Characterisation of ATRX, DMRT1, DMRT7 and WT1 in the platypus (Ornithorhynchus anatinus)

2009 ◽  
Vol 21 (8) ◽  
pp. 985 ◽  
Author(s):  
Enkhjargal Tsend-Ayush ◽  
Shu Ly Lim ◽  
Andrew J. Pask ◽  
Diana Demiyah Mohd Hamdan ◽  
Marilyn B. Renfree ◽  
...  
Keyword(s):  
Sex Determination ◽  
Expression Pattern ◽  
Sexual Development ◽  
Sex Chromosome ◽  
Z Chromosome ◽  
Testis Development ◽  
Y Chromosomes ◽  
Evolutionarily Conserved ◽  
Sex Chromosome System ◽  
Conserved Gene

One of the most puzzling aspects of monotreme reproductive biology is how they determine sex in the absence of the SRY gene that triggers testis development in most other mammals. Although monotremes share a XX female/XY male sex chromosome system with other mammals, their sex chromosomes show homology to the chicken Z chromosome, including the DMRT1 gene, which is a dosage-dependent sex determination gene in birds. In addition, monotremes feature an extraordinary multiple sex chromosome system. However, no sex determination gene has been identified as yet on any of the five X or five Y chromosomes and there is very little knowledge about the conservation and function of other known genes in the monotreme sex determination and differentiation pathway. We have analysed the expression pattern of four evolutionarily conserved genes that are important at different stages of sexual development in therian mammals. DMRT1 is a conserved sex-determination gene that is upregulated in the male developing gonad in vertebrates, while DMRT7 is a mammal-specific spermatogenesis gene. ATRX, a chromatin remodelling protein, lies on the therian X but there is a testis-expressed Y-copy in marsupials. However, in monotremes, the ATRX orthologue is autosomal. WT1 is an evolutionarily conserved gene essential for early gonadal formation in both sexes and later in testis development. We show that these four genes in the adult platypus have the same expression pattern as in other mammals, suggesting that they have a conserved role in sexual development independent of genomic location.

scholarly journals A ZZ/ZW Sex Chromosome System in Cephalochordate Amphioxus

Genetics ◽  
2020 ◽  
Vol 214 (3) ◽  
pp. 617-622
Author(s):  
Chenggang Shi ◽  
Xiaotong Wu ◽  
Liuru Su ◽  
Chaoqi Shang ◽  
Xuewen Li ◽  
...  
Keyword(s):  
Sex Determination ◽  
Mutant Strain ◽  
Sex Chromosome ◽  
Female Offspring ◽  
Phylogenetic Position ◽  
Z Chromosome ◽  
Transcription Activator ◽  
Sex Chromosome System ◽  
Female Specific ◽  
Determination Mechanism

Sex determination is remarkably variable among animals with examples of environmental sex determination, male heterogametic (XX/XY) and female heterogametic (ZZ/ZW) chromosomal sex determination, and other genetic mechanisms. The cephalochordate amphioxus occupies a key phylogenetic position as a basal chordate and outgroup to vertebrates, but its sex determination mechanism is unknown. During the course of generating Nodal mutants with transcription activator-like effector nucleases (TALENs) in amphioxus Branchiostoma floridae, serendipitously, we generated three mutant strains that reveal the sex determination mechanism of this animal. In one mutant strain, all heterozygous mutant offspring over three generations were female and all wild-type descendants were male. This pattern suggests the Nodal allele targeted is on a female-specific W chromosome. A second mutant showed the same W-linked inheritance pattern, with a female heterozygote passing the mutation only to daughters. In a third mutant strain, both male and female offspring could be heterozygous, but a female heterozygote passed the mutation only to sons. This pattern is consistent with the targeted allele being on a Z chromosome. We found an indel polymorphism linked to a Nodal allele present in most females, but no males in our cultured population. Together, these results indicate that Nodal is sex chromosome-linked in B. floridae, and that B. floridae has a ZZ/ZW sex chromosome system.

scholarly journals A new Roncus species (Pseudoscorpiones: Neobisiidae) from Montseny Natural Park (Catalonia, Spain), with remarks on karyology

Zootaxa ◽  
2008 ◽  
Vol 1693 (1) ◽  
pp. 27 ◽  
Author(s):  
JUAN A. ZARAGOZA ◽  
FRANTI“EK ŠÿÁHLAVSKÝ
Keyword(s):  
New Species ◽  
Diploid Number ◽  
Sex Chromosome ◽  
Natural Park ◽  
Y Chromosomes ◽  
Sex Chromosome System ◽  
Acrocentric Chromosomes

