Genetic control of sex-chromosomal univalency in the spermatocytes of C57BL/6J and DBA/2J mice

1985 ◽  
Vol 27 (6) ◽  
pp. 741-750 ◽  
Author(s):  
F. G. Biddle ◽  
B. G. MacDonald ◽  
B. A. Eales
Keyword(s):  
Genetic Control ◽  
Y Chromosome ◽  
X Chromosome ◽  
Genetic Factors ◽  
Additive Effect ◽  
Unknown Number ◽  
Attachment Sites ◽  
Sufficient Distance ◽  
Strain Pair ◽  
Reciprocal Backcross

The genetic control of sex-chromosomal univalency was examined in the primary spermatocytes of the mouse. The C57BL/6J strain expresses 3% X–Y univalency and DBA/2J expresses 37% univalency. The reciprocal F1 and the eight types of reciprocal backcross males were examined. In the C57BL/6J–DBA/2J strain pair, X–Y univalency is controlled by three genetic systems. Autosomal factors of unknown number that are dominant in DBA/2J increase the probability of univalency from 3% in C57BL/6J to 12%. The DBA/2J-Y chromosome, in place of the C57BL/6J-Y chromosome, has an additive effect to increase the probability of univalency from 12 to 37% in the DBA/2J strain. Two X-chromosome factors that differ between C57BL/6J and DBA/2J regulate the probability of univalency. The X-chromosome factors appear to be separated by sufficient distance so that, with the DBA/2J-Y chromosome and dominant DBA/2J autosomal factors, there are two recombinant classes of X–Y univalency at 20 and 60%. The genetic factors in the univalency trait may be involved in the regulation or structure of the terminal attachment sites between the X and Y chromosomes.Key words: meiosis, mouse, sex-chromosomal univalency.

Clues from other animals and theoretical considerations

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 3-4
Author(s):  
Anne McLaren
Keyword(s):  
Sex Determination ◽  
Genetic Control ◽  
Y Chromosome ◽  
X Chromosome ◽  
X Chromosomes ◽  
The Third ◽  
Mouse Species ◽  
Primary Male ◽  
Theoretical Considerations ◽  
State Of Activity

In the first two papers of this volume, the genetic control of sex determination in Caenorhabditis and Drosophila is reviewed by Hodgkin and by Nöthiger & Steinmarin-Zwicky, respectively. Sex determination in both cases depends on the ratio of X chromosomes to autosomes, which acts as a signal to a cascade of règulatory genes located either on autosomes or on the X chromosome. The state of activity of the last gene in the sequence determines phenotypic sex. In the third paper, Erickson & Tres describe the structure of the mouse Y chromosome and the polymorphisms that have been detected in different mouse species and strains. As in all mammals, the Y carries the primary male-determining locus; autosomal genes may also be involved in sex determination, but they must act down-stream from the Y-linked locus.

Primary Genetic-Control of Sexual-Differentiation in Marsupials

1989 ◽  
Vol 37 (3) ◽  
pp. 443 ◽  
Author(s):  
G Shaw ◽  
MB Renfree ◽  
RV Short
Keyword(s):  
Genetic Control ◽  
Y Chromosome ◽  
X Chromosome ◽  
Sexual Differentiation ◽  
Hormonal Control ◽  
Sexually Dimorphic ◽  
Processus Vaginalis ◽  
X Chromosomes

Marsupials, like eutherians, normally require the presence of a Y chromosome for testicular formation. However some sexually dimorphic characters such as the scrotum, mammary anlagen, gubernaculum and processus vaginalis appear to be under direct genetic rather than secondary hormonal control. Scrota1 development occurs where only a single X chromosome is functional, whilst two X chromosomes are necessary for pouch formation.

Evolution of a Y Chromosome from an X Chromosome

2019 ◽  
Author(s):  
Roberta Bergero ◽  
Jim Gardner ◽  
Deborah Charlesworth
Keyword(s):  
Y Chromosome ◽  
X Chromosome

GENETIC FACTORS ON THE X CHROMOSOME

The Lancet ◽  
1961 ◽  
Vol 278 (7197) ◽  
pp. 317 ◽  
Author(s):  
J STEWART
Keyword(s):  
X Chromosome ◽  
Genetic Factors

scholarly journals Recombination between the mouse Y chromosome short arm and an additional Y short arm-derived chromosomal segment attached distal to the X chromosome PAR

Chromosoma ◽  
2015 ◽  
Vol 125 (2) ◽  
pp. 177-188
Author(s):  
Fanny Decarpentrie ◽  
Obah A. Ojarikre ◽  
Michael J. Mitchell ◽  
Paul S. Burgoyne
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Chromosomal Segment

