scholarly journals Molecular Cytogenetic and Y Copy Number Analysis of a Reciprocal ECAY-ECA13 Translocation in a Stallion with Complete Meiotic Arrest

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1892
Author(s):  
Caitlin Castaneda ◽  
Agustin J. Ruiz ◽  
Ahmed Tibary ◽  
Terje Raudsepp

We present a detailed molecular cytogenetic analysis of a reciprocal translocation between horse (ECA) chromosomes Y and 13 in a Friesian stallion with complete meiotic arrest and azoospermia. We use dual-color fluorescence in situ hybridization with select ECAY and ECA13 markers and show that the translocation breakpoint in ECAY is in the multicopy region and in ECA13, at the centromere. One resulting derivative chromosome, Y;13p, comprises of ECAY heterochromatin (ETSTY7 array), a small single copy and partial Y multicopy region, and ECA13p. Another derivative chromosome 13q;Y comprises of ECA13q and most of the single copy ECAY, the pseudoautosomal region and a small part of the Y multicopy region. A copy number (CN) analysis of select ECAY multicopy genes shows that the Friesian stallion has significantly (p < 0.05) reduced CNs of TSPY, ETSTY1, and ETSTY5, suggesting that the translocation may not be completely balanced, and genetic material is lost. We discuss likely meiotic behavior of abnormal chromosomes and theorize about the possible effect of the aberration on Y regulation and the progression of meiosis. The study adds a unique case to equine clinical cytogenetics and contributes to understanding the role of the Y chromosome in male meiosis.

2011 ◽  
Vol 96 (2) ◽  
pp. E404-E412 ◽  
Author(s):  
S. Benito-Sanz ◽  
E. Barroso ◽  
D. Heine-Suñer ◽  
A. Hisado-Oliva ◽  
V. Romanelli ◽  
...  

abstract Context: Léri-Weill dyschondrosteosis (LWD) is a skeletal dysplasia characterized by disproportionate short stature and the Madelung deformity of the forearm. SHOX mutations and pseudoautosomal region 1 deletions encompassing SHOX or its enhancers have been identified in approximately 60% of LWD and approximately 15% of idiopathic short stature (ISS) individuals. Recently SHOX duplications have been described in LWD/ISS but also in individuals with other clinical manifestations, thus questioning their pathogenicity. Objective: The objective of the study was to investigate the pathogenicity of SHOX duplications in LWD and ISS. Design and Methods: Multiplex ligation-dependent probe amplification is routinely used in our unit to analyze for SHOX/pseudoautosomal region 1 copy number changes in LWD/ISS referrals. Quantitative PCR, microsatellite marker, and fluorescence in situ hybridization analysis were undertaken to confirm all identified duplications. Results: During the routine analysis of 122 LWD and 613 ISS referrals, a total of four complete and 10 partial SHOX duplications or multiple copy number (n &gt; 3) as well as one duplication of the SHOX 5′ flanking region were identified in nine LWD and six ISS cases. Partial SHOX duplications appeared to have a more deleterious effect on skeletal dysplasia and height gain than complete SHOX duplications. Importantly, no increase in SHOX copy number was identified in 340 individuals with normal stature or 104 overgrowth referrals. Conclusion: MLPA analysis of SHOX/PAR1 led to the identification of partial and complete SHOX duplications or multiple copies associated with LWD or ISS, suggesting that they may represent an additional class of mutations implicated in the molecular etiology of these clinical entities.


2014 ◽  
Vol 83 (4) ◽  
pp. 317-323 ◽  
Author(s):  
Maria Virginia Sanchez-Puerta

This review focuses on plant-to-plant horizontal gene transfer (HGT) involving the three DNA-containing cellular compartments. It highlights the great incidence of HGT in the mitochondrial genome (mtDNA) of angiosperms, the increasing number of examples in plant nuclear genomes, and the lack of any convincing evidence for HGT in the well-studied plastid genome of land plants. Most of the foreign mitochondrial genes are non-functional, generally found as pseudogenes in the recipient plant mtDNA that maintains its functional native genes. The few exceptions involve chimeric HGT, in which foreign and native copies recombine leading to a functional and single copy of the gene. Maintenance of foreign genes in plant mitochondria is probably the result of genetic drift, but a possible evolutionary advantage may be conferred through the generation of genetic diversity by gene conversion between native and foreign copies. Conversely, a few cases of nuclear HGT in plants involve functional transfers of novel genes that resulted in adaptive evolution. Direct cell-to-cell contact between plants (e.g. host-parasite relationships or natural grafting) facilitate the exchange of genetic material, in which HGT has been reported for both nuclear and mitochondrial genomes, and in the form of genomic DNA, instead of RNA. A thorough review of the literature indicates that HGT in mitochondrial and nuclear genomes of angiosperms is much more frequent than previously expected and that the evolutionary impact and mechanisms underlying plant-to-plant HGT remain to be uncovered.


