scholarly journals Comparison of sex determination mechanism of germ cells between birds and fish: Cloning and expression analyses of chicken forkhead box L3 ‐like gene

2019 ◽  
Vol 248 (9) ◽  
pp. 826-836
Author(s):  
Kennosuke Ichikawa ◽  
Ryo Ezaki ◽  
Shuichi Furusawa ◽  
Hiroyuki Horiuchi
Keyword(s):  
Sex Determination ◽  
Germ Cells ◽  
Cloning And Expression ◽  
Forkhead Box ◽  
Determination Mechanism

Induction of female Sex-lethal RNA splicing in male germ cells: implications for Drosophila germline sex determination

Development ◽  
1997 ◽  
Vol 124 (24) ◽  
pp. 5033-5048 ◽  
Author(s):  
J.H. Hager ◽  
T.W. Cline
Keyword(s):  
Sex Determination ◽  
Germ Cells ◽  
Rna Splicing ◽  
Feedback Loop ◽  
Dose Effect ◽  
Male Germ Cells ◽  
Control Female ◽  
Sex Lethal ◽  
Specific Regulation ◽  
Female Specific

With a focus on Sex-lethal (Sxl), the master regulator of Drosophila somatic sex determination, we compare the sex determination mechanism that operates in the germline with that in the soma. In both cell types, Sxl is functional in females (2X2A) and nonfunctional in males (1X2A). Somatic cell sex is determined initially by a dose effect of X:A numerator genes on Sxl transcription. Once initiated, the active state of SXL is maintained by a positive autoregulatory feedback loop in which Sxl protein insures its continued synthesis by binding to Sxl pre-mRNA and thereby imposing the productive (female) splicing mode. The gene splicing-necessary factor (snf), which encodes a component of U1 and U2 snRNPs, participates in this RNA splicing control. Here we show that an increase in the dose of snf+ can trigger the female Sxl RNA splicing mode in male germ cells and can feminize triploid intersex (2X3A) germ cells. These snf+ dose effects are as dramatic as those of X:A numerator genes on Sxl in the soma and qualify snf as a numerator element of the X:A signal for Sxl in the germline. We also show that female-specific regulation of Sxl in the germline involves a positive autoregulatory feedback loop on RNA splicing, as it does in the soma. Neither a phenotypically female gonadal soma nor a female dose of X chromosomes in the germline is essential for the operation of this feedback loop, although a female X-chromosome dose in the germline may facilitate it. Engagement of the Sxl splicing feedback loop in somatic cells invariably imposes female development. In contrast, engagement of the Sxl feedback loop in male germ cells does not invariably disrupt spermatogenesis; nevertheless, it is premature to conclude that Sxl is not a switch gene in germ cells for at least some sex-specific aspects of their differentiation. Ironically, the testis may be an excellent organ in which to study the interactions among regulatory genes such as Sxl, snf, ovo and otu which control female-specific processes in the ovary.

Key aspects of the primary sex determination mechanism are conserved across the genus Drosophila

Development ◽  
1998 ◽  
Vol 125 (16) ◽  
pp. 3259-3268 ◽  
Author(s):  
J.W. Erickson ◽  
T.W. Cline
Keyword(s):  
Sex Determination ◽  
Rapid Onset ◽  
Amino Acid Identity ◽  
Bzip Transcription Factor ◽  
Regulatory Sequence ◽  
Tightly Coupled ◽  
Pole Cells ◽  
High Level ◽  
Key Aspects ◽  
Determination Mechanism

In D. melanogaster, a set of ‘X:A numerator genes’, which includes sisterlessA (sisA), determines sex by controlling the transcription of Sex-lethal (Sxl). We characterized sisA from D. pseudoobscura and D. virilis and studied the timing of sisA and Sxl expression with single cell-cycle resolution in D. virilis, both to guide structure-function studies of sisA and to help understand sex determination evolution. We found that D. virilis sisA shares 58% amino acid identity with its melanogaster ortholog. The identities confirm sisA as an atypical bZIP transcription factor. Although virilis sisA can substitute for melanogaster sisA, the protein is not fully functional in a heterologous context. The putative sisA regulatory sequence CAGGTAG is a potential ‘numerator box,’ since it is shared with the other strong X:A numerator gene, sisB, and its target, SxlPe. Temporal and spatial features of sisA and SxlPe expression are strikingly conserved, including rapid onset and cessation of transcription in somatic nuclei, early cessation of sisA transcription in budding pole cells and persistent high-level sisA expression in yolk nuclei. Expression of sisA and Sxl is as tightly coupled in virilis as it is in melanogaster. Taken together, these data indicate that the same primary sex determination mechanism exists throughout the genus Drosophila.

