scholarly journals A duplicated amh is the master sex-determining gene for Sebastes rockfish in the Northwest Pacific

Open Biology ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 210063
Author(s):  
Weihao Song ◽  
Yuheng Xie ◽  
Minmin Sun ◽  
Xuemei Li ◽  
Cristín K. Fitzpatrick ◽  
...  

Teleost fish are the most diverse group of vertebrates and provide opportunities to study the evolution of sex determination (SD) systems. Using genomic and functional analyses, we identified a male-specific duplication of anti-Müllerian hormone ( amh ) gene as the male master sex-determining (MSD) gene in Sebastes schlegelii . By resequencing 10 males and 10 females, we characterized a 5 kb-long fragment in HiC_Scaffold_12 as a male-specific region, which contained an amh gene (named amhy ). We then demonstrated that amhy is a duplication of autosomal amh that was later translocated to the ancestral Y chromosome. amha and amhy shared high-nucleotide identity with the most significant difference being two insertions in intron 4 of amhy . Furthermore, amhy overexpression triggered female-to-male sex reversal in S. schlegelii , displaying its fundamental role in driving testis differentiation. We developed a PCR assay which successfully identified sexes in two species of northwest Pacific rockfish related to S. schlegelii . However, the PCR assay failed to distinguish the sexes in a separate clade of northeast Pacific rockfish. Our study provides new examples of amh as the MSD in fish and sheds light on the convergent evolution of amh duplication as the driving force of sex determination in different fish taxa.

Food Control ◽  
2010 ◽  
Vol 21 (5) ◽  
pp. 726-731 ◽  
Author(s):  
W.L. Bai ◽  
R.H. Yin ◽  
S.J. Zhao ◽  
C. Li ◽  
Z.J. Ma ◽  
...  

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 25-32
Author(s):  
Robert P. Erickson ◽  
Edward J. Durbin ◽  
Laura L. Tres

Mice provide material for studies of Y-chromosomal and autosomal sequences involved in sex determination. Eicher and coworkers have identified four subregions in the mouse Y chromosome, one of which corresponds to the Sxr fragment. This fragment demonstrates that only a small portion of the Y is necessary for male sex determination. The mouse Y chromosome also shows variants: the BALB/cWt Y chromosome, which causes nondisjunction of the Y in some germ cells leading to XO and XYY cells and resulting in many infertile true hermaphrodites; the YDom, a wild-type chromosome which can result in sex reversal on a C57BL/6J background; and Y-chromosomal variants detected with Y-derived genomic DNA clones among inbred strains. Two different autosomal loci affecting sex differentiation have been identified in the mouse by Eicher and coworkers. The first of these has not been mapped to a particular chromosome and has been designated Tda-1 (Testis-determining autosomal-1). This is the locus in C57BL/6J mice at which animals must be homozygous in order to develop as true hermaphrodites or sex-reversed animals in the presence of YDom. The other locus has been identified on proximal chromosome 17. This locus also caused hermaphrodites on the C57BL/6J background and it is most easily interpreted as a locus deleted in 7hp. It is located in a region on chromosome 17 containing other genes or DNA sequences that may be related to sex determination. These include both the Hye (histocompatibility Y expression) locus that affects the amount of male-specific antigen detected by serological and cell-mediated assays and a concentration of Bkm sequences. Despite the Y and chromosomal 17 localizations of Bkm sequences, there is no evidence that transcripts from these are involved in sex determination: RNA hybridizing to sense and anti-sense Bkm clones can be detected in day-14 fetal gonads of both sexes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mateus C. Adolfi ◽  
Kang Du ◽  
Susanne Kneitz ◽  
Cédric Cabau ◽  
Margot Zahm ◽  
...  

AbstractArapaima gigas is one of the largest freshwater fish species of high ecological and economic importance. Overfishing and habitat destruction are severe threats to the remaining wild populations. By incorporating a chromosomal Hi-C contact map, we improved the arapaima genome assembly to chromosome-level, revealing an unexpected high degree of chromosome rearrangements during evolution of the bonytongues (Osteoglossiformes). Combining this new assembly with pool-sequencing of male and female genomes, we identified id2bbY, a duplicated copy of the inhibitor of DNA binding 2b (id2b) gene on the Y chromosome as candidate male sex-determining gene. A PCR-test for id2bbY was developed, demonstrating that this gene is a reliable male-specific marker for genotyping. Expression analyses showed that this gene is expressed in juvenile male gonads. Its paralog, id2ba, exhibits a male-biased expression in immature gonads. Transcriptome analyses and protein structure predictions confirm id2bbY as a prime candidate for the master sex-determiner. Acting through the TGFβ signaling pathway, id2bbY from arapaima would provide the first evidence for a link of this family of transcriptional regulators to sex determination. Our study broadens our current understanding about the evolution of sex determination genetic networks and provide a tool for improving arapaima aquaculture for commercial and conservation purposes.