2017 ◽  
Author(s):  
Sabrina Z. Jan ◽  
Aldo Jongejan ◽  
Cindy M. Korver ◽  
Saskia K. M. van Daalen ◽  
Ans M. M. van Pelt ◽  
...  

To prevent chromosomal aberrations to be transmitted to the offspring, strict meiotic checkpoints are in place to remove aberrant spermatocytes. However, in about 1% of all males these checkpoints cause complete meiotic arrest leading to azoospermia and subsequent infertility. We here unravel two clearly distinct meiotic arrest mechanisms that act during the prophase of human male meiosis. Type I arrested spermatocytes display severe asynapsis of the homologous chromosomes, disturbed XY-body formation and increased expression of the Y-chromosome encoded gene ZFY and seem to activate a DNA damage pathway leading to induction of p63 mediated spermatocyte elimination. Type II arrested spermatocytes display normal chromosome synapsis, normal XY-body morphology and meiotic crossover formation but have a lowered expression of several cell cycle regulating genes and fail to properly silence the X-chromosome encoded gene ZFX. Discovery and understanding of these meiotic arrest mechanisms increases our knowledge on how genomic stability is guarded during human germ cell development.


Genetics ◽  
1992 ◽  
Vol 132 (1) ◽  
pp. 221-228 ◽  
Author(s):  
J R Brown ◽  
A T Beckenbach ◽  
M J Smith

Abstract Southern blot analysis was used to quantify the extent of mtDNA D-loop length variation in two populations of white sturgeon, Acipenser transmontanus. Over 42% of individuals were heteroplasmic for up to six different mtDNA length variants attributable to varying copy numbers of an 82-bp repeat sequence. Chi-square analyses revealed that the frequencies of length genotypes and the incidence of heteroplasmy were significantly different between Fraser and Columbia River sturgeon populations but not between restriction site haplotypes. Heteroplasmic fish have, on average, higher copy number than homoplasmic fish. Forty-five of 101 homoplasmic individuals carry only a single copy of the repeat, while none of the 73 heteroplasmic fish has the single repeat as the predominant variant. On the basis of differences in frequency distributions of copy number within and between fish, we suggest that (1) heteroplasmy is maintained by high recurrent mutation of multiple copy genomes, favoring increased copy number and (2) the mutation pressure toward higher copy number heteroplasmy is partially offset by selection to reduced genome size and segregation to the homoplasmic condition.


Animals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Ting Sun ◽  
Quratulain Hanif ◽  
Hong Chen ◽  
Chuzhao Lei ◽  
Ruihua Dang

Copy number variation (CNV), a significant source of genetic diversity in the mammalian Y chromosome, is associated with the development of many complex phenotypes, such as spermatogenesis and male fertility. The contribution of Y-linked CNVs has been studied in various species, however, water buffalo has not been explored in this area and the genetic information still remains unknown. The aim of the current study was to investigate the CNVs of four Y-linked genes, including, sex determining Region of Y-Chromosome (SRY), ubiquitously transcribed tetratricopeptide repeat gene protein on the chromosome Y (UTY), DEAD-box helicase 3 Y-linked (DDX3Y, also known as DBY), and oral-facial-digital syndrome 1 Y-linked (OFD1Y) in 254 swamp buffaloes from 15 populations distributed across China, Vietnam, and Laos using quantitative real-time PCR (qPCR). Our results revealed the prevalence of a single-copy UTY gene in buffaloes. The DBY and OFD1Y represented CNVs among and within different buffalo breeds. The SRY showed CNVs only in Vietnamese and Laotian buffaloes. In conclusion, this study indicated that DBY, OFD1Y, and SRY showed CNVs, while the UTY was a single-copy gene in swamp buffaloes.


2020 ◽  
Vol 12 (11) ◽  
pp. 1961-1964
Author(s):  
Maki Fukami ◽  
Yasuko Fujisawa ◽  
Hiroyuki Ono ◽  
Tomoko Jinno ◽  
Tsutomu Ogata

Abstract Mammalian male meiosis requires homologous recombination between the X and Y chromosomes. In humans, such recombination occurs exclusively in the short arm pseudoautosomal region (PAR1) of 2.699 Mb in size. Although it is known that complete deletion of PAR1 causes spermatogenic arrest, no studies have addressed to what extent male meiosis tolerates PAR1 size reduction. Here, we report two families in which PAR1 partial deletions were transmitted from fathers to their offspring. Cytogenetic analyses revealed that a ∼400-kb segment at the centromeric end of PAR1, which accounts for only 14.8% of normal PAR1 and 0.26% and 0.68% of the X and Y chromosomes, respectively, is sufficient to mediate sex chromosomal recombination during spermatogenesis. These results highlight the extreme recombinogenic activity of human PAR1. Our data, in conjunction with previous findings from animal studies, indicate that the minimal size requirement of mammalian PARs to maintain male fertility is fairly small.


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