriptome sequencing and comparative analysis of adult ovary and testis identify potential gonadal maintenance-related genes in Mauremys reevesii with temperature-dependent sex determination

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6557 ◽  
Author(s):  
Lei Xiong ◽  
Jinxiu Dong ◽  
Hui Jiang ◽  
Jiawei Zan ◽  
Jiucui Tong ◽  
...  
Keyword(s):  
Sex Determination ◽  
Signaling Pathway ◽  
Hedgehog Signaling ◽  
Sex Differentiation ◽  
Wnt Signaling Pathway ◽  
Gonad Development ◽  
Hippo Signaling ◽  
Rna Seq ◽  
Temperature Dependent ◽  
Type 3

Mauremys reevesii is a classical organism with temperature-dependent sex determination (TSD). Gonad development in early life has recently received considerable attention but gonadal maintenance after sex differentiation in turtles with TSD remains a mystery. In this study, we sequenced the transcriptomes for the adult testis and ovary using RNA-seq, and 36,221 transcripts were identified. In total, 1,594 differentially expressed genes (DEGs) were identified where 756 DEGs were upregulated in the testis and 838 DEGs were upregulated in the ovary. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that the TGF-beta signaling pathway and Hedgehog signaling pathway have important roles in testis maintenance and spermatogenesis, whereas the Hippo signaling pathway and Wnt signaling pathway are likely to participate in ovary maintenance. We determined the existence of antagonistic networks containing significant specific-expressed genes and pathways related to gonadal maintenance and gametogenesis in the adult gonads of M. reevesii. The candidate gene Fibronectin type 3 and ankyrin repeat domains 1 (FANK1) might be involved with the regulation of testis spermatogenesis.

Quantitative EM of gap junction distribution in mutant drosophila wing discs

1983 ◽  
Vol 41 ◽  
pp. 720-721
Author(s):  
J.S. Ryerse
Keyword(s):  
Gap Junctions ◽  
Growth Control ◽  
Intercellular Junctions ◽  
Wing Disc ◽  
En Bloc ◽  
Metabolic Cooperation ◽  
Drosophila Wing ◽  
Adult Wing ◽  
Wing Discs ◽  
Wing Pouch

Gap junctions are intercellular junctions found in both vertebrates and invertebrates through which ions and small molecules can pass. Their distribution in tissues could be of critical importance for ionic coupling or metabolic cooperation between cells or for regulating the intracellular movement of growth control and pattern formation factors. Studies of the distribution of gap junctions in mutants which develop abnormally may shed light upon their role in normal development. I report here the distribution of gap junctions in the wing pouch of 3 Drosophila wing disc mutants, vg (vestigial) a cell death mutant, 1(2)gd (lethal giant disc) a pattern abnormality mutant and 1(2)gl (lethal giant larva) a neoplastic mutant and compare these with wildtype wing discs.The wing pouch (the anlagen of the adult wing blade) of a wild-type wing disc is shown in Fig. 1 and consists of columnar cells (Fig. 5) joined by gap junctions (Fig. 6). 14000x EMs of conventionally processed, UA en bloc stained, longitudinally sectioned wing pouches were enlarged to 45000x with a projector and tracings were made on which the lateral plasma membrane (LPM) and gap junctions were marked.

scholarly journals Single cell transcriptomics reveal temporal dynamics of critical regulators of germ cell fate during mouse sex determination

2019 ◽  
Author(s):  
Chloé Mayère ◽  
Yasmine Neirijnck ◽  
Pauline Sararols ◽  
Chris M Rands ◽  
Isabelle Stévant ◽  
...  
Keyword(s):  
Sex Determination ◽  
Germ Cell ◽  
Single Cell ◽  
Cell Fate ◽  
Gene Networks ◽  
Network Inference ◽  
Temporal Dynamics ◽  
Intron Retention ◽  
Gonad Development ◽  
Altered Expression

SummaryDespite the importance of germ cell (GC) differentiation for sexual reproduction, the gene networks underlying their fate remain unclear. Here, we comprehensively characterize the gene expression dynamics during sex determination based on single-cell RNA sequencing of 14,914 XX and XY mouse GCs between embryonic days (E) 9.0 and 16.5. We found that XX and XY GCs diverge transcriptionally as early as E11.5 with upregulation of genes downstream of the Bone morphogenic protein (BMP) and Nodal/Activin pathways in XY and XX GCs, respectively. We also identified a sex-specific upregulation of genes associated with negative regulation of mRNA processing and an increase in intron retention consistent with a reduction in mRNA splicing in XY testicular GCs by E13.5. Using computational gene regulation network inference analysis, we identified sex-specific, sequential waves of putative key regulator genes during GC differentiation and revealed that the meiotic genes are regulated by positive and negative master modules acting in an antagonistic fashion. Finally, we found that rare adrenal GCs enter meiosis similarly to ovarian GCs but display altered expression of master genes controlling the female and male genetic programs, indicating that the somatic environment is important for GC function. Our data is available on a web platform and provides a molecular roadmap of GC sex determination at single-cell resolution, which will serve as a valuable resource for future studies of gonad development, function and disease.

scholarly journals Ionizing radiation induces stem cell-like properties in a caspase-dependent manner in Drosophila

