scholarly journals The Size and Content of the Sex-Determining Region of the Y Chromosome in Dioecious Mercurialis annua, a Plant with Homomorphic Sex Chromosomes

2018 ◽  
Author(s):  
Paris Veltsos ◽  
Guillaume Cossard ◽  
Emmanuel Beaudoing ◽  
Genséric Beydon ◽  
Camille Roux ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sequence Length ◽  
Bacterial Artificial Chromosomes ◽  
Dioecious Plants ◽  
Artificial Chromosomes ◽  
Males And Females ◽  
Male Specific ◽  
Y Chromosome Degeneration ◽  
Mercurialis Annua

Many dioecious plants have sex chromosomes that are cytologically heteromorphic, but about half of species lack cytological differences between males and females and are thus homomorphic. Very little is known about the size and content of the non-recombining sex-determining region (SDR) in these species. Here, we assess the size and content of the SDR of the diploid dioecious herb Mercurialis annua, which has homomorphic sex chromosomes and shows signatures of mild Y-chromosome degeneration. We used RNAseq to identify new Y-linked markers for M. annua. Twelve of 24 transcripts with male-specific and male-biased expression could only be PCR-amplified from males and are thus Y-linked. We found a further six Y-linked sequences that were present in males but not females using genome capture data from multiple populations. We used the Y-linked sequences to identify and sequence 17 sex-linked bacterial artificial chromosomes (BACs), which form 11 groups of non-overlapping sequence, covering a total sequence length of about 1.5 Mb. Content analysis of this region suggests it is enriched for repeats, has a low gene density and contains few candidate sex-determining genes. The BACs map to a subset of the sex-linked region of the genetic map, which is estimated to be at least 14.5 Mb. This is substantially larger than estimates for other dioecious plants with homomorphic sex chromosomes, especially given the small genome size of M. annua. Our data provide a rare, high-resolution view of the homomorphic Y chromosome of a dioecious plant.

Y chromosome specific markers and the evolution of dioecy in the genus Silene

Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Y Hi Zhang ◽  
Veronica S Stilio ◽  
Farah Rehman ◽  
Amy Avery ◽  
David Mulcahy ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Silene Latifolia ◽  
Dioecious Species ◽  
Sequence Characterized Amplified Region ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes ◽  
Males And Females ◽  
Genus Silene ◽  
Evolution Of Dioecy

Sex determination in plants has been most thoroughly investigated in Silene latifolia, a dioecious species possessing heteromorphic sex chromosomes. We have identified several new Y chromosome linked RAPD markers and converted these to more reliable sequence characterized amplified region (SCAR) markers by cloning the RAPD fragments and developing longer primers. Of the primer pairs for seven SCARs, five amplify a single, unique fragment from the DNA of male S. latifolia. Two sets of primers also amplify additional fragments common to males and females. Homology between the X and Y chromosomes is sufficient to allow the amplification of fragments from females under less stringent PCR conditions. Five of the SCARs also distinguish between the sexes of closely related dioecious taxa of the section Elisanthe, but not between the sexes of distantly related dioecious species. These markers will be useful for continued investigations into the evolution of sex, phylogenetic relationships among taxa, and population dynamics of sex ratios in the genus Silene.Key words: Melandrium, RAPDs, sex chromosomes, SCARs.

Non-invasive genetic sexing technique for analysis of short-beaked echidna (Tachyglossus aculeatus) populations

2019 ◽  
Vol 31 (7) ◽  
pp. 1289
Author(s):  
Tahlia Perry ◽  
Deborah Toledo-Flores ◽  
Wan X. Kang ◽  
Arthur Ferguson ◽  
Belinda Laming ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
External Genitalia ◽  
Hair Follicles ◽  
Wild Populations ◽  
Genetic Sexing ◽  
Captive Management ◽  
Non Invasive ◽  
Polymerase Chain ◽  
Male Specific

Identifying male and female echidnas is challenging due to the lack of external genitalia or any other differing morphological features. This limits studies of wild populations and is a major problem for echidna captive management and breeding. Non-invasive genetic approaches to determine sex minimise the need for handling animals and are used extensively in other mammals. However, currently available approaches cannot be applied to monotremes because their sex chromosomes share no homology with sex chromosomes in other mammals. In this study we used recently identified X and Y chromosome-specific sequences to establish a non-invasive polymerase chain reaction-based technique to determine the sex of echidnas. Genomic DNA was extracted from echidna hair follicles followed by amplification of two Y chromosome (male-specific) genes (mediator complex subunit 26 Y-gametolog (CRSPY) and anti-Müllerian hormone Y-gametolog (AMHY)) and the X chromosome gene (anti-Müllerian hormone X-gametolog (AMHX)). Using this technique, we identified the sex of 10 juvenile echidnas born at Perth Zoo, revealing that eight of the 10 echidnas were female. Future use of the genetic sexing technique in echidnas will inform captive management, continue breeding success and can be used to investigate sex ratios and population dynamics in wild populations.

