On the ordered arrangement of the haploid complement in radial metaphases of secondary meiocytes of male grasshoppers, Euchorthippus pulvinatus gallicus

1985 ◽  
Vol 70 (3) ◽  
pp. 240-244
Author(s):  
B. Jódar ◽  
E. Ferrer ◽  
J. -R. Lacadena
Keyword(s):  
Haploid Complement

scholarly journals JOINT SEGREGATION OF BIOCHEMICAL LOCI IN SALMONIDAE. II. LINKAGE ASSOCIATIONS FROM A HYBRIDIZED SALVELINUS GENOME (S. NAMAYCUSH x S. FONTINALIS)

Genetics ◽  
1980 ◽  
Vol 95 (3) ◽  
pp. 707-726
Author(s):  
Bernie May ◽  
Mark Stoneking ◽  
James E Wright
Keyword(s):  
Brook Trout ◽  
Lake Trout ◽  
Salvelinus Fontinalis ◽  
De Novo ◽  
Homeologous Chromosome ◽  
Homeologous Chromosomes ◽  
Joint Segregation ◽  
Duplicate Loci ◽  
Haploid Complement

ABSTRACT The results of more than 300 parwise examinations of biochemical loci for joint segregation in brook trout (Salvelinus fontinalis) and in the hybridized genome of lake trout (S. namaycush) × brook trout are summarized. Nineteen loci have been assigned to the following eight linkage groupings on the basis of nonrandom assortment, including cases of both classical linkage and pseudolinkage: ODH with PMI with PGI-3, PGI-2 with SDH, ADA-1 with AGP-2, AAT-(1,2) with AGP-1 with MDH-I, MDH-3 with MDH-4, LDH-3 with LDH-4, IDH-3 with ME-2 and GUS with CPK-I. Pseudolinkage (an excess of nonparental progeny types) was observed only for male testcross parents. The results suggest that this phenomenon involves homeologous chromosome arms as evidenced by the de novo association of presumed duplicate loci in each case. Classical linkage has not been found for the five pairs of duplicate loci examined in Salvelinus, suggesting that not all of the eight metacentrics in the haploid complement involve fusions of homeologous chromosomes. Females consistently showed a greater degree of recombination.

THE CHROMOSOMAL COMPLEMENT OF THE YELLOW-CHEEKED VOLE: Microtus xanthognathus (Leach)

1974 ◽  
Vol 16 (2) ◽  
pp. 267-272 ◽  
Author(s):  
V. R. Rausch ◽  
R. L. Rausch
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Medium Size ◽  
Fundamental Number ◽  
Chromosomal Number ◽  
Chromosomal Complement ◽  
History Of ◽  
Haploid Complement

The karyotype of Microtus xanthognathus (Leach) is described, based on material from one female and one male vole. The diploid chromosomal number was found to be 54, and the fundamental number 62. The metacentric X-chromosome was of medium size and averaged 6.6% of the haploid complement. The designated Y-chromosome was near acrocentric. The specific distinction of M. xanthognathus and Microtus chrotorrhinus (Miller) was confirmed by the recognition of major differences in karyotype and differences in fundamental number. The distributional history of M. xanthognathus is briefly discussed.

KARYOLOGICAL STUDIES IN AMORPHOPHALLUS CAMPANULATUS

1970 ◽  
Vol 12 (1) ◽  
pp. 187-196 ◽  
Author(s):  
R. Krishnan ◽  
M. L. Magoon ◽  
K. Vijaya Bai
Keyword(s):  
Differential Staining ◽  
Root Tip ◽  
Pollen Mitosis ◽  
General Morphology ◽  
Chromosomal Complement ◽  
Morphological Criteria ◽  
Two Stages ◽  
Haploid Complement

Karyomorphological studies of Amorphophallus campanulatus Blume (Araceae) were pursued at pachytene and at root tip and pollen mitotic metaphases. The haploid complement (n = 14) at root and pollen mitoses could be categorized under six types including two nucleolar chromosomes. The karyotypes at these two stages were in agreement except for the relative lengths of one of the nucleolar chromosomes. The chromosomes at prophase of pollen mitosis and pachytene were characterized by differential staining. The two nucleolar chromosomes at pollen mitosis and pachytene were similar in general morphology and length relationships. Adopting suitable morphological criteria, the haploid chromosomal complement is identified. Based on this data and other considerations, a polyploid origin for this species was suggested and the urgent need for a comprehensive cytological survey of this genus is stressed.

