scholarly journals Transgenic and knockout analyses of Masculinizer and doublesex illuminated the unique functions of doublesex in germ cell sexual development of the silkworm, Bombyx mori

2020 ◽  
Author(s):  
Tomohisa Yuzawa ◽  
Misato Matsuoka ◽  
Megumi Sumitani ◽  
Fugaku Aoki ◽  
Hideki Sezutsu ◽  
...  

Abstract Background: Masculinizer (Masc) plays a pivotal role in male sex determination in the silkworm, Bombyx mori. Masc is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. The male isoform of Bmdsx (BmdsxM) induces male differentiation in somatic cells, while females express the female isoform of Bmdsx (BmdsxF), which promotes female differentiation in somatic cells. Our previous findings suggest that Masc could direct the differentiation of genetically female (ZW) germ cells into sperms. However, it remains unclear whether Masc directly induces spermatogenesis or if it promotes male differentiation in germ cells indirectly by inducing the expression of BmdsxM. Results: In this study, we performed genetic analyses using the transgenic line that expressed Masc, as well as various Bmdsx knockout lines. We found that Masc-expressing females with a homozygous mutation in BmdsxM showed normal development in ovaries. The formation of testis-like tissues was abolished in these females. On the other hand, Masc-expressing females carrying a homozygous mutation in BmdsxF exhibited almost complete male-specific development in gonads and germ cells. These results suggest that BmdsxM has an ability to induce male development in germ cells as well as internal genital organs, while BmdsxF inhibits BmdsxM activity and represses male differentiation. To investigate whether MASC directly controls male-specific splicing of Bmdsx and identify RNAs that form complexes with MASC in testes, we performed RNA immunoprecipitation (RIP) using an anti-MASC antibody. We found that MASC formed a complex with AS1 lncRNA, which is a testis-specific factor involved in the male-specific splicing of Bmdsx pre-mRNA. Conclusions: Taken together, our findings suggest that Masc induces male differentiation in germ cells by enhancing the production of BmdsxM. Physical interaction between MASC and AS1 lncRNA may be important for the BmdsxM expression in the testis. Unlike in the Drosophila dsx, BmdsxM was able to induce spermatogenesis in genetically female (ZW) germ cells. To the best of our knowledge, this is the first report that the role of dsx in germ cell sexual development is different between insect species.

2020 ◽  
Author(s):  
Tomohisa Yuzawa ◽  
Misato Matsuoka ◽  
Megumi Sumitani ◽  
Fugaku Aoki ◽  
Hideki Sezutsu ◽  
...  

Abstract Background: Masculinizer (Masc) plays a pivotal role in male sex determination in the silkworm, Bombyx mori. Masc is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. The male isoform of Bmdsx (BmdsxM) induces male differentiation in somatic cells, while females express the female isoform of Bmdsx (BmdsxF), which promotes female differentiation in somatic cells. Our previous findings suggest that Masc could direct the differentiation of genetically female (ZW) germ cells into sperms. However, it remains unclear whether Masc directly induces spermatogenesis or if it promotes male differentiation in germ cells indirectly by inducing the expression of BmdsxM. Results: In this study, we performed genetic analyses using the transgenic line that expressed Masc, as well as various Bmdsx knockout lines. We found that Masc-expressing females with a homozygous mutation in BmdsxM showed normal development in ovaries. The formation of testis-like tissues was abolished in these females. On the other hand, Masc-expressing females carrying a homozygous mutation in BmdsxF exhibited almost complete male-specific development in gonads and germ cells. These results suggest that BmdsxM has an ability to induce male development in germ cells as well as internal genital organs, while BmdsxF inhibits BmdsxM activity and represses male differentiation. To investigate whether MASC directly controls male-specific splicing of Bmdsx and identify RNAs that form complexes with MASC in testes, we performed RNA immunoprecipitation (RIP) using an anti-MASC antibody. We found that MASC formed a complex with AS1 lncRNA, which is a testis-specific factor involved in the male-specific splicing of Bmdsx pre-mRNA. Conclusions: Taken together, our findings suggest that Masc induces male differentiation in germ cells by enhancing the production of BmdsxM. Physical interaction between MASC and AS1 lncRNA may be important for the BmdsxM expression in the testis. Unlike in the Drosophila dsx, BmdsxM was able to induce spermatogenesis in genetically female (ZW) germ cells. To the best of our knowledge, this is the first report that the role of dsx in germ cell sexual development is different between insect species.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Tomohisa Yuzawa ◽  
Misato Matsuoka ◽  
Megumi Sumitani ◽  
Fugaku Aoki ◽  
Hideki Sezutsu ◽  
...  

