scholarly journals The detection of female cell activity in male sex chromosome chimeric Rideau Arcott sheep, using the Xist gene product as a marker

SURG Journal ◽  
2008 ◽  
Vol 1 (2) ◽  
pp. 20-25
Author(s):  
Okimi Peters ◽  
W. Allan King
Keyword(s):  
Y Chromosome ◽  
Sex Chromosome ◽  
Cell Activity ◽  
Xist Gene ◽  
Specific Gene ◽  
Xist Expression ◽  
Female Cell ◽  
Male Sex ◽  
Polymerase Chain ◽  
Xy Female

The detection of the SRY (Sex-determining region on the Y chromosome) gene is a popular method used for the identification of freemartins (XX/XY female chimeras). This method relies on the fact that the SRY gene is a Y chromosome specific gene and is thus normally only present in males therefore detecting its presence in a female indicates the presence of male cells (XY cells) within the female. This concept can be extrapolated to the male counterparts of freemartins with regards to the Xist gene. This gene is normally only widely expressed in females and can be used as a marker for identifying females. Therefore, detecting Xist gene expression in males (in tissues other than the testes, as the Xist gene is expressed exclusively in the testes of males) may indicate that these males contain transcriptionally competent female cells and thus necessarily labels them as sex-chromosome chimeras. In the present study four previously identified male sex chromosome chimeras were screened for the expression of the Xist gene using reverse transcription Polymerase Chain Reaction (PCR), and it was detected in three of the four chimeras. Xist expression was not detected in one of the chimeras because the proportion of female cells in its blood is significantly low and thus it is likely that the blood sample used in the study did not possess female cells. None-the-less it was concluded that the detection of Xist expression in male sex chromosome chimeras can be used as an indication of the presence and transcriptional competence of female cells within them.

XY female mice resulting from a heritable mutation in the primary testis-determining gene, Tdy

Development ◽  
1990 ◽  
Vol 109 (3) ◽  
pp. 635-646 ◽  
Author(s):  
R. Lovell-Badge ◽  
E. Robertson
Keyword(s):  
Y Chromosome ◽  
Southern Blotting ◽  
Es Cells ◽  
Embryonic Stem ◽  
Chromosome Analysis ◽  
Specific Gene ◽  
Es Cell ◽  
Karyotypic Analysis ◽  
Testis Determination ◽  
Xy Female

Chimeric mice constructed with XY embryonic stem (ES) cells that had been multiply infected with a retroviral vector were used in a genetic screen to look for mutations affecting the sex determination pathway in mice. From a small number of chimeras screened one was identified that gave rise to a low proportion of XY females amongst his offspring. Analysis of the segregating patterns of retroviral insertions demonstrated that the mutation was found in a subset of the offspring derived from one originally infected ES cell. However, the mutation appeared to have occurred subsequent to the infection. Some of the XY females proved to be fertile, and the mutant phenotype was found to segregate exclusively with the Y chromosome. Analysis of the offspring also confirmed the absence of any retroviral insertion that could be correlated with the mutation. Further characterisation of the Y chromosome carrying the mutation by karyotypic analysis, and by Southern blotting with a range of Y-specific DNA probes suggested that there has been no gross deletion or rearrangement of the Y carrying the mutation. There also appeared to be no loss of Y-specific gene functions apart from that of testis determination. Moreover, the mutation is complemented by Sxr', the minimum portion of the mouse Y known to carry Tdy. From the phenotype and deduced location of the mutation, we conclude that it is within the Tdy locus. This is the first such mutation to be described in mice.

scholarly journals Effect of the pH in the enrichment of X or Y sex chromosome-bearing sperm in bovine

2019 ◽  
Vol 12 (8) ◽  
pp. 1299-1303 ◽  
Author(s):  
Nidhi P. Raval ◽  
Tejas M. Shah ◽  
Linz-Buoy George ◽  
Chaitanya G. Joshi
Keyword(s):  
Polymerase Chain Reaction ◽  
Y Chromosome ◽  
Sex Chromosome ◽  
Bos Indicus ◽  
Dna Probe ◽  
Chain Reaction ◽  
Sperm Sample ◽  
Bottom Fraction ◽  
Polymerase Chain ◽  
Digital Polymerase Chain Reaction

Background and Aim: Studies have shown that the pH of the vagina during the course of fertilization may influence the migration of X- and Y-bearing spermatozoa and thus leading to skewness in the sex of the offspring. Hence, this study was carried out to check the effect of the pH in the enrichment of X or Y sex chromosome-bearing sperm in bovine (Bos indicus). Materials and Methods: To check the effect of pH in the enrichment of X or Y sex chromosome-bearing sperm in bovine, we used buffers of various pH ranging from 5.5 to 9.0 for swim-up procedure of sperm sample and collected upper and bottom fraction from the same buffer and checked the abundance of X- and Y-bearing spermatozoa by droplet digital polymerase chain reaction using X- and Y-chromosome-specific DNA probe. Results: The abundance of X- and Y-bearing spermatozoa was not differed significantly in either of the fraction collected. Conclusion: Thus, it appears to be unlikely that an immediate impact of pH on sperm can be a solitary impact on the sex of offspring in bovine. Keywords: droplet digital polymerase chain reaction, spermatozoa, swim-up.

