VaAPRT3 Gene is Associated With Sex Determination in Vitis amurensis

In the past decade, progress has been made in sex determination mechanism in Vitis. However, genes responsible for sexual differentiation and its mechanism in V. amurensis remain unknown. Here, we identify a sex determination candidate gene coding adenine phosphoribosyl transferase 3 (VaAPRT3) in V. amurensis. Cloning and sequencing of the VaAPRT3 gene allowed us to develop a molecular marker able to discriminate female individuals from males or hermaphrodites based on a 22-bp InDel. Gene expression and endogenous cytokinin content analysis revealed that the VaAPRT3 gene is involved in sex determination or, to be precise, in female organ differentiation, through regulating cytokinin metabolism in V. amurensis. This study enlarged the understanding of sex determination mechanism in the genus Vitis, and the sex marker could be used as a helpful tool for sexual identification in breeding programs as well as in investigation and collection of V. amurensis germplasms.

"Get Your Gavel Out of My Pants": Replacing the Medical and Legal Scrutiny of Trans Bodies with Self-Identification as a Basis for Changing Sex Markers on Birth Certificates

<p>Section 28 of the Births, Deaths, Marriages, and Relationships Registration Act 1995 allows people to apply to the Family Court to change the sex marker on their birth certificate. This essay argues that this provision is out-dated and does not serve the needs of the trans community. It is based on the medical model of sex, and requires medical evidence that the applicant’s body conforms sufficiently to that of the “nominated sex”. This essay suggests a reform based on the self-identification model, which exists in Argentina for birth certificates, and in New Zealand for passports and drivers’ licences. Such a reform of s 28 would bring birth certificates in line with these other documents, leading to more consistency and increased respect for the human rights of trans people.</p>

"Get Your Gavel Out of My Pants": Replacing the Medical and Legal Scrutiny of Trans Bodies with Self-Identification as a Basis for Changing Sex Markers on Birth Certificates

<p>Section 28 of the Births, Deaths, Marriages, and Relationships Registration Act 1995 allows people to apply to the Family Court to change the sex marker on their birth certificate. This essay argues that this provision is out-dated and does not serve the needs of the trans community. It is based on the medical model of sex, and requires medical evidence that the applicant’s body conforms sufficiently to that of the “nominated sex”. This essay suggests a reform based on the self-identification model, which exists in Argentina for birth certificates, and in New Zealand for passports and drivers’ licences. Such a reform of s 28 would bring birth certificates in line with these other documents, leading to more consistency and increased respect for the human rights of trans people.</p>

The genome of New Zealand trevally (Carangidae: Pseudocaranx georgianus) uncovers a XY sex determination locus

Background The genetic control of sex determination in teleost species is poorly understood. This is partly because of the diversity of mechanisms that determine sex in this large group of vertebrates, including constitutive genes linked to sex chromosomes, polygenic constitutive mechanisms, environmental factors, hermaphroditism, and unisexuality. Here we use a de novo genome assembly of New Zealand silver trevally (Pseudocaranx georgianus) together with sex-specific whole genome sequencing data to detect sexually divergent genomic regions, identify candidate genes and develop molecular makers. Results The de novo assembly of an unsexed trevally (Trevally_v1) resulted in a final assembly of 579.4 Mb in length, with a N50 of 25.2 Mb. Of the assembled scaffolds, 24 were of chromosome scale, ranging from 11 to 31 Mb in length. A total of 28,416 genes were annotated after 12.8 % of the assembly was masked with repetitive elements. Whole genome re-sequencing of 13 wild sexed trevally (seven males and six females) identified two sexually divergent regions located on two scaffolds, including a 6 kb region at the proximal end of chromosome 21. Blast analyses revealed similarity between one region and the aromatase genes cyp19 (a1a/b) (E-value < 1.00E-25, identity > 78.8 %). Males contained higher numbers of heterozygous variants in both regions, while females showed regions of very low read-depth, indicative of male-specificity of this genomic region. Molecular markers were developed and subsequently tested on 96 histologically-sexed fish (42 males and 54 females). Three markers amplified in absolute correspondence with sex (positive in males, negative in females). Conclusions The higher number of heterozygous variants in males combined with the absence of these regions in females support a XY sex-determination model, indicating that the trevally_v1 genome assembly was developed from a male specimen. This sex system contrasts with the ZW sex-determination model documented in closely related carangid species. Our results indicate a sex-determining function of a cyp19a1a-like gene, suggesting the molecular pathway of sex determination is somewhat conserved in this family. The genomic resources developed here will facilitate future comparative work, and enable improved insights into the varied sex determination pathways in teleosts. The sex marker developed in this study will be a valuable resource for aquaculture selective breeding programmes, and for determining sex ratios in wild populations.