Cross-sexual Transfer

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Sex Determination ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Alternative Phenotypes ◽  
Opposite Sex ◽  
Critical Age ◽  
Sexual Traits ◽  
Discrete Traits ◽  
Dimorphic Species ◽  
Determination Mechanism

Distinctive male and female traits are perhaps the most familiar of all divergent specializations within species. In cross-sexual transfer, discrete traits that are expressed exclusively in one sex in an ancestral species appear in the opposite sex of descendants. An example is the expression of brood care by males in a lineage where ancestral females are the exclusive caretakers of the young, as in some voles (Thomas and Birney, 1979). Despite the prominence of sexual dimorphism and sex reversals in nature, and an early explicit treatment by Darwin, discussed in the next section, cross-sexual transfer is not often recognized as a major factor in the evolution of novelty (but see, on animals, Mayr, 1963, pp. 435-439; Mayr, 1970, p. 254; on plants, Iltis, 1983). When more widely investigated, cross-sexual transfer may prove to rival heterochrony and duplication as an important source of novelties in sexually dimorphic lineages. For this reason, I devote more attention here to cross-sexual transfer than to these other, well-established general patterns of change. The male and female of a sexually dimorphic species may be so different that it is easy to forget that each individual carries most or all of the genes necessary to produce the phenotype of the opposite sex. Sex determination, like caste determination and other switches between alternative phenotypes, depends on only a few genetic loci or, in many species, environmental factors (Bull, 1983). There is considerable flexibility in sex determination and facultative reversal in some taxa. Among fish, for example, there is even a species wherein sex is determined by juvenile size at a critical age (Francis and Barlow, 1993). The sex determination mechanism, whatever its nature, leads to a series of sex-limited responses, often coordinated by hormones and not necessarily all occurring at once. A distinguishing aspect of sexually dimorphic traits in adults is that there is often a close homology between the secondary sexual traits that are differently modified in the two sexes.

scholarly journals Ⅰ-3. Sex Determination Mechanism in Seriola Fishes

2019 ◽  
Vol 85 (2) ◽  
pp. 188-188
Author(s):  
TAKASHI KOYAMA ◽  
MASATOSHI NAKAMOTO ◽  
KAGAYAKI MORISHIMA ◽  
TAKEFUMI YAMASHITA ◽  
NAOKI MIZUNO ◽  
...  
Keyword(s):  
Sex Determination ◽  
Determination Mechanism

Molecular Cloning and Expression of Dead End Homologue in Chicken Germ Cells.

2008 ◽  
Vol 78 (Suppl_1) ◽  
pp. 298-299
Author(s):  
Shinya Aramaki ◽  
Takako Kato ◽  
Tomoki Soh ◽  
Nobuhiko Yamauchi ◽  
Yukio Kato ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Germ Cells ◽  
Cloning And Expression ◽  
Dead End

scholarly journals Identification of Sex-Specific Markers Through 2b-RAD Sequencing in the Sea Urchin (Mesocentrotus nudus)

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhouping Cui ◽  
Jian Zhang ◽  
Zhihui Sun ◽  
Bingzheng Liu ◽  
Chong Zhao ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sea Urchin ◽  
Sex Differentiation ◽  
Pcr Amplification ◽  
Open Reading Frames ◽  
Genome Survey ◽  
A Genome ◽  
Mesocentrotus Nudus ◽  
Female Specific ◽  
Determination Mechanism

Sex-specific markers play an important role in revealing sex-determination mechanism. Sea urchin (Mesocentrotus nudus) is an economically important mariculture species in several Asian countries and its gonads are the sole edible parts for people. However, growth rate and immunocompetence differ by sex in this species, sex-specific markers have not been identified, and the sex-determination mechanism of sea urchin remains undetermined. In this study, type IIB endonuclease restriction-site associated DNA sequencing (2b-RAD-seq) and a genome survey of M. nudus were performed, and three female-specific markers and three female heterogametic single nucleotide polymorphism (SNP) loci were identified. We validated these sex-specific markers via PCR amplification in a large number of individuals, including wild and artificially bred populations. Several open reading frames (ORFs) were predicted, although there are no potential genes known for sex determination and sex differentiation within the scaffold in which the sex-specific markers are located. Importantly, the female-specific sequences and female heterozygous SNP loci indicate that a female heterogametic and male homogametic ZW/ZZ sex-determination system should exist in M. nudus. The results provide a solid basis for revealing the sex-determination mechanism of this species, and open up new possibilities for developing sex-control breeding in sea urchin.

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.

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