KARYOTYPE ANALYSIS OF HEXAPLOID TRITICALE

1971 ◽  
Vol 13 (3) ◽  
pp. 585-591 ◽  
Author(s):  
S. Shigenaga ◽  
E. N. Larter
Keyword(s):  
Karyotype Analysis ◽  
Chromosome Complement ◽  
Hexaploid Triticale ◽  
The Cross ◽  
Haploid Complement

Karyotype analysis of hexaploid triticale cultivar 'Rosner' (2n = 42 = AABBRR) revealed that its chromosome complement consists of five satellited, five median, nine submedian, and two subterminal chromosomes. In addition to Rosner, the karyotype of the F1 hybrid (2n = 28 = ABRR) obtained from the cross between Rosner and rye cultivar 'Prolific' was analysed. Since in the ABRR hybrid only the chromosomes of the R genome were present in pairs, it was possible to classify the chromosomes of rye separately from the single chromosomes of the A and B genomes of wheat. From the idiogram constructed from these studies it was demonstrated that the rye chromosomes of the Rosner karyotype were the longest of the entire haploid complement; three of these were satellited, two were median, and two were submedian in structure.

A cytogenetic study on the rodent tapewormRodentolepis myoxi

2000 ◽  
Vol 74 (2) ◽  
pp. 109-112 ◽  
Author(s):  
J.C. Casanova ◽  
M. Spakulová ◽  
N. Laplana
Keyword(s):  
Cytogenetic Study ◽  
Chromosome Length ◽  
Congeneric Species ◽  
Total Length ◽  
Pair Group ◽  
Karyotype Structure ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
Haploid Complement

AbstractThe karyotype of glirid tapewormRodentolepismyoxi(Rudolphi, 1819) (Cestoda: Hymenolepididae) comprises six pairs of small bi-armed chromosomes (2n = 12). All pairs of chromosomes possess uniform morphology, i.e. metacentric, submetacentric or meta-submetacentric types of structures. The formula of the karyotype structure is n = 2m + 1m-sm + 3sm. The absolute chromosome length ranges from 3.78 to 2.00 μm. The mean total length of the haploid complement is 15.98 μm. The first pair (group A) is the largest, pairs 2 and 3 can be grouped into group B while pairs 4–6 are smaller and can be classified as group C. The number of chromosomes ofR.myoxiis the same for the congeneric species, however, karyological characteristics differ from all recently known karyotypes of rodent hymenolepidids.

scholarly journals Sexual conflict and the alternation of haploid and diploid generations

2006 ◽  
Vol 361 (1466) ◽  
pp. 335-343 ◽  
Author(s):  
David Haig ◽  
Amity Wilczek
Keyword(s):  
Mate Choice ◽  
Sexual Reproduction ◽  
Genomic Imprinting ◽  
Segregation Distortion ◽  
Asexual Reproduction ◽  
Sexual Conflict ◽  
Land Plants ◽  
Maternal Genome ◽  
Selective Forces ◽  
Haploid Complement

Land plants possess a multicellular diploid stage (sporophyte) that begins development while attached to a multicellular haploid progenitor (gametophyte). Although the closest algal relatives of land plants lack a multicellular sporophyte, they do produce a zygote that grows while attached to the maternal gametophyte. The diploid offspring shares one haploid set of genes with the haploid mother that supplies it with resources and a paternal haploid complement that is not shared with the mother. Sexual conflict can arise within the diploid offspring because the offspring's maternal genome will be transmitted in its entirety to all other sexual and asexual offspring that the mother may produce, but the offspring's paternally derived genes may be absent from these other offspring. Thus, the selective forces favouring the evolution of genomic imprinting may have been present from the origin of modern land plants. In bryophytes, where gametophytes are long-lived and capable of multiple bouts of asexual and sexual reproduction, we predict strong sexual conflict over allocation to sporophytes. Female gametophytes of pteridophytes produce a single sporophyte and often lack means of asexual reproduction. Therefore, sexual conflict is predicted to be attenuated. Finally, we explore similarities among models of mate choice, offspring choice and segregation distortion.

