Karyotypic analysis of Membranosorus heterantherae (Plasmodiophoromycetes)

1989 ◽  
Vol 67 (4) ◽  
pp. 1219-1220 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Chromosome Number ◽  
Serial Section ◽  
Karyotypic Analysis ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes ◽  
Section Analysis

Synaptonemal complexes in nuclei of transitional plasmodia of Membranosorus heterantherae were counted through serial section analysis. The haploid chromosome number was determined to be 35, which distinguishes Membranosorus from other plasmodiophorid genera.

Karyotypic analysis of Ligniera verrucosa (Plasmodiophoromycetes)

1989 ◽  
Vol 67 (4) ◽  
pp. 1216-1218 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Chromosome Number ◽  
Serial Section ◽  
Karyotypic Analysis ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes ◽  
Section Analysis

Synaptonemal complexes in nuclei of transitional plasmodia of Ligniera verrucosa were counted through serial section analysis. The haploid chromosome number was determined to be 38, which distinguishes Ligniera from other plasmodiophorid genera, particularly Polymyxa (n = 30) and Sorosphaera (n = 33).

Karyotypic analysis of Polymyxa betae (Plasmodiophoromycetes) based on serial thin sections of pachytene nuclei

1983 ◽  
Vol 61 (12) ◽  
pp. 3202-3206 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Chromosome Number ◽  
Plasmodiophora Brassicae ◽  
Polymyxa Betae ◽  
Karyotypic Analysis ◽  
Thin Sections ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes

Three pachytene nuclei of Polymyxa betae Keskin were reconstructed from serial thin sections. Thirty synaptonemal complexes (SCs) were counted, indicating a haploid chromosome number of 30. SCs of Polymyxa were similar to those of Sorosphaera veronicae Schroeter and Membranosorus heterantherae Ostenfeld and Peterson but differed from SCs of Plasmodiophora brassicae Woron. and Woronina pythii Goldie-Smith.

Ultrastructural karyology of Spongospora subterranea (Plasmodiophoromycetes)

1992 ◽  
Vol 70 (6) ◽  
pp. 1228-1233 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Electron Microscopy ◽  
Single Unit ◽  
Spongospora Subterranea ◽  
Unit Membrane ◽  
Potato Tubers ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes ◽  
Transmission Electron ◽  
Host Parasite ◽  
Section Analysis

Sporogenic (cystogenous) stages of development of Spongospora subterranea (Wallroth) Lagerheim f.sp. subterranea Tomlinson infecting potato tubers were examined with transmission electron microscopy. Volume of nuclei in transitional Plasmodia was 28.2 ± 8.3 μm3. Serial section analysis revealed 37 synaptonemal complexes, hence the haploid chromosome number was considered to be 37. Total length of synaptonemal complexes per nucleus was 74.6 ± 1.4 μm, with individual synaptonemal complexes ranging in length from 1.34 ± 0.07 μm to 3.48 ± 0.17 μm. No polycomplexes were observed in transitional nuclei. Electron-opaque thickenings of lateral elements occurred irregularly. Additional ultrastructural features of sporogenic plasmodia included end-to-end paired centrioles defining the poles of the nuclei and a host–parasite boundary of a single unit membrane. Key words: karyotype, Plasmodiophoromycetes, Spongospora, synaptonemal complex.

scholarly journals A long reads-based de-novo assembly of the genome of the Arlee homozygous line reveals chromosomal rearrangements in rainbow trout

2021 ◽  
Author(s):  
Guangtu Gao ◽  
Susana Magadan ◽  
Geoffrey C Waldbieser ◽  
Ramey C Youngblood ◽  
Paul A Wheeler ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Chromosome Number ◽  
Genome Assembly ◽  
De Novo Assembly ◽  
De Novo ◽  
Sequence Data ◽  
Structural Variations ◽  
High Coverage ◽  
Haploid Chromosome Number ◽  
Long Reads

Abstract Currently, there is still a need to improve the contiguity of the rainbow trout reference genome and to use multiple genetic backgrounds that will represent the genetic diversity of this species. The Arlee doubled haploid line was originated from a domesticated hatchery strain that was originally collected from the northern California coast. The Canu pipeline was used to generate the Arlee line genome de-novo assembly from high coverage PacBio long-reads sequence data. The assembly was further improved with Bionano optical maps and Hi-C proximity ligation sequence data to generate 32 major scaffolds corresponding to the karyotype of the Arlee line (2 N = 64). It is composed of 938 scaffolds with N50 of 39.16 Mb and a total length of 2.33 Gb, of which ∼95% was in 32 chromosome sequences with only 438 gaps between contigs and scaffolds. In rainbow trout the haploid chromosome number can vary from 29 to 32. In the Arlee karyotype the haploid chromosome number is 32 because chromosomes Omy04, 14 and 25 are divided into six acrocentric chromosomes. Additional structural variations that were identified in the Arlee genome included the major inversions on chromosomes Omy05 and Omy20 and additional 15 smaller inversions that will require further validation. This is also the first rainbow trout genome assembly that includes a scaffold with the sex-determination gene (sdY) in the chromosome Y sequence. The utility of this genome assembly is demonstrated through the improved annotation of the duplicated genome loci that harbor the IGH genes on chromosomes Omy12 and Omy13.