Roncus montsenyensis sp. nov. is described from Montseny Natural Park (Catalonia, Spain). The new species is geographically and morphologically close to Roncus cadinensis Zaragoza, 2007, but can be separated from it by palpal morphometrics, the chelal microsetae pattern and karyology. The diploid number was found to be 2n=16 in R. montsenyensis, with only biarmed chromosomes. The diploid number was found to be 2n=38 in R. cadinensis, with a predominance of acrocentric chromosomes. Both species possess the XY sex chromosome system and the X and Y chromosomes are only weakly differentiated.

scholarly journals In SituGene Mapping of Two Genes Supports Independent Evolution of Sex Chromosomes in Cold-Adapted Antarctic Fish

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Laura Ghigliotti ◽  
C.-H. Christina Cheng ◽  
Céline Bonillo ◽  
Jean-Pierre Coutanceau ◽  
Eva Pisano
Keyword(s):  
Sex Chromosome ◽  
Antarctic Fish ◽  
5S Rdna ◽  
Cold Adapted ◽  
Antifreeze Glycoprotein ◽  
Y Chromosomes ◽  
Pagothenia Borchgrevinki ◽  
History Of ◽  
Sex Chromosome System

Two genes, that is, 5S ribosomal sequences and antifreeze glycoprotein (AFGP) genes, were mapped onto chromosomes of eight Antarctic notothenioid fish possessing a X1X1X2X2/X1X2Y sex chromosome system, namely,Chionodraco hamatusandPagetopsis macropterus(family Channichthyidae),Trematomus hansoni,T. newnesi,T. nicolai,T. lepidorhinus, andPagothenia borchgrevinki(family Nototheniidae), andArtedidraco skottsbergi(family Artedidraconidae). Through fluorescencein situhybridization (FISH), we uncovered distinct differences in the gene content of the Y chromosomes in the eight species, withC. hamatusandP. macropterusstanding out among others in bearing 5S rDNA and AFGP sequences on their Y chromosomes, respectively. Both genes were absent from the Y chromosomes of any analyzed species. The distinct patterns of Y and non-Y chromosome association of the 5S rDNA and AFGP genes in species representing different Antarctic fish families support an independent origin of the sex heterochromosomes in notothenioids with interesting implications for the evolutionary/adaptational history of these fishes living in a cold-stable environment.

scholarly journals Seed sexing revealed female bias in two Rumex species

2011 ◽  
Vol 80 (2) ◽  
pp. 93-97 ◽  
Author(s):  
Dagmara Kwolek ◽  
Andrzej J. Joachimiak
Keyword(s):  
Sex Ratio ◽  
Sex Chromosomes ◽  
Dna Markers ◽  
Sex Chromosome ◽  
Sex Ratios ◽  
Ratio Bias ◽  
Sex Ratio Bias ◽  
Y Chromosomes ◽  
Sex Chromosome System ◽  
Female Bias

Sex-ratio bias in seeds of dioecious <em>Rumex</em> species with sex chromosomes is an interesting and still unsettled issue. To resolve gender among seeds of <em>R. acetosa</em> and <em>R. thyrsiflorus</em> (two species with an XX/XY1Y2 sex chromosome system), this work applied a PCR-based method involving DNA markers located on Y chromosomes. Both species showed female-biased primary sex ratios, with female bias greater in <em>R. acetosa</em> than in <em>R. thyrsiflorus</em>. The observed predominance of female seeds is consistent with the view that the female biased sex ratios in <em>Rumex </em>are conditioned not only postzygotically but also prezygotically.

scholarly journals The Amazonian Red Side-Necked Turtle Rhinemys rufipes (Spix, 1824) (Testudines, Chelidae) Has a GSD Sex-Determining Mechanism with an Ancient XY Sex Microchromosome System

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2088 ◽  
Author(s):  
Patrik F. Viana ◽  
Eliana Feldberg ◽  
Marcelo B. Cioffi ◽  
Vinicius Tadeu de Carvalho ◽  
Sabrina Menezes ◽  
...  
Keyword(s):  
South America ◽  
Sex Determination ◽  
Sex Chromosome ◽  
River Basins ◽  
Molecular Cytogenetic ◽  
Neotropical Species ◽  
Small Streams ◽  
Sex Chromosome System ◽  
Biological Aspects

The Amazonian red side-necked turtle Rhynemis rufipes is an endemic Amazonian Chelidae species that occurs in small streams throughout Colombia and Brazil river basins. Little is known about various biological aspects of this species, including its sex determination strategies. Among chelids, the greatest karyotype diversity is found in the Neotropical species, with several 2n configurations, including cases of triploidy. Here, we investigate the karyotype of Rhinemys rufipes by applying combined conventional and molecular cytogenetic procedures. This allowed us to discover a genetic sex-determining mechanism that shares an ancestral micro XY sex chromosome system. This ancient micro XY system recruited distinct repeat motifs before it diverged from several South America and Australasian species. We propose that such a system dates back to the earliest lineages of the chelid species before the split of South America and Australasian lineages.

