Polymorphism of the X-chromosome, Y-chromosome and autosomes in the Australian hopping mice, Notomys alexis, N. cervinus and N. fuscus (Rodentia, Muridae)

Chromosoma ◽  
1977 ◽  
Vol 61 (3) ◽  
pp. 243-256 ◽  
Author(s):  
P. R. Baverstock ◽  
C. H. S. Watts ◽  
Jane T. Hogarth
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Chromosome Y

scholarly journals First Report on Karyotypic, Morphometric and Meiotic Analysis of a Predatory Bombardier Beetle Pherosophus catoirai (Coleoptera: Carabidae) from Jammu region of Outer Himalayas, India

2021 ◽  
Vol 18 (4) ◽  
pp. 817-822
Author(s):  
Arshad Ayoub Bhatti ◽  
Nidhi Slathia ◽  
Manvi K
Keyword(s):  
Chromosome Number ◽  
Y Chromosome ◽  
X Chromosome ◽  
Chromosome Complement ◽  
Diploid Chromosome Number ◽  
Meiotic Analysis ◽  
Chromosome Y ◽  
First Report ◽  
Metaphase Stage ◽  
Spermatogonial Metaphase

Chromosomal studies and manual karyotyping are the aged techniques for determining the identity of a species on evolutionary scale; however, these techniques are simple, reliable and inexpensive to authenticate the existence of a particular species. In the present work, the chromosome complement and meiotic processes of a predatory bombardier beetle Pherosophus catoirai were investigated. This species presented 2n=35 as diploid chromosome number and the chromosomal formula was found to be 12m+8sm+12st+X0. Sex mechanism was X0 type with metacentric X chromosome. Y chromosome was absent in this species. Karyotype revealed small chromosomes except X chromosome which is found to be largest in the spermatogonial metaphase stage. Meiotic stages were pachytene, diplotene, diakinesis and metaphase-I. Present study may find importance to analyse evolution of chromosomes in order Coleoptera particularly in family Carabidae.

Heterochromatin organization in the nucleus of Indian muntjac (Muntiacus muntjak)

1986 ◽  
Vol 28 (4) ◽  
pp. 628-630 ◽  
Author(s):  
Ram S. Verma ◽  
Jessey P. Jacob ◽  
Arvind Babu
Keyword(s):  
Restriction Endonuclease ◽  
Y Chromosome ◽  
X Chromosome ◽  
General Pattern ◽  
Banding Technique ◽  
Chromosome Y ◽  
Heterochromatic Segment ◽  
Indian Muntjac ◽  
Muntiacus Muntjak

The heterochromatin in Indian muntjac (Muntiacus muntjak) is located at the periphery of primary constrictions of all the chromosomes. The X chromosome contains significantly larger amounts of heterochromatin than the rest of the complement by C-banding technique. However, the small portion of C-band region was found to be resistant by restriction endonuclease HaeIII (5′… GG ↓ CC … 3′) and was clearly visible on the nucleus. Therefore, the position of this large heterochromatic segment is examined at somatic metaphases. The distribution of the heterochromatin of the X chromosome observed in Indian muntjac is contrary to the general pattern observed in other species, i.e., the chromosomes consisting greater amount of heterochromatin are located more peripherally than those with lesser amount. However, the smaller Y chromosome (Y1) is frequently found at the periphery. The present findings suggest that the role of heterochromatin organization in the nucleus vary between different heterochromatic segments of the same species and vary from species to species.Key words: heterochromatin, chromosome, nucleus, metaphase, Muntiacus muntjak.

Evolution of a Y Chromosome from an X Chromosome

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

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.

Somatically Acquired Isodicentric Y and Mosaic Loss of Chromosome Y in a Boy with Hypospadias

2018 ◽  
Vol 154 (3) ◽  
pp. 122-125 ◽  
Author(s):  
Mami Miyado ◽  
Koji Muroya ◽  
Momori Katsumi ◽  
Kazuki Saito ◽  
Masafumi Kon ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Cytogenetic Analysis ◽  
Chromosomal Rearrangements ◽  
Related Phenomenon ◽  
Limited Evidence ◽  
Elderly Men ◽  
Chromosome Y ◽  
Chromosomal Genes

