scholarly journals Spot Urine for Sex Determination Forensic Identifications with Amelogenin Locus and Y chromosomes (DYS 19). Bercak Urin untuk Identifikasi Forensik Jenis Kelamin dengan Lokus Amelogenin dan Y Kromosom (DYS19)

2018 ◽  
Vol 20 (3) ◽  
pp. 180
Author(s):  
Yeti Eka Sispita Sari

AbstractBackground:  Amelogenin gene was a single copy gene located in an X chromosome and a Y chromosome. The location of amelogenin gene for identification of sex chromosome has good variability between the form and the shape of the X chromosome and the Y chromosome and between Amelogenin alleles among different populations. Purpose: To prove urine spot examination on the results of the sex determination through Deoxyribo Nucleid Acid (DNA) isolation using amelogenin and Y chromosome loci (DYS19). Methods: Spotting the microscopic examination of urine samples to determine the presence or absence of urethral epithelial cells, followed by isolation Deoxyribo nucleid Acid (DNA) in order to determine the extent and purity of DNA amplification. Then performed Polymerase Chain Reaction (PCR) amelogenin locus at 106bp - 112bp and Y chromosomes (DYS19) at 232 -268 bp. Results: in 9 samples of men from 3 families with 3 kinship of different regions shows the results of different tests, because Amel Y variation between individual and populations method of determining the sex of 100% was inaccurate. In some men Amel Y can be removed entirely. This research should be visualized one band on the Y chromosome (DYS19) and the Amelogenin two bands during electrophoresis occurs misidentification of the sample as a woman. Conclusions: Identification of sex using Amelogenin locus and Y chromosomes (DYS19) has six identical and ambiguous results because the two samples shown as the sign of men but visualized as women, another sample was not visualized because of the thick level and concentration of Deoxyribo nucleid Acid (DNA).Keywords: Urine Spot, Sex Determination, Amelogenin, Y chromosome (DYS19).

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 39-39
Author(s):  
P. N. Goodfellow

DNA probes isolated from the human Y chromosome have been used to resolve two fundamental problems concerning the biology of sex determination in man. Coincidentally, resolution of these problems has generated genetic maps of the short arm of the human Y chromosome and has allowed the regional localization of TDF. The first problem to be solved was the origin of XX males (de la Chapelle, this symposium): the majority of XX males are caused by a telomeric exchange between the X and Y chromosomes that results in TDF and a variable amount of Y-derived material being transferred to the X chromosome. The differing amounts of Y-derived material present in XX males has been used as the basis of a ‘deletion’ map of the Y chromosome (Müller; Ferguson-Smith & Affara; this symposium).


Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1770
Author(s):  
Paul A. Saunders ◽  
Frédéric Veyrunes

Therian mammals have among the oldest and most conserved sex-determining systems known to date. Any deviation from the standard XX/XY mammalian sex chromosome constitution usually leads to sterility or poor fertility, due to the high differentiation and specialization of the X and Y chromosomes. Nevertheless, a handful of rodents harbor so-called unusual sex-determining systems. While in some species, fertile XY females are found, some others have completely lost their Y chromosome. These atypical species have fascinated researchers for over 60 years, and constitute unique natural models for the study of fundamental processes involved in sex determination in mammals and vertebrates. In this article, we review current knowledge of these species, discuss their similarities and differences, and attempt to expose how the study of their exceptional sex-determining systems can further our understanding of general processes involved in sex chromosome and sex determination evolution.


2014 ◽  
Author(s):  
Benjamin M Skinner ◽  
Carole A Sargent ◽  
Carol Churcher ◽  
Toby Hunt ◽  
Javier Herrero ◽  
...  