Roles of Anti-Müllerian hormone (Amh) and its duplicates in sex determination and germ cell proliferation of Nile tilapia

Genetics ◽  
2021 ◽  
Author(s):  
Xingyong Liu ◽  
Shengfei Dai ◽  
Jiahong Wu ◽  
Xueyan Wei ◽  
Xin Zhou ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sex Determination ◽  
Germ Cell ◽  
Y Chromosome ◽  
X Chromosome ◽  
Nile Tilapia ◽  
Critical Period ◽  
Sex Reversal ◽  
Homozygous Mutation ◽  
Germ Cell Proliferation

Abstract Duplicates of amh are crucial for fish sex determination and differentiation. In Nile tilapia, unlike in other teleosts, amh is located on X chromosome. The Y chromosome amh (amh△-y) is mutated with 5 bp insertion and 233 bp deletion in the coding sequence, and tandem duplicate of amh on Y chromosome (amhy) has been identified as the sex determiner. However, the expression of amh, amh△-y and amhy, their roles in germ cell proliferation and the molecular mechanism of how amhy determines sex is still unclear. In this study, expression and functions of each duplicate were analyzed. Sex reversal occurred only when amhy was mutated as revealed by single, double and triple mutation of the three duplicates in XY fish. Homozygous mutation of amhy in YY fish also resulted in sex reversal. Earlier and higher expression of amhy/Amhy was observed in XY gonads compared with amh/Amh during sex determination. Amhy could inhibit the transcription of cyp19a1a through Amhr2/Smads signaling. Loss of cyp19a1a rescued the sex reversal phenotype in XY fish with amhy mutation. Interestingly, mutation of both amh and amhy in XY fish or homozygous mutation of amhy in YY fish resulted in infertile females with significantly increased germ cell proliferation. Taken together, these results indicated that up-regulation of amhy during the critical period of sex determination makes it the sex-determining gene, and it functions through repressing cyp19a1a expression via Amhr2/Smads signaling pathway. Amh retained its function in controlling germ cell proliferation as reported in other teleosts, while amh△-y was nonfunctionalized.

Genetic and environmental influences on psychological distress in the population: General Health Questionnaire analyses in UK twins

2003 ◽  
Vol 33 (5) ◽  
pp. 793-801 ◽  
Author(s):  
F. V. RIJSDIJK ◽  
H. SNIEDER ◽  
J. ORMEL ◽  
P. SHAM ◽  
D. P. GOLDBERG ◽  
...  
Keyword(s):  
Genetic Control ◽  
General Health ◽  
Genetic Factors ◽  
General Health Questionnaire ◽  
Model Fitting ◽  
Regression Method ◽  
Health Questionnaire ◽  
Twin Data ◽  
Score Distribution ◽  
Shared Genetic

Background. The General Health Questionnaire (GHQ) is the most popular screening instrument for detecting psychiatric disorders in community samples. Using longitudinal data of a large sample of UK twin pairs, we explored (i) heritabilities of the four scales and the total score; (ii) the genetic stability over time; and (iii) the existence of differential heritable influences at the high (ill) and low (healthy) tail of the distribution.Method. At baseline we assessed the GHQ in 627 MZ and 1323 DZ female pairs and at a second occasion (3·5 years later) for a small subsample (90 MZ and 270 DZ pairs). Liability threshold models and raw ordinal maximum likelihood were used to estimate twin correlations and to fit longitudinal genetic models. We estimated extreme group heritabilities of the GHQ distribution by using a model-fitting implementation of the DeFries–Fulker regression method for selected twin data.Results. Heritabilities for Somatic Symptoms, Anxiety, Social Dysfunction, Depression and total score were 0·37, 0·40, 0·20, 0·42 and 0·44, respectively. The contribution of shared genetic factors to the correlations between time points is substantial for the total score (73%). Group heritabilities of 0·48 and 0·43 were estimated for the top and bottom 10% of the total GHQ score distribution, respectively.Conclusion. The overall heritability of the GHQ as a measure of psychosocial distress was substantial (44%), with all scales having significant additive genetic influences that persisted across time periods. Extreme group analyses suggest that the genetic control of resilience is as important as the genetic control of vulnerability.

GENETIC FACTORS ON THE X CHROMOSOME

The Lancet ◽  
1961 ◽  
Vol 278 (7199) ◽  
pp. 434 ◽  
Author(s):  
MaryF. Lyon
Keyword(s):  
X Chromosome ◽  
Genetic Factors
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