The End of Compulsory Gender Verification: Is It Progress for Inclusion of Women in Sports?

Recently, the so-called Semenya case has brought the problem of gender in sports competitions back into the spotlight. But the fact is that it is not a unique case; rather, it seems a recurrent and inconclusive problem in the history of sports. In this context, the Spanish athlete Martínez-Patiño is an important figure in the history of sport and gender verification, as well as the Indian sprinter Dutee Chand. Martínez-Patiño’s story thus serves as an important case study of the gender-based anxieties that hampered women’s advancement in track and field. Martínez-Patiño’s experience in Spanish athletics demonstrates the difficulties women faced when attempting to compete in track and field, both in Spain and internationally. Moreover, her experience with gender policies shows the inadequacies of the chromosomal check as a sex marker, as well as the harms caused by the technique. Finally, Martínez-Patiño’s protest of the International Association of Athletics Federations’ policy started to dismantle compulsory sex verification used as a criterion for gender eligibility. The publicity surrounding her case pushed the track and field federation to abandon mandatory, on-site testing in 1992. Seven years later, the International Olympic Committee also dropped its compulsory control. Martínez-Patiño became the face of the fight against sex/gender verification in sport and helped dismantle the practice. The case of Martinez-Patiño remains in the collective memory of elite sports and serves as an argument for national and international sporting institutions to reconsider discriminating policies in the context of progress being made for women’s rights.

Assessing genetic diversity and connectivity in a tule elk (Cervus canadensis nannodes) metapopulation in Northern California

The tule elk (Cervus canadensis nannodes) is a California endemic subspecies that experienced an extreme bottleneck (potentially two individuals) in the mid-1800s. Through active management, including reintroductions, the subspecies has grown to approximately 6000 individuals spread across 22 recognized populations. The populations tend to be localized and separated by unoccupied intervening habitat, prompting targeted translocations to ensure gene flow. However, little is known about the genetic status or connectivity among adjacent populations in the absence of active translocations. We used 19 microsatellites and a sex marker to obtain baseline data on the genetic effective population sizes and functional genetic connectivity of four of these populations, three of which were established since the 1980s and one of which was established ~ 100 years ago. A Bayesian assignment approach suggested the presence of 5 discrete genetic clusters, which corresponded to the four primary populations and two subpopulations within the oldest of them. Effective population sizes ranged from 15 (95% CI 10–22) to 51 (95% CI 32–88). We detected little or no evidence of gene flow among most populations. Exceptions were a signature of unidirectional gene flow to one population founded by emigrants of the other 30 years earlier, and bidirectional gene flow between subpopulations within the oldest population. We propose that social cohesion more than landscape characteristics explained population structure, which developed over many generations corresponding to population expansion. Whether or which populations can grow and reach sufficient effective population sizes on their own or require translocations to maintain genetic diversity and population growth is unclear. In the future, we recommend pairing genetic with demographic monitoring of these and other reintroduced elk populations, including targeted monitoring following translocations to evaluate their effects and necessity.

The genome of New Zealand trevally (Carangidae: Pseudocaranx georgianus) uncovers a XY sex determination locus

Background: The genetic control of sex determinism in teleost species is poorly understood. This is partly because of the diversity of sex determining mechanisms in this large group, including constitutive genes linked to sex chromosomes, polygenic constitutive mechanisms, environmental factors, hermaphroditism, and unisexuality. Here we use a de novo genome assembly of New Zealand silver trevally (Pseudocaranx georgianus) together with whole genome sequencing to detect sexually divergent regions, identify candidate genes and develop molecular makers. Results: The de novo assembly of an unsexed trevally (Trevally_v1) resulted in an assembly of 579.4 Mb in length, with a N50 of 25.2 Mb. Of the assembled scaffolds, 24 were of chromosome scale, ranging from 11 to 31 Mb. A total of 28416 genes were annotated after 12.8% of the assembly was masked with repetitive elements. Whole genome re-sequencing of 13 sexed trevally (7 males, 6 females) identified sexually divergent regions located on two scaffolds, including a 6 kb region at the proximal end of chromosome 21. Blast analyses revealed similarity between one region and the aromatase genes cyp19 (a1a/b). Males contained higher numbers of heterozygous variants in both regions, while females showed regions of very low read-depth, indicative of deletions. Molecular markers tested on 96 histologically-sexed fish (42 males, 54 females). Three markers amplified in absolute correspondence with sex. Conclusions: The higher number of heterozygous variants in males combined with deletions in females support a XY sex-determination model, indicating the trevally_v1 genome assembly was based on a male. This sex system contrasts with the ZW-type sex system documented in closely related species. Our results indicate a likely sex-determining function of the cyp19b-like gene, suggesting the molecular pathway of sex determination is somewhat conserved in this family. Our genomic resources will facilitate future comparative genomics works in teleost species, and enable improved insights into the varied sex determination pathways in this group of vertebrates. The sex marker will be a valuable resource for aquaculture breeding programmes, and for determining sex ratios and sex-specific impacts in wild fisheries stocks of this species.