We have generated an improved assembly and gene annotation of the pig X chromosome, and a first draft assembly of the pig Y chromosome, by sequencing BAC and fosmid clones, and incorporating information from optical mapping and fibre-FISH. The X chromosome carries 1,014 annotated genes, 689 of which are protein-coding. Gene order closely matches that found in Primates (including humans) and Carnivores (including cats and dogs), which is inferred to be ancestral. Nevertheless, several protein-coding genes present on the human X chromosome were absent from the pig (e.g. the cancer/testis antigen family) or inactive (e.g. AWAT1), and 38 pig-specific X-chromosomal genes were annotated, 22 of which were olfactory receptors. The pig Y chromosome assembly focussed on two clusters of male-specific low-copy number genes, separated by an ampliconic region including the HSFY gene family, which together make up most of the short arm. Both clusters contain palindromes with high sequence identity, presumably maintained by gene conversion. The long arm of the chromosome is almost entirely repetitive, containing previously characterised sequences. Many of the ancestral X-related genes previously reported in at least one mammalian Y chromosome are represented either as active genes or partial sequences. This sequencing project has allowed us to identify genes - both single copy and amplified - on the pig Y, to compare the pig X and Y chromosomes for homologous sequences, and thereby to reveal mechanisms underlying pig X and Y chromosome evolution.


2018 ◽  
Author(s):  
Ziad Jowhar ◽  
Sigal Shachar ◽  
Prabhakar R. Gudla ◽  
Darawalee Wangsa ◽  
Erin Torres ◽  
...  

AbstractSex chromosome aneuploidies (SCAs) are common genetic syndromes characterized by the presence of an aberrant number of X and Y chromosomes due to meiotic defects. These conditions impact structure and function of diverse tissues, but the proximal effects of SCA on genome organization are unknown. Here, to determine the consequences of SCAs on global genome organization, we have analyzed multiple architectural features of chromosome organization in a comprehensive set of primary cells from SCA patients with various ratios of X and Y chromosomes by use of imaging-based high-throughput Chromosome Territory Mapping (HiCTMap). We find that X chromosome supernumeracy does not affect the size, volume or nuclear position of the Y chromosome or an autosomal chromosome. In contrast, the active X chromosome undergoes architectural changes as a function of increasing X copy number, as measured by a decrease in size and an increase in circularity, which is indicative of chromatin compaction. With Y chromosome supernumeracy, Y chromosome size is reduced suggesting higher chromatin condensation. The radial positioning of chromosomes is unaffected in SCA karyotypes. Taken together, these observations document changes in genome architecture in response to alterations in sex chromosome numbers and point to trans-effects of dosage compensation on chromosome organization.


PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009704
Author(s):  
Deborah Charlesworth ◽  
Roberta Bergero ◽  
Chay Graham ◽  
Jim Gardner ◽  
Karen Keegan

The sex chromosome pairs of many species do not undergo genetic recombination, unlike the autosomes. It has been proposed that the suppressed recombination results from natural selection favouring close linkage between sex-determining genes and mutations on this chromosome with advantages in one sex, but disadvantages in the other (these are called sexually antagonistic mutations). No example of such selection leading to suppressed recombination has been described, but populations of the guppy display sexually antagonistic mutations (affecting male coloration), and would be expected to evolve suppressed recombination. In extant close relatives of the guppy, the Y chromosomes have suppressed recombination, and have lost all the genes present on the X (this is called genetic degeneration). However, the guppy Y occasionally recombines with its X, despite carrying sexually antagonistic mutations. We describe evidence that a new Y evolved recently in the guppy, from an X chromosome like that in these relatives, replacing the old, degenerated Y, and explaining why the guppy pair still recombine. The male coloration factors probably arose after the new Y evolved, and have already evolved expression that is confined to males, a different way to avoid the conflict between the sexes.


2018 ◽  
Vol 29 (20) ◽  
pp. 2458-2469 ◽  
Author(s):  
Ziad Jowhar ◽  
Sigal Shachar ◽  
Prabhakar R. Gudla ◽  
Darawalee Wangsa ◽  
Erin Torres ◽  
...  

Sex chromosome aneuploidies (SCAs) are common genetic syndromes characterized by the presence of an aberrant number of X and Y chromosomes due to meiotic defects. These conditions impact the structure and function of diverse tissues, but the proximal effects of SCAs on genome organization are unknown. Here, to determine the consequences of SCAs on global genome organization, we have analyzed multiple architectural features of chromosome organization in a comprehensive set of primary cells from SCA patients with various ratios of X and Y chromosomes by use of imaging-based high-throughput chromosome territory mapping (HiCTMap). We find that X chromosome supernumeracy does not affect the size, volume, or nuclear position of the Y chromosome or an autosomal chromosome. In contrast, the active X chromosome undergoes architectural changes as a function of increasing X copy number as measured by a decrease in size and an increase in circularity, which is indicative of chromatin compaction. In Y chromosome supernumeracy, Y chromosome size is reduced suggesting higher chromatin condensation. The radial positioning of chromosomes is unaffected in SCA karyotypes. Taken together, these observations document changes in genome architecture in response to alterations in sex chromosome numbers and point to trans-effects of dosage compensation on chromosome organization.