scholarly journals Isolation of Y Chromosome-Specific Sequences From Silene latifolia and Mapping of Male Sex-Determining Genes Using Representational Difference Analysis

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1893-1901 ◽  
Author(s):  
Iain S Donnison ◽  
Jiri Siroky ◽  
Boris Vyskot ◽  
Heinz Saedler ◽  
Sarah R Grant
Keyword(s):  
Y Chromosome ◽  
Sex Chromosome ◽  
Silene Latifolia ◽  
Representational Difference Analysis ◽  
Chromosomal Dna ◽  
Restriction Fragments ◽  
Difference Analysis ◽  
Specific Restriction ◽  
Male Sex ◽  
Male Specific

The genomic subtraction method representational difference analysis (RDA) was used to identify male-specific restriction fragments in the dioecious plant Silene latifolia. Male-specific restriction fragments are linked to the male sex chromosome (the Y chromosome). Four RDA-derived male-specific restriction fragments were used to identify polymorphisms in a collection of X-ray-generated mutant plants with either hermaphroditic or asexual flowers. Some of the mutants have cytologically detectable deletions in the Y chromosome that were correlated with loss of male-specific restriction fragments. One RDA-derived probe detected a restriction fragment present in all mutants, indicating that each has retained Y chromosomal DNA. The other three probes detected genomic fragments that were linked in a region deleted in some hermaphroditic and some asexual mutants. Based on the mutant phenotypes and the correlation of cytologically visible deletions with loss of male-specific restriction fragments, these markers were assigned to positions on the Y chromosome close to the carpel suppression locus. This RDA mapping also revealed a Y-linked locus, not previously described, which is responsible for early stamen development.

scholarly journals PCR vs karyotype for CVS and amniocentesis—the experience at one tertiary fetal medicine unit

2021 ◽  
Author(s):  
Catherine Finnegan ◽  
Suzanne Smyth ◽  
Orla Smith ◽  
Karen Flood ◽  
Jane Dalrymple ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
Pregnancy Termination ◽  
Normal Pregnancy ◽  
Screening Tests ◽  
Fetal Medicine ◽  
Non Invasive ◽  
Fetal Aneuploidy ◽  
Polymerase Chain ◽  
Normal Ultrasound ◽  
Fetal Karyotype

Abstract Purpose Despite the rise of non-invasive screening tests for fetal aneuploidy, invasive testing during pregnancy remains the definitive diagnostic tool for fetal genetic anomalies. Results are rapidly available with polymerase chain reaction (PCR) tests, but cases have been reported whereby initial results were not confirmed after pregnancy termination and the fetal karyotype was ultimately normal. We sought to examine the potential discordance between PCR and karyotype for fetal aneuploidy. Methods The results from all amniocentesis and CVS tests performed over a 6-year period in a large tertiary level fetal medicine unit were reviewed. The results of PCR and karyotype were recorded and discrepancies examined. Pregnancy outcomes were also recorded. Results A total of 1222 invasive tests were performed (716 amniocentesis and 506 CVS). Within the cohort having amniocentesis, 11 had discrepant results (normal QF-PCR result but with a subsequent abnormal karyotype). There was 1 case among this group which QF-PCR should have identified. Within the CVS group, 7 patients had discrepant results. All had a diploid QF-PCR and would not have been identified as abnormal by it. Conclusion PCR can be reliably used to determine aneuploidy of chromosomes 13, 18, and 21. However, in cases of sex chromosome aneuploidy, its performance is less reliable and warrants waiting for a complete karyotype. Given such discordance, we advise waiting for karyotype for all invasive tests performed in the presence of a normal ultrasound before advising a patient of a diploid QF-PCR result or potentially terminating a normal pregnancy.

