X and Y chromosome pairing and disjunction in a male mouse with an XYY sex-chromosome constitution

1973 ◽  
Vol 12 (2) ◽  
pp. 87-92 ◽  
Author(s):  
R. Rathenberg ◽  
D. Müller
Keyword(s):  
Y Chromosome ◽  
Chromosome Pairing ◽  
Male Mouse ◽  
Sex Chromosome ◽  
Chromosome Constitution

An XXY sex chromosome anomaly in the mouse

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 41-43 ◽  
Author(s):  
A. Endo ◽  
T. Watanabe ◽  
T. Fujita
Keyword(s):  
Male Mouse ◽  
Sex Chromosome ◽  
Male Offspring ◽  
Chromosome Constitution ◽  
Chromosome Anomaly ◽  
Breeding Colony

A cryptorchid male mouse with 41,XXY chromosome constitution was found in 300 male offspring that were born to our XO mice breeding colony. This individual had small testes with no sign of spermatogenesis at autopsy at 10 months of age.Key words: 41,XXY, mouse, XO mice colony, testes, spermatogenesis.

scholarly journals Sex chromosome configurations in pachytene spermatocytes of an XYY mouse

1990 ◽  
Vol 56 (2-3) ◽  
pp. 129-133 ◽  
Author(s):  
Charles Tease
Keyword(s):  
Sex Chromosomes ◽  
Male Mouse ◽  
Sex Chromosome ◽  
Chromosome Constitution ◽  
Sterile Male ◽  
Xy Bivalent ◽  
Pachytene Spermatocytes ◽  
Metaphase I

SummaryKaryotypic investigation of a phenotypically normal but sterile male mouse showed the presence of an XYY sex chromosome constitution. The synaptic behaviour of the three sex chromosomes was examined in 65 pachytene cells. The sex chromosomes formed a variety of synaptic configurations: an XYY trivalent (40%); an XY bivalent and Y univalent (38·5%); an X univalent and YY bivalent (13·8%); or X, Y, Y univalence (7·7%). There was considerable variation in the extent of synapsis and some of the associations clearly involved nonhomologous pairing. These observations have been compared with previously published information on chromosome configurations at metaphase I from other XYY males.

Absence of a sex vesicle in meiotic foetal germ cells is consistent with an XY sex chromosome constitution

Development ◽  
1985 ◽  
Vol 88 (1) ◽  
pp. 327-332
Author(s):  
Heather Hogg ◽  
Anne Mclaren
Keyword(s):  
Y Chromosome ◽  
Germ Cells ◽  
Adult Male ◽  
Sex Chromosome ◽  
Chromosome Constitution ◽  
Drying Method ◽  
Air Drying ◽  
Male And Female

Sex vesicles were not seen in meiotic germ cells isolated from male and female foetal adrenals, although they were readily identified in adult male meiotic germ cells prepared by the same air-drying method. It is suggested that the failure of the XY germ cells from the male adrenals to develop a sex vesicle is due to their embarking on oogenesis rather than spermatogenesis, and that the absence of a sex vesicle does not necessarily indicate lack of a Y chromosome.

ABSENCE OF THE Y CHROMOSOME (XO SEX-CHROMOSOME CONSTITUTION) IN A HUMAN INTERSEX WITH AN EXTRA-ABDOMINAL TESTIS

The Lancet ◽  
1962 ◽  
Vol 280 (7245) ◽  
pp. 20-23 ◽  
Author(s):  
Leonard Atkins ◽  
Eric Engel ◽  
DAVIDA. Flory ◽  
Mireille Engel
Keyword(s):  
Y Chromosome ◽  
Sex Chromosome ◽  
Chromosome Constitution ◽  
Abdominal Testis

scholarly journals Unusual Mammalian Sex Determination Systems: A Cabinet of Curiosities

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1770
Author(s):  
Paul A. Saunders ◽  
Frédéric Veyrunes
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Sex Chromosome ◽  
Current Knowledge ◽  
Chromosome Constitution ◽  
Y Chromosomes ◽  
Similarities And Differences ◽  
Cabinet Of Curiosities ◽  
Review Current

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.