scholarly journals Isolation of X and Y Chromosome-Specific DNA Markers From a Liverwort, Marchantia polymorpha, by Representational Difference Analysis

Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 981-985
Author(s):  
Masaki Fujisawa ◽  
Kiwako Hayashi ◽  
Tomohisa Nishio ◽  
Tomoyuki Bando ◽  
Sachiko Okada ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Dna Markers ◽  
Representational Difference Analysis ◽  
Marchantia Polymorpha ◽  
Dna Fragments ◽  
Difference Analysis ◽  
Y Chromosomes ◽  
Female Specific ◽  
Male Specific

Abstract The liverwort Marchantia polymorpha has X and Y chromosomes in the respective female and male haploids. Here we report the successful exploitation of representational difference analyses to isolate DNA markers for the sex chromosomes. Two female-specific and six male-specific DNA fragments were genetically confirmed to originate from the X and Y chromosomes, respectively.

scholarly journals Early sex-chromosome evolution in the diploid dioecious plant Mercurialis annua

2017 ◽  
Author(s):  
Paris Veltsos ◽  
Kate E. Ridout ◽  
Melissa A. Toups ◽  
Santiago C. González-Martínez ◽  
Aline Muyle ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Gene Loss ◽  
Sex Chromosome ◽  
Sequence Divergence ◽  
Sex Chromosome Evolution ◽  
Dioecious Plant ◽  
Suppressed Recombination ◽  
Mercurialis Annua

AbstractSuppressed recombination around a sex-determining locus allows divergence between homologous sex chromosomes and the functionality of their genes. Here, we reveal patterns of the earliest stages of sex-chromosome evolution in the diploid dioecious herb Mercurialis annua on the basis of cytological analysis, de novo genome assembly and annotation, genetic mapping, exome resequencing of natural populations, and transcriptome analysis. Both genetic mapping and exome resequencing of individuals across the species range independently identified the largest linkage group, LG1, as the sex chromosome. Although the sex chromosomes of M. annua are karyotypically homomorphic, we estimate that about a third of the Y chromosome has ceased recombining, a region containing 568 transcripts and spanning 22.3 cM in the corresponding female map. Patterns of gene expression hint at the possible role of sexually antagonistic selection in having favored suppressed recombination. In total, the genome assembly contained 34,105 expressed genes, of which 10,076 were assigned to linkage groups. There was limited evidence of Y-chromosome degeneration in terms of gene loss and pseudogenization, but sequence divergence between the X and Y copies of many sex-linked genes was higher than between M. annua and its dioecious sister species M. huetii with which it shares a sex-determining region. The Mendelian inheritance of sex in interspecific crosses, combined with the other observed pattern, suggest that the M. annua Y chromosome has at least two evolutionary strata: a small old stratum shared with M. huetii, and a more recent larger stratum that is probably unique to M. annua and that stopped recombining about one million years ago.Article summaryPlants that evolved separate sexes (dioecy) recently are ideal models for studying the early stages of sex-chromosome evolution. Here, we use karyological, whole genome and transcriptome data to characterize the homomorphic sex chromosomes of the annual dioecious plant Mercurialis annua. Our analysis reveals many typical hallmarks of dioecy and sex-chromosome evolution, including sex-biased gene expression and high X/Y sequence divergence, yet few premature stop codons in Y-linked genes and very little outright gene loss, despite 1/3 of the sex chromosome having ceased recombination in males. Our results confirm that the M. annua species complex is a fertile system for probing early stages in the evolution of sex chromosomes.

scholarly journals MEIOSIS IN MALE DROSOPHILA MELANOGASTER I. ISOLATION AND CHARACTERIZATION OF MEIOTIC MUTANTS AFFECTING SECOND CHROMOSOME DISJUNCTION

Genetics ◽  
1974 ◽  
Vol 78 (4) ◽  
pp. 1127-1142
Author(s):  
Richard C Gethmann
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome Loss ◽  
Meiotic Mutants ◽  
Isolation And Characterization ◽  
Males And Females ◽  
Chromosome Nondisjunction ◽  
Chromosome Disjunction

