Identification of male-specific SNP markers and development of PCR-based genetic sex identification technique in crucifix crab (Charybdis feriatus) with implication of an XX/XY sex determination system

Sexual reproduction is widespread among eukaryotes, and the sex-determining processes vary greatly among species. While genetic sex determination (GSD) has been intensively described in bilaterian species, no example has yet been recorded among non-bilaterians. However, the quasi-ubiquitous repartition of GSD among multicellular species suggests that similar evolutionary forces can promote this system, and that these forces could occur also in non-bilaterians. Studying sex determination across the range of Metazoan diversity is indeed important to understand better the evolution of this mechanism and its lability. We tested the existence of sex-linked genes in the gonochoric red coral ( Corallium rubrum , Cnidaria) using restriction site-associated DNA sequencing. We analysed 27 461 single nucleotide polymorphisms (SNPs) in 354 individuals from 12 populations including 53 that were morphologically sexed. We found a strong association between the allele frequencies of 472 SNPs and the sex of individuals, suggesting an XX/XY sex-determination system. This result was confirmed by the identification of 435 male-specific loci. An independent test confirmed that the amplification of these loci enabled us to identify males with absolute certainty. This is the first demonstration of a GSD system among non-bilaterian species and a new example of its convergence in multicellular eukaryotes.

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Sex-determination and sex chromosomes are shared across the radiation of dioecious Nepenthes pitcher plants

10.1101/240259 ◽

2017 ◽

Author(s):

Mathias Scharmann ◽

T. Ulmar Grafe ◽

Faizah Metali ◽

Alex Widmer

Keyword(s):

Sex Determination ◽

Sex Chromosomes ◽

High Throughput Sequencing ◽

Silene Latifolia ◽

Wild Populations ◽

Sequencing Data ◽

Pitcher Plants ◽

Determination System ◽

Sex Determination System ◽

Male Specific

AbstractPlants with separate sexes (dioecy) represent a minority but dioecy has evolved multiple times independently in plants. Our understanding of sex determination systems in plants and of the ecological factors and molecular changes associated with the evolution of dioecy remain limited. Here, we study the sex-determination system in dioecious plants that lack heteromorphic sex chromosomes and are not amenable to controlled breeding: Nepenthes pitcher plants. We genotyped wild populations of flowering males and females of three Nepenthes taxa using ddRAD-seq, and sequenced a male inflorescence transcriptome. We developed a novel statistical tool (privacy rarefaction) to distinguish true sex-specificity from stochastic noise in high-throughput sequencing data. Our results support XY-systems in all three Nepenthes taxa and in Silene latifolia which was used as a positive control for its known XY-system. The male-specific region of the Y chromosome showed little conservation among the three Nepenthes taxa, except for the essential pollen development gene DYT1 which was also male-specific in additional taxa. Hence, this homomorphic XY sex-determination system likely has a unique origin older than the crown of the genus Nepenthes at c. 17.7 My. In addition to the characterisation of the previously unknown sex chromosomes of Nepenthes, our work contributes an innovative, highly sensitive statistical method to efficiently detect sex-specific genomic regions in wild populations in general.

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Sex-Biased Gene Expression and Isoform Profile of Brine Shrimp Artemia franciscana by Transcriptome Analysis

Animals ◽

10.3390/ani11092630 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2630

Author(s):

Euna Jo ◽

Seung-Jae Lee ◽

Eunkyung Choi ◽

Jinmu Kim ◽

Jun-Hyuck Lee ◽

...

Keyword(s):

Sex Determination ◽

Brine Shrimp ◽

Model Organism ◽

Enrichment Analysis ◽

Go Enrichment ◽

Determination System ◽

Sex Determination System ◽

Female Specific ◽

Male Specific ◽

Go Enrichment Analysis

The brine shrimp Artemia has a ZW sex determination system with ZW chromosomes in females and ZZ chromosomes in males. Artemia has been considered a promising model organism for ZW sex-determining systems, but the genes involved in sex determination and differentiation of Artemia have not yet been identified. Here, we conducted transcriptome sequencing of female and male A. franciscana using PacBio Iso-Seq and Illumina RNA-Seq techniques to identify candidate sex determination genes. Among the 42,566 transcripts obtained from Iso-Seq, 23,514 were analyzed. Of these, 2065 (8.8%) were female specific, 2513 (10.7%) were male specific, and 18,936 (80.5%) were co-expressed in females and males. Based on GO enrichment analysis and expression values, we found 10 female-biased and 29 male-biased expressed genes, including DMRT1 and Sad genes showing male-biased expression. Our results showed that DMRT1 has three isoforms with five exons, while Sad has seven isoforms with 2–11 exons. The Sad gene is involved in ecdysteroid signaling related to molting and metamorphosis in arthropods. Further studies on ecdysteroid biosynthetic genes are needed to improve our understanding of Artemia sex determination. This study will provide a valuable resource for sex determination and differentiation studies on Artemia and other crustaceans with ZW systems.

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Isolation of a Male-Specific Molecular Marker and Development of a Genetic Sex Identification Technique in Spotted Knifejaw (Oplegnathus punctatus)

Marine Biotechnology ◽

10.1007/s10126-020-09966-3 ◽

2020 ◽

Vol 22 (4) ◽

pp. 467-474

Author(s):

Ming Li ◽

Hao Xu ◽

Wenteng Xu ◽

Qian Zhou ◽

Xiwen Xu ◽

...

Keyword(s):

Molecular Marker ◽

Sex Identification ◽

Identification Technique ◽

Genetic Sex Identification ◽

Male Specific

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The Snakeskin Gourami (Trichopodus pectoralis) Tends to Exhibit XX/XY Sex Determination

Fishes ◽

10.3390/fishes6040043 ◽

2021 ◽

Vol 6 (4) ◽

pp. 43

Author(s):

Thitipong Panthum ◽

Nararat Laopichienpong ◽

Ekaphan Kraichak ◽

Worapong Singchat ◽

Dung Ho My Nguyen ◽

...

Keyword(s):

Sex Differences ◽

Sex Determination ◽

Y Chromosome ◽

Cytogenetic Analysis ◽

Genotyping By Sequencing ◽

Sexually Dimorphic ◽

Determination System ◽

Sex Determination System ◽

Male Specific ◽

Determination Mechanism

The snakeskin gourami (Trichopodus pectoralis) has a high meat yield and is one of the top five aquaculture freshwater fishes in Thailand. The species is not externally sexually dimorphic, and its sex determination system is unknown. Understanding the sex determination system of this species will contribute to its full-scale commercialization. In this study, a cytogenetic analysis did not reveal any between-sex differences in chromosomal patterns. However, we used genotyping-by-sequencing to identify 4 male-linked loci and 1 female-linked locus, indicating that the snakeskin gourami tends to exhibit an XX/XY sex determination system. However, we did not find any male-specific loci after filtering the loci for a ratio of 100:0 ratio of males:females. This suggests that the putative Y chromosome is young and that the sex determination region is cryptic. This approach provides solid information that can help identify the sex determination mechanism and potential sex determination regions in the snakeskin gourami, allowing further investigation of genetic improvements in the species.

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