Abstract Background Masculinizer (Masc) plays a pivotal role in male sex determination in the silkworm, Bombyx mori. Masc is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. The male isoform of Bmdsx (BmdsxM) induces male differentiation in somatic cells, while females express the female isoform of Bmdsx (BmdsxF), which promotes female differentiation in somatic cells. Our previous findings suggest that Masc could direct the differentiation of genetically female (ZW) germ cells into sperms. However, it remains unclear whether Masc directly induces spermatogenesis or if it promotes male differentiation in germ cells indirectly by inducing the expression of BmdsxM. Results In this study, we performed genetic analyses using the transgenic line that expressed Masc, as well as various Bmdsx knockout lines. We found that Masc-expressing females with a homozygous mutation in BmdsxM showed normal development in ovaries. The formation of testis-like tissues was abolished in these females. On the other hand, Masc-expressing females carrying a homozygous mutation in BmdsxF exhibited almost complete male-specific development in gonads and germ cells. These results suggest that BmdsxM has an ability to induce male development in germ cells as well as internal genital organs, while BmdsxF inhibits BmdsxM activity and represses male differentiation. To investigate whether MASC directly controls male-specific splicing of Bmdsx and identify RNAs that form complexes with MASC in testes, we performed RNA immunoprecipitation (RIP) using an anti-MASC antibody. We found that MASC formed a complex with AS1 lncRNA, which is a testis-specific factor involved in the male-specific splicing of Bmdsx pre-mRNA. Conclusions Taken together, our findings suggest that Masc induces male differentiation in germ cells by enhancing the production of BmdsxM. Physical interaction between MASC and AS1 lncRNA may be important for the BmdsxM expression in the testis. Unlike in the Drosophila dsx, BmdsxM was able to induce spermatogenesis in genetically female (ZW) germ cells. To the best of our knowledge, this is the first report that the role of dsx in germ cell sexual development is different between insect species.


2020 ◽  
Author(s):  
Tomohisa Yuzawa ◽  
Misato Matsuoka ◽  
Megumi Sumitani ◽  
Fugaku Aoki ◽  
Hideki Sezutsu ◽  
...  

Abstract Background: Masculinizer (Masc) plays a pivotal role in male sex determination in the silkworm, Bombyx mori. Masc is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. The male isoform of Bmdsx (BmdsxM) induces male differentiation in somatic cells, while females express the female isoform of Bmdsx (BmdsxF), which promotes female differentiation in somatic cells. Our previous findings suggest that Masc could direct the differentiation of genetically female (ZW) germ cells into sperms. However, it remains unclear whether Masc directly induces spermatogenesis of if it promotes male differentiation in germ cells indirectly by inducing the expression of BmdsxM. Results: In this study, we performed genetic analyses using a transgenic line that expressed Masc, as well as various Bmdsx knockout lines. Masc-expressing females express both BmdsxF and BmdsxM and have degenerated ovaries combined with testis-like tissues, which produce sperm. We found that Masc-expressing females with a homozygous mutation in BmdsxM showed normal development in ovaries. The formation of testis-like tissues was abolished in these females. In comparison, Masc-expressing females carrying a homozygous mutation in BmdsxF exhibited almost complete male-specific development in gonads and germ cells. These results suggest that BmdsxM can induce male development in germ cells and internal genital organs, while BmdsxF inhibits BmdsxM activity and represses male differentiation. To investigate whether MASC directly controls male-specific splicing of Bmdsx and identify RNAs that form complexes with MASC in testes, we performed RNA immunoprecipitation (RIP) using an anti-MASC antibody. We found that MASC formed a complex with AS1 lncRNA , which is a testis-specific factor involved in the male-specific splicing of Bmdsx pre-mRNA . Conclusions: Taken together, our findings suggest that Masc induces male differentiation in gonads and germ cells by enhancing the production of BmdsxM. Physical interaction between MASC and AS1 lncRNA may be important for the BmdsxM expression in the testis. Unlike Drosophila dsx, BmdsxM was able to induce spermatogenesis in genetically female (ZW) germ cells. To the best of our knowledge, this is the first report that the role of dsx in germ cell sexual development is different between insect species.


2020 ◽  
Author(s):  
Tomohisa Yuzawa ◽  
Misato Matsuoka ◽  
Megumi Sumitani ◽  
Fugaku Aoki ◽  
Hideki Sezutsu ◽  
...  

