Sex differentiation in bilaterally allophenic animals produced by cloning of two bipartite male/female chimaeras of Lineus sanguineus

Development ◽  
1981 ◽  
Vol 65 (1) ◽  
pp. 173-184
Author(s):  
S. Sivaradjam ◽  
J. Bierne
Keyword(s):  
Ovarian Development ◽  
Sex Differentiation ◽  
Sex Reversal ◽  
Testicular Development ◽  
Gonadal Differentiation ◽  
Male And Female ◽  
Diffusible Factor ◽  
Male Sex ◽  
The Many ◽  
The Right

Two bipartite chimaeras were constructed in Lineus sanguineus by grafting the lateral halves from a phenotypically dark-brown male onto the anatomically complementary halves from a phenotypically light-brown female. Regeneration of a large number of pieces transected from these two bilaterally allogeneic chimaeras produced two clones of bilaterally allophenic nemertines (♂/♀ and ♀/♂) Sex differentiation in the cloned worms started with a transitory stage of gonad developmental autonomy, termed the primary gynandromorphous state; at this stage there were young testes in the originally male lateral halves and juvenile ovaries in the originally female ones, the only abnormality then was that the ovarian development was more advanced than the testicular development relative to those in male and female controls. Then, unilateral sex reversal occurred, with feminization of the testes, i.e. oogenesis took the place of spermatogenesis in the many male gonads located in either the right or the left side of allophenic worms according to the symmetry patterns of the two clones. Finally, when the gonads reached maturity, both sides of allophenic L. sanguineus contained only ovaries with ripe oocytes. The complete feminization of these allophenic worms and the previously observed masculinization of ‘heterosexual’ chimaeras in L. ruber suggest that a diffusible factor controls gonadal differentiation in worms of the prevailing sex, which is the female sex in L. sanguineus and the male sex in L. ruber.

scholarly journals The Role of Anti-Müllerian Hormone in Testis Differentiation Reveals the Significance of the TGF-β Pathway in Reptilian Sex Determination

Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1317-1327 ◽  
Author(s):  
Yingjie Zhou ◽  
Wei Sun ◽  
Han Cai ◽  
Haisheng Bao ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Sex Determination ◽  
Messenger Rna ◽  
Sex Differentiation ◽  
Sex Reversal ◽  
Testicular Development ◽  
Loss Of Function ◽  
Specific Expression ◽  
Male Sex ◽  
Specific Expression Pattern ◽  
Reptilian Species

Anti-Müllerian hormone (Amh, or Müllerian-inhibiting substance, Mis), a member of TGF-β superfamily, has been well documented in some vertebrates as initiator or key regulator in sexual development, and particularly in fish. However, its functional role has not yet been identified in reptiles. Here, we characterized the Amh gene in the Chinese soft-shelled turtle Pelodiscus sinensis, a typical reptilian species exhibiting ZZ/ZW sex chromosomes. The messenger RNA of Amh was initially expressed in male embryonic gonads by stage 15, preceding gonadal sex differentiation, and exhibited a male-specific expression pattern throughout embryogenesis. Moreover, Amh was rapidly upregulated during female-to-male sex reversal induced by aromatase inhibitor letrozole. Most importantly, Amh loss of function by RNA interference led to complete feminization of genetic male (ZZ) gonads, suppression of the testicular marker Sox9, and upregulation of the ovarian regulator Cyp19a1. Conversely, overexpression of Amh in ZW embryos resulted in female-to-male sex reversal, characterized by the formation of a testis structure, ectopic activation of Sox9, and a remarkable decline in Cyp19a1. Collectively, these findings provide the first solid evidence that Amh is both necessary and sufficient to drive testicular development in a reptilian species, P. sinensis, highlighting the significance of the TGF-β pathway in reptilian sex determination.

scholarly journals Green light irradiation during sex differentiation induces female-to-male sex reversal in the medaka Oryzias latipes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Oki Hayasaka ◽  
Yutaka Takeuchi ◽  
Kazuhiro Shiozaki ◽  
Kazuhiko Anraku ◽  
Tomonari Kotani
Keyword(s):  
Sex Differentiation ◽  
Green Light ◽  
Oryzias Latipes ◽  
Sex Reversal ◽  
Light Irradiation ◽  
Male Sex