scholarly journals Multi-Tissue Transcriptome Analysis Identifies Key Sexual Development-Related Genes of the Ornate Spiny Lobster (Panulirus ornatus)

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1150
Author(s):  
Tomer Ventura ◽  
Jennifer C. Chandler ◽  
Tuan V. Nguyen ◽  
Cameron J. Hyde ◽  
Abigail Elizur ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sexual Development ◽  
Molecular Mechanisms ◽  
Sex Chromosome ◽  
Spiny Lobster ◽  
Homology Search ◽  
Previous Knowledge ◽  
Key Factors ◽  
Factors Associated ◽  
Sex Determination Mechanisms

Sexual development involves the successive and overlapping processes of sex determination, sexual differentiation, and ultimately sexual maturation, enabling animals to reproduce. This provides a mechanism for enriched genetic variation which enables populations to withstand ever-changing environments, selecting for adapted individuals and driving speciation. The molecular mechanisms of sexual development display a bewildering diversity, even in closely related taxa. Many sex determination mechanisms across animals include the key family of “doublesex- and male abnormal3-related transcription factors” (Dmrts). In a few exceptional species, a single Dmrt residing on a sex chromosome acts as the master sex regulator. In this study, we provide compelling evidence for this model of sex determination in the ornate spiny lobster Panulius ornatus, concurrent with recent reports in the eastern spiny lobster Sagmariasus verreauxi. Using a multi-tissue transcriptomic database established for P. ornatus, we screened for the key factors associated with sexual development (by homology search and using previous knowledge of these factors from related species), providing an in-depth understanding of sexual development in decapods. Further research has the potential to close significant gaps in our understanding of reproductive development in this ecologically and commercially significant order.

Aberrant chromosomal sex-determining mechanisms in mammals, with special reference to species with XY females

1988 ◽  
Vol 322 (1208) ◽  
pp. 83-95 ◽  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Mammalian Species ◽  
Y Chromosomes ◽  
Wood Lemming ◽  
Xx Males ◽  
Original Size ◽  
Myopus Schisticolor ◽  
Dicrostonyx Torquatus

Both mouse and man have the common XX/XY sex chromosome mechanism. The X chromosome is of original size (5-6% of female haploid set) and the Y is one of the smallest chromosomes of the complement. But there are species, belonging to a variety of orders, with composite sex chromosomes and multiple sex chromosome systems: XX/XY 1 Y 2 and X 1 X 1 X 2 X 2 /X 1 X 2 Y. The original X or the Y, respectively, have been translocated on to an autosome. The sex chromosomes of these species segregate regularly at meiosis; two kinds of sperm and one kind of egg are produced and the sex ratio is the normal 1:1. Individuals with deviating sex chromosome constitutions (XXY, XYY, XO or XXX) have been found in at least 16 mammalian species other than man. The phenotypic manifestations of these deviating constitutions are briefly discussed. In the dog, pig, goat and mouse exceptional XX males and in the horse XY females attract attention. Certain rodents have complicated mechanisms for sex determination: Ellobius lutescens and Tokudaia osimensis have XO males and females. Both sexes of Microtus oregoni are gonosomic mosaics (male OY/XY, female XX/XO). The wood lemming, Myopus schisticolor , the collared lemming, Dicrostonyx torquatus , and perhaps also one or two species of the genus Akodon have XX and XY females and XY males. The XX, X*X and X*Y females of Myopus and Dicrostonyx are discussed in some detail. The wood lemming has proved to be a favourable natural model for studies in sex determination, because a large variety of sex chromosome aneuploids are born relatively frequently. The dosage model for sex determination is not supported by the wood lemming data. For male development, genes on both the X and the Y chromosomes are necessary.

scholarly journals The sequence of a male-specific genome region containing the sex determination switch in Aedes aegypti

2017 ◽  
Author(s):  
Joe Turner ◽  
Ritesh Krishna ◽  
Arjen E. Van’t Hof ◽  
Elizabeth R. Sutton ◽  
Kelly Matzen ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Sex Determination ◽  
Sex Chromosome ◽  
Bac Library ◽  
Principal Vector ◽  
Genome Region ◽  
Large Gene ◽  
Y Chromosomes ◽  
Repetitive Nature ◽  
Male Specific