Use of Amplified Fragment Length Polymorphism and Sequence Characterized Amplified Region Marker for Identifying the Sex of the Oxyeleotris marmorata

There is a huge demand for the Oxyeleotris marmorata, especially in Asian markets. However, farmers are unable to provide a constant supply of this fish to meet the demand, which is estimated to be around 100 metric tonnes per annum. One of the reasons that are hindering the supply is the low success rate of O. marmorata breeding programs. These breeding programs rely on many factors for their success, one of which is the use of genuine male and female adults, although determining these could be a daunting task. This research was carried out in an attempt to determine a sex marker for the O. marmorata using the amplified fragment length polymorphism (AFLP) method. Of the 30×30 AFLP primer mixtures screened, the E-TAA and M-CTT primer pair had an amplified ~600 bp marker that was specific to the female. This ~600 bp AFLP marker was later used to design a 464 bp sequence characterized amplified region (SCAR) marker. Thus, it has been suggested that the SCAR marker obtained has the potential to be used for the sexual identification of the O. marmorata at the juvenile stage, thereby enabling them to be used in breeding programs.

The genetic basis of sex determination in Populus provides molecular markers across the genus and indicates convergent evolution

Many dioecious angiosperms are trees, which only flower after years of vegetative development and do not usually exhibit marked secondary sexual dimorphism. Nevertheless, if the genetic basis of sex determination is known, the sex of an individual can be determined using molecular markers. Here, we report that in the genus Populus sect. Populus an XY system of sex determination, which is found in P. tremula and P. tremuloides, likely re-evolved from a ZW system present in P. alba, P. adenopoda and P. qiongdaoensis. Strikingly, this new XY system is mechanistically identical to the older system found in several species of the Populus sections Tacamahaca, Aigeiros and Turanga demonstrating a remarkable example of convergent evolution. In both XY systems, male-specific inversely repeated sequences appear to silence the ARR17 gene, which functions as a sex switch, via small interfering RNAs and DNA methylation. In the ZW system, female-specific copies of ARR17 appear to regulate dioecy. With this detailed information on the genetic basis of sex determination it was possible to develop molecular markers that can be utilized to determine the sex in seedlings and non-flowering trees of different poplar species. We used the female-specific ARR17 gene to develop a sex marker for P. alba and P. adenopoda. For P. grandidentata, we employed the male-specific ARR17 inverted repeat. Finally, we summarize previously described markers for P. tremula, P. tremuloides, P. trichocarpa, P. deltoides and P. nigra. These markers can be useful for poplar ecologists, geneticists and breeders.

Molecular screening of XY SRY-negative sex reversal cases in horses revealed anomalies in amelogenin testing

Male-to-female sex reversal in horses is a developmental disorder in which phenotypic females have a male genetic constitution. Male-to-female sex reversal is the second most common genetic sex abnormality, after X chromosome monosomy. All male-to-female sex reversal cases studied to date have been found to be infertile. Therefore, a screening test is particularly useful in laboratories doing DNA genotyping in horses. Our laboratory has tested > 209,000 horses for parentage using a panel of microsatellite markers and the sex marker gene amelogenin ( AMEL). Suspect XY sex reversal cases are reported females with a male profile by AMEL testing. After routine genotyping, 49 cases were detected and further tested using the sex-determining region Y ( SRY) gene, confirming the XY SRY-negative genotype of suspect sex reversal cases. When some inconsistencies arose in the initial result, a molecular panel of X- and Y-linked markers was analyzed for these samples. Of the 49 cases, 33 were confirmed as XY SRY-negative. The remaining 16 cases were identified as false-positives as a result of anomalies of AMEL testing in horses.