scholarly journals Y chromosome functions in mammalian spermatogenesis

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jeremie Subrini ◽  
James Turner
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Mouse Models ◽  
Evolutionary History ◽  
Male Reproduction ◽  
Gene Deletions ◽  
Functional Studies ◽  
Current State ◽  
Male Sex ◽  
State Of Research

The mammalian Y chromosome is critical for male sex determination and spermatogenesis. However, linking each Y gene to specific aspects of male reproduction has been challenging. As the Y chromosome is notoriously hard to sequence and target, functional studies have mostly relied on transgene-rescue approaches using mouse models with large multi-gene deletions. These experimental limitations have oriented the field toward the search for a minimum set of Y genes necessary for male reproduction. Here, considering Y-chromosome evolutionary history and decades of discoveries, we review the current state of research on its function in spermatogenesis and reassess the view that many Y genes are disposable for male reproduction.

CYTOTAXONOMY AND SEX DETERMINATION OF RUMEX PAUCIFOLIUS

1956 ◽  
Vol 34 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Áskell Löve ◽  
Nina Sarkar
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Sex Chromosomes ◽  
The Other ◽  
Large Chromosome ◽  
Dioecious Species ◽  
The Third ◽  
Male Sex ◽  
Morphological Differences

The western North American dioecious species Rumex paucifolius is shown to be a tetraploid with 2n = 28 chromosomes. It is the third tetraploid known within the subgenus Acetosa, and the first polyploid dioecious taxon of that group, the others having either 2n = 14 ♂, 15 ♀ (R. Acetosa and relatives), or 2n = 8 ♂, 9 ♀ (R. hastatulus). The sex chromosomes of R. paucifolius are of the XX:XY type, the male sex being heterogametic. The X is a large chromosome, while the Y is the smallest chromosome of the complement. The mechanism of sex determination of R. paucifolius follows the Melandrium–Acetosella scheme with strongly epistatic male determinants in the Y–chromosome. Other dioecious Acetosae follow the Drosophila–Acetosa scheme of sex determination with a balance between the number of X and autosome complements, the Y being sexually inert. It is concluded from the observed cytogenetical and morphological differences that R. paucifolius should constitute a section of its own, Paucifoliae, which should be placed as far as possible from the section Acetosa, though within the same subgenus. The other American dioecious endemic, R. hastatulus, is placed in a subsection of the section Acetosa.

Sex determination in mice: Y and chromosome 17 interactions

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 25-32
Author(s):  
Robert P. Erickson ◽  
Edward J. Durbin ◽  
Laura L. Tres
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Dna Sequences ◽  
Sex Differentiation ◽  
Specific Antigen ◽  
Inbred Strains ◽  
Chromosome 17 ◽  
Male Sex ◽  
Male Specific ◽  
Type Chromosome

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.

scholarly journals A duplicated copy of id2b is an unusual sex-determining candidate gene on the Y chromosome of arapaima (Arapaima gigas)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mateus C. Adolfi ◽  
Kang Du ◽  
Susanne Kneitz ◽  
Cédric Cabau ◽  
Margot Zahm ◽  
...  
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Habitat Destruction ◽  
Specific Marker ◽  
Contact Map ◽  
Arapaima Gigas ◽  
Male Sex ◽  
Male Specific ◽  
Inhibitor Of Dna Binding ◽  
High Degree

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.

Sex determination and Y chromosome constitutive heterochromatin

2019 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Abyt Ibraimov
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Constitutive Heterochromatin ◽  
Sex Differentiation ◽  
Secondary Sexual Characteristics ◽  
Biological Meaning ◽  
Heterochromatin Block ◽  
Sexual Characteristics ◽  
Open Question ◽  
Efficient Elimination

In many animals, including us, the genetic sex is determined at fertilization by sex chromosomes. Seemingly, the sex determination (SD) in human and animals is determined by the amount of constitutive heterochromatin on Y chromosome via cell thermoregulation. It is assumed the medulla and cortex tissue cells in the undifferentiated embryonic gonads (UEG) differ in vulnerability to the increase of the intracellular temperature. If the amount of the Y chromosome constitutive heterochromatin is enough for efficient elimination of heat difference between the nucleus and cytoplasm in rapidly growing UEG cells the medulla tissue survives. Otherwise it doomed to degeneration and a cortex tissue will remain in the UEG. Regardless of whether our assumption is true or not, it remains an open question why on Y chromosome there is a large constitutive heterochromatin block? What is its biological meaning? Does it relate to sex determination, sex differentiation and development of secondary sexual characteristics? If so, what is its mechanism: chemical or physical? There is no scientifically sound answer to these questions.