Aedes aegypti is the principal vector of several important arboviruses. Among the methods of vector control to limit transmission of disease are genetic strategies that involve the release of sterile or genetically modified non-biting males (Alphey 2014), which has generated interest in manipulating mosquito sex ratios (Gilles et al. 2014; Adelman and Tu 2016). Sex determination in Ae. aegypti is controlled by a non-recombining Y chromosome-like region called the M locus (Craig et al. 1960), yet characterisation of this locus has been thwarted by the repetitive nature of the genome (Hall et al. 2015). In 2015, an M locus gene named Nix was identified that displays the qualities of a sex determination switch (Hall et al. 2015). With the use of a whole-genome BAC library, we amplified and sequenced a ~200kb region containing this male-determining gene. In this study, we show that Nix is comprised of two exons separated by a 99kb intron, making it an unusually large gene. The intron sequence is highly repetitive and exhibits features in common with old Y chromosomes, and we speculate that the lack of recombination at the M locus has allowed the expansion of repeats in a manner characteristic of a sex-limited chromosome, in accordance with proposed models of sex chromosome evolution in insects.

scholarly journals Dynamic expression of long noncoding RNAs reveals their potential roles in spermatogenesis and fertility†

2017 ◽  
Vol 97 (2) ◽  
pp. 313-323 ◽  
Author(s):  
Lauren Wichman ◽  
Saigopal Somasundaram ◽  
Christine Breindel ◽  
Dana M. Valerio ◽  
John R. McCarrey ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Noncoding Rna ◽  
Sex Chromosome ◽  
Sperm Count ◽  
Noncoding Rnas ◽  
Long Noncoding Rnas ◽  
Small Noncoding Rnas ◽  
Meiotic Sex Chromosome Inactivation ◽  
Y Chromosomes ◽  
Dynamic Expression

Abstract Mammalian reproduction requires that males and females produce functional haploid germ cells through complex cellular differentiation processes known as spermatogenesis and oogenesis, respectively. While numerous studies have functionally characterized protein-coding genes and small noncoding RNAs (microRNAs and piRNAs) that are essential for gametogenesis, the roles of regulatory long noncoding RNAs (lncRNAs) are yet to be fully characterized. Previously, we and others have demonstrated that intergenic regions of the mammalian genome encode thousands of long noncoding RNAs, and many studies have now demonstrated their critical roles in key biological processes. Thus, we postulated that some lncRNAs may also impact mammalian spermatogenesis and fertility. In this study, we identified a dynamic expression pattern of lncRNAs during murine spermatogenesis. Importantly, we identified a subset of lncRNAs and very few mRNAs that appear to escape meiotic sex chromosome inactivation, an epigenetic process that leads to the silencing of the X- and Y-chromosomes at the pachytene stage of meiosis. Further, some of these lncRNAs and mRNAs show a strong testis expression pattern suggesting that they may play key roles in spermatogenesis. Lastly, we generated a mouse knockout of one X-linked lncRNA, Tslrn1 (testis-specific long noncoding RNA 1), and found that males carrying a Tslrn1 deletion displayed normal fertility but a significant reduction in spermatozoa. Our findings demonstrate that dysregulation of specific mammalian lncRNAs is a novel mechanism of low sperm count or infertility, thus potentially providing new biomarkers and therapeutic strategies.

A cytological study of species in Cnephia s. str. (Diptera: Simuliidae)

1982 ◽  
Vol 60 (11) ◽  
pp. 2866-2878 ◽  
Author(s):  
William S. Procunier
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Cytological Study ◽  
Chromosome Complement ◽  
Nucleolar Organizer ◽  
Sympatric Speciation ◽  
Basic Chromosome ◽  
Y Chromosomes ◽  
Norwegian Population ◽  
Sex Chromosome System

Cytological descriptions and phylogenetic relationships are presented for the genus Cnephia s. str. All members are male achiasmate. Cnephia lapponica is unique in that its basic chromosome complement is reduced from n = 3 to n = 2 metacentrics as a result of a fusion of chromosomes II and III. Sex chromosome differentiation varies from nonobservable in C. ornithophilia and C. eremites through C. pecuarum in which the standard and IS-5 sequences are distributed differentially over X and Y chromosomes, to the polytypic system of C. lapponica in which the X chromosome is fixed for expression of the nucleolar organizer (NO) and the Y chromosome for nonexpression. Further, in a Norwegian population of C. lapponica, males are additionally interchange heterozygotes. Thus, a multiple sex chromosome system exists in which all the chromosomes are sex chromosomes. Closest members occur sympatrically and differ by sex chromosomes and at least one fixed inversion; more distant taxa differ by a number of fixed inversions as well as sex chromosomes. The identical bands 17B and 24C, which appear in a thin or enhanced form, are polymorphic, sex-linked, fixed, or lost in different members of the group. This study supports a model for sympatric speciation.

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