Haploid Number

2001 ◽  
pp. 911
Author(s):  
M.A. Ferguson-Smith
Keyword(s):  
Haploid Number

Somatic Nuclear Division in Stemphylium botryosum

Bothalia ◽  
1971 ◽  
Vol 10 (2) ◽  
pp. 329-334 ◽  
Author(s):  
K. T. Van Warmelo
Keyword(s):  
Nuclear Division ◽  
Vegetative Mycelium ◽  
Haploid Number ◽  
Chromosome Counts ◽  
Stemphylium Botryosum ◽  
Late Anaphase

Nuclear division in an isolate of  Stemphylium botryosum obtained from lucerne was investigated using the HCI-Giemsa technique. Vegetative mycelium was predominantly monokaryotic. Chromosome counts at metaphase gave a tentative haploid number of six. Six chromosomes could again be distinguished at late anaphase. Migration of nuclei between hyphae was observed. The conclusion is drawn that somatic divisions in this fungus are strictly mitotic.

PERICENTRIC REARRANGEMENT POLYMORPHISM IN A NORTH AMERICAN DOLICHODERINE ANT (HYMENOPTERA: FORMICIDAE)

1970 ◽  
Vol 12 (3) ◽  
pp. 541-546 ◽  
Author(s):  
R. H. Crozier
Keyword(s):  
North American ◽  
Acrocentric Chromosome ◽  
Haploid Number ◽  
Tapinoma Melanocephalum

Tapinoma melanocephalum has a haploid number of 5, comprising four metacentrics and one acrocentric chromosome. T. sessile karyotypes (n = 8) comprise seven metacentric chromosomes and one that has acrocentric, subacrocentric and metacentric alternatives. In some haploid sessile preparations with acrocentric or subacrocentric chromosomes present, an acromatic gap, sometimes with an interstitial granule, is seen in the long arm of the non-metacentric.

Karyotypic analysis of Polymyxa graminis (Plasmodiophoromycetes) based on serial sections of synaptonemal complexes

1984 ◽  
Vol 62 (11) ◽  
pp. 2414-2416 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Polymyxa Betae ◽  
Serial Sections ◽  
Haploid Number ◽  
Karyotypic Analysis ◽  
Thin Sections ◽  
Polymyxa Graminis ◽  
Synaptonemal Complexes

Three pachytene nuclei of Polymyxa graminis Ledingham were reconstructed from serial thin sections. Thirty synaptonemal complexes (SCs) were counted, indicating the identical haploid number (30) that was reported for Polymyxa betae. SCs of P. graminis and P. betae were similar in structure, and nuclear volumes and total lengths of SCs per nucleus were not significantly different for the two species.

A cytological study of the early oocysts of seven species of Plasmodium and the occurrence of post-zygotic meiosis

Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 559-585 ◽  
Author(s):  
L. Bano
Keyword(s):  
Cytological Study ◽  
Reduction Division ◽  
Characteristic Form ◽  
Specific Character ◽  
Haploid Number ◽  
The Times

1. The cytological study of 4–8 hr. old zygotes of seven species of Plasmodium, i.e. P. gallinaceum, P. berghei, P. cynomolgi, P. gonderi, P. inui, P. knowlesi and P. vivax, revealed a uninucleate condition at the resting phase.2. Ookinetes of these species at 12–24 hr were uninucleate and of the usual dimorphic form.3. In the present studies post-zygotic meiosis was demonstrated in the early oocysts of the above seven species of Plasmodium. The times of investigation for the beginning and completion of meiosis in the early oocysts of these species of Plasmodium were as follows:4. Different forms of spireme at prophases were observed in the early oocysts of the above species of Plasmodium. This fact indicated that each species has its own characteristic form of spireme; for instance, ‘bow-shaped’ in P. gallinaceum, beaded, filamentous net-work in P. cynomolgi.5. The diploid and haploid number of chromosomes were demonstrated step by step, during the first reduction division in the early oocysts of seven species of Plasmodium.6. The succeeding nuclear divisions following the post-zygotic meiosis were traced in early oocysts of seven species of Plasmodium. The divisions took place mitotically, giving rise to tetra- to multinucleate oocysts. The haploid group of chromosomes in each species was quite distinct during the different mitotic phases found in these oocysts.7. The results obtained from the cytological study of different meiotic and mitotic phases found in the early oocysts of seven species of Plasmodium show that the number of chromosomes is a specific character, for instance, P. gallinaceum has a complex of two haploid chromosomes, P. cynomolgi, four; P. gonderi, three; P. inui, four; P. knowlesi, P. berghei and P. vivax, two.

Observations on a monocystid gregarine, Apolocystis elongata n.sp., in the seminal vesicles of Eisenia foetida (Sav.)

Parasitology ◽  
1946 ◽  
Vol 37 (1-2) ◽  
pp. 65-74 ◽  
Author(s):  
Nada E. Phillips ◽  
Doris L. Mackinnon
Keyword(s):  
Systematic Position ◽  
Reduction Division ◽  
Seminal Vesicles ◽  
Eisenia Foetida ◽  
Haploid Number ◽  
Chromosome Cycle

1. A new monocystid gregarine is reported from the seminal vesicles of brandling worms, Eisenia foetida Sav. The morphology and movements of the trophozoite are described, and the stages of gametogony and sporogony are outlined.2. The chromosome cycle is investigated. The haploid number of chromosomes is four, and the reduction division is shown to be zygotic.3. The systematic position of the gregarine is discussed, and it is placed in the genus Apolocystis as A. elongata n.sp.

scholarly journals Comparative Karyotype Analysis Of Slugs Of The Genus Arion (Gastropoda, Pulmonata, Arionidae)