ABSTRACT Two second chromosome, EMS-induced, meiotic mutants which cause an increase in second chromosome nondisjunction are described. The first mutant is recessive and causes an increase in second chromosome nondisjunction in both males and females. It causes no increase in nondisjunction of the sex chromosomes in either sex, nor of the third chromosome in females. No haplo-4-progeny were recovered from either sex. Thus, it appears that this mutant, which is localized to the second chromosome, affects only second chromosome disjunction and acts in both sexes.—The other mutant affects chromosome disjunction in males and has no effect in females. Nondisjunction occurs at the first meiotic division. Sex chromosome disjunction in the presence of this mutant is similar to that of sc4sc8, with an excess of X and nullo-XY sperm relative to Y and XY sperm. In some lines, there is an excess of nullo-2 sperm relative to diplo-2 sperm, which appears to be regulated, in part, by the Y chromosome. A normal Y chromosome causes an increase in nullo-2 sperm, where BsY does not. There is also a high correlation between second and sex chromosome nondisjunction. Nearly half of the second chromosome exceptions are also nondisjunctional for the sex chromosomes. Among the double exceptions, there is an excess of XY nullo-2 and nullo-XY diplo-2 gametes. Meiotic drive, chromosome loss and nonhomologous pairing are considered as possible explanations for the double exceptions.

scholarly journals Divergence and Remarkable Diversity of the Y Chromosome in Guppies

2020 ◽  
Author(s):  
Pedro Almeida ◽  
Benjamin A Sandkam ◽  
Jake Morris ◽  
Iulia Darolti ◽  
Felix Breden ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Haplotype Diversity ◽  
Low Frequency ◽  
Color Variation ◽  
Recombination Suppression ◽  
Specific Sequence ◽  
Y Chromosome Evolution ◽  
Male Specific

Abstract The guppy sex chromosomes show an extraordinary diversity in divergence across populations and closely related species. In order to understand the dynamics of the guppy Y chromosome, we used linked-read sequencing to assess Y chromosome evolution and diversity across upstream and downstream population pairs that vary in predator and food abundance in three replicate watersheds. Based on our population-specific genome assemblies, we first confirmed and extended earlier reports of two strata on the guppy sex chromosomes. Stratum I shows significant accumulation of male-specific sequence, consistent with Y divergence, and predates the colonization of Trinidad. In contrast, Stratum II shows divergence from the X, but no Y-specific sequence, and this divergence is greater in three replicate upstream populations compared with their downstream pair. Despite longstanding assumptions that sex chromosome recombination suppression is achieved through inversions, we find no evidence of inversions associated with either Stratum I or Stratum II. Instead, we observe a remarkable diversity in Y chromosome haplotypes within each population, even in the ancestral Stratum I. This diversity is likely due to gradual mechanisms of recombination suppression, which, unlike an inversion, allow for the maintenance of multiple haplotypes. In addition, we show that this Y diversity is dominated by low-frequency haplotypes segregating in the population, suggesting a link between haplotype diversity and female preference for rare Y-linked color variation. Our results reveal the complex interplay between recombination suppression and Y chromosome divergence at the earliest stages of sex chromosome divergence.

Isolation of a Y-Chromosomal DNA Probe Capable of Determining Genetic Sex in Chinook Salmon (Oncorhynchus tshawytscha)

1991 ◽  
Vol 48 (9) ◽  
pp. 1606-1612 ◽  
Author(s):  
Robert H. Devlin ◽  
B. Kelly McNeil ◽  
T. David D. Groves ◽  
Edward M. Donaldson
Keyword(s):  
Y Chromosome ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Subtractive Hybridization ◽  
Specific Pattern ◽  
Dna Probe ◽  
Chromosomal Dna ◽  
Males And Females ◽  
Dna Fragment ◽  
Male Specific

We have used subtractive hybridization methodologies to selectively clone a DNA fragment from the Y chromosome of chinook salmon (Oncorhynchus tshawytscha). This clone specifically detects a single 8-kb Bam HI restriction fragment in Southern blots of male genomic DNA that is absent in females. This sex-specific pattern was observed in over 50 individuals from five separate chinook stocks, suggesting that the organization of this sequence is conserved in this species. The strength of the hybridization signal, and the pattern observed in multiple enzyme digests, indicates that this sequence is repeated in the male chinook genome. With long autoradiographic exposures, fainter additional sequences can also be detected both in males and females, suggesting that other similar sequences not organized in a sex-specific fashion are found on the X chromosome and/or autosomes. Examination of the segregation of this DNA sequence in families showed that the male-specific pattern segregates from father to son, providing strong evidence that the DNA probe is from the Y chromosome. The application of Y-chromosomal probes to the commercial culture of this species will simplify the synthesis of new monosex strains and allow verification of existing genotypic female, phenotypic male stocks.

scholarly journals Divergence and Remarkable Diversity of the Y Chromosome in Guppies

2020 ◽  
Author(s):  
Pedro Almeida ◽  
Benjamin A. Sandkam ◽  
Jake Morris ◽  
Iulia Darolti ◽  
Felix Breden ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Haplotype Diversity ◽  
Low Frequency ◽  
Recombination Suppression ◽  
Specific Sequence ◽  
Y Chromosome Evolution ◽  
Male Specific ◽  
Genome Assemblies