Genetics ◽  
1994 ◽  
Vol 138 (4) ◽  
pp. 1199-1206 ◽  
Author(s):  
X Guo ◽  
S K Allen

Abstract Mulinia lateralis, the dwarf surfclam, is a suitable model for bivalve genetics because it is hardy and has a short generation time. In this study, gynogenetic and triploid M. lateralis were successfully induced. For gynogenesis, eggs were fertilized with sperm irradiated with ultraviolet light and subsequently treated with cytochalasin B to block the release of the second polar body (PB2). Triploidy was induced by blocking PB2 in normally fertilized eggs. The survival of gynogenetic diploids was very low, only 0.7% to 8 days post-fertilization (PF), compared with 15.2% in the triploid groups and 27.5% in the normal diploid control. Larvae in all groups metamorphosed at 8-10 days PF, and there was no significant post-larval mortality. At sexual maturation (2-3 months PF), all gynogenetic diploids were female, and there was no significant difference (P > 0.05) in sex ratio between diploids and triploids. These results suggested that the dwarf surfclam may have an XX-female, XY-male sex determination with Y-domination. Compared with diploids, triploids had a relative fecundity of 59% for females and 80% for males. Eggs produced by triploid females were 53% larger (P < 0.001) in volume than those from diploid females. In both length and weight measurements at three months PF, the gynogenetic diploids were not significantly (P > 0.33) different from normal diploid females, suggesting that inbreeding depression was minimal in meiosis II gynogens. Triploid clams were significantly larger (P < 0.001) than normal diploids. We hypothesize that the increased body-size in triploids was caused by a polyploid gigantism due to the increased cell volume and a lack of cell-number compensation.


Author(s):  
Ming Wen ◽  
Romain Feron ◽  
Qiaowei Pan ◽  
Justine Guguin ◽  
Elodie Jouanno ◽  
...  

AbstractBackgroundGoldfish is an important model for various areas of research, including neural development and behavior and a species of significant importance in aquaculture, especially as an ornamental species. It has a male heterogametic (XX/XY) sex determination system that relies on both genetic and environmental factors, with high temperatures being able to produce female-to-male sex reversal. Little, however, is currently known on the molecular basis of genetic sex determination in this important cyprinid model. We used sequencing approaches to better characterize sex determination and sex-chromosomes in goldfish.ResultsOur results confirmed that sex determination in goldfish is a mix of environmental and genetic factors and that its sex determination system is male heterogametic (XX/XY). Using reduced representation (RAD-seq) and whole genome (pool-seq) approaches, we characterized sex-linked polymorphisms and developed male specific genetic markers. These male specific markers were used to distinguish sex-reversed XX neomales from XY males and to demonstrate that XX female-to-male sex reversal could even occur at a relatively low rearing temperature (18°C), for which sex reversal has been previously shown to be close to zero. We also characterized a relatively large non-recombining region (∼11.7 Mb) on goldfish linkage group 22 (LG22) that contained a high-density of male-biased genetic polymorphisms. This large LG22 region harbors 373 genes, including a single candidate as a potential master sex gene, i.e., the anti-Mullerian hormone gene (amh). However, no sex-linked polymorphisms were detected in the goldfish amh gene or its 5 kb proximal promoter sequence.ConclusionsThese results show that goldfish have a relatively large sex locus on LG22, which is likely the goldfish Y chromosome. The presence of a few XX males even at low temperature also suggests that other environmental factors in addition to temperature could trigger female-to-male sex reversal. Finally, we also developed sex-linked genetic markers in goldfish, which will be important for future research on sex determination and aquaculture applications in this species.