2018 ◽  
Author(s):  
Shilpi Verghese ◽  
Tin Tin Su
Keyword(s):  
Stem Cell ◽  
Ionizing Radiation ◽  
Cancer Cells ◽  
Wing Disc ◽  
Lineage Tracing ◽  
Dependent Manner ◽  
Cancer Treatments ◽  
Therapeutic Success ◽  
Wing Discs ◽  
Regenerative Cells

ABSTRACTCancer treatments including ionizing radiation (IR) can induce cancer stem cell-like properties in non-stem cancer cells, an outcome that can interfere with therapeutic success. Yet, we understand little about what consequences of IR induces stem cell like properties and why some cancer cells show this response but not others. In previous studies, we identified a pool of epithelial cells in Drosophila larval wing discs that display IR-induced stem cell-like properties. These cells are resistant to killing by IR and, after radiation damage, change fate and translocate to regenerate parts of the disc that suffered more cell death. Here, we addressed how IR exposure results in the induction of stem cell-like behavior, and found a requirement for caspase activity. Unexpectedly, this requirement was mapped to the regenerative cells, suggesting a non-apoptotic role for caspases in the induction of stem cell-like behavior. We also performed a systematic probing of different regions of the wing disc by lineage tracing, in order to identify additional pools of cells with IR-induced regenerative properties. We identified two new populations of such cells. Unlike the original pool that helps regenerate the disc, the new pools of cells undergo abnormal regeneration to produce an ectopic, supernumerary wing disc. We also identified cells that lack the ability to display IR-induced regenerative behavior. Identification of different cell populations with different IR-induced regenerative potential will allow us to probe the molecular basis for these differences in the future.AUTHOR SUMMARYIonizing Radiation (IR), alone or in combination with other therapies, is used to treat an estimated half of all cancer patients. Yet, we understand little about why some tumors cells respond to treatment while others grow back (regenerate). We identified specific pools of cells within a Drosophila organ that are capable of regeneration after damage by IR. We also identified what it is about IR damage that allows these cells to regenerate. These results help us understand how cells regenerate after IR damage and will aid in designing better therapies that involve radiation.

scholarly journals Vertebrate sex determination: many means to an end

Reproduction ◽  
2002 ◽  
pp. 447-457 ◽  
Author(s):  
BC Morrish ◽  
AH Sinclair
Keyword(s):  
Sex Determination ◽  
Regulatory Network ◽  
Gonadal Dysgenesis ◽  
Developmental Process ◽  
Gonad Development ◽  
Complex Interplay ◽  
Specific Expression ◽  
Sex Specificity ◽  
Bipotential Gonad

The differentiation of a testis or ovary from a bipotential gonadal primordium is a developmental process common to mammals, birds and reptiles. Since the discovery of SRY, the Y-linked testis-determining gene in mammals, extensive efforts have failed to find its orthologue in other vertebrates, indicating evolutionary plasticity in the switch that triggers sex determination. Several other genes are known to be important for sex determination in mammals, such as SOX9, AMH, WT1, SF1, DAX1 and DMRT1. Analyses of these genes in humans with gonadal dysgenesis, mouse models and using in vitro cell culture assays have revealed that sex determination results from a complex interplay between the genes in this network. All of these genes are conserved in other vertebrates, such as chickens and alligators, and show gonad-specific expression in these species during the period of sex determination. Intriguingly, the sequence, sex specificity and timing of expression of some of these genes during sex determination differ among species. This finding indicates that the interplay between genes in the regulatory network leading to gonad development differs between vertebrates. However, despite this, the development of a testis or ovary from a bipotential gonad is remarkably similar across vertebrates.

scholarly journals Endocytosis of Wingless via a dynamin-independent pathway is necessary for signaling in Drosophila wing discs

2016 ◽  
Vol 113 (45) ◽  
pp. E6993-E7002 ◽  
Author(s):  
Anupama Hemalatha ◽  
Chaitra Prabhakara ◽  
Satyajit Mayor
Keyword(s):  
Signal Transduction ◽  
Wing Disc ◽  
Low Ph ◽  
Endocytic Pathway ◽  
Apical Surface ◽  
Receptor Complexes ◽  
Drosophila Wing ◽  
Wing Discs ◽  
Ph Dependent ◽  
Endocytic Pathways

Endocytosis of ligand-receptor complexes regulates signal transduction during development. In particular, clathrin and dynamin-dependent endocytosis has been well studied in the context of patterning of the Drosophila wing disc, wherein apically secreted Wingless (Wg) encounters its receptor, DFrizzled2 (DFz2), resulting in a distinctive dorso-ventral pattern of signaling outputs. Here, we directly track the endocytosis of Wg and DFz2 in the wing disc and demonstrate that Wg is endocytosed from the apical surface devoid of DFz2 via a dynamin-independent CLIC/GEEC pathway, regulated by Arf1, Garz, and class I PI3K. Subsequently, Wg containing CLIC/GEEC endosomes fuse with DFz2-containing vesicles derived from the clathrin and dynamin-dependent endocytic pathway, which results in a low pH-dependent transfer of Wg to DFz2 within the merged and acidified endosome to initiate Wg signaling. The employment of two distinct endocytic pathways exemplifies a mechanism wherein cells in tissues leverage multiple endocytic pathways to spatially regulate signaling.

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