scholarly journals The Chromosomes and Systematic Position of the Marsupial Mole, Notoryctes typhlops

1974 ◽  
Vol 27 (5) ◽  
pp. 529 ◽  
Author(s):  
JH Calaby ◽  
LK Corbett ◽  
GB Sharman ◽  
PG Johnston
Keyword(s):  
Chromosome Number ◽  
Cytological Study ◽  
Systematic Position ◽  
Diploid Chromosome Number ◽  
Heterogametic Sex

A cytological study showed that the diploid chromosome number in N. typhlops is 2n = 20. All autosomes are submetacentric and three pairs are somewhat larger than the remainder. The male is the heterogametic sex, and the unpaired chromosomes are a submetacentric one (X) about the same size as the smaller autosomes, and a small acrocentric one (Y).

scholarly journals One more Microtus species with asynaptic sex chromosomes

2018 ◽  
Vol 70 (3) ◽  
pp. 443-447
Author(s):  
Jelena Blagojevic ◽  
Marija Rajicic ◽  
Vladimir Jovanovic ◽  
Tanja Adnadjevic ◽  
Ivana Budinski ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Sex Chromosomes ◽  
Diploid Chromosome Number ◽  
First Finding ◽  
Chromosomal Polymorphisms ◽  
Southeastern Serbia

Arvicoline voles are known as a karyotypically extremely polymorphic group in which the genus Microtus leads with the highest rate of karyotype change. A member of this genus, the European pine vole Microtus subterraneus (de Selys-Longchamps, 1836), is widely distributed in Europe and parts of Asia. There are two cytotypes differing in diploid chromosome number, 2n=54 and 52, each showing different chromosomal polymorphisms. At two localities in southeastern Serbia, Mt. Jastrebac and Vlasina, we found the 2n=52 cytotype. Meiotic preparations from males revealed the presence of asynaptic sex chromosomes. Although asynaptic sex chromosomes are frequent in Microtus, this is the first finding for M. subterraneus. From summarized data it appears that two-thirds of the studied species, mainly from Microtus and Terricola subgenera, possess asynaptic sex chromosomes.

Sources of progesterone during gestation in Barbary sheep (Ammotragus lervia)

1983 ◽  
Vol 98 (2) ◽  
pp. 283-NP ◽  
Author(s):  
A. P. F. Flint ◽  
R. D. Burton ◽  
R. B. Heap
Keyword(s):  
Chromosome Number ◽  
Corpus Luteum ◽  
Late Pregnancy ◽  
Hydroxysteroid Dehydrogenase ◽  
Point Of View ◽  
Diploid Chromosome Number ◽  
Domestic Sheep ◽  
Ammotragus Lervia ◽  
Barbary Sheep ◽  
Venous Plasma

Concentrations of progesterone in arterial and ovarian, uterine and jugular venous plasma were determined in four Barbary sheep at various stages of pregnancy. The results, together with ovarian histology, show that the corpus luteum regresses before term in Barbary sheep, as in most breeds of domestic ewes. Uterine synthesis of progesterone was demonstrated in late pregnancy in two animals in which uterine venous levels of progesterone were increased two- to fourfold above arterial concentrations. The placenta contained 3β-hydroxysteroid dehydrogenase. Barbary sheep (diploid chromosome number, 2N = 58) therefore resemble the domestic sheep (2N = 54) rather than the goat (2N = 60) from the point of view of the source of the progesterone required for maintenance of pregnancy.

An Extraordinarily Low Diploid Chromosome Number in the Reptile Gonatodes taniae (Squamata, Gekkonidae)

1994 ◽  
Vol 85 (4) ◽  
pp. 255-260 ◽  
Author(s):  
M. Schmid ◽  
W. Felchtinger ◽  
I. Nanda ◽  
R. Schakowski ◽  
R. Visbal Garcia ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Diploid Chromosome Number

The Chromosome Numbers and Nuclear Cytology of Some Common British Serpulids

1960 ◽  
Vol s3-101 (56) ◽  
pp. 395-400
Author(s):  
S. DASGUPTA ◽  
A. P. AUSTIN
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Cells ◽  
Diploid Chromosome Number ◽  
Iron Alum ◽  
Artificial Fertilization ◽  
Nuclear Cytology

The chromosome numbers of Hydroides norvegica, Mercierella enigmatica, and Pomatoceros triqueter were determined from squashes of somatic cells in young embryos obtained by artificial fertilization, and stained with iron-alum/aceto-carmine. All had a diploid count of zn = 26 chromosomes. Mitotic and meiotic divisions in the 5 species of Spirorbis examined, and in Filograna implexa, all revealed a diploid chromosome number of 2n = 20. A diploid chromosome number of 14 is suggested for the ancestral serpulid.