Isodicentric Y chromosome [idic(Y)] represents a relatively common subtype of Y chromosomal rearrangements in the germline; however, limited evidence supports the postzygotic occurrence of idic(Y). Here, we report a boy with hypospadias and somatically acquired idic(Y). The 3.5-year-old boy has been identified in our previous study for patients with hypospadias. In the present study, cytogenetic analysis including FISH revealed a 45,X[5]/46,X,idic(Y)[7]/46,XY[8] karyotype. MLPA showed a mosaic deletion involving PPP1R12BP1 and RBMY2DP. The idic(Y) was likely to have been formed through aberrant recombination between P1 palindromes and subsequently underwent mosaic loss. The patient's phenotype was attributable to deletion of some Y chromosomal genes and/or mosaic loss of chromosome Y (mLOY). The results suggest that idic(Y) can originate in postzygotic cells via palindrome-mediated crossovers. Moreover, our data indicate that somatically acquired idic(Y) can trigger mLOY, which usually appears as an aging-related phenomenon in elderly men.

scholarly journals Immune defects and cardiovascular risk in X chromosome monosomy mosaicism mediated by loss of chromosome Y. A risk factor for SARS-CoV-2 vulnerability in elderly men?

2020 ◽  
Author(s):  
Luis A. Pérez-Jurado ◽  
Alejandro Cáceres ◽  
Tonu Esko ◽  
Juan R. González
Keyword(s):  
Cardiovascular Risk ◽  
X Chromosome ◽  
Large Scale ◽  
Case Fatality ◽  
Peripheral Blood Cell ◽  
Coagulation Activity ◽  
Chromosome Y ◽  
Immune System Dysfunction ◽  
Cell Counts ◽  
Multiple Biomarkers

AbstractThe ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) has an estimated overall case fatality ratio of 1.38% in China, being 53% higher in males and increasing exponentially with age. Mosaicism for X chromosome monosomy (XCM) shows a similar increase in aging population mostly driven by loss of chromosome Y in males (LOY), and is associated with a raise in all-cause mortality. Using comparative transcriptomic data, we have defined that XCM/LOY is associated with abnormal peripheral blood cell counts with decreased progenitor cells and multiple biomarkers of immune system dysfunction, pro-coagulation activity and increased cardiovascular risk. Several differentially down-regulated genes in XCM/LOY individuals are involved in the initial immune response to SARS-CoV-2 (OR of enrichment=7.23, p=1.5×10−7), mainly interferon-induced genes that code for inhibitors of viral processes. Thus, our data suggest that XCM mosaicism underlies at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential relevance for modulating prognosis and therapeutic response, we propose that evaluation of LOY and XCM by currently established methods should be implemented as biomarkers in infected patients, including currently ongoing clinical trials with different medications and vaccines for COVID-19. Testing for LOY/XCM at large scale among elderly people may also be helpful to identify still unexposed people who may be especially vulnerable to severe Covid-19 disease.

scholarly journals Chromosome Y Isodicentrics in two Cases with Ambiguous genitalia and Features of Turner Syndrome

2008 ◽  
Vol 11 (2) ◽  
pp. 51-58
Author(s):  
A Lungeanu ◽  
A Arghir ◽  
S Arps ◽  
G Cardos ◽  
N Dumitriu ◽  
...  
Keyword(s):  
Turner Syndrome ◽  
Y Chromosome ◽  
Ambiguous Genitalia ◽  
Peripheral Blood Lymphocytes ◽  
Chromosome Y ◽  
Y Chromosomes ◽  
New Information ◽  
Pathway Perturbation

Chromosome Y Isodicentrics in two Cases with Ambiguous genitalia and Features of Turner SyndromeKaryotype investigations using classical cytogenetics, fluorescencein situhybridization (FISH) and polymerase chain reaction (PCR) techniques were used for the characterization of Y chromosome structural anomalies found in two patients with ambiguous genitalia and features of Turner syndrome. Both exhibited mosaic karyotypes of peripheral blood lymphocytes. The karyotype was 45, X[90]/ 46, X, idic(Y)(p11.3).ish idic(Y) (wcpY+, DXYS130++,SRY++,DYZ3++,DYZ1++, DYS224++)[10] in one case, and the karyotype was 45, X[65]/46, X, idic(Y) (q11).ish idic(Y)(SRY++, RP11-140H23-)[35] in the other case. Derivative Y chromosomes were different in shape and size and positive for the SRY gene, a common underlying element of ambiguous genitalia phenotypes. These results add new information concerning the role of Y chromosome structural abnormalities in sex determination pathway perturbation which are poorly understood, and highlight the importance of the sex chromosomes integrity for a normal sex phenotype development.

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