The Chromosomal Basis of Sex-Differentiation in Marsupials

1989 ◽  
Vol 37 (3) ◽  
pp. 451 ◽  
Author(s):  
GB Sharman ◽  
RL Hughes ◽  
DW Cooper
Keyword(s):  
Body Size ◽  
Y Chromosome ◽  
X Chromosome ◽  
Sex Chromosome ◽  
Mammary Glands ◽  
Chromosome Constitution ◽  
Mammary Tissue ◽  
Reproductive Systems ◽  
Ductus Deferens ◽  
Male Type

Data on ten intersexual marsupials, eight of which were of known karyotype, are presented and reviewed. Three of the intersexes were known or suspected XO/XX or XO/XX/XXX, two were XXY, one was XXY/XY/XX and two were XY in sex chromosome constitution. In all three intersexes which had an XO cell line, but in which no Y chromosome was found in any cell, a small empty scrotum was found to one side of the midline or in the midline. Those which had a non-midline scrotum had mammary tissue on the opposite side and a partial or complete pouch. The intersex with the midline scrotum had no pouch or mammary glands. Unilateral or bilateral putative spermatic cords, not containing a ductus deferens, descended to the scrotum, but in all other respects the internal reproductive systems were like those of normal XX female marsupials. Intersexes with no Y chromosome were of female body size when adult. The XXY and XXY/XY/XX intersexes all had complete pouches and mammary glands and none had a scrotum. All had well developed male internal reproductive systems and undescended testis-like gonads, and were of intermediate body size. Both XY intersexes also had complete pouches and mammary glands, no scrotum, and male-type internal reproductive systems with undescended testes which were normal except for absence of post- primary spermatocyte stages of spermatogenesis. One XY intersex was fully adult and it did not differ from normal XY males of the same species in body measurements, body weight and secondary sex coloration. One of the intersexes of unknown karyotype, but of suspected XX chromosome constitution, was morphologically like the XO/XX/XXX mosaic with a centrally placed scrotum. The other, of suspected XY chromosome constitution, was essentially comparable to the XY intersexes. The data are interpreted, at the whole chromosome level, as follows. In the presence of a single active X chromosome scrotal and spermatic cord development were initiated, whereas they were inhibited in the presence of two X chromosomes. Complete scrotal development completely inhibited, and unilateral scrotal development partly inhibited, pouch and mammary gland development. The Y chromosome was responsible for primary gonadal sex and, apparently through production of MIS, eliminated the Miillerian (i.e. female) sex ducts. Development of a male type of reproductive system was dependent on presence of a Y chromosome and, apparently, androgen production from testes or testis-like gonads. At the gene level the data may be interpreted in terms of a hypothetical S or 'switch' locus, carried on the X chromosome, which induced scrotal development in single dose and a pouch and mammary glands in double dose. If this hypothesis is correct, it would explain the occurrence of incomplete X-chromosome inactivation in marsupials; complete X-inactivation is impossible in marsupials because it would leave each female with a scrotum, not a pouch.

Evolution of the Sex Chromosomes in Beetles. I. The Loss of the Y Chromosome

2017 ◽  
Vol 152 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Anne-Marie Dutrillaux ◽  
Bernard Dutrillaux
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Silver Staining ◽  
Sex Chromosome ◽  
B Chromosomes ◽  
Chromosome Constitution ◽  
Chromosome Loss ◽  
Autosomal Bivalents ◽  
C Banding ◽  
Nucleolar Proteins