B-chromosome Systems in the Greater Glider (Petauroides volans volans) (Marsupialia : Petauridae). I. B-chromosome Distribution

1985 ◽  
Vol 38 (1) ◽  
pp. 189 ◽  
Author(s):  
Leon R McQuade
Keyword(s):  
Bone Marrow ◽  
Chromosome Number ◽  
Y Chromosome ◽  
Stable Equilibrium ◽  
Bone Marrow Cells ◽  
B Chromosome ◽  
B Chromosomes ◽  
Diploid Chromosome Number ◽  
Body Tissues ◽  
Distinct Distribution

Variations in diploid chromosome number, due to the presence of B chromosomes, are found within the distribution of P. v. volans. B chromosomes vary in number between one and eight per animal, are mitotically stable in various body tissues and, unlike the Y chromosome in male P. v. volans, are not eliminated from bone marrow cells. Animals possessing B chromosomes have a distinct distribution, and it appears that a stable equilibrium between the forces of B chromosome accumulation or elimination is operating in those populations possessing these chromosomes.

First Record on Sex Chromosomes in a Species of the Family Cynodontidae: Cynodon gibbus (Agassiz, 1829)

2020 ◽  
Vol 160 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Vanessa S. Pinheiro Figliuolo ◽  
Leonardo Goll ◽  
Patrik Ferreira Viana ◽  
Eliana Feldberg ◽  
Maria C. Gross
Keyword(s):  
Chromosome Number ◽  
Repetitive Dna ◽  
Sex Chromosomes ◽  
First Record ◽  
Diploid Chromosome Number ◽  
Fish Family ◽  
Female Heterogamety ◽  
The Family

The fish family Cynodontidae belongs to the superfamily Curimatoidea, together with the Hemiodontidae, Serrasalmidae, Parodontidae, Prochilodontidae, Chilodontidae, Curimatidae, and Anostomidae. The majority of the species of this superfamily that have been analyzed to date have a diploid chromosome number of 2n = 54. Differentiated sex chromosomes (with female heterogamety) have been observed only in the Prochilodontidae, Parodontidae, and Anostomidae. The present study provides the first description of differentiated sex chromosomes in the cynodontid species Cynodon gibbus, which has a ZZ/ZW system, and shows that repetitive DNA has played a fundamental role in the differentiation of these sex chromosomes.

scholarly journals Morphological, anatomical and karyological investigations of the Turkish endemic species Lathyrus woronowii Bornm. (Fabaceae)

2017 ◽  
Vol 76 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Fatma Güneş ◽  
Çiler Meriç
Keyword(s):  
Chromosome Number ◽  
Cross Sections ◽  
Endemic Species ◽  
Diploid Chromosome Number ◽  
Dam Construction ◽  
Annual Species ◽  
International Union ◽  
First Time ◽  
Iucn Criteria ◽  
General Appearance

AbstractLathyrus woronowiiBornm., an endemic species of Turkey, is threatened with extinction due to dam construction. It exists only in the Çoruh valley, Artvin. This annual species is in the critically endangered (CR) category according to the International Union of Conservation of Nature (IUCN) criteria. Its morphology, anatomy and karyology are studied here for the first time. A detailed description is given and the general appearance of the species has been drawn; cross sections from the stem and leaf have been taken and examined; and the diploid chromosome number (2n = 14) has been reported and illustrated for the first time.

scholarly journals First illustration of chromosomes and genetic system of Lecanodiaspidinae (Homoptera, Coccinea, Asterolecaniidae s.l.)

2018 ◽  
Vol 12 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Ilya A. Gavrilov-Zimin
Keyword(s):  
Chromosome Number ◽  
Genetic System ◽  
B Chromosomes ◽  
Scale Insects ◽  
Diploid Chromosome Number ◽  
Embryonic Cells ◽  
Paternal Genome ◽  
Cytogenetic Data ◽  
Males And Females ◽  
First Time

The karyotype of Psoraleococcusmultipori (Morrison, 1921) was studied for the first time, based on material from Indonesia (Sulawesi). The diploid chromosome number was found to be 18 in both males and females, but some cells contained also additional small chromosomal elements, probably B chromosomes. About 50 % of the studied embryos demonstrated paternal genome heterochromatinization of one haploid set of chromosomes (PGH) suggesting presence of a Lecanoid genetic system. The embryos with PGH are known to be always the male embryos in scale insects and so, bisexual reproduction may be presumed for P.multipori. The information provided represents the first probative cytogenetic data for the subfamily Lecanodiaspidinae Targioni Tozzetti, 1896 as a whole. A detailed morphological figure and photos of female and male embryonic cells are given. Additionally, it was discovered that the females of P.multipori exhibit complete ovoviviparity.

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