MEIOSIS IN COPRINUS ATRAMENTARIUS

1967 ◽  
Vol 45 (2) ◽  
pp. 215-219 ◽  
Author(s):  
Milton McClaren
Keyword(s):  
Chromosome Number ◽  
Meiotic Division ◽  
Diploid Chromosome Number ◽  
Meiosis I

Meiosis in Coprinus atramentarius Fries was studied by the use of an acetocarmine squash technique. Discrete chromosomes were noted only during meta-phase–anaphase of the first meiotic division. The diploid chromosome number was determined as six. During the second meiotic division chromatin masses, rather than discrete chromosomes, were seen to separate. In both meiosis I and II, centrosomes were formed at the poles of the division figures.

scholarly journals The Reduction of Chromosome Number in Meiosis Is Determined by Properties Built into the Chromosomes

2000 ◽  
Vol 150 (6) ◽  
pp. 1223-1232 ◽  
Author(s):  
Leocadia V. Paliulis ◽  
R. Bruce Nicklas
Keyword(s):  
Chromosome Number ◽  
Meiotic Division ◽  
Spindle Pole ◽  
The Other ◽  
Whole Cell ◽  
Sister Chromatids ◽  
Meiosis I

In meiosis I, two chromatids move to each spindle pole. Then, in meiosis II, the two are distributed, one to each future gamete. This requires that meiosis I chromosomes attach to the spindle differently than meiosis II chromosomes and that they regulate chromosome cohesion differently. We investigated whether the information that dictates the division type of the chromosome comes from the whole cell, the spindle, or the chromosome itself. Also, we determined when chromosomes can switch from meiosis I behavior to meiosis II behavior. We used a micromanipulation needle to fuse grasshopper spermatocytes in meiosis I to spermatocytes in meiosis II, and to move chromosomes from one spindle to the other. Chromosomes placed on spindles of a different meiotic division always behaved as they would have on their native spindle; e.g., a meiosis I chromosome attached to a meiosis II spindle in its normal fashion and sister chromatids moved together to the same spindle pole. We also showed that meiosis I chromosomes become competent meiosis II chromosomes in anaphase of meiosis I, but not before. The patterns for attachment to the spindle and regulation of cohesion are built into the chromosome itself. These results suggest that regulation of chromosome cohesion may be linked to differences in the arrangement of kinetochores in the two meiotic divisions.

New cytogenetic data on Coreoidea (Hemiptera: Heteroptera) with special reference to Coreidae

Zootaxa ◽  
2012 ◽  
Vol 3313 (1) ◽  
pp. 53 ◽  
Author(s):  
HAILIN YANG ◽  
HU LI ◽  
XUN DAI ◽  
JIAN CHANG ◽  
WANZHI CAI
Keyword(s):  
Chromosome Number ◽  
Special Reference ◽  
Sex Chromosomes ◽  
Meiotic Division ◽  
Phylogenetic Relationships ◽  
Male Meiosis ◽  
Point Of View ◽  
Diploid Chromosome Number ◽  
Holokinetic Chromosomes ◽  
The Family

Some cytogenetic aspects of six Chinese species of Coreoidea were studied. The material included five species from the familyCoreidae: Hydarella orientalis (Distant), Homoeocerus bannaensis Hsiao, Cletus graminis Hsiao & Cheng, Paradasynus lon-girostris Hsiao, Acanthocoris scaber (Linnaeus), and one species from the family Stenocephalidae: Stenocephalus femoralisReuter. All species show holokinetic chromosomes, post-reductional meiotic division of XO sex chromosomes, a pre-reduc-tional type of meiosis for autosomes and m-chromosomes, intersticial chiasmata in most autosomes, and one chiasma per biva-lent in male meiosis. In the species studied, the diploid chromosome number ranged from 13 to 21. It was 13 in S. femoralis (10+ 2m + XO), 15 in Hy. orientalis (12 + 2m + XO), 17 in Ho. bannaensis (14 + 2m + XO) and C. graminis (14 + 2m + XO), 19in P. longirostris (16 + 2m + XO), and 21 in A. scaber (18 + 2m + XO). Hy. orientalis represents the first cytogenetically stud-ied species in subfamily Hydarinae. The phylogenetic relationships among Coreoidea are briefly discussed from a cytogenetic point of view.

Protostrongylus rufescens: a cytogenetic study

1987 ◽  
Vol 61 (1) ◽  
pp. 72-76
Author(s):  
C. Cutillas ◽  
D. C. Guevara ◽  
A. Valero ◽  
C. Ariza
Keyword(s):  
Chromosome Number ◽  
Meiotic Division ◽  
Cytogenetic Study ◽  
Diploid Chromosome Number ◽  
Genetic Behaviour ◽  
Diakinesis Stage ◽  
Sex Determinism ◽  
Made In

ABSTRACTThe diploid chromosome number of Protostrongylus rufescens is 2n=11 for males and 2n=12 for females. So, the sex determinism mechanism is XO/XX. The study of the genetic behaviour of this species has been made. In diakinesis stage the bivalents show typical tetrads with cross, Ø, and lineal configurations. The division of the sexual chromosome is prereductional for the first meiotic division.

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.

Changes in DNA content and chromosome number during spermatogenesis in the gall midge Monarthropalpus buxi (Cecidomyiidae, Diptera)

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 244-250 ◽  
Author(s):  
B. Jazdowska-Zagrodzinska ◽  
R. Dallai ◽  
C. A. Redi
Keyword(s):  
Chromosome Number ◽  
Key Words ◽  
Meiotic Division ◽  
Dna Content ◽  
Germ Line ◽  
Gall Midge ◽  
Key Words Dna ◽  
Further Development

In this paper we analyze the course of spermatogenesis in Monarthropalpus buxi. The first meiotic division occurs without any chromosomes pairing. As a result one spermatocyte II appears from which two sperms originate, and one residual cell, which does not undergo any further division. We found variations in chromosome number and DNA content between germ line cells of different individuals. Such variations were observed in the spermatocytes I and II, and in the sperms. In contrast, the residual cells, which did not take part in further development, always had the same DNA content and constantly inherited 20 chromosomes: 4 constituting one haploid set of the somatic type (S chromosomes) and 16 of the germ line limited type (E chromosomes).Key words: DNA content, chromosome number, Cecidomyiidae, germ line, spermatogenesis.

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.

Polyploidy in Sporobolus virginicus (L.) Kunth

1979 ◽  
Vol 27 (4) ◽  
pp. 429 ◽  
Author(s):  
AR Smith-White
Keyword(s):  
Salt Marsh ◽  
Chromosome Number ◽  
Meiotic Division ◽  
Distribution Patterns ◽  
Meiotic Behaviour ◽  
Polyploid Complex ◽  
South Eastern ◽  
Sporobolus Virginicus ◽  
Eastern Australia ◽  
Tetraploid Cytotypes

Chromosome number and meiotic behaviour was examined in Sporobolus virginicus Kunth from south-eastern Australia. Var. minor Bail. forms a polyploid complex with diploid (2n = 20), triploid and tetraploid cytotypes. Meiosis in tetraploid plants of this variety is substantially normal, which indicates an alloploid origin. Var. virginicus, which has been found only in the tetraploid state, has irregular meiotic division, which suggests autoploidy. Most cytotypes were collected from sandy and well-drained situations along the coast. However, tetraploid var. minor plants were generally found in poorly aerated salt marsh swamps. This apparent edaphic adaption of tetraploid cytotypes may be important in explaining distribution patterns.

Sign in / Sign up

Export Citation Format

Share Document