AbstractThe guppy sex chromosomes show an extraordinary diversity in divergence across populations and closely related species. In order to understand the dynamics of the guppy Y chromosome, we used linked-read sequencing to assess Y chromosome evolution and diversity across upstream and downstream population pairs that vary in predator and food abundance in three replicate watersheds. Based on our population-specific genome assemblies, we first confirmed and extended earlier reports of two strata on the guppy sex chromosomes. Stratum I shows significant accumulation of male-specific sequence, consistent with Y divergence, and predates the colonization of Trinidad. In contrast, Stratum II shows divergence from the X, but no Y-specific sequence, and this divergence is greater in three replicate upstream populations compared to their downstream pair. Despite longstanding assumptions that sex chromosome recombination suppression is achieved through inversions, we find no evidence of inversions associated with either Stratum I or Stratum II. Instead, we observe a remarkable diversity in Y chromosome haplotypes within each population, even in the ancestral Stratum I. This diversity is likely due to gradual mechanisms of recombination suppression, which, unlike an inversion, allow for the maintenance of multiple haplotypes. In addition, we show that this Y diversity is dominated by low-frequency haplotypes segregating in the population, suggesting a link between haplotype diversity and female-preference for rare Y-linked colour variation. Our results reveal the complex interplay between recombination suppression and Y chromosome divergence at the earliest stages of sex chromosome divergence.

scholarly journals Enhanced leaky sex expression is an adaptive plastic response to pollen limitation in the dioecious plant Mercurialis annua

2019 ◽  
Author(s):  
Guillaume G. Cossard ◽  
John R. Pannell
Keyword(s):  
Pollen Limitation ◽  
Sex Expression ◽  
Adaptive Plasticity ◽  
Plastic Response ◽  
Dioecious Plants ◽  
Environmental Signals ◽  
Opposite Sex ◽  
Males And Females ◽  
Male Flowers ◽  
Mercurialis Annua

AbstractPhenotypic plasticity is almost ubiquitous across the tree of life, but clear demonstrations that it is adaptive are rare. In dioecious plants, males and females frequently show ‘leaky’ sex expression, with individuals occasionally producing flowers of the opposite sex. Here, we demonstrate that leaky sex expression in the wind-pollinated dioecious herb Mercurialis annua is plastically responsive to its mating context. We compared experimental populations of females growing either with or without males. Females growing in the absence of males were leakier in their sex expression than controls with males, producing more than twice as many male flowers. Moreover, because greater leakiness was more highly represented in the population’s progeny, we conclude that enhanced leakiness in sex expression is adaptive in M. annua. We discuss differences in the degree of plasticity between ploidal races of Mercurialis annua in terms of likely differences in the reliability of the signal plants may perceive for the presence of males in their populations. Our results provide a striking instance of adaptive plasticity in the reproductive behavior of plants and draw attention to possible constraints on plasticity when the environmental signals that individuals receive are unreliable.

scholarly journals Remnant of Unrelated Amniote Sex Chromosomal Linkage Sharing on the Same Chromosome in House Gecko Lizards, Providing a Better Understanding of the Ancestral Super-Sex Chromosome

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2969
Author(s):  
Worapong Singchat ◽  
Thitipong Panthum ◽  
Syed Farhan Ahmad ◽  
Sudarath Baicharoen ◽  
Narongrit Muangmai ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome 2 ◽  
Bacterial Artificial Chromosomes ◽  
Microsatellite Repeat ◽  
Artificial Chromosomes ◽  
Chromosome Maps ◽  
Partial Homology ◽  
Intrachromosomal Rearrangements ◽  
Hemidactylus Frenatus

Comparative chromosome maps investigating sex chromosomal linkage groups in amniotes and microsatellite repeat motifs of a male house gecko lizard (Hemidactylus frenatus, HFR) and a flat-tailed house gecko lizard (H. platyurus, HPL) of unknown sex were examined using 75 bacterial artificial chromosomes (BACs) from chicken and zebra finch genomes. No massive accumulations of microsatellite repeat motifs were found in either of the gecko lizards, but 10 out of 13 BACs mapped on HPL chromosomes were associated with other amniote sex chromosomes. Hybridization of the same BACs onto multiple different chromosome pairs suggested transitions to sex chromosomes across amniotes. No BAC hybridization signals were found on HFR chromosomes. However, HFR diverged from HPL about 30 million years ago, possibly due to intrachromosomal rearrangements occurring in the HFR lineage. By contrast, heterochromatin likely reshuffled patterns between HPL and HFR, as observed from C-positive heterochromatin distribution. Six out of ten BACs showed partial homology with squamate reptile chromosome 2 (SR2) and snake Z and/or W sex chromosomes. The gecko lizard showed shared unrelated sex chromosomal linkages—the remnants of a super-sex chromosome. A large ancestral super-sex chromosome showed a correlation between SR2 and snake W sex chromosomes.

Sign in / Sign up

Export Citation Format

Share Document