Igf3 is essential for ovary differentiation in zebrafish†

2020 ◽  
Author(s):  
Yuxin Xie ◽  
Duo Huang ◽  
Lianhe Chu ◽  
Yun Liu ◽  
Xiao Sun ◽  
...  
Keyword(s):  
Sexual Differentiation ◽  
Gene Knockout ◽  
Sex Differentiation ◽  
Sex Reversal ◽  
Estrogen Signaling ◽  
Differential Expression Pattern ◽  
Male Sex ◽  
In Vitro Treatment

Abstract Zebrafish gonadal sexual differentiation is an important but poorly understood subject. Previously, we have identified a novel Igf named Igf3 in teleosts. The importance of Igf3 in oocyte maturation and ovulation has been recently demonstrated by us in zebrafish. In this study, we have further found the essential role of Igf3 in gonadal sexual differentiation of zebrafish. A differential expression pattern of igf3 between ovary and testis during sex differentiation (higher level in ovary than in testis) was found in zebrafish. An igf3 knockout zebrafish line was established using TALENs-mediated gene knockout technique. Intriguingly, all igf3 homozygous mutants were males due to the female-to-male sex reversal occurred during sex differentiation. Further analysis showed that Igf3 did not seem to affect the formation of so-called juvenile ovary and oocyte-like germ cells. Oocyte development was arrested at primary growth stage, and the ovary was gradually sex-reversed to testis before 60 dpf. Such sex reversal was likely due to decreased germ cell proliferation by suppressing PI3K/Akt pathway in early ovaries of igf3 mutants. Estrogen is considered as a master regulator in fish sex differentiation. Here, we found that igf3 expression could be up-regulated by estrogen in early stages of ovarian follicles as evidenced in in vitro treatment assays and cyp19a1a mutant zebrafish, and E2 failed to rescue the defects of igf3 mutants in ovarian development, suggesting that Igf3 may serve as a downstream factor of estrogen signaling in sex differentiation. Taken together, we demonstrated that Igf3 is essential for ovary differentiation in zebrafish.

scholarly journals Germline sexual fate is determined by the antagonistic action of dmrt1 and foxl3/foxl2 in tilapia

Development ◽  
2021 ◽  
pp. dev.199380
Author(s):  
Shengfei Dai ◽  
Shuangshuang Qi ◽  
Xueyan Wei ◽  
Xingyong Liu ◽  
Yibing Li ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Sex Reversal ◽  
Testicular Development ◽  
Antagonistic Action ◽  
Male And Female ◽  
Fate Decision

Germline sexual fate has long been believed to be determined by the somatic environment, but this idea is challenged by recent studies of foxl3 mutants in medaka. Here we demonstrate that the sexual fate of tilapia germline is determined by the antagonistic interaction of dmrt1 and foxl3, which are transcriptionally repressed in male and female germ cells, respectively. Loss of dmrt1 rescued the germ cell sex reversal in foxl3Δ7/Δ7 XX fish, and loss of foxl3 partially rescued germ cell sex reversal but not somatic cell fate in dmrt1Δ5/Δ5 XY fish. Interestingly, germ cells lost sexual plasticity in dmrt1Δ5/Δ5 XY and foxl3Δ7/Δ7 XX single mutants, as aromatase inhibitor and estrogen treatment failed to rescue the respective phenotypes. However, recovery of germ cell sexual plasticity was observed in dmrt1/foxl3 double mutants. Importantly, mutation of somatic cell specific foxl2 resulted in testicular development in foxl3Δ7/Δ7 or dmrt1Δ5/Δ5 mutants. Our findings demonstrate that sexual plasticity of germ cells relies on the presence of both dmrt1 and foxl3. The existence of dmrt1 and foxl3 allows environmental factors to influence the sex fate decision in vertebrates.

scholarly journals Müllerian-inhibiting substance (MIS) is both necessary and sufficient for testicular differentiation in Chinese soft-shelled turtle Pelodiscus sinensis

2019 ◽  
Author(s):  
Yingjie Zhou ◽  
Wei Sun ◽  
Han Cai ◽  
Haisheng Bao ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Sex Reversal ◽  
Testicular Development ◽  
Loss Of Function ◽  
Pelodiscus Sinensis ◽  
Specific Expression ◽  
Müllerian Inhibiting Substance ◽  
Male Sex ◽  
Necessary And Sufficient ◽  
Reptilian Species ◽  
Mullerian Inhibiting Substance

