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Prenatal Diagnosis Mar 2020Non-invasive prenatal testing (NIPT) can determine the sex of the fetus very accurately and very early in gestation. There are concerns that the ease, timing, and... (Review)
Review
Non-invasive prenatal testing (NIPT) can determine the sex of the fetus very accurately and very early in gestation. There are concerns that the ease, timing, and accuracy of NIPT sex determination will facilitate sex-selective termination of pregnancy (TOP). Here, we review current practices, the evidence for a link between NIPT and sex-selective TOP, and associated ethical issues. Sex-selective TOP, usually motivated by son preference, has had serious demographic consequences in countries such as India and China. Currently, ultrasound is the primary method by which parents determine the sex of the fetus. The diffusion of ultrasound technology has had a direct impact on the rates of sex-selective TOP. Although NIPT is currently more costly, it is feasible that increased uptake of this technology could have a similar effect. Partly because NIPT is a relatively recent development in prenatal screening, there is little data on the impact of NIPT on sex selection practices. Evidence that NIPT is playing a role in sex-selective TOP remains largely anecdotal. Further research is required to assess and quantify TOP resulting from NIPT sex determination. The use of these technologies for sex selection raises a number of ethical issues, in addition to practical demographic consequences.
Topics: Abortion, Eugenic; China; Humans; India; Noninvasive Prenatal Testing; Sex Determination Analysis; Sex Preselection; Ultrasonography, Prenatal; United States
PubMed: 31499588
DOI: 10.1002/pd.5555 -
Sexual Development : Genetics,... 2021Sex determination and differentiation varies widely across vertebrates, but is most dramatically diverse in fishes. Among fishes sex reversal and sex change are observed... (Review)
Review
Sex determination and differentiation varies widely across vertebrates, but is most dramatically diverse in fishes. Among fishes sex reversal and sex change are observed in 41 teleost families spanning 7 orders. These sex-changing fish perhaps highlight better than any other system that sex determination is not the narrow and fixed construct we once thought, but a plastic trait that is better viewed as a reaction norm. However, while this stunning transformation is increasingly understood, a fundamental question arises, which is why some fish species have retained this inherent plasticity in sexual fate, while others have not? Here, we explore our current understanding of sex change in fish, some of the factors that permit and constrain sex reversal, and posit that gene duplication and neofunctionalization contribute to the sexual lability observed in fish.
Topics: Animals; Fishes; Gene Duplication; Phenotype; Sex Determination Analysis; Vertebrates
PubMed: 34167118
DOI: 10.1159/000515425 -
PLoS Genetics Jul 2020There is currently a requirement for single-sex litters for many applications, including agriculture, pest control, and reducing animal culling in line with the 3Rs... (Review)
Review
There is currently a requirement for single-sex litters for many applications, including agriculture, pest control, and reducing animal culling in line with the 3Rs principles: Reduction, Replacement, and Refinement. The advent of CRISPR/Cas9 genome editing presents a new opportunity with which to potentially generate all-female or all-male litters. We review some of the historical nongenetic strategies employed to generate single-sex litters and investigate how genetic and genome editing techniques are currently being used to produce all-male or all-female progeny. Lastly, we speculate on future technologies for generating single-sex litters and the possible associated challenges.
Topics: Animals; CRISPR-Cas Systems; Female; Gene Editing; Male; Reproduction; Sex Determination Analysis; Sex Determination Processes
PubMed: 32701961
DOI: 10.1371/journal.pgen.1008898 -
Scientific Reports Apr 2024The present study tested the combination of mandibular and dental dimensions for sex determination using machine learning. Lateral cephalograms and dental casts were...
The present study tested the combination of mandibular and dental dimensions for sex determination using machine learning. Lateral cephalograms and dental casts were used to obtain mandibular and mesio-distal permanent teeth dimensions, respectively. Univariate statistics was used for variables selection for the supervised machine learning model (alpha = 0.05). The following algorithms were trained: logistic regression, gradient boosting classifier, k-nearest neighbors, support vector machine, multilayer perceptron classifier, decision tree, and random forest classifier. A threefold cross-validation approach was adopted to validate each model. The areas under the curve (AUC) were computed, and ROC curves were constructed. Three mandibular-related measurements and eight dental size-related dimensions were used to train the machine learning models using data from 108 individuals. The mandibular ramus height and the lower first molar mesio-distal size exhibited the greatest predictive capability in most of the evaluated models. The accuracy of the models varied from 0.64 to 0.74 in the cross-validation stage, and from 0.58 to 0.79 when testing the data. The logistic regression model exhibited the highest performance (AUC = 0.84). Despite the limitations of this study, the results seem to show that the integration of mandibular and dental dimensions for sex prediction would be a promising approach, emphasizing the potential of machine learning techniques as valuable tools for this purpose.