Abstract Background Masculinizer (Masc) plays a pivotal role in male sex determination in the silkworm, Bombyx mori. Masc is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. The male isoform of Bmdsx (BmdsxM) induces male differentiation in somatic cells, while females express the female isoform of Bmdsx (BmdsxF), which promotes female differentiation in somatic cells. However, the importance of Bmdsx in sexual differentiation in germ cells remains unclear. In Drosophila melanogaster, mechanisms regulating sexual differentiation differ between germ cells and somatic cells. dsx is not required within female or male germ cells for sexual development. However, it remains unclear whether this is also the case in other insect species. Results In this study, we performed genetic analyses using a transgenic line that expressed Masc, as well as various Bmdsx knockout lines. Masc-expressing females express both BmdsxF and BmdsxM and have degenerated ovaries combined with testis-like tissues, which produce sperm. We found that Masc-expressing females with a homozygous mutation in BmdsxM showed normal development in ovaries. The formation of testis-like tissues was abolished in these females. In comparison, Masc-expressing females carrying a homozygous mutation in BmdsxF exhibited almost complete male-specific development in gonads and germ cells. These results suggest that BmdsxM can induce male development in germ cells and internal genital organs, while BmdsxF inhibits BmdsxM activity and represses male differentiation. To investigate whether MASC directly controls male-specific splicing of Bmdsx and identify RNAs that form complexes with MASC in testes, we performed RNA immunoprecipitation (RIP) using an anti-MASC antibody. We found that MASC formed a complex with Bmdsx-AS1 lncRNA, which is a testis-specific factor involved in the male-specific splicing of Bmdsx pre-mRNA. Conclusions Combined, our findings suggest that Masc induces male differentiation in gonads and germ cells by interacting with Bmdsx-AS1 lncRNA and enhancing the production of BmdsxM. Unlike Drosophila dsx, BmdsxM was able to induce spermatogenesis in genetically female (ZW) germ cells. To our knowledge, this is the first report indicating the role of dsx in germ cell sexual development differs among insect species.


Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.


Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 655-666 ◽  
Author(s):  
H.T. Broihier ◽  
L.A. Moore ◽  
M. Van Doren ◽  
S. Newman ◽  
R. Lehmann

In Drosophila as well as many vertebrate systems, germ cells form extraembryonically and migrate into the embryo before navigating toward gonadal mesodermal cells. How the gonadal mesoderm attracts migratory germ cells is not understood in any system. We have taken a genetic approach to identify genes required for germ cell migration in Drosophila. Here we describe the role of zfh-1 in germ cell migration to the gonadal mesoderm. In zfh-1 mutant embryos, the initial association of germ cells and gonadal mesoderm is blocked. Loss of zfh-1 activity disrupts the development of two distinct mesodermal populations: the caudal visceral mesoderm and the gonadal mesoderm. We demonstrate that the caudal visceral mesoderm facilitates the migration of germ cells from the endoderm to the mesoderm. Zfh-1 is also expressed in the gonadal mesoderm throughout the development of this tissue. Ectopic expression of Zfh-1 is sufficient to induce additional gonadal mesodermal cells and to alter the temporal course of gene expression within these cells. Finally, through analysis of a tinman zfh-1 double mutant, we show that zfh-1 acts in conjunction with tinman, another homeodomain protein, in the specification of lateral mesodermal derivatives, including the gonadal mesoderm.


Reproduction ◽  
2017 ◽  
Vol 154 (6) ◽  
pp. 723-733 ◽  
Author(s):  
Huijuan Zhang ◽  
Guishuan Wang ◽  
Lin Liu ◽  
Xiaolin Liang ◽  
Yu Lin ◽  
...  

The chromatoid body (CB) is a specific cloud-like structure in the cytoplasm of haploid spermatids. Recent findings indicate that CB is identified as a male germ cell-specific RNA storage and processing center, but its function has remained elusive for decades. In somatic cells, KH-type splicing regulatory protein (KSRP) is involved in regulating gene expression and maturation of select microRNAs (miRNAs). However, the function of KSRP in spermatogenesis remains unclear. In this study, we showed that KSRP partly localizes in CB, as a component of CB. KSRP interacts with proteins (mouse VASA homolog (MVH), polyadenylate-binding protein 1 (PABP1) and polyadenylate-binding protein 2 (PABP2)), mRNAs (Tnp2 and Odf1) and microRNAs (microRNA-182) in mouse CB. Moreover, KSRP may regulate the integrity of CB via DDX5-miRNA-182 pathway. In addition, we found abnormal expressions of CB component in testes of Ksrp-knockout mice and of patients with hypospermatogenesis. Thus, our results provide mechanistic insight into the role of KSRP in spermatogenesis.


Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 211-222
Author(s):  
Wai Chang Ho ◽  
Kathleen B. Bechtol

Four monoclonal antibodies, XT-I, MT-23, MT-24 and MT-29, that bind the XT-1-differentiation-antigen of male germ cells have been used to investigate the biological role of the XT-1-molecule of germ cells in short-term primary culture. Cultures from 10 days postpartum mice demonstrate increasing numbers of antigen-positive germ cells and increased antigen expression per cell with succeeding days of culture. Treatment of the antigen-positive cultures with three of the monoclonal antibodies, XT-I, MT-23 and MT-24, increases germ cell-germ cell adhesion in a dose-dependent fashion. Treatment with the fourth monoclonal antibody, MT-29, does not induce cell adhesion. The monovalent, Fab fragment of XT-I-antibody also elicits tight cell adhesion, thus ruling out antibody cross linking of molecules or cells. Saturating or near saturating amounts of the positive antibodies are required to produce adhesion, a result consistent with perturbation of a function that is performed by the sum of action of many of the XT-1-molecules on the cell. The ability of germ cells to undergo antibody-elicited tight adhesion is dependent on germ cell age and/or XT-1-antigen concentration. We hypothesize that the XT- 1-molecule is involved in regulation of cell adhesion, an event which must occur in normal development.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Min Chen ◽  
Min Chen ◽  
Suren Chen ◽  
Jingjing Zhou ◽  
Fangfang Dong ◽  
...  

The interaction between germ cell and somatic cell plays important roles in germ cell development. However, the exact function of gonad somatic cell in germ cell differentiation is unclear. In the present study, the function of gonad somatic cell in germ cell meiosis was examined by using mouse models with aberrant somatic cell differentiation. In Wt1R394W/R394W mice, the genital ridge is absent due to the apoptosis of coelomic epithelial cells. Interestingly, in both male and female Wt1R394W/R394W germ cells, STRA8 was detected at E12.5 and the scattered SYCP3 foci were observed at E13.5 which was consistent with control females. In Wt1-/flox; Cre-ERTM mice, Wt1 was inactivated by the injection of tamoxifen at E9.5 and the differentiation of Sertoli and granulosa cells was completely blocked. We found that most germ cells were located outside of genital ridge after Wt1 inactivation. STRA8, SYCP3, and γH2AX proteins were detected in germ cells of both male and female Wt1-/flox; Cre-ERTM gonads, whereas no thread-like SYCP3 signal was observed. Our study demonstrates that aberrant development of gonad somatic cells leads to ectopic expression of meiosis-associated genes in germ cells, but meiosis was arrested before prophase I. These results suggest that the proper differentiation of gonad somatic cells is essential for germ cell meiosis.


2011 ◽  
Vol 22 (10) ◽  
pp. 1766-1779 ◽  
Author(s):  
Karina Kaczmarek ◽  
Maja Studencka ◽  
Andreas Meinhardt ◽  
Krzysztof Wieczerzak ◽  
Sven Thoms ◽  
...  

 Peroxisomal testis-specific 1 gene (Pxt1) is the only male germ cell–specific gene that encodes a peroxisomal protein known to date. To elucidate the role of Pxt1 in spermatogenesis, we generated transgenic mice expressing a c-MYC-PXT1 fusion protein under the control of the PGK2 promoter. Overexpression of Pxt1 resulted in induction of male germ cells’ apoptosis mainly in primary spermatocytes, finally leading to male infertility. This prompted us to analyze the proapoptotic character of mouse PXT1, which harbors a BH3-like domain in the N-terminal part. In different cell lines, the overexpression of PXT1 also resulted in a dramatic increase of apoptosis, whereas the deletion of the BH3-like domain significantly reduced cell death events, thereby confirming that the domain is functional and essential for the proapoptotic activity of PXT1. Moreover, we demonstrated that PXT1 interacts with apoptosis regulator BAT3, which, if overexpressed, can protect cells from the PXT1-induced apoptosis. The PXT1-BAT3 association leads to PXT1 relocation from the cytoplasm to the nucleus. In summary, we demonstrated that PXT1 induces apoptosis via the BH3-like domain and that this process is inhibited by BAT3.


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