2015 ◽  
Vol 49 (4) ◽  
pp. 299-304
Author(s):  
A. V. Harbar ◽  
N. S. Kadlubovska ◽  
D. A. Harbar
Keyword(s):  
United Kingdom ◽  
Karyotype Analysis ◽  
Haploid Number ◽  
The United Kingdom ◽  
Identical Number

Abstract Karyotypes of four species of the genus Arion were investigated, namely, A. distinctus (2n = 48m + 8sm = 56; FN = 112), A. lusitanicus s. l. (2n = 4 4m + 6 sm + 2st = 52; FN = 104), A. fuscus (n = 26, 2n = 52, FN = 104) and A. fasciatus (n = 29, 2n = 58, FN = 116). The karyotype of A. lusitanicus s. l. was identical to those of A. fuscus, A. ater and A. rufus. The karyotype of A. fasciatus in the haploid number of chromosomes is identical to another close species — A. circumscriptus (n = 29) from the United Kingdom. The identical number of chromosomes in species of the subgenus Arion (A. lusitanicus s. l., A. ater, A. rufus) and species of the subgenus Mesarion (A. fuscus) (n = 26) may be a reason for their merging.

scholarly journals Check-list of chromosome numbers of the family Hygromiidae (Gastropoda: Stylommatophora) with new data on Circassina frutis

2021 ◽  
Vol 64 (2) ◽  
pp. 7-20
Author(s):  
Nana Bakhtadze ◽  
Nino Gabroshvili ◽  
Levan Mumladze ◽  
Nino Gabroshvili
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Land Snail ◽  
Haploid Number ◽  
Check List ◽  
Fundamental Number ◽  
Diploid Complement ◽  
The Family ◽  
Karyotype Formula ◽  
First Time

Chromosome number data on the Hygromiidae (Gastropoda: Stylommatophora) are summarized and reviewed briefly in the context of the phylogeny of the family. In hygromiids, the haploid chromosome numbers range from 21 to 26. It is supposed that n = 21 is the ancestral chromosome number in the family. The modal haploid number for Hygromiidae is 23. Description of karyotype in terms of chromosome number and morphology of hygromiid land snail Circassina frutis is provided for the first time. The diploid chromosome number of this species is 2n = 46. The karyotype is symmetric and consists of 21 pairs of metacentric and 2 pairs of submetacentric chromosomes. The karyotype formula is as follows: 2n = 42m + 4sm (n = 21m + 2sm). The fundamental number (FN) is 92. Chromosomes range in length from 2.53 μm for the smallest pair to 6.00 μm for the largest pair. The total length of chromosomes in diploid complement (TCL) is 170.40 ± 3.22 μm.

scholarly journals A Preliminary Note on the Pollen Development of Lathyrus Odoratus

1925 ◽  
Vol 2 (2) ◽  
pp. 199-209
Author(s):  
JOAN LATTER
Keyword(s):  
Nuclear Membrane ◽  
Pollen Development ◽  
Cell Walls ◽  
Crossing Over ◽  
Haploid Number ◽  
Preliminary Note ◽  
Homologous Chromosomes ◽  
Lathyrus Odoratus ◽  
Thread Formation ◽  
Contraction Stage

1. In this paper the main points in the pollen development of Lathyrus odoratus are briefly described. At the beginning of the meiotic phase the reticulum contracts from the nuclear membrane and exhibits an entirely granular appearance. 2. During thread formation, occasional amœboid nucleoli are observed. Nucleolar "budding" is also seen. 3. Connecting strands are constantly found between the synizetic knot and the nucleolus. 4. The thread at all stages appears usually to be a continuous structure. 5. The synizetic knot is followed by a stage in which the thread is thrown into seven definite loops which radiate out from the centre of the nucleus. For this stage, which has frequently been called the second contraction stage in cytological literature, the name broxonema is proposed. 6. The haploid number of chromosomes in Lathyrus odoratus is seven. Each loop represents one pair of homologous chromosomes joined distally end to end. 7. The arms of each loop are twisted round one another at one period. This affords opportunity for exchange of segments of chromosomes, and gives a possible physical basis for crossing over in a telosynaptic form. 8. These stages are followed by typical diakinesis and heterotypic divisions. 9. During homotypic telophase evanescent cell plates occur between the daughter nuclei. Later, the cell walls are formed by furrowing. 10. The tapetum remains uninucleate throughout.

Cytotaxonomy of Simulium (Montisimulium) ghoomense (Diptera: Simuliidae) from the Darjeeling Hills, India

Zootaxa ◽  
2011 ◽  
Vol 2872 (1) ◽  
pp. 49
Author(s):  
WILLIE HENRY ◽  
SACHIN THAPA ◽  
PETER H. ADLER ◽  
SUBRATA KUMAR DEY ◽  
RAKESH VARMA
Keyword(s):  
Sibling Species ◽  
Sex Chromosomes ◽  
Polytene Chromosomes ◽  
Haploid Number ◽  
Total Complement ◽  
Chromosomal Map

The polytene chromosomes are mapped for a scarce Himalayan simuliid, Simulium (Montisimulium) ghoomense Datta, from the Darjeeling area of India. This species has three tightly paired polytene chromosomes with a haploid number of 3. Chromosomes I, II, and III account for 39.6%, 30.3%, and 30.1% of the total complement length, respectively. The centromeres of chromosomes II and III consistently form a putative partial chromocenter. Sex chromosomes are undifferentiated and polymorphisms and sibling species are lacking in a sample of 35 larvae. This is the first chromosomal map for a species in the subgenus Montisimulium in India.

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