Topics: Humans; Mandible; Male; Female; Machine Learning; Adult; Young Adult; Cephalometry; Adolescent; Sex Determination Analysis; Tooth; Algorithms; ROC Curve; Logistic Models
PubMed: 38671054
DOI: 10.1038/s41598-024-59556-9 -
PloS One 2022Non-avian reptiles, unlike mammals and birds, have undergone numerous sex determination changes. Casque-Headed Lizards have replaced the ancestral XY system shared...
Non-avian reptiles, unlike mammals and birds, have undergone numerous sex determination changes. Casque-Headed Lizards have replaced the ancestral XY system shared across pleurodonts with a new pair of XY chromosomes. However, the evolutionary forces that triggered this transition have remained unclear. An interesting hypothesis suggests that species with intermediate states, with sex chromosomes but also thermal-induced sex reversal at specific incubation temperatures, could be more susceptible to sex determination turnovers. We contrasted genotypic data (presence/absence of the Y chromosome) against the histology of gonads of embryos from stages 35-37 incubated at various temperatures, including typical male-producing (26°C) and female-producing (32°C) temperatures. Our work apparently reports for the first time the histology of gonads, including morphological changes, from stages 35-37 of development in the family Corytophanidae. We also observed that all embryos developed hemipenes, suggesting sex-linked developmental heterochrony. We observed perfect concordance between genotype and phenotype at all temperatures. However, analysis of transcriptomic data from embryos incubated at 26°C and 32°C identified transcript variants of the chromatin modifiers JARID2 and KDM6B that have been linked to temperature-dependent sex determination in other reptiles. Our work tested the validity of a mixed sex determination system in the family Corytophanidae. We found that XY chromosomes are dominant; however, our work supports the hypothesis of a conserved transcriptional response to incubation temperatures across non-avian reptiles that could be a reminiscence of an ancestral sex determination system.
Topics: Animals; Female; Gonads; Lizards; Male; Mammals; Sex Chromosomes; Sex Determination Analysis; Sex Determination Processes; Temperature; Y Chromosome
PubMed: 35797377
DOI: 10.1371/journal.pone.0263804 -
British Medical Journal Mar 1979
Topics: Animals; Dogs; Female; Genitalia; H-Y Antigen; Humans; Male; Mice; Sex Determination Analysis; X Chromosome; Y Chromosome
PubMed: 435744
DOI: No ID Found -
PloS One 2022Molecular biology techniques are increasingly being used in sex identification of skeletal remains when traditional anthropometric analyzes are not successful in...
Molecular biology techniques are increasingly being used in sex identification of skeletal remains when traditional anthropometric analyzes are not successful in identifying sex of remains that are incomplete, fragmented and /or of immature individuals. In the present work, we investigated the possibility of determining sex by using the qPCR-duplex method for both ancient and modern DNA samples. This method involves the co-amplification of two genes in a single reaction system and the subsequent analysis of the fusion curves; the gene sequences used for the construction of suitable primers are those of steroid sulfatase (STS) and testis specific protein Y-linked 1 (TSPY) genes which turned out to be two sensitive markers as they have a detection limit of 60 pg and 20 pg respectively on modern DNA. The validity of the method was verified on modern DNA in which gender was identified in all the samples with 100% accuracy; thus, allowing for the same results as the classic method with amelogenin, but in a faster and more immediate way, as it allows for sex determination solely by analyzing the denaturation curves without having to perform an electrophoretic run. The proposed molecular technique proves to be sensitive and precise even on degraded DNA, in fact on 9 archaeological finds dating from the VII-XII century in which sex had been identified through anthropometric analysis, it confirmed the sex of 8 out of 9 finds correctly.