Contribution to the caryological study of the African grass Aristida rhiniochloa Hochst., based on specimens from the Southern Hemisphere

Bothalia ◽  
1972 ◽  
Vol 10 (4) ◽  
pp. 555-5564 ◽  
Author(s):  
Pierre Bourreil ◽  
Alain Geslot ◽  
Monique Gorlier ◽  
Bernard De Winter
Keyword(s):  
Chromosome Number ◽  
Southern Hemisphere ◽  
North Africa ◽  
Diploid Number ◽  
Diploid Species ◽  
Basic Number ◽  
Meiotic Behaviour ◽  
African Grass ◽  
Haploid Complement

The chromosome number established for Aristida rhiniochloa Hochst. by the study of material from three localities in the Southern Hemisphere confirms the results obtained on material from North Africa. The haploid complement (n = 11) and the diploid number (2n = 22) of this species conform to the basic number x = 11 typical for the Aristideae. It is shown that the caryotype of this species is sub-symmetrical. Preliminary studies o f material from two localities show that the meiotic behaviour conforms to that found in the diploid species with n bivalents.

Taxonomy, ecology, and karyology of a new species of Phagocata from Spain, with a discussion on the phylogenetic systematics of the genus Phagocata s.l. (Platyhelminthes, Tricladida, Paludicola)

1995 ◽  
Vol 73 (3) ◽  
pp. 557-568
Author(s):  
Ronald Sluys ◽  
Maria Ribas ◽  
Jaume Baguñà
Keyword(s):  
New Species ◽  
Body Length ◽  
Ejaculatory Duct ◽  
The Body ◽  
Ebro Delta ◽  
Phylogenetic Systematics ◽  
A New Species ◽  
Haploid Complement

The new species Phagocata ullala Sluys, sp.nov. is described from two localities in Spain, the Ebro delta and Pyrenean Massif. The species is characterized by brown dorsal pigmentation, principally ventral testes throughout the body length, vasa deferentia that fuse to form the ejaculatory duct in the proximal section of the cone-shaped penis papilla, and a basic haploid complement of 17 chromosomes. Animals from the Pyrenees may be polyploid, with complements of 4n, 8n, 10n, and 14n. At present, the genus Phagocata s.l. is diagnosed only by plesiomorphic features. The paper explores possible apomorphic characters of several groups within this genus. It is suggested that "Albiplanaria" and Atrioplanaria are monophyletic taxa and that together "Albiplanaria," Fonticola olivacea, and Phagocata s.str. form a monophylum.

Meiosis and sporogenesis in a haploid plant of Pellaea glabella var. occidentalis

1975 ◽  
Vol 53 (9) ◽  
pp. 894-900 ◽  
Author(s):  
S. Jane Rigby
Keyword(s):  
Haploid Plant ◽  
Restitution Nucleus ◽  
Prophase I ◽  
Spore Walls ◽  
Total Lack ◽  
Mother Cells ◽  
Induced Apogamy ◽  
Haploid Complement

In spore mother cells of a sporophyte of Pellaea glabella var. occidentalis (E. Nelson) Butters resulting from induced apogamy, the chromosomes did not pair during prophase I and separated randomly, usually into two groups. Meiosis II generally produced tetrads with nuclei of unequal sizes. Spore walls began to form around these nuclei, but most of the spores eventually aborted. One apparently normal spore, which later germinated, is assumed to have resulted from the formation of a restitution nucleus at the end of meiosis I.The total lack of pairing among the 29 chromosomes of this plant is evidence that this number represents the basic haploid complement of the species.

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