1923 ◽  
Vol s2-67 (266) ◽  
pp. 203-218
Author(s):  
A. W. GREENWOOD

In the three animals studied the total number of chromosomes in the male is as follows : Phascolarctus 16 (14 autosomes + XY). Sarcophilus 14 (12 autosomes + XY). Dasyurus 14 (12 autosomes + XY). In the female the number of chromosomes is as follows : Phascolarctus 16 (14 autosomes + XX). Sarcophilus 14 (12 autosomes + XX). In all animals dealt with in this paper the Y-chromosome is very minute in size compared with the other chromosomes; also the X-chromosome is much smaller than any of the autosomes. Chromomeres are conspicuous during syndesis, early pachytene, and early diplotene stages. The early pachytene stage is followed by a late pachytene stage in which the threads become diffuse and lose their capacity for taking up the stain. Except in the early meiotic prophase the sex chromosome remains compact and deeply stained and does not thread out like the autosomes. In all the above animals the first meiotic division is reductional, separating the X- and the Y-chromosomes, and the second division is equational, in each cell the sex chromosome dividing. The spermatozoa are therefore of two kinds, one containing an X-chromosome and the other containing a Y-chromosome. No further reduction in the number of chromosomes takes place during the second meiotic division. The Y-chromosome could not be identified during the meiotic phase until the metaphase of the first meiotic division. At this stage in Phascolarctus the sex chromosomes are separate and do not form a bivalent. The archoplasm seems to exert some influence on the chromatin threads at synizesis and during the early pachytene stage. In the former case the contraction takes place to that side of the nucleus at which the archoplasmic mass is situated; in the latter the chromosomes are in the form of thick loops with the ends of the chromosomes pointing towards the archoplasmic mass. In Phascolarctus the Sertoli cells are very large and possess peculiar rod-like bodies, the origin and function of which was not arrived at. The result of experiments seem to show that the rods are not affected by the action of digestive fluids.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lingzhan Xue ◽  
Yu Gao ◽  
Meiying Wu ◽  
Tian Tian ◽  
Haiping Fan ◽  
...  

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.


Genetics ◽  
2021 ◽  
Author(s):  
Xingyong Liu ◽  
Shengfei Dai ◽  
Jiahong Wu ◽  
Xueyan Wei ◽  
Xin Zhou ◽  
...  

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.


Genetics ◽  
2021 ◽  
Author(s):  
Takahiro Sakamoto ◽  
Hideki Innan

Abstract Muller’s ratchet is a process in which deleterious mutations are fixed irreversibly in the absence of recombination. The degeneration of the Y chromosome, and the gradual loss of its genes, can be explained by Muller’s ratchet. However, most theories consider single-copy genes, and may not be applicable to Y chromosomes, which have a number of duplicated genes in many species, which are probably undergoing concerted evolution by gene conversion. We developed a model of Muller’s ratchet to explore the evolution of the Y chromosome. The model assumes a non-recombining chromosome with both single-copy and duplicated genes. We used analytical and simulation approaches to obtain the rate of gene loss in this model, with special attention to the role of gene conversion. Homogenization by gene conversion makes both duplicated copies either mutated or intact. The former promotes the ratchet, and the latter retards, and we ask which of these counteracting forces dominates under which conditions. We found that the effect of gene conversion is complex, and depends upon the fitness effect of gene duplication. When duplication has no effect on fitness, gene conversion accelerates the ratchet of both single-copy and duplicated genes. If duplication has an additive fitness effect, the ratchet of single-copy genes is accelerated by gene duplication, regardless of the gene conversion rate, whereas gene conversion slows the degeneration of duplicated genes. Our results suggest that the evolution of the Y chromosome involves several parameters, including the fitness effect of gene duplication by increasing dosage and gene conversion rate.


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