scholarly journals Chromosomal and DNA barcode analysis of the Melitaea ala Staudinger, 1881 species complex (Lepidoptera, Nymphalidae)

2021 ◽  
Vol 15 (2) ◽  
pp. 199-216
Author(s):  
Vladimir A. Lukhtanov ◽  
Anastasia V. Gagarina ◽  
Elena A. Pazhenkova
Keyword(s):  
Chromosome Number ◽  
Central Asia ◽  
Species Complex ◽  
Dna Barcode ◽  
Monophyletic Group ◽  
Geographic Proximity ◽  
Haploid Chromosome Number ◽  
East Central ◽  
North East ◽  
Peter The Great

The species of the Melitaea ala Staudinger, 1881 complex are distributed in Central Asia. Here we show that this complex is a monophyletic group including the species, M. ala, M. kotshubeji Sheljuzhko, 1929 and M. enarea Fruhstorfer, 1917. The haploid chromosome number n=29 is found in M. ala and M. kotshubeji and is, most likely, a symplesiomorphy of the M. ala complex. We show that M. ala consists of four subspecies: M. ala zaisana Lukhtanov, 1999 (=M. ala irtyshica Lukhtanov, 1999, syn. nov.) (South Altai, Zaisan Lake valley), M. ala ala (Dzhungarian Alatau), M. ala bicolor Seitz, 1908 (North, East, Central and West Tian-Shan) and M. ala determinata Bryk, 1940 (described from “Fu-Shu-Shi”, China). We demonstrate that M. kotshubeji kotshubeji (Peter the Great Mts in Tajikistan) and M. kotshubeji bundeli Kolesnichenko, 1999 (Alai Mts in Tajikistan and Kyrgyzstan) are distinct taxa despite their geographic proximity in East Tajikistan. Melitaea enarea is widely distributed in the southern part of Central Asia and is sympatric with M. kotshubeji.

scholarly journals Unprecedented reorganization of holocentric chromosomes provides insights into the enigma of lepidopteran chromosome evolution

2019 ◽  
Vol 5 (6) ◽  
pp. eaau3648 ◽  
Author(s):  
Jason Hill ◽  
Pasi Rastas ◽  
Emily A. Hornett ◽  
Ramprasad Neethiraj ◽  
Nathan Clark ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Evolution ◽  
Chromosome Structure ◽  
Holocentric Chromosomes ◽  
Chromosome Counts ◽  
Pieris Napi ◽  
Haploid Chromosome Number ◽  
Genome Wide ◽  
The Face ◽  
Chromosome Level

Chromosome evolution presents an enigma in the mega-diverse Lepidoptera. Most species exhibit constrained chromosome evolution with nearly identical haploid chromosome counts and chromosome-level gene collinearity among species more than 140 million years divergent. However, a few species possess radically inflated chromosomal counts due to extensive fission and fusion events. To address this enigma of constraint in the face of an exceptional ability to change, we investigated an unprecedented reorganization of the standard lepidopteran chromosome structure in the green-veined white butterfly (Pieris napi). We find that gene content in P. napi has been extensively rearranged in large collinear blocks, which until now have been masked by a haploid chromosome number close to the lepidopteran average. We observe that ancient chromosome ends have been maintained and collinear blocks are enriched for functionally related genes suggesting both a mechanism and a possible role for selection in determining the boundaries of these genome-wide rearrangements.

A contribution towards elucidating the life history of Palmaria palmate (=Rhodymenia palmata)

1976 ◽  
Vol 54 (24) ◽  
pp. 2903-2906 ◽  
Author(s):  
J. P. van der Meer
Keyword(s):  
Life History ◽  
Chromosome Number ◽  
Atlantic Coast ◽  
Palmaria Palmata ◽  
Haploid Chromosome Number ◽  
History Of

Palmaria palmata from a region of the Atlantic coast of Canada has been examined cytologically. Plants bearing tetrasporangia were found to be diploid with meiosis occurring in the tetrasporangia. Spermatangial plants and sporelings growing from tetraspores were haploid. The haploid chromosome number appears to be 22–23.

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.

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