In the males of Coleoptera, the most frequent sex chromosome constitution is XY. At metaphase I of meiosis, the X and Y are linked by nucleolar proteins, forming the so-called parachute bivalent (Xyp), which is assumed to allow the non-synapsed X and Y to segregate correctly at anaphase I. However, X0 males are not exceptional, and we explored the relationships between the X and nucleolar proteins in the absence of the Y chromosome in 6 species belonging to different families/subfamilies. Using C-banding and silver staining, we show that nucleolar proteins always remain in contact with the X until anaphase I. These proteins are generally more abundant than in the Xyp bivalent, may remain associated with the NOR during diakinesis, and frequently link the X to 1 or 2 autosomal bivalents, which seem to play the same role as the Y. This role may also be played by B chromosomes, which appear to be more frequent in X0 than in XY males. In conclusion, following Y chromosome loss, various strategies using nucleolar proteins have been developed to facilitate the migration of the unique X at meiotic anaphase I.

Somatic and germ-cell sex in mammals

1988 ◽  
Vol 322 (1208) ◽  
pp. 3-9 ◽  
Keyword(s):  
Germ Cell ◽  
Y Chromosome ◽  
Sertoli Cells ◽  
Sex Chromosome ◽  
Cell Lineage ◽  
Small Region ◽  
Supporting Cell ◽  
Chromosome Constitution ◽  
Cellular Environment ◽  
Male Animal

The phenotypic sex of an individual mammal is determined by the sex of its gonads, i.e. testes or ovaries. This in turn is determined by the presence or absence of a small region of the Y chromosome, located near the X-Y pairing region in man and on the short arm of the Y chromosome in the mouse. The testis-determining region of the Y appears to exert its primary effect by directing the supporting-cell lineage of the gonad to differentiate as Sertoli cells, acting at least in part cell-autonomously. The phenotypic sex of a germ cell, i.e. whether it undergoes spermatogenesis or oogenesis, is determined at least in the mouse by whether or not it enters meiotic prophase before birth. This depends not on its own sex chromosome constitution, but on its cellular environment. A germ cell in or near normal testis cords (made up mainly of Sertoli cells) is inhibited from entering meiosis until after birth; one that escapes this inhibition will develop into an oocyte even if it is in a male animal and is itself XY in chromosome constitution.

X-4 Translocations and Meiotic Drive in Drosophila melanogaster Males: Role of Sex Chromosome Pairing

Genetics ◽  
1987 ◽  
Vol 116 (3) ◽  
pp. 409-413
Author(s):  
Bruce McKee
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
X Chromosome ◽  
Chromosome Pairing ◽  
Sex Chromosome ◽  
Meiotic Drive ◽  
Meiotic Pairing ◽  
Size Dependent ◽  
Chromosome Breakpoint

ABSTRACT Males carrying certain X-4 translocations exhibit strongly skewed sperm recovery ratios. The XP4D half of the translocation disjoins regularly from the Y chromosome and the 4PXD half disjoins regularly from the normal 4. Yet the smaller member of each bivalent is recovered in excess of its pairing partner, apparently due to differential gametic lethality. Chromosome recovery probabilities are multiplicative; the viability of each genotype is the product of the recovery probability of its component chromosomes. Meiotic drive can also be caused by deficiency for X heterochromatin. In(1)sc4Lsc8R males show the same size dependent chromosome recoveries and multiplicative recovery probabilities found in T(1;4)BS males. Meiotic drive in In(1)sc4Lsc8R males has been shown to be due to X-Y pairing failure. Although pairing is regular in the T(X;4) males, the striking phenotypic parallels suggest a common explanation. The experiments described below show that the two phenomena are, in fact, one and the same. X-4 translocations are shown to have the same effect on recovery of independently assorting chromosomes as does In(1)sc4Lsc8R. Addition of pairing sites to the 4PXD half of the translocation eliminates drive. A common explanation—failure of the distal euchromatic portion of the X chromosome to participate in X:Y meiotic pairing—is suggested as the cause for drive. The effect of X chromosome breakpoint on X-4 translocation induced meiotic drive is investigated. It is found that translocations with breakpoints distal to 13C on the salivary map do not cause drive while translocations broken proximal to 13C cause drive. The level of drive is related to the position of the breakpoint—the more proximal the breakpoint the greater the drive.

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