Topics: Amelogenin; DNA; DNA, Ancient; Humans; Male; Real-Time Polymerase Chain Reaction; Sex Determination Analysis
PubMed: 35687599
DOI: 10.1371/journal.pone.0269913 -
PloS One 2013Pyropia haitanensis has a biphasic life cycle with macroscopic gametophytic blade (n) and microscopic filamentous conchocelis (2n) phase. Its gametophytic blades have...
Pyropia haitanensis has a biphasic life cycle with macroscopic gametophytic blade (n) and microscopic filamentous conchocelis (2n) phase. Its gametophytic blades have long been believed to be mainly dioecious. However, when crossing the red mutant (R, ♀) with the wild type (W, ♂), the parental colors were segregated in F1 blades, of which 96.1% were linearly sectored with 2-4 color sectors. When color sectors were excised from the color-sectored blades and cultured singly, 99.7% of the color sectors appeared to be unisexual with an equal sex ratio. Although the sex of color sector did not genetically link with its color, the boundaries of both sex and color sectors coincided precisely. About 87.9% of the examined color-sectored blades were monoecious and the percentage increased with the number of color sectors of a blade. The gametophytic blades from each conchocelis strain produced by parthenogenesis of the excised color sectors were unisexual and unicolor, showing the same sex and color as their original sectors. These results indicate that most of the sexually reproduced Py. haitanensis blades are monoecious, and their sex is controlled by segregation of a pair of alleles during meiosis of conchospore, forming a sex-sectored tetrad. During the subsequent development of blades, one or two lower cell(s) of the tetrad contribute mainly to rhizoid formation, and rarely show their sexual phenotype, leading to reduced frequency of full sex phenotype of the meiotic blades. Moreover, the aberrant segregations of sex genes or color genes in a few of F1 blades were probably due to gene conversions, but there was no sex transfer in Py. haitanensis.
Topics: Color; Germ Cells, Plant; Rhodophyta; Sex Determination Analysis
PubMed: 23991194
DOI: 10.1371/journal.pone.0073414 -
Scientific Reports Mar 2020Temperature-dependent sex determination, present in most turtle species, is a mechanism that uses temperature to direct the sex of the embryo. The rapid increase of...
Temperature-dependent sex determination, present in most turtle species, is a mechanism that uses temperature to direct the sex of the embryo. The rapid increase of global temperatures highlights the need for a clear assessment of how sex ratios of organisms with TSD are affected. In turtles with TSD, quantifying primary sex ratios is challenging because they lack external dimorphism and heteromorphic sex chromosomes. Here we describe a new technique used to identify sex in neonate turtles of two TSD species, a freshwater turtle (Trachemys scripta) and a marine turtle (Caretta caretta) via analysis of small blood samples. We used an immunoassay approach to test samples for the presence of several proteins known to play an important role in sex differentiation. Our results show that Anti-Mullerian Hormone (AMH) can be reliably detected in blood samples from neonate male turtles but not females and can be used as a sex-specific marker. Verification of sex via histology or laparoscopy revealed that this method was 100% reliable for identifying sex in both T. scripta and C. caretta 1-2 day-old hatchlings and 90% reliable for identifying sex in 83-177 day-old (120-160 g) loggerhead juveniles. The method described here is minimally invasive, and for the first time, greatly enhances our ability to measure neonate turtle sex ratios at population levels across nesting sites worldwide, a crucial step in assessing the impact of climate change on imperiled turtle species.
Topics: Animals; Animals, Newborn; Anti-Mullerian Hormone; Biomarkers; Climate Change; Female; Immunoassay; Male; Sex Determination Analysis; Sex Ratio; Temperature; Turtles
PubMed: 32193464
DOI: 10.1038/s41598-020-61984-2 -
Journal of Medical Genetics Jun 1978
Review
Topics: Amphibians; Animals; Aphids; Birds; Chromosomes; Cricetinae; Diptera; Drosophila; Female; Fertilization; Fishes; Guinea Pigs; Humans; Hymenoptera; Karyotyping; Lepidoptera; Meiosis; Mice; Mitosis; Nematoda; Oligochaeta; Parthenogenesis; Ploidies; Reptiles; Sex Determination Analysis
PubMed: 353283
DOI: 10.1136/jmg.15.3.165