2020 ◽  
Vol 14 (2) ◽  
pp. 97-107
Author(s):  
Andrew Harbottle ◽  
Andrea Maggrah ◽  
Robert Usher ◽  
Elise Desa ◽  
Jennifer M Creed

Aim: To evaluate an 8.7-kb mitochondrial DNA (mtDNA) deletion as a potential biomarker of endometriosis. Materials & methods: We tested the diagnostic accuracy of the 8.7-kb deletion real-time PCR assay using 182 prospectively collected blood samples from females presenting with symptoms of endometriosis in a case–control format. Results: The assay differentiated between endometriosis and controls (area under curve: 0.74–0.89) with a statistically significant difference (p < 0.05) in 8.7-kb deletion levels measured for all disease subtypes and stages. No correlation was seen between 8.7-kb deletion levels and participant or specimen age, hormone status or menstrual phase. Conclusion: The diagnostic accuracy of the 8.7-kb deletion for endometriosis suggests potential utility in the clinic to improve patient management.


2014 ◽  
Vol 2 (1) ◽  
pp. 23-27
Author(s):  
B Sharma ◽  
N Balaji ◽  
MK Sumathi

Background and objectives: Identification, an aspect of forensic anthropology, is the recognition of an individual based on the physical characteristics unique to the individual. Among the four main attributes i.e. gender, age, stature and ethnic or racial background of an individual’s biological identity, sex determination is usually the first step in the human identification process. Teeth can be used as a means of sex determination as teeth are resistant to post-mortem degradation and survive deliberate, accidental or natural change. This study was carried out with an objective to determine the sexual dimorphism of maxillary and mandibular canine by linear tooth diameter for permanent dentition in Moradabad population. Material and Methods: A total number of 40 subjects (20 Males and 20 Females) were included in this study. After obtaining an informed written consent, alginate impression was taken with help of perforated impression trays and study models were prepared with type IV dental stone. Linear (MD, BL, Crown Height) were taken with digital vernier caliper. Results: It was observed that males’ shows more mean linear crown diameter as compared to females. Also, the mesiodistal and buccolingual measurement shows statistically significant difference for all canines, being higher for males than females. Conclusion: The present study has expressed sexual dimorphism of permanent canine using Student’s test and indicate that linear dimension of maxillary canine can be used for sexual diamorphism with accuracy along with other accepted procedure for sex determination. DOI: http://dx.doi.org/10.3126/jmcjms.v2i1.11392   Janaki Medical College Journal of Medical Sciences (2014) Vol. 2 (1): 23-27


2021 ◽  
Author(s):  
Boudjema Imarazene ◽  
Kang Du ◽  
Séverine Beille ◽  
Elodie Jouanno ◽  
Romain Feron ◽  
...  

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Dung T Nguyen ◽  
Kasper G Lauridsen ◽  
Josephine Johnsen ◽  
Kristian Krogh ◽  
Bo Løfgren

Background: The European Resuscitation Council (ERC) 2015 basic life support (BLS) guidelines introduced a simplified algorithm compared to the ERC 2010 BLS guidelines. This was intended to improve adherence to guidelines and retention of skills. This study aimed to compare the retention of BLS skills 3 months after training using the ERC 2010 or 2015 guidelines. Methods: This was an observational study including video recordings of laypersons being skill tested 3 months after participation in a standardized ERC BLS/AED course using either the ERC 2010 guidelines or the simplified ERC 2015 guidelines. The endpoints were 1) remembering the correct sequence of BLS/AED algorithm, 2) remembering the correct sequence of the BLS/AED algorithm and performing all skills correctly, 3) time to: emergency medical service (EMS) call, first compression, and shock delivery. Results: We analyzed videos of 133 laypersons skill tested 3 months after initial training; 64 trained using the 2010 guidelines (mean ±standard deviation (SD) age: 40 ±11 years, male sex: 19 (30%)) and 69 trained using the 2015 guidelines (age: 44 ±10 years, male sex: 36 (52%)). Participants in the 2015 guidelines group improved the retention of the BLS/AED algorithm compared to the 2010 guidelines group (29 (42%) vs. 10 (16%), relative risk (RR): 2.7 (95% confidence interval (CI): 1.4 - 5.1) P=0.001). Both BLS/AED algorithm and all skills were correctly performed by 13 (19%) vs. 3 (5%) (RR: 4.0 (95% CI: 1.2 - 13.5) P=0.01) in the 2015 and 2010 groups respectively. No significant difference was found in time to EMS call (difference: 3 sec (95% CI: -2 - 9 sec) P=0.27), time to first compression (difference: 4 sec, (95% CI: -3 - 10 sec) P=0.28), and time to first shock (difference: 4 sec (95% CI: -5 - 14 sec) P=0.33) between the groups. Conclusion: BLS/AED training using ERC 2015 guidelines was associated with better skill retention compared to training using ERC 2010 guidelines. There was no difference in time to EMS call, first compression, or shock delivery.


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