In situ Localization of (GATA)n and (TTAGGG)n Repeated DNAs and W Sex Chromosome Differentiation in Parodontidae (Actinopterygii: Characiformes)

2015 ◽  
Vol 144 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Kaline Ziemniczak ◽  
Josiane B. Traldi ◽  
Viviane Nogaroto ◽  
Mara C. Almeida ◽  
Roberto F. Artoni ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
Chromosome Differentiation ◽  
Repeated Dnas

Monotreme Genetics and Cytology and a Model for Sex-Chromosome Evolution

1989 ◽  
Vol 37 (3) ◽  
pp. 385 ◽  
Author(s):  
JM Watson
Keyword(s):  
X Chromosome ◽  
Sex Chromosome ◽  
In Situ Hybridisation ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Gene Location ◽  
Control Mechanisms ◽  
Syntenic Group ◽  
Chromosome Differentiation

The protherian mammals consist of three species: the platypus, the Australian echidna and the Niugini echidna. These mammals diverged from the therian line of descent about 150-200 million years ago; hence comparisons of gene arrangements and gene control mechanisms between prototherian and therian mammals may yield significant data about gene rearrangements during mammalian evolution and about the evolution of complex genetic control systems. The chromosome complements of the three monotreme species are highly conserved. In particular, the X (or X1) chromosomes are G-band identical and share considerable G-band homology with the Y chromosomes. Replication asynchrony between X chromosomes suggests that X chromosome inactivation operates in females, and is apparently tissue- specific (as it is in marsupials), and confined to the differential region of the X (X1) chromosome (as it is in eutherian mammals). These results suggest that sex chromosome differentiation in the monotremes represents an intermediate stage in the evolution of the dimorphic sex chromosomes of therian mammals and that X-chromosome inactivation may also represent a comparatively primitive stage. Studies of gene location in the platypus using platypus-rodent cell hybrids suggested that HPRT and PGK are syntenic in the platypus, but it was not possible to assign the syntenic group to a particular chromosome. In situ hybridisation was used to assign three genes, located on the X in eutherians and marsupials, to the monotreme X. However, human X short-arm markers were found by in situ hybridisation to be autosomal in monotremes (as they are in marsupials). A model for the evolution of mammalian sex chromosome differentiation and X-chromosome inactivation is presented in which a gradual reduction of the Y chromosome, and recruitment of newly unpaired loci on the X into a system of X-chromosome inactivation, has accompanied eutherian evolution.

Fluorescence In Situ Hybridization Analysis of Sex-Chromosome Mosaicism in Azoospermic Men

2001 ◽  
Vol 22 (6) ◽  
pp. 970-972 ◽  
Author(s):  
HIROSHI OKADA ◽  
MASAKI DOBASHI ◽  
TAKAFUMI YAMAZAKI ◽  
MASATO FUJISAWA ◽  
SOICHI ARAKAWA ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Sex Chromosome ◽  
Hybridization Analysis ◽  
Chromosome Mosaicism

scholarly journals Rapid and simple prenatal diagnosis of common chromosome disorders: advantages and disadvantages of the molecular methods FISH and QF-PCR

Reproduction ◽  
2003 ◽  
pp. 279-297 ◽  
Author(s):  
MA Hulten ◽  
S Dhanjal ◽  
B Pertl
Keyword(s):  
Prenatal Diagnosis ◽  
Sex Chromosome ◽  
Chromosome Analysis ◽  
Maternal Serum ◽  
Molecular Techniques ◽  
Maternal Serum Screening ◽  
Advantages And Disadvantages ◽  
Microscopy Analysis ◽  
Chromosome Disorder

Molecular techniques have been developed for prenatal diagnosis of the most common chromosome disorders (trisomies 21, 13, 18 and sex chromosome aneuploidies) where results are available within a day or two. This involves fluorescence in situ hybridization (FISH) and microscopy analysis of fetal cells or quantitative fluorescence polymerase chain reaction (QF-PCR) on fetal DNA. Guidance is provided on the technological pitfalls in setting up and running these methods. Both methods are reliable, and the risk for misdiagnosis is low, although slightly higher for FISH. FISH is also more labour intensive than QF-PCR, the latter lending itself more easily to automation. These tests have been used as a preamble to full chromosome analysis by microscopy. However, there is a trend to apply the tests as 'stand-alone' tests for women who are at relatively low risk of having a baby with a chromosome disorder, in particular that associated with advanced age or results of maternal serum screening programmes. These women comprise the majority of those currently offered prenatal diagnosis with respect to fetal chromosome disorders and if introduced on a larger scale, the use of FISH and QF-PCR would lead to substantial economical savings. The implication, on the other hand, is that around one in 500 to one in 1000 cases with a mentally and/or physically disabling chromosome disorder would remain undiagnosed.

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.

scholarly journals Sex chromosome differentiation in Belostoma (Insecta: Heteroptera: Belostomatidae)

2012 ◽  
Vol 11 (3) ◽  
pp. 2476-2486 ◽  
Author(s):  
V.B. Bardella ◽  
A.L. Dias ◽  
L. Giuliano-Caetano ◽  
J.R.I. Ribeiro ◽  
R. da Rosa
Keyword(s):  
Sex Chromosome ◽  
Chromosome Differentiation

Analysis of BAC clones containing homologous sequences on the end of the Xq arm and on chromosome 7 in the dioecious plant Silene latifolia

Genome ◽  
2010 ◽  
Vol 53 (4) ◽  
pp. 311-320 ◽  
Author(s):  
Kotaro Ishii ◽  
Yasuhito Amanai ◽  
Yusuke Kazama ◽  
Miho Ikeda ◽  
Hiroshi Kamada ◽  
...  
Keyword(s):  
Satellite Dna ◽  
Sex Chromosome ◽  
Artificial Chromosome ◽  
Chromosome 7 ◽  
Silene Latifolia ◽  
Dioecious Plant ◽  
Homologous Sequences ◽  
Autosomal Region ◽  
Single Primer

Silene latifolia is a model dioecious plant with morphologically distinguishable XY sex chromosomes. The end of the Xq arm is quite different from that of the Yp arm, although both are located at opposite ends of their respective chromosomes relative to a pseudo-autosomal region. The Xq arm does not seem to originate from the same autosome as the Yp arm. Bacterial artificial chromosome clone #15B12 has an insert containing a 130-kb stretch in which a 313-bp satellite DNA is repeated 420 times. PCR with a single primer revealed that this 130-kb stretch consists of three reversals of the orientation of the satellite DNA. A non-long terminal repeat retroelement and two sequences that share homology with an Oryza sativa RING zinc finger and a putative Arabidopsis thaliana protein, respectively, were found in the sequences that flank the satellite DNA. Fluorescence in situ hybridization carried out using this low-copy region of #15B12 as a probe confirmed that these sequences originated from the X chromosome and that homologous sequences exist at the end of chromosome 7. The region distal to DD44X on the Xq arm is postulated to have recombined with a region containing satellite DNA on chromosome 7 during the process of sex chromosome evolution.

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