ABSTRACTMüllerian-inhibiting substance (Mis, or anti-müllerian hormone, Amh), a member of TGF-β superfamily, as initiator or key regulator in sexual development has been well documented in some vertebrates, especially in fish. However, its functional role has not been identified yet in reptiles. Here we characterized the Mis gene in Chinese soft-shelled turtle Pelodiscus sinensis (P. sinensis), a typical reptilian species exhibiting ZZ/ZW sex chromosomes. The mRNA of Mis was initially expressed in male embryonic gonads by stage 15, preceding gonadal sex differentiation, and exhibited male-specific expression pattern throughout embryogenesis. Moreover, Mis was rapidly up-regulated during female-to-male sex reversal induced by aromatase inhibitor letrozole. Most importantly, Mis loss of function by RNA interference led to complete feminization of genetic male (ZZ) gonads, suppression of the testicular marker Sox9, and upregulation of the ovarian regulator Cyp19a1. Conversely, overexpression of Mis in ZW embryos resulted in female-to-male sex reversal, characterized by the formation of testis structure, ectopic activation of Sox9, and a remarkable decline in Cyp19a1. Collectively, these findings provide the first solid evidence that Mis is both necessary and sufficient to drive testicular development in a reptilian species, P. sinensis, highlighting the significance of the TGF-β pathway in reptilian sex determination.

scholarly journals Metabolism and Sex Differentiation in Animals from a Starvation Perspective

2021 ◽  
pp. 1-11
Author(s):  
Yuta Sakae ◽  
Minoru Tanaka
Keyword(s):  
Sex Determination ◽  
Environmental Changes ◽  
Sex Differentiation ◽  
Green Light ◽  
Acid Synthesis ◽  
Sex Reversal ◽  
Environmental Sex Determination ◽  
Biological Factors ◽  
Signal Transducers ◽  
Male Sex

Animals determine their sex genetically (GSD: genetic sex determination) and/or environmentally (ESD: environmental sex determination). Medaka (<i>Oryzias latipes</i>) employ a XX/XY GSD system, however, they display female-to-male sex reversal in response to various environmental changes such as temperature, hypoxia, and green light. Interestingly, we found that 5 days of starvation during sex differentiation caused female-to-male sex reversal. In this situation, the metabolism of pantothenate and fatty acid synthesis plays an important role in sex reversal. Metabolism is associated with other biological factors such as germ cells, HPG axis, lipids, and epigenetics, and supplys substances and acts as signal transducers. In this review, we discuss the importance of metabolism during sex differentiation and how metabolism contributes to sex differentiation.

scholarly journals Impact of butyl benzyl phthalate on development of the reproductive system of European pikeperch, Sander lucioperca (L.)

2014 ◽  
Vol 62 (3) ◽  
pp. 397-407 ◽  
Author(s):  
Sylwia Jarmołowicz ◽  
Krystyna Demska-Zakęś ◽  
Zdzisław Zakęś
Keyword(s):  
Sex Ratio ◽  
Sex Differentiation ◽  
Testicular Development ◽  
Gonadal Differentiation ◽  
Differentiation Process ◽  
Sander Lucioperca ◽  
Butyl Benzyl Phthalate ◽  
Gonad Differentiation ◽  
Survival And Growth ◽  
Differentiation Period

The effect of butyl benzyl phthalate (BBP) on the sex differentiation process of fish is practically unknown. The experimental material of this study was juvenile European pikeperch [Sander lucioperca (L.)], which is gonochoristic, undergoes immediate sex differentiation, and has a fixed gonad differentiation period. The fish were fed a diet supplemented with BBP (during the sex differentiation phase: age 61–96 days post hatch) in the following quantities: 1.0; 2.0; 4.0; 8.0; 16.0 g BBP kg−1 feed. The control feed was a xenobiotic-free base feed. In the present experiment lasting 10 weeks, the survival and growth of fish, the histopathological changes of the fish gonads and the sex ratio were evaluated. After administration of the two highest doses of BBP, growth inhibition of the fish was observed. BBP also seriously disturbed the gonadal differentiation process of pikeperch. All analysed concentrations of BBP delayed testicular development and, at concentrations of 4.0, 8.0 and 16.0 g BBP kg−1, induction of the feminisation process was observed. The sex ratio was distinctly disrupted in groups receiving 8.0 and 16.0 g BBP kg−1.