Detection of specific mRNAs in single nephron segments by use of the polymerase chain reaction

1990 ◽  
Vol 258 (5) ◽  
pp. F1470-F1474 ◽  
Author(s):  
T. Moriyama ◽  
H. R. Murphy ◽  
B. M. Martin ◽  
A. Garcia-Perez
Keyword(s):  
Polymerase Chain Reaction ◽  
Aldose Reductase ◽  
Collecting Duct ◽  
Specific Gene ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Nephron Segments ◽  
Single Nephron ◽  
Specific Mrnas ◽  
Polymerase Chain

We have developed a procedure to detect specific mRNAs in single renal nephron segments. This approach combines microdissection, reverse transcription (RT) of the target mRNA, and amplification of the resulting cDNA using the polymerase chain reaction (PCR). After microdissection, the sample is placed in a tube where it is permeabilized and where all reactions are performed directly without the need for isolation of the RNA. Our model target was the mRNA for aldose reductase. This enzyme catalyzes the conversion of glucose to sorbitol. Its expression is modulated by changes in extracellular osmolality in the renal medulla. RT-PCR of inner medullary collecting duct (1 mm) and glomeruli (6-10) yielded a product of the predicted length (670 base pairs) defined by the PCR primers. Its identity was confirmed by a specific oligonucleotide probe that differed from the primers. RT-PCR of proximal tubules (1 mm) resulted in no aldose reductase-specific amplification product. RT-PCR is generally applicable for measuring specific gene expression in single nephron segments or small numbers of cultured cells. Utility, limitations, and refinements of this approach are discussed.

scholarly journals X and Y Chromosome Complement Influence Adiposity and Metabolism in Mice

Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1092-1104 ◽  
Author(s):  
Xuqi Chen ◽  
Rebecca McClusky ◽  
Yuichiro Itoh ◽  
Karen Reue ◽  
Arthur P. Arnold
Keyword(s):  
Body Weight ◽  
Y Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Gonadal Hormones ◽  
Xy Model ◽  
Second Sex ◽  
Metabolic Variables ◽  
Novel Model

Abstract Three different models of MF1 strain mice were studied to measure the effects of gonadal secretions and sex chromosome type and number on body weight and composition, and on related metabolic variables such as glucose homeostasis, feeding, and activity. The 3 genetic models varied sex chromosome complement in different ways, as follows: 1) “four core genotypes” mice, comprising XX and XY gonadal males, and XX and XY gonadal females; 2) the XY* model comprising groups similar to XO, XX, XY, and XXY; and 3) a novel model comprising 6 groups having XO, XX, and XY chromosomes with either testes or ovaries. In gonadally intact mice, gonadal males were heavier than gonadal females, but sex chromosome complement also influenced weight. The male/female difference was abolished by adult gonadectomy, after which mice with 2 sex chromosomes (XX or XY) had greater body weight and percentage of body fat than mice with 1 X chromosome. A second sex chromosome of either type, X or Y, had similar effects, indicating that the 2 sex chromosomes each possess factors that influence body weight and composition in the MF1 genetic background. Sex chromosome complement also influenced metabolic variables such as food intake and glucose tolerance. The results reveal a role for the Y chromosome in metabolism independent of testes and gonadal hormones and point to a small number of X–Y gene pairs with similar coding sequences as candidates for causing these effects.

A supernumerary “B-sex” chromosome drives male sex determination in the Pachón cavefish, Astyanax mexicanus

2021 ◽  
Author(s):  
Boudjema Imarazene ◽  
Kang Du ◽  
Séverine Beille ◽  
Elodie Jouanno ◽  
Romain Feron ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Astyanax Mexicanus ◽  
Male Sex

scholarly journals Telomere-to-telomere assembly of a fish Y chromosome reveals the origin of a young sex chromosome pair

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lingzhan Xue ◽  
Yu Gao ◽  
Meiying Wu ◽  
Tian Tian ◽  
Haiping Fan ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Pair ◽  
Sex Chromosome ◽  
Structural Variations ◽  
Recombination Suppression ◽  
Chromosome Differentiation ◽  
Y Chromosomes ◽  
Recent Origin ◽  
Mastacembelus Armatus

Abstract Background The origin of sex chromosomes requires the establishment of recombination suppression between the proto-sex chromosomes. In many fish species, the sex chromosome pair is homomorphic with a recent origin, providing species for studying how and why recombination suppression evolved in the initial stages of sex chromosome differentiation, but this requires accurate sequence assembly of the X and Y (or Z and W) chromosomes, which may be difficult if they are recently diverged. Results Here we produce a haplotype-resolved genome assembly of zig-zag eel (Mastacembelus armatus), an aquaculture fish, at the chromosomal scale. The diploid assembly is nearly gap-free, and in most chromosomes, we resolve the centromeric and subtelomeric heterochromatic sequences. In particular, the Y chromosome, including its highly repetitive short arm, has zero gaps. Using resequencing data, we identify a ~7 Mb fully sex-linked region (SLR), spanning the sex chromosome centromere and almost entirely embedded in the pericentromeric heterochromatin. The SLRs on the X and Y chromosomes are almost identical in sequence and gene content, but both are repetitive and heterochromatic, consistent with zero or low recombination. We further identify an HMG-domain containing gene HMGN6 in the SLR as a candidate sex-determining gene that is expressed at the onset of testis development. Conclusions Our study supports the idea that preexisting regions of low recombination, such as pericentromeric regions, can give rise to SLR in the absence of structural variations between the proto-sex chromosomes.

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