Culturally Responsive Pedagogy in Mathematics

2020 ◽  
Vol 2 ◽  
pp. 145-158
Author(s):  
Kenta Nagasawa
Keyword(s):  
Professional Development ◽  
Teacher Education ◽  
Culturally Responsive ◽  
Latino Students ◽  
Culturally Responsive Pedagogy ◽  
Mathematics Teacher Education ◽  
Development Program ◽  
Current State ◽  
Responsive Pedagogy ◽  
State Of Research

Purpose: This paper is a thematic literature review to examine the current state of research about Culturally Responsive Pedagogy in mathematics. The main themes are students’ perception, teacher education for pre-service teacher and professional development for teachers. Research methods/ approach: Literature was collected from Eric, which is a research engine of the education field. Also, Google Scholar is used to find articles of major scholars introduced by Dr. Rich Milner, who is the instructor of this course. Findings: Students faced microaggressions in mathematics class, which discouraged them to learn mathematics. The effect of teacher education was inconsistent in terms of the awareness of culturally responsive pedagogy and lesson plans. Research of professional development mentioned that mathematics was cultural. Implications for research and practice: It is more interesting to conduct long term or follow-up research to find the teacher’s practice after a taking professional development program. Also, it is critical to expand research scope besides African American and Latino students. Finally, evidence-based research is needed to change the political situation. Keywords: culturally responsive teaching, mathematics, teacher education, professional development, student’s perception

Editorial

2013 ◽  
Vol 1 (2) ◽  
pp. 1-3
Author(s):  
João José Pinto Ferreira ◽  
Anne-Laure Mention ◽  
Marko Torkkeli
Keyword(s):  
Economic Development ◽  
Education Research ◽  
Research And Development ◽  
Research Integrity ◽  
Academic Community ◽  
Human Knowledge ◽  
Academic Institutions ◽  
Current State ◽  
State Of Research ◽  
Successive Generations

The expansion of human knowledge in all areas is largely the outcome of the activity of academic institutions and the result of their mission to contribute to the cultural, intellectual and economic development of the society, involving education, research and university extension activities. For many years, the academic community has been organizing itself in all different ways to respond to current and future needs, ensuring research integrity and recognition, and building on successive generations of peers to validate and support the launching and development of novel research streams. We owe the current state of research and development of our society to generations of scholars and scientists that have brought all of us here.(...)

ORGANOPHOSPHORUS NEUROTOXINS

2020 ◽  
Author(s):  
Mariya Andriyanova ◽  
Aslanli Aslanli ◽  
Nataliya Basova ◽  
Viktor Bykov ◽  
Sergey Varfolomeev ◽  
...  
Keyword(s):  
Crop Protection ◽  
Chemical Warfare Agents ◽  
Agricultural Crop ◽  
Current State ◽  
Physicochemical Biology ◽  
Chemical Agents ◽  
Warfare Agents ◽  
History Of ◽  
Physicochemical Methods ◽  
State Of Research

The collective monograph is devoted to discussing the history of creation, studying the properties, neutralizing and using organophosphorus neurotoxins, which include chemical warfare agents, agricultural crop protection chemical agents (herbicides and insecticides) and medicines. The monograph summarizes the results of current scientific research and new prospects for the development of this field of knowledge in the 21st century, including the use of modern physicochemical methods for experimental study and theoretical analysis of biocatalysis and its mechanisms based on molecular modeling with supercomputer power. The book is intended for specialists who are interested in the current state of research in the field of organophosphorus neurotoxins. The monograph will be useful for students, graduate students, researchers specializing in the field of physical chemistry, physicochemical biology, chemical enzymology, toxicology, biochemistry, molecular biology and genetics, biotechnology, nanotechnology and biomedicine.

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