scholarly journals Transcriptional Regulation of the Y-Linked Mammalian Testis-Determining Gene SRY

2021 ◽  
pp. 1-9
Author(s):  
Naoki Okashita ◽  
Makoto Tachibana
Keyword(s):  
Sex Determination ◽  
Sex Differentiation ◽  
Disorders Of Sex Development ◽  
Sex Reversal ◽  
Cis Acting ◽  
Male Development ◽  
Sex Development ◽  
Epigenetic Modifier ◽  
Male Sex ◽  
Testis Determining Gene

Mammalian male sex differentiation is triggered during embryogenesis by the activation of the Y-linked testis-determining gene <i>SRY</i>. Since insufficient or delayed expression of <i>SRY</i> results in XY gonadal sex reversal, accurate regulation of <i>SRY</i> is critical for male development in XY animals. In humans, dysregulation of <i>SRY</i> may cause disorders of sex development. Mouse <i>Sry</i> is the most intensively studied mammalian model of sex determination. <i>Sry</i> expression is controlled in a spatially and temporally stringent manner. Several transcription factors play a key role in sex determination as trans-acting factors for <i>Sry</i> expression. In addition, recent studies have shown that several epigenetic modifications of <i>Sry</i> are involved in sex determination as cis-acting factors for <i>Sry</i> expression. Herein, we review the current understanding of transcription factor- and epigenetic modifier-mediated regulation of <i>SRY</i>/<i>Sry</i> expression.

scholarly journals Possible Epigenetic Origin of a Recurrent Gynandromorph Pattern in Megachile Wild Bees

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 437
Author(s):  
Daniele Sommaggio ◽  
Giuseppe Fusco ◽  
Marco Uliana ◽  
Alessandro Minelli
Keyword(s):  
Current Knowledge ◽  
Sex Differentiation ◽  
General Pattern ◽  
Body Parts ◽  
Wild Bees ◽  
Male And Female ◽  
Female Phenotype ◽  
In The Wild ◽  
Gene Transcripts ◽  
Individual Body

Gynandromorphs, i.e., individuals with a mix of male and female traits, are common in the wild bees of the genus Megachile (Hymenoptera, Apoidea). We described new transverse gynandromorphs in Megachile pilidens Alfkeen, 1924 and analyze the spatial distribution of body parts with male vs. female phenotype hitherto recorded in the transverse gynandromorphs of the genus Megachile. We identified 10 different arrangements, nine of which are minor variants of a very general pattern, with a combination of male and female traits largely shared by the gynandromorphs recorded in 20 out of 21 Megachile species in our dataset. Based on the recurrence of the same gynandromorph pattern, the current knowledge on sex determination and sex differentiation in the honey bee, and the results of recent gene-knockdown experiments in these insects, we suggest that these composite phenotypes are possibly epigenetic, rather than genetic, mosaics, with individual body parts of either male or female phenotype according to the locally expressed product of the alternative splicing of sex-determining gene transcripts.

Governmental Censorship in War-Time

1942 ◽  
Vol 36 (5) ◽  
pp. 837-849 ◽  
Author(s):  
Byron Price
Keyword(s):  
National Security ◽  
Free Enterprise ◽  
Individual Liberty ◽  
News Stories ◽  
Radio Industry ◽  
Democratic Principles ◽  
The Many ◽  
The Right ◽  
Free People ◽  
Magazine Articles

To a free people, the very word “censorship” always has been distasteful. In its theory, it runs counter to all democratic principles; in practice, it can never be made popular, can never please anyone.Everything the censor does is contrary to all that we have been taught to believe is right and proper. The Post Office Department, for example, has two proud mottoes: “The mail must go through,” and “The privacy of the mail must be protected at all hazards.” But censorship stops the mail, it invades the privacy of the mail, it disposes of the mail as may seem best. The same thing holds true in the publishing business. Censorship limits the lively competition and free enterprise of reporters. It relegates many a scoop to the waste basket. It wields a blue pencil—both theoretical and actual—on news stories, magazine articles, advertisements, and photographs. Censorship also enters the radio industry, where it may edit scripts and in some cases stop entire programs.Yet even the most vociferous critics of the principle of censorship agree that in war-time some form and amount of censorship is a necessity. It then becomes not merely a curtailment of individual liberty, but a matter of national security. It is one of the many restrictions that must be imposed on people fighting for the right to throw off those restrictions when peace returns.

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